refacto: refacto repo layer code while adding new usecase methods

refacto: add db tx as a possible input for repo methods
feat: implement repo expense methods
2024-10-26 17:27:33 +02:00 · 2024-10-25 23:52:43 +02:00 · 2024-10-24 23:39:13 +02:00 · 2024-10-24 22:33:24 +02:00 · 2024-10-24 22:32:57 +02:00 · 2024-10-23 23:29:44 +02:00
61 changed files with 2855 additions and 160 deletions
--- a/2
+++ b/2
@ -46,7 +46,7 @@ format: # format code.

 .PHONY: add-copyright
 add-copyright: # add license to file headers.
-	@addlicense -v -f $(ROOT_DIR)/LICENSE $(ROOT_DIR) --skip-files=database.yml --skip-dirs=$(OUTPUT_DIR),deployment,migrations,configs,sqlc,web
+	@addlicense -v -f $(ROOT_DIR)/LICENSE $(ROOT_DIR) --skip-files=database.yml --skip-dirs=$(OUTPUT_DIR),deployment,migrations,configs,sqlc,web,mock

 .PHONY: swagger
 swagger: # Run swagger.
--- a/README.md
+++ b/README.md
@ -19,6 +19,13 @@
      - [The choice of the front end framework](#the-choice-of-the-front-end-framework)
    - [2024/10/08](#20241008)
    - [2024/10/09](#20241009)
+    - [2024/10/11](#20241011)
+    - [2024/10/13](#20241013)
+    - [2024/10/15](#20241015)
+    - [2024/10/16](#20241016)
+    - [2024/10/17](#20241017)
+    - [2024/10/18](#20241018)
+    - [2024/10/19](#20241019)
 <!--toc:end-->

 A tricount like expense-sharing system written in Go
@ -376,3 +383,202 @@ functionalities well decoupled and interfaces well defined.

 I will add some tests for existing code and then it's time to move on to
 my core business logic.
+
+### 2024/10/16
+
+I am facing a design problem. My way to implement the business logic is to
+first write the core logic code in the domain service level. It will help me
+to identify if there are any missing part in my model design. Thus, when
+some of the business logic is done, I can create database migrations and then
+implement the adapter level's code.
+
+The problem is that my design depends heavily on the database. Taking the
+example of adding an expense to en event.
+
+Input is a valid `ExpenseDTO` which has the `event`, `paiements` and
+`receptions`. What I must do is to open a database transaction where I:
+
+1. Get the Event. (Most importantly the `TotalAmount`)
+2. For each `paiemnt` and `reception` create a transaction related to the
+`User`. And insert them into the database.
+3. Update the `TotalAmount`
+4. Update the caches if any
+
+If any step fails, the transaction rolls back.
+
+This has barely no logic at all. I think it is not suitable to try to tie
+this operation to the domain model.
+
+However, there is something that worth a domain model level method, that
+is to calculate the share of each members of the event, where we will have
+the list of members and the amount of balance they have. And then we will
+do the calculate and send back a list of money one should pay for another.
+
+Finally, I think the business logic is still too simple to be put into a
+"Domain". For now, the service layer is just enough.
+
+### 2024/10/17
+
+The following basic use cases are to be implemented at the first time.
+
+- [X] A user signs up
+- [X] A user logs in
+- [ ] A user lists their events (pagination)
+- [ ] A user sees the detail of an event (description, members, amount)
+- [ ] A user sees the expenses of an event (total amount, personal expenses, pagination)
+- [ ] A user sees the detail of an expense: (time, amount, payers, recipients)
+- [ ] A user adds an expense
+- [ ] A user updates/changes an expense (may handle some extra access control)
+- [ ] A user can pay the debt to other members (just a special case of expense)
+- [ ] A user creates an event (and participate to it)
+- [ ] A user updates the event info
+- [ ] A user invites another user by sending a mail with a token.
+- [ ] A user joins an event by accepting an invitation
+- [ ] A user cannot see other user's information
+- [ ] A user cannot see the events that they didn't participated in.
+
+For the second stage:
+
+- [ ] A user can archive an event
+- [ ] A user deletes an expense (may handle some extra access control)
+- [ ] A user restore a deleted expense
+- [ ] Audit log for expense updates/deletes
+- [ ] ~A user quits an event (they cannot actually, but we can make as if they
+quitted)~ **No we can't quit!**
+
+With those functionalities, there will be an usable product. And then we can
+work on other aspects. For example:
+
+- introduce an admin to handle users.
+- user info updates
+- deleting user
+- More user related contents
+- Event related contents
+- ex. Trip journal...
+
+Stop dreaming... Just do the simple stuff first!
+
+### 2024/10/18
+
+I spent some time to figure out this one! But I don't actually need it for now.
+So I just keep it here:
+
+```SQL
+SELECT
+    e.id,
+    e.name,
+    e.description,
+    e.created_at,
+    json_build_object(
+        'id', o.id,
+        'first_name', o.first_name,
+        'last_name', o.last_name
+    ) AS owner,
+    json_agg(
+        json_build_object(
+            'id', u.id,
+            'first_name', u.first_name,
+            'last_name', u.last_name
+        )
+    ) AS users  -- Aggregation for users in the event
+FROM "event" e
+JOIN "participation" p ON p.event_id = e.id  -- participation linked with the event
+JOIN "user" u ON u.id = p.user_id            -- and the query user
+JOIN "user" o ON o.id = e.owner_id           -- get the owner info
+WHERE e.id IN (
+    SELECT pt.event_id FROM participation pt WHERE pt.user_id = $1
+    -- consider the events participated by user_id
+)
+GROUP BY
+    e.id, e.name, e.description, e.created_at,
+    o.id, o.first_name, o.last_name;
+
+```
+
+### 2024/10/19
+
+I don't plan to handle deletions at this first stage, but I note down what I
+have thought of.
+
+1. Just delete. But keep a replica at the front end of the object that we are
+deleting. And propose an option to restore (so a new record is added to the DB)
+2. Just delete, but wait. The request is sent to a queue with a timeout of
+several seconds, if the user regrets, they can cancel the request. This can be
+done on the front, but also on the back. I think it is better to do in on the
+front-end.
+3. Never deletes. But keep a state in the DB `deleted`. They will just be
+ignored when counting.
+4. Deletes when doing database cleanup. They lines deleted will be processed
+when we cleanup the DB. And they will be definitely deleted at that time.
+
+I can create a audit log table to log all the critical
+changes in my `expense` table (update or delete).
+
+Finished with the basic SQL commands. Learned a lot from SQL about `JOIN`,
+aggregation and `CTE`. SQL itself has quite amount of things to learn, this
+is on my future learning plan!
+
+_I found it quite interesting that simply with SQL, we can simulate the most
+business logic. It is a must-have competence for software design and
+development._
+
+### 2024/10/20
+
+I was thinking that I should write test for `sqlc` generated code. And then
+I found out `gomock` and see how it is done in the project of
+`techschoo/simplebank`. It's a great tutorial project. It makes me questioning
+my own project's structure. It seems overwhelmed at least at the repo level.
+
+I don't actually use the sqlc generated object, instead I do a conversion to
+my `Retrieved` objects. But with some advanced configuration we could make the
+output of sqlc object directly usable. That will save a lot of code.
+
+The problem I saw here is the dependency on `sqlc/models`, and the model
+designed there has no business logic. Everything is done in the handlers
+and the handlers query directly the DB.
+
+More concretely, `sqlc` generates `RawJSON` for some fields that are embedded
+structs. So I have to do the translation somewhere.
+
+So I will just stick to the plan and keep going with the predefined structure.
+
+I have to figure out how to use the generated mock files.
+
+The goals for the next week is to finish the basic operations for each level
+and run some integration tests with `curl`.
+
+### 2024/10/22
+
+I am facing come difficulties on testing of the `repo` functions.
+
+First, I have to keep the business logic in the service layer. That means I
+have to create the transaction at the service layer. I don't need to depend
+on the implementation detail. So I have created a Transaction interface.
+
+I don't care of the type of `tx` because I will pass it to repo layer and I
+suppose that it knows what it is doing. Considering this, my repo `Create`
+function will have to take an any and deduct the type of `tx`. So the layer
+becomes untestable, because I have to pass a *sql.Tx into it and create a
+querier.
+
+Since this repo layer is just a wrapping layer between the `sqlc.models` and
+my own models, I can extract the conversion part to functions and test them.
+I'm not testing the whole thing but I test what I can.
+
+### 2024/10/24
+
+When writing the tests. I am asking myself the differences between `[]T`,
+`[]*T` and `*[]T`.
+
+`*[]T` is simple, it is a reference to the original slice. So modifying it
+means modifying the original slice.
+
+But between `[]*T` and `[]T`, the only difference that I see (pointed out by
+`ChatGPT`) is how the memory is allocated. With `[]T` it might be better for
+the GC to deal with the memory free. I thing for my project I will stick to
+`[]T`.
+
+### 2024/10/25
+
+Read this [article](https://konradreiche.com/blog/two-common-go-interface-misuses/)
+today, maybe I am abusing the usage of interfaces?
--- a/go.mod
+++ b/go.mod
@ -18,7 +18,7 @@ require (
 	github.com/stretchr/testify v1.9.0
 	go.uber.org/zap v1.27.0
 	golang.org/x/crypto v0.27.0
-	golang.org/x/net v0.25.0
+	golang.org/x/net v0.26.0
 )

 require (
--- a/go.sum
+++ b/go.sum
@ -153,8 +153,8 @@ golang.org/x/crypto v0.27.0 h1:GXm2NjJrPaiv/h1tb2UH8QfgC/hOf/+z0p6PT8o1w7A=
 golang.org/x/crypto v0.27.0/go.mod h1:1Xngt8kV6Dvbssa53Ziq6Eqn0HqbZi5Z6R0ZpwQzt70=
 golang.org/x/exp v0.0.0-20230905200255-921286631fa9 h1:GoHiUyI/Tp2nVkLI2mCxVkOjsbSXD66ic0XW0js0R9g=
 golang.org/x/exp v0.0.0-20230905200255-921286631fa9/go.mod h1:S2oDrQGGwySpoQPVqRShND87VCbxmc6bL1Yd2oYrm6k=
-golang.org/x/net v0.25.0 h1:d/OCCoBEUq33pjydKrGQhw7IlUPI2Oylr+8qLx49kac=
-golang.org/x/net v0.25.0/go.mod h1:JkAGAh7GEvH74S6FOH42FLoXpXbE/aqXSrIQjXgsiwM=
+golang.org/x/net v0.26.0 h1:soB7SVo0PWrY4vPW/+ay0jKDNScG2X9wFeYlXIvJsOQ=
+golang.org/x/net v0.26.0/go.mod h1:5YKkiSynbBIh3p6iOc/vibscux0x38BZDkn8sCUPxHE=
 golang.org/x/sync v0.8.0 h1:3NFvSEYkUoMifnESzZl15y791HH1qU2xm6eCJU5ZPXQ=
 golang.org/x/sync v0.8.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
--- a/internal/howmuch/adapter/controller/session.go
+++ b/internal/howmuch/adapter/controller/session.go
@ -64,7 +64,7 @@ type createParams struct {
 // Since we use JWT method, this token is not stored anywhere. Thus it
 // stops at the controller level.
 func (sc *SessionController) Create(ctx *gin.Context) {
-	var user model.UserExistDTO
+	var user model.UserExistRequest

 	if err := ctx.Bind(&user); err != nil {
 		log.ErrorLog("param error", "err", err)
--- a/internal/howmuch/adapter/controller/session_test.go
+++ b/internal/howmuch/adapter/controller/session_test.go
@ -85,6 +85,14 @@ func TestSessionCreate(t *testing.T) {
 			Email:    "unregistered@error.com",
 			Password: "strong password",
 		}, usecase.UserNotExist},
+		{"wrong email", createParams{
+			Email:    "error.com",
+			Password: "strong password",
+		}, UserParamsErr},
+		{"no passwrd", createParams{
+			Email:    "no@error.com",
+			Password: "",
+		}, UserParamsErr},
 	}

 	token.Init("secret", 1*time.Second)
--- a/internal/howmuch/adapter/controller/usecasemock/testuserusecase.go
+++ b/internal/howmuch/adapter/controller/usecasemock/testuserusecase.go
@ -35,11 +35,14 @@ func NewtestUserUsecase() usecase.User {
 	return &testUserUsecase{}
 }

-func (*testUserUsecase) Create(ctx context.Context, u *model.UserCreateDTO) (*model.User, error) {
+func (*testUserUsecase) Create(
+	ctx context.Context,
+	u *model.UserCreateRequest,
+) (*model.UserInfoResponse, error) {
 	return nil, nil
 }

-func (*testUserUsecase) Exist(ctx context.Context, u *model.UserExistDTO) error {
+func (*testUserUsecase) Exist(ctx context.Context, u *model.UserExistRequest) error {
 	switch u.Email {
 	case "a@b.c":
 		if u.Password == "strong password" {
@ -53,3 +56,11 @@ func (*testUserUsecase) Exist(ctx context.Context, u *model.UserExistDTO) error
 	// Should never reach here
 	return nil
 }
+
+func (*testUserUsecase) GetUserBaseResponseByID(
+	ctx context.Context,
+	userID int,
+) (*model.UserBaseResponse, error) {
+	// TODO:
+	return nil, nil
+}
--- a/internal/howmuch/adapter/controller/user.go
+++ b/internal/howmuch/adapter/controller/user.go
@ -57,14 +57,14 @@ func NewUserController(us usecase.User) User {
 }

 func (uc *UserController) Create(ctx core.Context) {
-	var userDTO model.UserCreateDTO
+	var userRequest model.UserCreateRequest

-	if err := ctx.Bind(&userDTO); err != nil {
+	if err := ctx.Bind(&userRequest); err != nil {
 		core.WriteResponse(ctx, UserParamsErr, nil)
 		return
 	}

-	_, err := uc.userUsecase.Create(ctx, &userDTO)
+	_, err := uc.userUsecase.Create(ctx, &userRequest)
 	if err != nil {
 		core.WriteResponse(ctx, err, nil)
 		return
--- a/internal/howmuch/adapter/repo/db.go
+++ b/internal/howmuch/adapter/repo/db.go
@ -25,7 +25,9 @@ package repo
 import (
 	"context"
 	"database/sql"
+	"time"

+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/adapter/repo/sqlc"
 	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/repo"
 	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/log"
 )
@ -34,6 +36,8 @@ type dbRepository struct {
 	db *sql.DB
 }

+const queryTimeout = 3 * time.Second
+
 func NewDBRepository(db *sql.DB) repo.DBRepository {
 	return &dbRepository{
 		db: db,
@ -66,3 +70,11 @@ func (dr *dbRepository) Transaction(
 	data, err := txFunc(ctx, tx)
 	return data, err
 }
+
+func getQueries(queries *sqlc.Queries, tx any) *sqlc.Queries {
+	transaction, ok := tx.(*sql.Tx)
+	if ok {
+		return sqlc.New(transaction)
+	}
+	return queries
+}
--- a/internal/howmuch/adapter/repo/event.go
+++ b/internal/howmuch/adapter/repo/event.go
@ -0,0 +1,276 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package repo
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"time"
+
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/adapter/repo/sqlc"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/repo"
+	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/log"
+)
+
+type eventRepository struct {
+	queries *sqlc.Queries
+}
+
+func NewEventRepository(db *sql.DB) repo.EventRepository {
+	return &eventRepository{
+		queries: sqlc.New(db),
+	}
+}
+
+// Create implements repo.EventRepository.
+func (e *eventRepository) Create(
+	ctx context.Context,
+	evEntity *model.EventEntity,
+	tx any,
+) (*model.EventEntity, error) {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(e.queries, tx)
+
+	event, err := queries.InsertEvent(timeoutCtx, sqlc.InsertEventParams{
+		Name:            evEntity.Name,
+		Description:     sql.NullString{String: evEntity.Description, Valid: true},
+		TotalAmount:     sql.NullInt32{Int32: int32(evEntity.TotalAmount), Valid: true},
+		DefaultCurrency: evEntity.DefaultCurrency,
+		OwnerID:         int32(evEntity.OwnerID),
+		CreatedAt:       time.Now(),
+		UpdatedAt:       time.Now(),
+	})
+	if err != nil {
+		return nil, err
+	}
+	return &model.EventEntity{
+		ID:              int(event.ID),
+		Name:            event.Name,
+		Description:     event.Description.String,
+		TotalAmount:     int(event.TotalAmount.Int32),
+		DefaultCurrency: event.DefaultCurrency,
+		OwnerID:         int(event.OwnerID),
+		CreatedAt:       event.CreatedAt,
+		UpdatedAt:       event.UpdatedAt,
+	}, nil
+}
+
+func convToEventRetrieved(eventDTO *sqlc.GetEventByIDRow) (*model.EventRetrieved, error) {
+	// marshal owner and users
+	var owner model.UserBaseRetrieved
+	err := json.Unmarshal(eventDTO.Owner, &owner)
+	if err != nil {
+		// Unexpected
+		log.ErrorLog("json unmarshal error", "err", err)
+		return nil, err
+	}
+
+	var users []model.UserBaseRetrieved
+	err = json.Unmarshal(eventDTO.Users, &users)
+	if err != nil {
+		// Unexpected
+		log.ErrorLog("json unmarshal error", "err", err)
+		return nil, err
+	}
+
+	eventRetrieved := &model.EventRetrieved{
+		ID:          int(eventDTO.ID),
+		Name:        eventDTO.Name,
+		Description: eventDTO.Description.String,
+		TotalAmount: model.MakeMoney(
+			int(eventDTO.TotalAmount.Int32),
+			model.Currency(eventDTO.DefaultCurrency),
+		),
+		DefaultCurrency: model.Currency(eventDTO.DefaultCurrency),
+		CreatedAt:       eventDTO.CreatedAt,
+		UpdatedAt:       eventDTO.UpdatedAt,
+		Owner:           &owner,
+		Users:           users,
+	}
+
+	return eventRetrieved, nil
+}
+
+// GetByID implements repo.EventRepository.
+func (e *eventRepository) GetByID(
+	ctx context.Context,
+	eventID int,
+	tx any,
+) (*model.EventRetrieved, error) {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(e.queries, tx)
+
+	eventDTO, err := queries.GetEventByID(timeoutCtx, int32(eventID))
+	if err != nil {
+		log.ErrorLog("query error", "err", err)
+		return nil, err
+	}
+
+	return convToEventRetrieved(&eventDTO)
+}
+
+func convToEventList(eventsDTO []sqlc.ListEventsByUserIDRow) ([]model.EventListRetrieved, error) {
+	events := make([]model.EventListRetrieved, len(eventsDTO))
+
+	for i, evDTO := range eventsDTO {
+		var owner model.UserBaseRetrieved
+		err := json.Unmarshal(evDTO.Owner, &owner)
+		if err != nil {
+			// Unexpected
+			log.ErrorLog("json unmarshal error", "err", err)
+			return nil, err
+		}
+		ev := model.EventListRetrieved{
+			ID:          int(evDTO.ID),
+			Name:        evDTO.Name,
+			Description: evDTO.Description.String,
+			Owner:       &owner,
+			CreatedAt:   evDTO.CreatedAt,
+		}
+
+		events[i] = ev
+	}
+
+	return events, nil
+}
+
+// ListEventsByUserID implements repo.EventRepository.
+func (e *eventRepository) ListEventsByUserID(
+	ctx context.Context,
+	userID int,
+	tx any,
+) ([]model.EventListRetrieved, error) {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(e.queries, tx)
+
+	eventsDTO, err := queries.ListEventsByUserID(timeoutCtx, int32(userID))
+	if err != nil {
+		log.ErrorLog("query error", "err", err)
+		return nil, err
+	}
+
+	return convToEventList(eventsDTO)
+}
+
+// UpdateInfo implements repo.EventRepository.
+func (e *eventRepository) UpdateEventByID(
+	ctx context.Context,
+	event *model.EventUpdateEntity,
+	tx any,
+) error {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(e.queries, tx)
+
+	err := queries.UpdateEventByID(timeoutCtx, sqlc.UpdateEventByIDParams{
+		ID:          int32(event.ID),
+		Name:        event.Name,
+		Description: sql.NullString{String: event.Description, Valid: true},
+		UpdatedAt:   time.Now(),
+	})
+	return err
+}
+
+// GetParticipation implements repo.EventRepository.
+func (e *eventRepository) GetParticipation(
+	ctx context.Context,
+	userID, eventID int,
+	tx any,
+) (*model.ParticipationEntity, error) {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(e.queries, tx)
+
+	partDTO, err := queries.GetParticipation(timeoutCtx, sqlc.GetParticipationParams{
+		UserID:  int32(userID),
+		EventID: int32(eventID),
+	})
+
+	if errors.Is(err, sql.ErrNoRows) {
+		// No error, but participation not found
+		return nil, nil
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &model.ParticipationEntity{
+		ID:              int(partDTO.ID),
+		UserID:          int(partDTO.UserID),
+		EventID:         int(partDTO.EventID),
+		InvitedByUserID: int(partDTO.InvitedByUserID.Int32),
+		CreatedAt:       partDTO.CreatedAt,
+		UpdatedAt:       partDTO.UpdatedAt,
+	}, nil
+}
+
+// InsertParticipation implements repo.EventRepository.
+func (e *eventRepository) InsertParticipation(
+	ctx context.Context,
+	userID int,
+	eventID int,
+	invitedByUserID int,
+	tx any,
+) (*model.ParticipationEntity, error) {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(e.queries, tx)
+
+	var invitedBy sql.NullInt32
+	if invitedByUserID == 0 {
+		invitedBy = sql.NullInt32{Int32: 0, Valid: false}
+	} else {
+		invitedBy = sql.NullInt32{Int32: int32(invitedByUserID), Valid: true}
+	}
+	participationDTO, err := queries.InsertParticipation(timeoutCtx, sqlc.InsertParticipationParams{
+		UserID:          int32(userID),
+		EventID:         int32(eventID),
+		InvitedByUserID: invitedBy,
+		CreatedAt:       time.Now(),
+		UpdatedAt:       time.Now(),
+	})
+	if err != nil {
+		return nil, err
+	}
+	return &model.ParticipationEntity{
+		ID:              int(participationDTO.ID),
+		UserID:          int(participationDTO.UserID),
+		EventID:         int(participationDTO.EventID),
+		InvitedByUserID: int(participationDTO.InvitedByUserID.Int32),
+		CreatedAt:       participationDTO.CreatedAt,
+		UpdatedAt:       participationDTO.UpdatedAt,
+	}, nil
+}
--- a/internal/howmuch/adapter/repo/event_test.go
+++ b/internal/howmuch/adapter/repo/event_test.go
@ -0,0 +1,122 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package repo
+
+import (
+	"database/sql"
+	"encoding/json"
+	"testing"
+	"time"
+
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/adapter/repo/sqlc"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestConvToEventRetrieved(t *testing.T) {
+	input := &sqlc.GetEventByIDRow{
+		ID:              123,
+		Name:            "event",
+		Description:     sql.NullString{Valid: false},
+		TotalAmount:     sql.NullInt32{Valid: false},
+		DefaultCurrency: "EUR",
+		CreatedAt:       time.Date(2000, time.April, 11, 0, 0, 0, 0, time.UTC),
+		UpdatedAt:       time.Date(2000, time.April, 11, 0, 0, 0, 0, time.UTC),
+		Owner:           json.RawMessage(`{"id":1, "first_name":"owner", "last_name":"owner"}`),
+		Users:           json.RawMessage(`[{"id":1, "first_name":"owner", "last_name":"owner"}]`),
+	}
+
+	want := &model.EventRetrieved{
+		ID:              123,
+		Name:            "event",
+		Description:     "",
+		TotalAmount:     model.Money{Amount: 0, Currency: "EUR"},
+		DefaultCurrency: model.Currency("EUR"),
+		CreatedAt:       time.Date(2000, time.April, 11, 0, 0, 0, 0, time.UTC),
+		UpdatedAt:       time.Date(2000, time.April, 11, 0, 0, 0, 0, time.UTC),
+		Owner: &model.UserBaseRetrieved{
+			ID:        1,
+			FirstName: "owner",
+			LastName:  "owner",
+		},
+		Users: []model.UserBaseRetrieved{
+			{
+				ID:        1,
+				FirstName: "owner",
+				LastName:  "owner",
+			},
+		},
+	}
+
+	got, err := convToEventRetrieved(input)
+	assert.NoError(t, err)
+	assert.Equal(t, want, got)
+}
+
+func TestConvToEventList(t *testing.T) {
+	input := []sqlc.ListEventsByUserIDRow{
+		{
+			ID:          123,
+			Name:        "event",
+			Description: sql.NullString{Valid: false},
+			CreatedAt:   time.Date(2000, time.April, 11, 0, 0, 0, 0, time.UTC),
+			Owner:       json.RawMessage(`{"id":1, "first_name":"owner", "last_name":"owner"}`),
+		},
+		{
+			ID:          456,
+			Name:        "event2",
+			Description: sql.NullString{String: "super event", Valid: true},
+			CreatedAt:   time.Date(2000, time.April, 11, 0, 0, 0, 0, time.UTC),
+			Owner:       json.RawMessage(`{"id":1, "first_name":"owner", "last_name":"owner"}`),
+		},
+	}
+
+	want := []model.EventListRetrieved{
+		{
+			ID:          123,
+			Name:        "event",
+			Description: "",
+			CreatedAt:   time.Date(2000, time.April, 11, 0, 0, 0, 0, time.UTC),
+			Owner: &model.UserBaseRetrieved{
+				ID:        1,
+				FirstName: "owner",
+				LastName:  "owner",
+			},
+		},
+		{
+			ID:          456,
+			Name:        "event2",
+			Description: "super event",
+			CreatedAt:   time.Date(2000, time.April, 11, 0, 0, 0, 0, time.UTC),
+			Owner: &model.UserBaseRetrieved{
+				ID:        1,
+				FirstName: "owner",
+				LastName:  "owner",
+			},
+		},
+	}
+
+	got, err := convToEventList(input)
+	assert.NoError(t, err)
+	assert.Equal(t, want, got)
+}
--- a/internal/howmuch/adapter/repo/expense.go
+++ b/internal/howmuch/adapter/repo/expense.go
@ -0,0 +1,267 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package repo
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"time"
+
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/adapter/repo/sqlc"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/repo"
+	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/log"
+)
+
+type expenseRepository struct {
+	queries *sqlc.Queries
+}
+
+func NewExpenseRepository(db *sql.DB) repo.ExpenseRepository {
+	return &expenseRepository{
+		queries: sqlc.New(db),
+	}
+}
+
+// DeleteExpense implements repo.ExpenseRepository.
+func (e *expenseRepository) DeleteExpense(ctx context.Context, expenseID int, tx any) error {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(e.queries, tx)
+	return queries.DeleteExpense(timeoutCtx, int32(expenseID))
+}
+
+// DeleteTransactionsOfExpense implements repo.ExpenseRepository.
+func (e *expenseRepository) DeleteTransactionsOfExpense(
+	ctx context.Context,
+	expenseID int,
+	tx any,
+) error {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(e.queries, tx)
+	return queries.DeleteTransactionsOfExpenseID(timeoutCtx, int32(expenseID))
+}
+
+// GetExpenseByID implements repo.ExpenseRepository.
+func (e *expenseRepository) GetExpenseByID(
+	ctx context.Context,
+	expenseID int,
+	tx any,
+) (*model.ExpenseRetrieved, error) {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(e.queries, tx)
+
+	expenseDTO, err := queries.GetExpenseByID(timeoutCtx, int32(expenseID))
+	if err != nil {
+		return nil, err
+	}
+	expense, err := convToExpenseRetrieved(&expenseDTO)
+	if err != nil {
+		return nil, err
+	}
+	return expense, nil
+}
+
+func convToPayments(raw json.RawMessage) ([]model.Payment, error) {
+	var paymentsRetrieved []model.PaymentRetrieved
+	err := json.Unmarshal(raw, &paymentsRetrieved)
+	if err != nil {
+		// Unexpected
+		log.ErrorLog("json unmarshal error", "err", err)
+		return nil, err
+	}
+
+	payments := make([]model.Payment, len(paymentsRetrieved))
+	for i, p := range paymentsRetrieved {
+		payment := model.Payment{
+			PayerID:        p.PayerID,
+			PayerFirstName: p.PayerFirstName,
+			PayerLastName:  p.PayerLastName,
+			Amount:         model.MakeMoney(p.Amount, model.Currency(p.Currency)),
+		}
+		payments[i] = payment
+	}
+
+	return payments, nil
+}
+
+func convToBenefits(raw json.RawMessage) ([]model.Benefit, error) {
+	var benefitsRetrieved []model.BenefitRetrieved
+	err := json.Unmarshal(raw, &benefitsRetrieved)
+	if err != nil {
+		// Unexpected
+		log.ErrorLog("json unmarshal error", "err", err)
+		return nil, err
+	}
+
+	benefits := make([]model.Benefit, len(benefitsRetrieved))
+	for i, b := range benefitsRetrieved {
+		benefit := model.Benefit{
+			RecipientID:        b.RecipientID,
+			RecipientFirstName: b.RecipientFirstName,
+			RecipientLastName:  b.RecipientLastName,
+			Amount:             model.MakeMoney(b.Amount, model.Currency(b.Currency)),
+		}
+		benefits[i] = benefit
+	}
+
+	return benefits, nil
+}
+
+func convToExpenseRetrieved(expenseDTO *sqlc.GetExpenseByIDRow) (*model.ExpenseRetrieved, error) {
+	payments, err := convToPayments(expenseDTO.Payments)
+	if err != nil {
+		// Unexpected
+		return nil, err
+	}
+
+	benefits, err := convToBenefits(expenseDTO.Benefits)
+	if err != nil {
+		// Unexpected
+		return nil, err
+	}
+
+	expenseRetrieved := &model.ExpenseRetrieved{
+		ID:        int(expenseDTO.ID),
+		CreatedAt: expenseDTO.CreatedAt,
+		UpdatedAt: expenseDTO.UpdatedAt,
+		Amount:    model.MakeMoney(int(expenseDTO.Amount), model.Currency(expenseDTO.Currency)),
+		EventID:   int(expenseDTO.EventID),
+		Detail: model.ExpenseDetail{
+			Name:  expenseDTO.Name.String,
+			Place: expenseDTO.Place.String,
+		},
+		Payments: payments,
+		Benefits: benefits,
+	}
+
+	return expenseRetrieved, nil
+}
+
+// InsertExpense implements repo.ExpenseRepository.
+func (e *expenseRepository) InsertExpense(
+	ctx context.Context,
+	expenseEntity *model.ExpenseEntity,
+	tx any,
+) (*model.ExpenseEntity, error) {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(e.queries, tx)
+
+	expenseDTO, err := queries.InsertExpense(timeoutCtx, sqlc.InsertExpenseParams{
+		CreatedAt: time.Now(),
+		UpdatedAt: time.Now(),
+		Amount:    int32(expenseEntity.Amount),
+		Currency:  expenseEntity.Currency,
+		EventID:   int32(expenseEntity.EventID),
+		Name:      sql.NullString{String: expenseEntity.Name, Valid: true},
+		Place:     sql.NullString{String: expenseEntity.Place, Valid: true},
+	})
+	if err != nil {
+		return nil, err
+	}
+	return &model.ExpenseEntity{
+		ID:        int(expenseDTO.ID),
+		CreatedAt: expenseDTO.CreatedAt,
+		UpdatedAt: expenseDTO.CreatedAt,
+		Amount:    int(expenseDTO.Amount),
+		Currency:  expenseDTO.Currency,
+		EventID:   int(expenseDTO.EventID),
+		Name:      expenseDTO.Name.String,
+		Place:     expenseDTO.Place.String,
+	}, nil
+}
+
+// ListExpensesByEventID implements repo.ExpenseRepository.
+func (e *expenseRepository) ListExpensesByEventID(
+	ctx context.Context,
+	id int,
+	tx any,
+) ([]model.ExpensesListRetrieved, error) {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(e.queries, tx)
+
+	listDTO, err := queries.ListExpensesByEventID(timeoutCtx, int32(id))
+	if err != nil {
+		return nil, err
+	}
+	res := make([]model.ExpensesListRetrieved, len(listDTO))
+	for i, dto := range listDTO {
+		elem := model.ExpensesListRetrieved{
+			ID:        int(dto.ID),
+			CreatedAt: dto.CreatedAt,
+			UpdatedAt: dto.UpdatedAt,
+			Amount:    model.MakeMoney(int(dto.Amount), model.Currency(dto.Currency)),
+			EventID:   int(dto.EventID),
+			Detail: model.ExpenseDetail{
+				Name:  dto.Name.String,
+				Place: dto.Place.String,
+			},
+		}
+		res[i] = elem
+	}
+	return res, nil
+}
+
+// UpdateExpenseByID implements repo.ExpenseRepository.
+func (e *expenseRepository) UpdateExpenseByID(
+	ctx context.Context,
+	expenseUpdate *model.ExpenseUpdateEntity,
+	tx any,
+) (*model.ExpenseEntity, error) {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(e.queries, tx)
+
+	expenseDTO, err := queries.UpdateExpenseByID(timeoutCtx, sqlc.UpdateExpenseByIDParams{
+		ID:        int32(expenseUpdate.ID),
+		UpdatedAt: time.Now(),
+		Amount:    int32(expenseUpdate.Amount),
+		Currency:  expenseUpdate.Currency,
+		Name:      sql.NullString{String: expenseUpdate.Name, Valid: true},
+		Place:     sql.NullString{String: expenseUpdate.Place, Valid: true},
+	})
+	if err != nil {
+		return nil, err
+	}
+	return &model.ExpenseEntity{
+		ID:        int(expenseDTO.ID),
+		CreatedAt: expenseDTO.CreatedAt,
+		UpdatedAt: expenseDTO.CreatedAt,
+		Amount:    int(expenseDTO.Amount),
+		Currency:  expenseDTO.Currency,
+		EventID:   int(expenseDTO.EventID),
+		Name:      expenseDTO.Name.String,
+		Place:     expenseDTO.Place.String,
+	}, nil
+}
--- a/internal/howmuch/adapter/repo/expense_test.go
+++ b/internal/howmuch/adapter/repo/expense_test.go
@ -0,0 +1,96 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package repo
+
+import (
+	"database/sql"
+	"encoding/json"
+	"testing"
+	"time"
+
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/adapter/repo/sqlc"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestConvToExpenseRetrieved(t *testing.T) {
+	input := &sqlc.GetExpenseByIDRow{
+		ID:        123,
+		CreatedAt: time.Date(2000, time.April, 11, 0, 0, 0, 0, time.UTC),
+		UpdatedAt: time.Date(2000, time.April, 11, 0, 0, 0, 0, time.UTC),
+		Amount:    123,
+		Currency:  "EUR",
+		EventID:   123,
+		Name:      sql.NullString{Valid: false},
+		Place:     sql.NullString{Valid: false},
+		Payments: json.RawMessage(
+			`[{"payer_id": 1, "payer_first_name": "toto", "payer_last_name": "titi", "amount": 10, "currency": "EUR"},
+            {"payer_id": 2, "payer_first_name": "tata", "payer_last_name": "titi", "amount": 10, "currency": "EUR"}]`,
+		),
+		Benefits: json.RawMessage(
+			`[{"recipient_id": 1, "recipient_first_name": "toto", "recipient_last_name": "titi", "amount": 10, "currency": "EUR"},
+            {"recipient_id": 2, "recipient_first_name": "tata", "recipient_last_name": "titi", "amount": 10, "currency": "EUR"}]`,
+		),
+	}
+
+	want := &model.ExpenseRetrieved{
+		ID:        123,
+		CreatedAt: time.Date(2000, time.April, 11, 0, 0, 0, 0, time.UTC),
+		UpdatedAt: time.Date(2000, time.April, 11, 0, 0, 0, 0, time.UTC),
+		Amount:    model.Money{Amount: 123, Currency: model.Currency("EUR")},
+		EventID:   123,
+		Detail:    model.ExpenseDetail{},
+		Payments: []model.Payment{
+			{
+				PayerID:        1,
+				PayerFirstName: "toto",
+				PayerLastName:  "titi",
+				Amount:         model.Money{Amount: 10, Currency: model.Currency("EUR")},
+			},
+			{
+				PayerID:        2,
+				PayerFirstName: "tata",
+				PayerLastName:  "titi",
+				Amount:         model.Money{Amount: 10, Currency: model.Currency("EUR")},
+			},
+		},
+		Benefits: []model.Benefit{
+			{
+				RecipientID:        1,
+				RecipientFirstName: "toto",
+				RecipientLastName:  "titi",
+				Amount:             model.Money{Amount: 10, Currency: model.Currency("EUR")},
+			},
+			{
+				RecipientID:        2,
+				RecipientFirstName: "tata",
+				RecipientLastName:  "titi",
+				Amount:             model.Money{Amount: 10, Currency: model.Currency("EUR")},
+			},
+		},
+	}
+
+	got, err := convToExpenseRetrieved(input)
+	assert.NoError(t, err)
+	assert.Equal(t, want, got)
+}
--- a/internal/howmuch/adapter/repo/sqlc/event.sql
+++ b/internal/howmuch/adapter/repo/sqlc/event.sql
@ -0,0 +1,64 @@
+-- name: InsertEvent :one
+INSERT INTO "event" (
+    name, description, total_amount, default_currency, owner_id, created_at, updated_at
+) VALUES ( $1, $2, $3, $4, $5, $6, $7 )
+RETURNING *;
+
+-- name: ListEventsByUserID :many
+SELECT
+    e.id,
+    e.name,
+    e.description,
+    e.created_at,
+    json_build_object(
+        'id', o.id,
+        'first_name', o.first_name,
+        'last_name', o.last_name
+    ) AS owner
+FROM "event" e
+JOIN "participation" p ON p.event_id = e.id  -- participation linked with the event
+JOIN "user" o ON o.id = e.owner_id           -- get the owner info
+WHERE e.id IN (
+    SELECT pt.event_id FROM participation pt WHERE pt.user_id = $1 -- consider the events participated by user_id
+)
+GROUP BY
+    e.id, e.name, e.description, e.created_at,
+    o.id, o.first_name, o.last_name;
+
+-- name: GetEventByID :one
+SELECT
+    e.id,
+    e.name,
+    e.description,
+    e.total_amount,
+    e.default_currency,
+    e.created_at,
+    e.updated_at,
+    json_build_object(
+        'id', o.id,
+        'first_name', o.first_name,
+        'last_name', o.last_name
+    ) AS owner,
+    json_agg(
+        json_build_object(
+            'id', u.id,
+            'first_name', u.first_name,
+            'last_name', u.last_name
+        )
+    ) AS users  -- Aggregation for users in the event
+FROM "event" e
+JOIN "participation" p ON p.event_id = e.id  -- participation linked with the event
+JOIN "user" u ON u.id = p.user_id            -- and the query user
+JOIN "user" o ON o.id = e.owner_id           -- get the owner info
+WHERE e.id = $1
+GROUP BY
+    e.id, e.name, e.description, e.created_at, e.updated_at,
+    e.total_amount, e.default_currency,
+    o.id, o.first_name, o.last_name;
+
+-- name: UpdateEventByID :exec
+UPDATE "event"
+SET name = $2, description = $3, updated_at = $4
+WHERE id = $1;
+
+
--- a/internal/howmuch/adapter/repo/sqlc/event.sql.go
+++ b/internal/howmuch/adapter/repo/sqlc/event.sql.go
@ -0,0 +1,197 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.27.0
+// source: event.sql
+
+package sqlc
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"time"
+)
+
+const getEventByID = `-- name: GetEventByID :one
+SELECT
+    e.id,
+    e.name,
+    e.description,
+    e.total_amount,
+    e.default_currency,
+    e.created_at,
+    e.updated_at,
+    json_build_object(
+        'id', o.id,
+        'first_name', o.first_name,
+        'last_name', o.last_name
+    ) AS owner,
+    json_agg(
+        json_build_object(
+            'id', u.id,
+            'first_name', u.first_name,
+            'last_name', u.last_name
+        )
+    ) AS users  -- Aggregation for users in the event
+FROM "event" e
+JOIN "participation" p ON p.event_id = e.id  -- participation linked with the event
+JOIN "user" u ON u.id = p.user_id            -- and the query user
+JOIN "user" o ON o.id = e.owner_id           -- get the owner info
+WHERE e.id = $1
+GROUP BY
+    e.id, e.name, e.description, e.created_at, e.updated_at,
+    e.total_amount, e.default_currency,
+    o.id, o.first_name, o.last_name
+`
+
+type GetEventByIDRow struct {
+	ID              int32
+	Name            string
+	Description     sql.NullString
+	TotalAmount     sql.NullInt32
+	DefaultCurrency string
+	CreatedAt       time.Time
+	UpdatedAt       time.Time
+	Owner           json.RawMessage
+	Users           json.RawMessage
+}
+
+func (q *Queries) GetEventByID(ctx context.Context, id int32) (GetEventByIDRow, error) {
+	row := q.db.QueryRowContext(ctx, getEventByID, id)
+	var i GetEventByIDRow
+	err := row.Scan(
+		&i.ID,
+		&i.Name,
+		&i.Description,
+		&i.TotalAmount,
+		&i.DefaultCurrency,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+		&i.Owner,
+		&i.Users,
+	)
+	return i, err
+}
+
+const insertEvent = `-- name: InsertEvent :one
+INSERT INTO "event" (
+    name, description, total_amount, default_currency, owner_id, created_at, updated_at
+) VALUES ( $1, $2, $3, $4, $5, $6, $7 )
+RETURNING id, name, description, default_currency, owner_id, created_at, updated_at, total_amount
+`
+
+type InsertEventParams struct {
+	Name            string
+	Description     sql.NullString
+	TotalAmount     sql.NullInt32
+	DefaultCurrency string
+	OwnerID         int32
+	CreatedAt       time.Time
+	UpdatedAt       time.Time
+}
+
+func (q *Queries) InsertEvent(ctx context.Context, arg InsertEventParams) (Event, error) {
+	row := q.db.QueryRowContext(ctx, insertEvent,
+		arg.Name,
+		arg.Description,
+		arg.TotalAmount,
+		arg.DefaultCurrency,
+		arg.OwnerID,
+		arg.CreatedAt,
+		arg.UpdatedAt,
+	)
+	var i Event
+	err := row.Scan(
+		&i.ID,
+		&i.Name,
+		&i.Description,
+		&i.DefaultCurrency,
+		&i.OwnerID,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+		&i.TotalAmount,
+	)
+	return i, err
+}
+
+const listEventsByUserID = `-- name: ListEventsByUserID :many
+SELECT
+    e.id,
+    e.name,
+    e.description,
+    e.created_at,
+    json_build_object(
+        'id', o.id,
+        'first_name', o.first_name,
+        'last_name', o.last_name
+    ) AS owner
+FROM "event" e
+JOIN "participation" p ON p.event_id = e.id  -- participation linked with the event
+JOIN "user" o ON o.id = e.owner_id           -- get the owner info
+WHERE e.id IN (
+    SELECT pt.event_id FROM participation pt WHERE pt.user_id = $1 -- consider the events participated by user_id
+)
+GROUP BY
+    e.id, e.name, e.description, e.created_at,
+    o.id, o.first_name, o.last_name
+`
+
+type ListEventsByUserIDRow struct {
+	ID          int32
+	Name        string
+	Description sql.NullString
+	CreatedAt   time.Time
+	Owner       json.RawMessage
+}
+
+func (q *Queries) ListEventsByUserID(ctx context.Context, userID int32) ([]ListEventsByUserIDRow, error) {
+	rows, err := q.db.QueryContext(ctx, listEventsByUserID, userID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []ListEventsByUserIDRow
+	for rows.Next() {
+		var i ListEventsByUserIDRow
+		if err := rows.Scan(
+			&i.ID,
+			&i.Name,
+			&i.Description,
+			&i.CreatedAt,
+			&i.Owner,
+		); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Close(); err != nil {
+		return nil, err
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
+const updateEventByID = `-- name: UpdateEventByID :exec
+UPDATE "event"
+SET name = $2, description = $3, updated_at = $4
+WHERE id = $1
+`
+
+type UpdateEventByIDParams struct {
+	ID          int32
+	Name        string
+	Description sql.NullString
+	UpdatedAt   time.Time
+}
+
+func (q *Queries) UpdateEventByID(ctx context.Context, arg UpdateEventByIDParams) error {
+	_, err := q.db.ExecContext(ctx, updateEventByID,
+		arg.ID,
+		arg.Name,
+		arg.Description,
+		arg.UpdatedAt,
+	)
+	return err
+}
--- a/internal/howmuch/adapter/repo/sqlc/expense.sql
+++ b/internal/howmuch/adapter/repo/sqlc/expense.sql
@ -0,0 +1,64 @@
+-- name: InsertExpense :one
+INSERT INTO "expense" (
+    created_at, updated_at, amount, currency, event_id, name, place
+) VALUES ( $1, $2, $3, $4, $5, $6, $7 )
+RETURNING *;
+
+-- name: DeleteExpense :exec
+DELETE FROM "expense" WHERE id = $1;
+
+-- name: DeleteTransactionsOfExpenseID :exec
+DELETE FROM "transaction" WHERE transaction.expense_id = $1;
+
+-- name: UpdateExpenseByID :one
+UPDATE "expense"
+SET updated_at = $2, amount = $3, currency = $4, name = $5, place = $6
+WHERE id = $1
+RETURNING *;
+
+-- name: ListExpensesByEventID :many
+SELECT
+    ex.id, ex.created_at, ex.updated_at, ex.amount, ex.currency, ex.event_id,
+    ex.name, ex.place
+FROM "expense" ex
+JOIN "event" ev ON ev.id = ex.event_id
+WHERE ev.id = $1;
+
+-- name: GetExpenseByID :one
+WITH payer_transaction as (
+    SELECT pt.expense_id,
+        json_agg(json_build_object(
+            'payer_id', p.id,
+            'payer_first_name', p.first_name,
+            'payer_last_name', p.last_name,
+            'amount', pt.amount,
+            'currency', pt.currency
+        )) AS payments
+    FROM "transaction" pt
+    JOIN "user" p ON p.id = pt.user_id
+    WHERE pt.is_income = FALSE
+    GROUP BY pt.expense_id
+), -- For each expense, aggregate payment info
+recipient_transaction as (
+    SELECT rt.expense_id,
+        json_agg(json_build_object(
+            'recipient_id', p.id,
+            'recipient_first_name', p.first_name,
+            'recipient_last_name', p.last_name,
+            'amount', rt.amount,
+            'currency', rt.currency
+        )) AS benefits
+    FROM "transaction" rt
+    JOIN "user" p ON p.id = rt.user_id
+    WHERE rt.is_income = TRUE
+    GROUP BY rt.expense_id
+) -- For each expense, aggregate benefits info
+SELECT
+    ex.id, ex.created_at, ex.updated_at, ex.amount, ex.currency, ex.event_id,
+    ex.name, ex.place,
+    COALESCE(pt.payments, '[]') AS payments,
+    COALESCE(rt.benefits, '[]') AS benefits
+FROM "expense" ex
+LEFT JOIN "payer_transaction" pt ON pt.expense_id = ex.id
+LEFT JOIN "recipient_transaction" rt ON rt.expense_id = ex.id
+WHERE ex.id = $1;
--- a/internal/howmuch/adapter/repo/sqlc/expense.sql.go
+++ b/internal/howmuch/adapter/repo/sqlc/expense.sql.go
@ -0,0 +1,223 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.27.0
+// source: expense.sql
+
+package sqlc
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"time"
+)
+
+const deleteExpense = `-- name: DeleteExpense :exec
+DELETE FROM "expense" WHERE id = $1
+`
+
+func (q *Queries) DeleteExpense(ctx context.Context, id int32) error {
+	_, err := q.db.ExecContext(ctx, deleteExpense, id)
+	return err
+}
+
+const deleteTransactionsOfExpenseID = `-- name: DeleteTransactionsOfExpenseID :exec
+DELETE FROM "transaction" WHERE transaction.expense_id = $1
+`
+
+func (q *Queries) DeleteTransactionsOfExpenseID(ctx context.Context, expenseID int32) error {
+	_, err := q.db.ExecContext(ctx, deleteTransactionsOfExpenseID, expenseID)
+	return err
+}
+
+const getExpenseByID = `-- name: GetExpenseByID :one
+WITH payer_transaction as (
+    SELECT pt.expense_id,
+        json_agg(json_build_object(
+            'payer_id', p.id,
+            'payer_first_name', p.first_name,
+            'payer_last_name', p.last_name,
+            'amount', pt.amount,
+            'currency', pt.currency
+        )) AS payments
+    FROM "transaction" pt
+    JOIN "user" p ON p.id = pt.user_id
+    WHERE pt.is_income = FALSE
+    GROUP BY pt.expense_id
+), -- For each expense, aggregate payment info
+recipient_transaction as (
+    SELECT rt.expense_id,
+        json_agg(json_build_object(
+            'recipient_id', p.id,
+            'recipient_first_name', p.first_name,
+            'recipient_last_name', p.last_name,
+            'amount', rt.amount,
+            'currency', rt.currency
+        )) AS benefits
+    FROM "transaction" rt
+    JOIN "user" p ON p.id = rt.user_id
+    WHERE rt.is_income = TRUE
+    GROUP BY rt.expense_id
+) -- For each expense, aggregate benefits info
+SELECT
+    ex.id, ex.created_at, ex.updated_at, ex.amount, ex.currency, ex.event_id,
+    ex.name, ex.place,
+    COALESCE(pt.payments, '[]') AS payments,
+    COALESCE(rt.benefits, '[]') AS benefits
+FROM "expense" ex
+LEFT JOIN "payer_transaction" pt ON pt.expense_id = ex.id
+LEFT JOIN "recipient_transaction" rt ON rt.expense_id = ex.id
+WHERE ex.id = $1
+`
+
+type GetExpenseByIDRow struct {
+	ID        int32
+	CreatedAt time.Time
+	UpdatedAt time.Time
+	Amount    int32
+	Currency  string
+	EventID   int32
+	Name      sql.NullString
+	Place     sql.NullString
+	Payments  json.RawMessage
+	Benefits  json.RawMessage
+}
+
+func (q *Queries) GetExpenseByID(ctx context.Context, id int32) (GetExpenseByIDRow, error) {
+	row := q.db.QueryRowContext(ctx, getExpenseByID, id)
+	var i GetExpenseByIDRow
+	err := row.Scan(
+		&i.ID,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+		&i.Amount,
+		&i.Currency,
+		&i.EventID,
+		&i.Name,
+		&i.Place,
+		&i.Payments,
+		&i.Benefits,
+	)
+	return i, err
+}
+
+const insertExpense = `-- name: InsertExpense :one
+INSERT INTO "expense" (
+    created_at, updated_at, amount, currency, event_id, name, place
+) VALUES ( $1, $2, $3, $4, $5, $6, $7 )
+RETURNING id, created_at, updated_at, amount, currency, event_id, name, place
+`
+
+type InsertExpenseParams struct {
+	CreatedAt time.Time
+	UpdatedAt time.Time
+	Amount    int32
+	Currency  string
+	EventID   int32
+	Name      sql.NullString
+	Place     sql.NullString
+}
+
+func (q *Queries) InsertExpense(ctx context.Context, arg InsertExpenseParams) (Expense, error) {
+	row := q.db.QueryRowContext(ctx, insertExpense,
+		arg.CreatedAt,
+		arg.UpdatedAt,
+		arg.Amount,
+		arg.Currency,
+		arg.EventID,
+		arg.Name,
+		arg.Place,
+	)
+	var i Expense
+	err := row.Scan(
+		&i.ID,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+		&i.Amount,
+		&i.Currency,
+		&i.EventID,
+		&i.Name,
+		&i.Place,
+	)
+	return i, err
+}
+
+const listExpensesByEventID = `-- name: ListExpensesByEventID :many
+SELECT
+    ex.id, ex.created_at, ex.updated_at, ex.amount, ex.currency, ex.event_id,
+    ex.name, ex.place
+FROM "expense" ex
+JOIN "event" ev ON ev.id = ex.event_id
+WHERE ev.id = $1
+`
+
+func (q *Queries) ListExpensesByEventID(ctx context.Context, id int32) ([]Expense, error) {
+	rows, err := q.db.QueryContext(ctx, listExpensesByEventID, id)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []Expense
+	for rows.Next() {
+		var i Expense
+		if err := rows.Scan(
+			&i.ID,
+			&i.CreatedAt,
+			&i.UpdatedAt,
+			&i.Amount,
+			&i.Currency,
+			&i.EventID,
+			&i.Name,
+			&i.Place,
+		); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Close(); err != nil {
+		return nil, err
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
+const updateExpenseByID = `-- name: UpdateExpenseByID :one
+UPDATE "expense"
+SET updated_at = $2, amount = $3, currency = $4, name = $5, place = $6
+WHERE id = $1
+RETURNING id, created_at, updated_at, amount, currency, event_id, name, place
+`
+
+type UpdateExpenseByIDParams struct {
+	ID        int32
+	UpdatedAt time.Time
+	Amount    int32
+	Currency  string
+	Name      sql.NullString
+	Place     sql.NullString
+}
+
+func (q *Queries) UpdateExpenseByID(ctx context.Context, arg UpdateExpenseByIDParams) (Expense, error) {
+	row := q.db.QueryRowContext(ctx, updateExpenseByID,
+		arg.ID,
+		arg.UpdatedAt,
+		arg.Amount,
+		arg.Currency,
+		arg.Name,
+		arg.Place,
+	)
+	var i Expense
+	err := row.Scan(
+		&i.ID,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+		&i.Amount,
+		&i.Currency,
+		&i.EventID,
+		&i.Name,
+		&i.Place,
+	)
+	return i, err
+}
--- a/internal/howmuch/adapter/repo/sqlc/models.go
+++ b/internal/howmuch/adapter/repo/sqlc/models.go
@ -5,6 +5,7 @@
 package sqlc

 import (
+	"database/sql"
 	"time"
 )

@ -15,6 +16,48 @@ type Admin struct {
 	AccessLevel int32
 }

+type Event struct {
+	ID              int32
+	Name            string
+	Description     sql.NullString
+	DefaultCurrency string
+	OwnerID         int32
+	CreatedAt       time.Time
+	UpdatedAt       time.Time
+	TotalAmount     sql.NullInt32
+}
+
+type Expense struct {
+	ID        int32
+	CreatedAt time.Time
+	UpdatedAt time.Time
+	Amount    int32
+	Currency  string
+	EventID   int32
+	Name      sql.NullString
+	Place     sql.NullString
+}
+
+type Participation struct {
+	ID              int32
+	UserID          int32
+	EventID         int32
+	InvitedByUserID sql.NullInt32
+	CreatedAt       time.Time
+	UpdatedAt       time.Time
+}
+
+type Transaction struct {
+	ID        int32
+	ExpenseID int32
+	UserID    int32
+	Amount    int32
+	Currency  string
+	IsIncome  bool
+	CreatedAt time.Time
+	UpdatedAt time.Time
+}
+
 type User struct {
 	ID        int32
 	Email     string
--- a/internal/howmuch/adapter/repo/sqlc/participation.sql
+++ b/internal/howmuch/adapter/repo/sqlc/participation.sql
@ -0,0 +1,10 @@
+-- name: InsertParticipation :one
+INSERT INTO participation (
+    user_id, event_id, invited_by_user_id, created_at, updated_at
+) VALUES ($1, $2, $3, $4, $5)
+RETURNING *;
+
+-- name: GetParticipation :one
+SELECT id, user_id, event_id, invited_by_user_id, created_at, updated_at
+FROM "participation"
+WHERE user_id = $1 AND event_id = $2;
--- a/internal/howmuch/adapter/repo/sqlc/participation.sql.go
+++ b/internal/howmuch/adapter/repo/sqlc/participation.sql.go
@ -0,0 +1,72 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.27.0
+// source: participation.sql
+
+package sqlc
+
+import (
+	"context"
+	"database/sql"
+	"time"
+)
+
+const getParticipation = `-- name: GetParticipation :one
+SELECT id, user_id, event_id, invited_by_user_id, created_at, updated_at
+FROM "participation"
+WHERE user_id = $1 AND event_id = $2
+`
+
+type GetParticipationParams struct {
+	UserID  int32
+	EventID int32
+}
+
+func (q *Queries) GetParticipation(ctx context.Context, arg GetParticipationParams) (Participation, error) {
+	row := q.db.QueryRowContext(ctx, getParticipation, arg.UserID, arg.EventID)
+	var i Participation
+	err := row.Scan(
+		&i.ID,
+		&i.UserID,
+		&i.EventID,
+		&i.InvitedByUserID,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
+
+const insertParticipation = `-- name: InsertParticipation :one
+INSERT INTO participation (
+    user_id, event_id, invited_by_user_id, created_at, updated_at
+) VALUES ($1, $2, $3, $4, $5)
+RETURNING id, user_id, event_id, invited_by_user_id, created_at, updated_at
+`
+
+type InsertParticipationParams struct {
+	UserID          int32
+	EventID         int32
+	InvitedByUserID sql.NullInt32
+	CreatedAt       time.Time
+	UpdatedAt       time.Time
+}
+
+func (q *Queries) InsertParticipation(ctx context.Context, arg InsertParticipationParams) (Participation, error) {
+	row := q.db.QueryRowContext(ctx, insertParticipation,
+		arg.UserID,
+		arg.EventID,
+		arg.InvitedByUserID,
+		arg.CreatedAt,
+		arg.UpdatedAt,
+	)
+	var i Participation
+	err := row.Scan(
+		&i.ID,
+		&i.UserID,
+		&i.EventID,
+		&i.InvitedByUserID,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
--- a/internal/howmuch/adapter/repo/sqlc/querier.go
+++ b/internal/howmuch/adapter/repo/sqlc/querier.go
@ -0,0 +1,30 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.27.0
+
+package sqlc
+
+import (
+	"context"
+)
+
+type Querier interface {
+	DeleteExpense(ctx context.Context, id int32) error
+	DeleteTransactionsOfExpenseID(ctx context.Context, expenseID int32) error
+	GetEventByID(ctx context.Context, id int32) (GetEventByIDRow, error)
+	GetExpenseByID(ctx context.Context, id int32) (GetExpenseByIDRow, error)
+	GetParticipation(ctx context.Context, arg GetParticipationParams) (Participation, error)
+	GetUserByEmail(ctx context.Context, email string) (User, error)
+	GetUserByID(ctx context.Context, id int32) (User, error)
+	InsertEvent(ctx context.Context, arg InsertEventParams) (Event, error)
+	InsertExpense(ctx context.Context, arg InsertExpenseParams) (Expense, error)
+	InsertParticipation(ctx context.Context, arg InsertParticipationParams) (Participation, error)
+	InsertTransaction(ctx context.Context, arg InsertTransactionParams) error
+	InsertUser(ctx context.Context, arg InsertUserParams) (User, error)
+	ListEventsByUserID(ctx context.Context, userID int32) ([]ListEventsByUserIDRow, error)
+	ListExpensesByEventID(ctx context.Context, id int32) ([]Expense, error)
+	UpdateEventByID(ctx context.Context, arg UpdateEventByIDParams) error
+	UpdateExpenseByID(ctx context.Context, arg UpdateExpenseByIDParams) (Expense, error)
+}
+
+var _ Querier = (*Queries)(nil)
--- a/internal/howmuch/adapter/repo/sqlc/transaction.sql
+++ b/internal/howmuch/adapter/repo/sqlc/transaction.sql
@ -0,0 +1,5 @@
+-- name: InsertTransaction :exec
+INSERT INTO "transaction" (
+    created_at, updated_at, amount, currency, expense_id, user_id, is_income
+) VALUES ( $1, $2, $3, $4, $5, $6, $7 )
+RETURNING *;
--- a/internal/howmuch/adapter/repo/sqlc/transaction.sql.go
+++ b/internal/howmuch/adapter/repo/sqlc/transaction.sql.go
@ -0,0 +1,41 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.27.0
+// source: transaction.sql
+
+package sqlc
+
+import (
+	"context"
+	"time"
+)
+
+const insertTransaction = `-- name: InsertTransaction :exec
+INSERT INTO "transaction" (
+    created_at, updated_at, amount, currency, expense_id, user_id, is_income
+) VALUES ( $1, $2, $3, $4, $5, $6, $7 )
+RETURNING id, expense_id, user_id, amount, currency, is_income, created_at, updated_at
+`
+
+type InsertTransactionParams struct {
+	CreatedAt time.Time
+	UpdatedAt time.Time
+	Amount    int32
+	Currency  string
+	ExpenseID int32
+	UserID    int32
+	IsIncome  bool
+}
+
+func (q *Queries) InsertTransaction(ctx context.Context, arg InsertTransactionParams) error {
+	_, err := q.db.ExecContext(ctx, insertTransaction,
+		arg.CreatedAt,
+		arg.UpdatedAt,
+		arg.Amount,
+		arg.Currency,
+		arg.ExpenseID,
+		arg.UserID,
+		arg.IsIncome,
+	)
+	return err
+}
--- a/internal/howmuch/adapter/repo/sqlc/user.sql
+++ b/internal/howmuch/adapter/repo/sqlc/user.sql
@ -1,25 +1,3 @@
-- MIT License
--
-- Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
--
-- Permission is hereby granted, free of charge, to any person obtaining a copy
-- of this software and associated documentation files (the "Software"), to deal
-- in the Software without restriction, including without limitation the rights
-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-- copies of the Software, and to permit persons to whom the Software is
-- furnished to do so, subject to the following conditions:
--
-- The above copyright notice and this permission notice shall be included in all
-- copies or substantial portions of the Software.
--
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-- SOFTWARE.
-
 -- name: InsertUser :one
 INSERT INTO "user" (
    email, first_name, last_name, password, created_at, updated_at
@ -30,3 +8,8 @@ RETURNING *;
 SELECT id, email, first_name, last_name, password, created_at, updated_at
    FROM "user"
    WHERE email = $1;
+
+-- name: GetUserByID :one
+SELECT id, email, first_name, last_name, password, created_at, updated_at
+    FROM "user"
+    WHERE id = $1;
--- a/internal/howmuch/adapter/repo/sqlc/user.sql.go
+++ b/internal/howmuch/adapter/repo/sqlc/user.sql.go
@ -31,8 +31,28 @@ func (q *Queries) GetUserByEmail(ctx context.Context, email string) (User, error
 	return i, err
 }

-const insertUser = `-- name: InsertUser :one
+const getUserByID = `-- name: GetUserByID :one
+SELECT id, email, first_name, last_name, password, created_at, updated_at
+    FROM "user"
+    WHERE id = $1
+`

+func (q *Queries) GetUserByID(ctx context.Context, id int32) (User, error) {
+	row := q.db.QueryRowContext(ctx, getUserByID, id)
+	var i User
+	err := row.Scan(
+		&i.ID,
+		&i.Email,
+		&i.FirstName,
+		&i.LastName,
+		&i.Password,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
+
+const insertUser = `-- name: InsertUser :one
 INSERT INTO "user" (
    email, first_name, last_name, password, created_at, updated_at
 ) VALUES ( $1, $2, $3, $4, $5, $6 )
@ -48,27 +68,6 @@ type InsertUserParams struct {
 	UpdatedAt time.Time
 }

-// MIT License
-//
-// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in all
-// copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-// SOFTWARE.
 func (q *Queries) InsertUser(ctx context.Context, arg InsertUserParams) (User, error) {
 	row := q.db.QueryRowContext(ctx, insertUser,
 		arg.Email,
--- a/internal/howmuch/adapter/repo/user.go
+++ b/internal/howmuch/adapter/repo/user.go
@ -31,52 +31,42 @@ import (
 	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/adapter/repo/sqlc"
 	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
 	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/repo"
-	"github.com/jackc/pgx/v5"
 )

 type userRepository struct {
-	db *sql.DB
+	queries *sqlc.Queries
 }

-const insertTimeout = 1 * time.Second
-
 func NewUserRepository(db *sql.DB) repo.UserRepository {
 	return &userRepository{
-		db: db,
+		queries: sqlc.New(db),
 	}
 }

 // Create
-func (ur *userRepository) Create(
+func (u *userRepository) Create(
 	ctx context.Context,
-	transaction interface{},
-	u *model.User,
-) (*model.User, error) {
-	timeoutCtx, cancel := context.WithTimeout(ctx, insertTimeout)
+	userEntity *model.UserEntity,
+	tx any,
+) (*model.UserEntity, error) {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
 	defer cancel()

-	args := sqlc.InsertUserParams{
-		Email:     u.Email,
-		FirstName: u.FirstName,
-		LastName:  u.LastName,
-		Password:  u.Password,
+	queries := getQueries(u.queries, tx)
+
+	userDB, err := queries.InsertUser(timeoutCtx, sqlc.InsertUserParams{
+		Email:     userEntity.Email,
+		FirstName: userEntity.FirstName,
+		LastName:  userEntity.LastName,
+		Password:  userEntity.Password,
 		CreatedAt: time.Now(),
 		UpdatedAt: time.Now(),
-	}
-
-	tx, ok := transaction.(*sql.Tx)
-	if !ok {
-		return nil, errors.New("transaction is not a pgx.Tx")
-	}
-
-	queries := sqlc.New(tx)
-
-	userDB, err := queries.InsertUser(timeoutCtx, args)
+	})
 	if err != nil {
 		return nil, err
 	}

-	return &model.User{
+	return &model.UserEntity{
 		ID:        int(userDB.ID),
 		Email:     userDB.Email,
 		FirstName: userDB.FirstName,
@ -88,17 +78,50 @@ func (ur *userRepository) Create(
 }

 // GetByEmail if not found, return nil for user but not error.
-func (ur *userRepository) GetByEmail(ctx context.Context, email string) (*model.User, error) {
-	queries := sqlc.New(ur.db)
-	userDB, err := queries.GetUserByEmail(ctx, email)
-	if errors.Is(err, pgx.ErrNoRows) {
+func (u *userRepository) GetByEmail(
+	ctx context.Context,
+	email string,
+	tx any,
+) (*model.UserEntity, error) {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(u.queries, tx)
+
+	userDB, err := queries.GetUserByEmail(timeoutCtx, email)
+	if errors.Is(err, sql.ErrNoRows) {
 		// No query error, but user not found
 		return nil, nil
 	} else if err != nil {
 		return nil, err
 	}

-	return &model.User{
+	return &model.UserEntity{
+		ID:        int(userDB.ID),
+		Email:     userDB.Email,
+		FirstName: userDB.FirstName,
+		LastName:  userDB.LastName,
+		Password:  userDB.Password,
+		CreatedAt: userDB.CreatedAt,
+		UpdatedAt: userDB.CreatedAt,
+	}, nil
+}
+
+func (u *userRepository) GetByID(ctx context.Context, id int, tx any) (*model.UserEntity, error) {
+	timeoutCtx, cancel := context.WithTimeout(ctx, queryTimeout)
+	defer cancel()
+
+	queries := getQueries(u.queries, tx)
+
+	userDB, err := queries.GetUserByID(timeoutCtx, int32(id))
+	if errors.Is(err, sql.ErrNoRows) {
+		// No query error, but user not found
+		return nil, nil
+	} else if err != nil {
+		return nil, err
+	}
+
+	return &model.UserEntity{
 		ID:        int(userDB.ID),
 		Email:     userDB.Email,
 		FirstName: userDB.FirstName,
--- a/internal/howmuch/model/event.go
+++ b/internal/howmuch/model/event.go
@ -24,15 +24,113 @@ package model

 import "time"

-type Event struct {
-	ID              int
+// {{{ Request Object (from controller to service)
+
+type EventCreateRequest struct {
+	Name            string   `json:"name"        binding:"requiered"`
+	Description     string   `json:"description"`
+	OwnerID         int      `json:"owner_id"    binding:"requiered,number"`
+	DefaultCurrency Currency `json:"currency"`
+}
+
+// }}}
+// {{{ Response View Object (from service to controller)
+
+type EventListResponse struct {
+	ID          int
+	Name        string
+	Description string
+	Owner       *UserBaseResponse
+	CreatedAt   time.Time
+}
+
+type EventInfoResponse struct {
+	ID int
+
+	Name        string
+	Description string
+
+	TotalAmount Money
+
+	Owner *UserBaseResponse
+
+	CreatedAt time.Time
+	UpdatedAt time.Time
+
+	Users []UserBaseResponse
+}
+
+// }}}
+// {{{ Entity (DB In)
+
+type EventEntity struct {
+	ID int
+
 	Name            string
 	Description     string
-	Users           []*User
-	Expenses        []*Expense
+	TotalAmount     int
+	DefaultCurrency string
+	OwnerID         int
+
+	CreatedAt time.Time
+	UpdatedAt time.Time
+}
+
+type EventUpdateEntity struct {
+	ID          int
+	Name        string
+	Description string
+	CreatedAt   time.Time
+	// TODO: maybe I can change owner too
+}
+
+// }}}
+// {{{ Retrieved (DB out)
+
+type EventRetrieved struct {
+	ID int
+
+	Name        string
+	Description string
+
+	Users []UserBaseRetrieved
+
 	TotalAmount     Money
 	DefaultCurrency Currency
-	CreatedBy       User
-	CreatedAt       time.Time
-	UpdatedAt       time.Time
+	Owner           *UserBaseRetrieved
+
+	CreatedAt time.Time
+	UpdatedAt time.Time
 }
+
+type EventListRetrieved struct {
+	ID          int
+	Name        string
+	Description string
+	CreatedAt   time.Time
+	Owner       *UserBaseRetrieved
+}
+
+// }}}
+// {{{ DO Domain Object (Contains the domain service)
+
+type Event struct {
+	ID int
+
+	Name        string
+	Description string
+
+	// lazy get using participation join
+	Users []UserDO
+	// lazy get
+	Expenses []Expense
+
+	TotalAmount     Money
+	DefaultCurrency Currency
+	Owner           *UserDO
+
+	CreatedAt time.Time
+	UpdatedAt time.Time
+}
+
+// }}}
--- a/internal/howmuch/model/expense.go
+++ b/internal/howmuch/model/expense.go
@ -24,19 +24,119 @@ package model

 import "time"

-type ExpenseDetail struct {
+// {{{ Requrest
+
+type ExpenseRequest struct {
+	Amount   Money         `json:"money"    binding:"required"`
+	Payments []Payment     `json:"payments" binding:"required"`
+	Benefits []Benefit     `json:"benefits" binding:"required"`
+	EventID  int           `json:"event_id" binding:"required"`
+	Detail   ExpenseDetail `json:"detail"`
+}
+
+// }}}
+// {{{ Response
+
+type (
+	ExpenseGetResponse Expense
+	ExpenseResponse    ExpenseRetrieved
+)
+
+// }}}
+// {{{ Retrieved
+
+type ExpenseRetrieved Expense
+
+type ExpensesListRetrieved struct {
+	ID        int       `json:"id"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+
+	Amount  Money `json:"money"`
+	EventID int   `json:"event_id"`
+
+	Detail ExpenseDetail `json:"detail"`
+}
+
+type PaymentRetrieved struct {
+	PayerID        int    `json:"payer_id"`
+	PayerFirstName string `json:"payer_first_name"`
+	PayerLastName  string `json:"payer_last_name"`
+	Amount         int    `json:"amount"`
+	Currency       string `json:"currency"`
+}
+
+type BenefitRetrieved struct {
+	RecipientID        int    `json:"recipient_id"`
+	RecipientFirstName string `json:"recipient_first_name"`
+	RecipientLastName  string `json:"recipient_last_name"`
+	Amount             int    `json:"amount"`
+	Currency           string `json:"currency"`
+}
+
+// }}}
+// {{{ Entity
+
+type ExpenseEntity struct {
+	ID        int
+	CreatedAt time.Time
+	UpdatedAt time.Time
+
+	Amount   int
+	Currency string
+	EventID  int
+
+	// ExpenseDetail
 	Name  string
 	Place string
 }

-type Expense struct {
-	ID           int
-	Amount       Money
-	Currency     Currency
-	PayerIDs     []int
-	RecipientIDs []int
-	EventID      int
-	Detail       ExpenseDetail
-	CreatedAt    time.Time
-	UpdatedAt    time.Time
+type ExpenseUpdateEntity struct {
+	ID        int
+	UpdatedAt time.Time
+
+	Amount   int
+	Currency string
+
+	// Expense Detail
+	Name  string
+	Place string
 }
+
+// }}}
+// {{{ Domain Models
+
+type ExpenseDetail struct {
+	Name  string `json:"name"`
+	Place string `json:"place"`
+}
+
+type Payment struct {
+	PayerID        int    `json:"payer_id"         binding:"required,number"`
+	PayerFirstName string `json:"payer_first_name"`
+	PayerLastName  string `json:"payer_last_name"`
+	Amount         Money  `json:"amount"           binding:"required"`
+}
+
+type Benefit struct {
+	RecipientID        int    `json:"recipient_id"         binding:"required,number"`
+	RecipientFirstName string `json:"recipient_first_name"`
+	RecipientLastName  string `json:"recipient_last_name"`
+	Amount             Money  `json:"amount"               binding:"required"`
+}
+
+type Expense struct {
+	ID        int       `json:"id"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+
+	Amount  Money `json:"money"`
+	EventID int   `json:"event_id"`
+
+	Detail ExpenseDetail `json:"detail"`
+
+	Payments []Payment `json:"payments"`
+	Benefits []Benefit `json:"benefits"`
+}
+
+// }}}
--- a/internal/howmuch/model/money.go
+++ b/internal/howmuch/model/money.go
@ -36,8 +36,8 @@ const (
 )

 type Money struct {
-	ammount  int
-	currency Currency
+	Amount   int      `json:"amount"   binding:"required,number"`
+	Currency Currency `json:"currency" binding:"required"`
 }

 func MakeMoney(amount int, currency Currency) Money {
@ -46,10 +46,10 @@ func MakeMoney(amount int, currency Currency) Money {

 func Add(cur Currency, money ...Money) Money {
 	var sum Money
-	sum.currency = cur
+	sum.Currency = cur

 	for _, m := range money {
-		sum.ammount += m.ammount
+		sum.Amount += m.Amount
 	}

 	return sum
@ -58,9 +58,9 @@ func Add(cur Currency, money ...Money) Money {
 func Diff(cur Currency, money1 Money, money2 Money) Money {
 	var diff Money

-	diff.currency = cur
+	diff.Currency = cur

-	diff.ammount = money1.ammount - money2.ammount
+	diff.Amount = money1.Amount - money2.Amount

 	return diff
 }
--- a/internal/howmuch/model/participation.go
+++ b/internal/howmuch/model/participation.go
@ -0,0 +1,39 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package model
+
+import "time"
+
+type ParticipationEntity Participation
+
+// Participation is the association between Users and Events
+type Participation struct {
+	ID int
+
+	UserID          int
+	EventID         int
+	InvitedByUserID int
+
+	CreatedAt time.Time
+	UpdatedAt time.Time
+}
--- a/internal/howmuch/model/transaction.go
+++ b/internal/howmuch/model/transaction.go
@ -0,0 +1,48 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package model
+
+import "time"
+
+// {{{ Entity
+
+type TransactionEntity Transaction
+
+// }}}
+// {{{ Domain object
+
+type Transaction struct {
+	ID int
+
+	ExpenseID int
+	UserID    int
+	Amount    int
+	Currency  string
+	IsIncome  bool // To note that the direction of the money (payment or income)
+
+	CreatedAt time.Time
+	UpdatedAt time.Time
+}
+
+// }}}
+// Transaction is the association between Expenses and Users
--- a/internal/howmuch/model/user.go
+++ b/internal/howmuch/model/user.go
@ -24,25 +24,77 @@ package model

 import "time"

-type UserCreateDTO struct {
+// {{{ Request  (from controller to service)
+
+type UserCreateRequest struct {
 	Email     string `json:"email"      binding:"required,email"`
 	FirstName string `json:"first_name" binding:"required"`
 	LastName  string `json:"last_name"  binding:"required"`
 	Password  string `json:"password"   binding:"required"`
 }

-type UserExistDTO struct {
+type UserExistRequest struct {
 	Email    string `json:"email"    binding:"required,email"`
 	Password string `json:"password" binding:"required"`
 }

-// User model
-type User struct {
-	ID        int
+// }}}
+// {{{ Response View Object (from service to controller)
+
+type UserBaseResponse UserBaseRetrieved
+
+type UserInfoResponse struct {
+	// UserBaseResponse
+	ID        int    `json:"id"`
+	FirstName string `json:"first_name"`
+	LastName  string `json:"last_name"`
+
+	Email     string `json:"email"`
+	CreatedAt time.Time
+	UpdatedAt time.Time
+}
+
+// }}}
+// {{{ Entity (DB In)
+
+type UserEntity struct {
+	ID int
+
 	Email     string
 	FirstName string
 	LastName  string
 	Password  string
+
 	CreatedAt time.Time
 	UpdatedAt time.Time
 }
+
+// }}}
+// {{{ Retrieved (DB out)
+
+type UserBaseRetrieved struct {
+	ID        int    `json:"id"`
+	FirstName string `json:"first_name"`
+	LastName  string `json:"last_name"`
+}
+
+// }}}
+// {{{ DO Domain Object (Contains the domain service)
+
+// TODO: For now I don't know what to do with this model
+type UserDO struct {
+	ID int
+
+	Email     string
+	FirstName string
+	LastName  string
+	Password  string
+
+	// Lazy aggregate with the Participation join
+	EventIDs []int
+
+	CreatedAt time.Time
+	UpdatedAt time.Time
+}
+
+// }}}
--- a/internal/howmuch/usecase/repo/db.go
+++ b/internal/howmuch/usecase/repo/db.go
@ -22,7 +22,9 @@

 package repo

-import "context"
+import (
+	"context"
+)

 type DBRepository interface {
 	Transaction(
--- a/internal/howmuch/usecase/repo/event.go
+++ b/internal/howmuch/usecase/repo/event.go
@ -0,0 +1,74 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package repo
+
+import (
+	"context"
+
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
+)
+
+type EventRepository interface {
+	Create(ctx context.Context, evEntity *model.EventEntity, tx any) (*model.EventEntity, error)
+
+	// UpdateEventByID updates the event related information (name, descriptions)
+	UpdateEventByID(ctx context.Context, event *model.EventUpdateEntity, tx any) error
+
+	GetByID(ctx context.Context, eventID int, tx any) (*model.EventRetrieved, error)
+
+	// related to events of a user
+	ListEventsByUserID(ctx context.Context, userID int, tx any) ([]model.EventListRetrieved, error)
+
+	InsertParticipation(
+		ctx context.Context,
+		userID, eventID, invitedByUserID int,
+		tx any,
+	) (*model.ParticipationEntity, error)
+
+	GetParticipation(
+		ctx context.Context,
+		userID, eventID int,
+		tx any,
+	) (*model.ParticipationEntity, error)
+}
+
+type ExpenseRepository interface {
+	DeleteExpense(ctx context.Context, expenseID int, tx any) error
+	DeleteTransactionsOfExpense(ctx context.Context, expenseID int, tx any) error
+	GetExpenseByID(ctx context.Context, expenseID int, tx any) (*model.ExpenseRetrieved, error)
+	InsertExpense(
+		ctx context.Context,
+		expenseEntity *model.ExpenseEntity,
+		tx any,
+	) (*model.ExpenseEntity, error)
+	ListExpensesByEventID(
+		ctx context.Context,
+		id int,
+		tx any,
+	) ([]model.ExpensesListRetrieved, error)
+	UpdateExpenseByID(
+		ctx context.Context,
+		expenseUpdate *model.ExpenseUpdateEntity,
+		tx any,
+	) (*model.ExpenseEntity, error)
+}
--- a/internal/howmuch/usecase/repo/user.go
+++ b/internal/howmuch/usecase/repo/user.go
@ -29,6 +29,11 @@ import (
 )

 type UserRepository interface {
-	Create(ctx context.Context, transaction interface{}, u *model.User) (*model.User, error)
-	GetByEmail(ctx context.Context, email string) (*model.User, error)
+	Create(
+		ctx context.Context,
+		u *model.UserEntity,
+		tx any,
+	) (*model.UserEntity, error)
+	GetByEmail(ctx context.Context, email string, tx any) (*model.UserEntity, error)
+	GetByID(ctx context.Context, id int, tx any) (*model.UserEntity, error)
 }
--- a/internal/howmuch/usecase/usecase/event.go
+++ b/internal/howmuch/usecase/usecase/event.go
@ -0,0 +1,190 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package usecase
+
+import (
+	"net/http"
+
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/repo"
+	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/errno"
+	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/log"
+	"golang.org/x/net/context"
+)
+
+type eventUsecase struct {
+	userUC      User
+	eventRepo   repo.EventRepository
+	expenseRepo repo.ExpenseRepository
+
+	dbRepo repo.DBRepository
+}
+
+var ErrNoParticipation = &errno.Errno{
+	HTTP:    http.StatusUnauthorized,
+	Code:    errno.ErrorCode(errno.AuthFailureCode, "NoParticipation"),
+	Message: "user doesn't have access to this event",
+}
+
+// For the controller
+type Event interface{}
+
+func NewEventUsecase(
+	uuc User,
+	ev repo.EventRepository,
+	ex repo.ExpenseRepository,
+	db repo.DBRepository,
+) Event {
+	return &eventUsecase{uuc, ev, ex, db}
+}
+
+func (evuc *eventUsecase) CreateEvent(
+	ctx context.Context,
+	evRequest *model.EventCreateRequest,
+) (*model.EventInfoResponse, error) {
+	// transfer evRequest to evEntity
+
+	evEntity := &model.EventEntity{
+		Name:            evRequest.Name,
+		Description:     evRequest.Description,
+		OwnerID:         evRequest.OwnerID,
+		TotalAmount:     0,
+		DefaultCurrency: string(evRequest.DefaultCurrency),
+	}
+
+	data, err := evuc.dbRepo.Transaction(
+		ctx,
+		func(txCtx context.Context, tx any) (any, error) {
+			// Create the event
+			created, err := evuc.eventRepo.Create(ctx, evEntity, tx)
+			if err != nil {
+				return nil, err
+			}
+
+			// participate to the event
+			participation, err := evuc.eventRepo.InsertParticipation(
+				ctx,
+				created.OwnerID,
+				created.ID,
+				0,
+				tx,
+			)
+			if err != nil {
+				return nil, err
+			}
+
+			if participation == nil {
+				// Unexpected error
+				log.ErrorLog(
+					"participation existed for event-user pair",
+					"userID",
+					created.OwnerID,
+					"eventID",
+					created.ID,
+				)
+				return nil, errno.InternalServerErr
+			}
+
+			// TODO: App log, maybe can be sent to some third party service.
+			log.InfoLog(
+				"created new event",
+				"name",
+				created.Name,
+				"owner",
+				created.OwnerID,
+			)
+
+			// Construct the response
+			ownerResponse, err := evuc.userUC.GetUserBaseResponseByID(ctx, created.OwnerID)
+			if err != nil {
+				return nil, err
+			}
+
+			evResponse := &model.EventInfoResponse{
+				ID:          created.ID,
+				Name:        created.Name,
+				Description: created.Description,
+				TotalAmount: model.MakeMoney(
+					created.TotalAmount,
+					model.Currency(created.DefaultCurrency),
+				),
+				Owner:     ownerResponse,
+				CreatedAt: created.CreatedAt,
+				UpdatedAt: created.UpdatedAt,
+				Users:     []model.UserBaseResponse{*ownerResponse},
+			}
+			return evResponse, err
+		},
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	res := data.(*model.EventInfoResponse)
+
+	return res, err
+}
+
+func (evuc *eventUsecase) ListEvents(
+	ctx context.Context,
+	userID int,
+) ([]model.EventListResponse, error) {
+	eventListRetrieved, err := evuc.eventRepo.ListEventsByUserID(ctx, userID, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// Check if the user is a member of the event
+
+	responses := make([]model.EventListResponse, len(eventListRetrieved))
+
+	for i, retrieved := range eventListRetrieved {
+		ownner := model.UserBaseResponse(*retrieved.Owner)
+		res := model.EventListResponse{
+			ID:          retrieved.ID,
+			Name:        retrieved.Name,
+			Description: retrieved.Description,
+			Owner:       &ownner,
+			CreatedAt:   retrieved.CreatedAt,
+		}
+		responses[i] = res
+	}
+	return responses, nil
+}
+
+// GetEventDetail
+func (evuc *eventUsecase) GetEventDetail(
+	ctx context.Context,
+	userID, eventID int,
+) (*model.EventInfoResponse, error) {
+	// Check if the user has the right to get this event
+	// err := evuc.participationRepo.CheckParticipation(ctx, userID, eventID)
+	// if err != nil {
+	// 	return nil, ErrNoParticipation
+	// }
+
+	// Get the eventDetail
+	// TODO: This can also be put into the cache
+
+	return nil, nil
+}
--- a/internal/howmuch/usecase/usecase/repomock/testdbrepo.go
+++ b/internal/howmuch/usecase/usecase/repomock/testdbrepo.go
@ -22,7 +22,9 @@

 package repomock

-import "context"
+import (
+	"context"
+)

 type TestDBRepository struct{}

--- a/internal/howmuch/usecase/usecase/repomock/testuserrepo.go
+++ b/internal/howmuch/usecase/usecase/repomock/testuserrepo.go
@ -36,9 +36,9 @@ type TestUserRepository struct{}

 func (tur *TestUserRepository) Create(
 	ctx context.Context,
-	transaction interface{},
-	u *model.User,
-) (*model.User, error) {
+	u *model.UserEntity,
+	tx any,
+) (*model.UserEntity, error) {
 	user := *u

 	user.ID = 123
@ -50,11 +50,15 @@ func (tur *TestUserRepository) Create(
 	return &user, nil
 }

-func (ur *TestUserRepository) GetByEmail(ctx context.Context, email string) (*model.User, error) {
+func (tur *TestUserRepository) GetByEmail(
+	ctx context.Context,
+	email string,
+	tx any,
+) (*model.UserEntity, error) {
 	hashedPwd, _ := bcrypt.GenerateFromPassword([]byte("strongHashed"), 12)
 	switch email {
 	case "a@b.c":
-		return &model.User{
+		return &model.UserEntity{
 			ID:       123,
 			Email:    "a@b.c",
 			Password: string(hashedPwd),
@ -67,3 +71,24 @@ func (ur *TestUserRepository) GetByEmail(ctx context.Context, email string) (*mo

 	return nil, UserTestDummyErr
 }
+
+func (tur *TestUserRepository) GetByID(
+	ctx context.Context,
+	id int,
+	tx any,
+) (*model.UserEntity, error) {
+	hashedPwd, _ := bcrypt.GenerateFromPassword([]byte("strongHashed"), 12)
+	switch id {
+	case 123:
+		return &model.UserEntity{
+			ID:       123,
+			Email:    "a@b.c",
+			Password: string(hashedPwd),
+		}, nil
+	case 456:
+		return nil, UserTestDummyErr
+	case 789:
+		return nil, nil
+	}
+	return nil, UserTestDummyErr
+}
--- a/internal/howmuch/usecase/usecase/user.go
+++ b/internal/howmuch/usecase/usecase/user.go
@ -60,8 +60,9 @@ type userUsecase struct {
 }

 type User interface {
-	Create(ctx context.Context, u *model.UserCreateDTO) (*model.User, error)
-	Exist(ctx context.Context, u *model.UserExistDTO) error
+	Create(ctx context.Context, u *model.UserCreateRequest) (*model.UserInfoResponse, error)
+	Exist(ctx context.Context, u *model.UserExistRequest) error
+	GetUserBaseResponseByID(ctx context.Context, userID int) (*model.UserBaseResponse, error)
 }

 func NewUserUsecase(r repo.UserRepository, d repo.DBRepository) User {
@ -71,7 +72,10 @@ func NewUserUsecase(r repo.UserRepository, d repo.DBRepository) User {
 	}
 }

-func (uuc *userUsecase) Create(ctx context.Context, u *model.UserCreateDTO) (*model.User, error) {
+func (uuc *userUsecase) Create(
+	ctx context.Context,
+	u *model.UserCreateRequest,
+) (*model.UserInfoResponse, error) {
 	// Hash the password
 	encrypted, err := bcrypt.GenerateFromPassword([]byte(u.Password), 12)
 	if err != nil {
@ -82,12 +86,12 @@ func (uuc *userUsecase) Create(ctx context.Context, u *model.UserCreateDTO) (*mo
 	data, err := uuc.dbRepo.Transaction(
 		ctx,
 		func(txCtx context.Context, tx interface{}) (interface{}, error) {
-			created, err := uuc.userRepo.Create(txCtx, tx, &model.User{
+			created, err := uuc.userRepo.Create(txCtx, &model.UserEntity{
 				Email:     u.Email,
 				Password:  u.Password,
 				FirstName: u.FirstName,
 				LastName:  u.LastName,
-			})
+			}, tx)
 			if err != nil {
 				match, _ := regexp.MatchString("SQLSTATE 23505", err.Error())
 				if match {
@ -100,9 +104,9 @@ func (uuc *userUsecase) Create(ctx context.Context, u *model.UserCreateDTO) (*mo
 			log.InfoLog(
 				"created new user",
 				"email",
-				u.Email,
+				created.Email,
 				"name",
-				fmt.Sprintf("%s %s", u.FirstName, u.LastName),
+				fmt.Sprintf("%s %s", created.FirstName, created.LastName),
 			)

 			return created, err
@ -113,13 +117,22 @@ func (uuc *userUsecase) Create(ctx context.Context, u *model.UserCreateDTO) (*mo
 		return nil, err
 	}

-	user := data.(*model.User)
+	userEntity := data.(*model.UserEntity)
+
+	user := &model.UserInfoResponse{
+		ID:        userEntity.ID,
+		Email:     userEntity.Email,
+		FirstName: userEntity.FirstName,
+		LastName:  userEntity.LastName,
+		CreatedAt: userEntity.CreatedAt,
+		UpdatedAt: userEntity.UpdatedAt,
+	}

 	return user, nil
 }

-func (uuc *userUsecase) Exist(ctx context.Context, u *model.UserExistDTO) error {
-	got, err := uuc.userRepo.GetByEmail(ctx, u.Email)
+func (uuc *userUsecase) Exist(ctx context.Context, u *model.UserExistRequest) error {
+	got, err := uuc.userRepo.GetByEmail(ctx, u.Email, nil)
 	// Any query error?
 	if err != nil {
 		return err
@ -138,3 +151,23 @@ func (uuc *userUsecase) Exist(ctx context.Context, u *model.UserExistDTO) error

 	return nil
 }
+
+func (uuc *userUsecase) GetUserBaseResponseByID(
+	ctx context.Context,
+	userID int,
+) (*model.UserBaseResponse, error) {
+	// TODO: should try first to get from the cache
+	// If not exists, get from the DB. And then put back
+	// into the cache with a timeout.
+	// Refresh the cache when the user data is updated (for now it cannot be updated)
+	got, err := uuc.userRepo.GetByID(ctx, userID, nil)
+	if err != nil {
+		return nil, err
+	}
+	userBaseVo := &model.UserBaseResponse{
+		ID:        got.ID,
+		FirstName: got.FirstName,
+		LastName:  got.LastName,
+	}
+	return userBaseVo, nil
+}
--- a/internal/howmuch/usecase/usecase/user_test.go
+++ b/internal/howmuch/usecase/usecase/user_test.go
@ -29,42 +29,31 @@ import (
 	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
 	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/usecase/repomock"
 	"github.com/stretchr/testify/assert"
-	"golang.org/x/crypto/bcrypt"
 )

 func TestCreateUser(t *testing.T) {
 	t.Run("normal create", func(t *testing.T) {
 		ctx := context.Background()
 		userUsecase := NewUserUsecase(&repomock.TestUserRepository{}, &repomock.TestDBRepository{})
-		input := &model.UserCreateDTO{
+		input := &model.UserCreateRequest{
 			Email:     "a@b.c",
 			FirstName: "James",
 			LastName:  "Bond",
 			Password:  "verystrong",
 		}
-		want := &model.User{
-			ID:        123,
-			Email:     input.Email,
-			FirstName: input.FirstName,
-			LastName:  input.LastName,
-			// Password is hashed
-			Password: "verystrong",
+		want := &model.UserInfoResponse{
+			ID: 123,
 		}

 		got, err := userUsecase.Create(ctx, input)
 		assert.NoError(t, err)
 		assert.Equal(t, want.ID, got.ID)
-
-		assert.NoError(
-			t,
-			bcrypt.CompareHashAndPassword([]byte(got.Password), []byte(want.Password)),
-		)
 	})

 	t.Run("duplicate create", func(t *testing.T) {
 		ctx := context.Background()
 		userUsecase := NewUserUsecase(&repomock.TestUserRepository{}, &repomock.TestDBRepository{})
-		input := &model.UserCreateDTO{
+		input := &model.UserCreateRequest{
 			Email:     "duplicate@error.com",
 			FirstName: "James",
 			LastName:  "Bond",
@ -79,22 +68,22 @@ func TestCreateUser(t *testing.T) {
 func TestUserExist(t *testing.T) {
 	testCases := []struct {
 		Name   string
-		User   *model.UserExistDTO
+		User   *model.UserExistRequest
 		ExpErr error
 	}{
-		{"user exists", &model.UserExistDTO{
+		{"user exists", &model.UserExistRequest{
 			Email:    "a@b.c",
 			Password: "strongHashed",
 		}, nil},
-		{"query error", &model.UserExistDTO{
+		{"query error", &model.UserExistRequest{
 			Email:    "query@error.com",
 			Password: "strongHashed",
 		}, repomock.UserTestDummyErr},
-		{"user doesn not exist", &model.UserExistDTO{
+		{"user doesn not exist", &model.UserExistRequest{
 			Email:    "inexist@error.com",
 			Password: "strongHashed",
 		}, UserNotExist},
-		{"wrong password", &model.UserExistDTO{
+		{"wrong password", &model.UserExistRequest{
 			Email:    "a@b.c",
 			Password: "wrongHashed",
 		}, UserWrongPassword},
--- a/migrations/20241017215433_create_event_table.postgres.down.sql
+++ b/migrations/20241017215433_create_event_table.postgres.down.sql
@ -0,0 +1 @@
+DROP TABLE "event"
--- a/migrations/20241017215433_create_event_table.postgres.up.sql
+++ b/migrations/20241017215433_create_event_table.postgres.up.sql
@ -0,0 +1,10 @@
+CREATE TABLE "event" (
+  "id" serial NOT NULL,
+  PRIMARY KEY ("id"),
+  "name" character varying(255) NOT NULL,
+  "description" character varying(10000) NULL,
+  "default_currency" character varying(255) NOT NULL,
+  "owner_id" integer NOT NULL,
+  "created_at" date NOT NULL,
+  "updated_at" date NOT NULL
+);
--- a/migrations/20241017215923_create_participation_table.postgres.down.sql
+++ b/migrations/20241017215923_create_participation_table.postgres.down.sql
@ -0,0 +1 @@
+DROP TABLE participation;
--- a/migrations/20241017215923_create_participation_table.postgres.up.sql
+++ b/migrations/20241017215923_create_participation_table.postgres.up.sql
@ -0,0 +1,16 @@
+CREATE TABLE "participation" (
+  "id" serial NOT NULL,
+  PRIMARY KEY ("id"),
+  "user_id" integer NOT NULL,
+  "event_id" integer NOT NULL,
+  "invited_by_user_id" integer NULL,
+  "created_at" date NOT NULL,
+  "updated_at" date NOT NULL
+);
+
+ALTER TABLE "participation"
+ADD FOREIGN KEY ("event_id") REFERENCES "event" ("id") ON DELETE CASCADE ON UPDATE CASCADE;
+
+ALTER TABLE "participation"
+ADD FOREIGN KEY ("user_id") REFERENCES "user" ("id") ON DELETE CASCADE ON UPDATE CASCADE;
+
--- a/migrations/20241017220309_event_add_total_amount.postgres.down.sql
+++ b/migrations/20241017220309_event_add_total_amount.postgres.down.sql
--- a/migrations/20241017220309_event_add_total_amount.postgres.up.sql
+++ b/migrations/20241017220309_event_add_total_amount.postgres.up.sql
@ -0,0 +1,2 @@
+ALTER TABLE "event"
+ADD "total_amount" integer NULL;
--- a/migrations/20241018175610_participation_add_unique_keys.postgres.down.sql
+++ b/migrations/20241018175610_participation_add_unique_keys.postgres.down.sql
--- a/migrations/20241018175610_participation_add_unique_keys.postgres.up.sql
+++ b/migrations/20241018175610_participation_add_unique_keys.postgres.up.sql
@ -0,0 +1,2 @@
+ALTER TABLE "participation"
+ADD CONSTRAINT unique_user_event UNIQUE ("user_id", "event_id");
--- a/migrations/20241019110734_create_transaction_table.postgres.down.sql
+++ b/migrations/20241019110734_create_transaction_table.postgres.down.sql
@ -0,0 +1 @@
+
--- a/migrations/20241019110734_create_transaction_table.postgres.up.sql
+++ b/migrations/20241019110734_create_transaction_table.postgres.up.sql
@ -0,0 +1,14 @@
+CREATE TABLE "transaction" (
+  "id" serial NOT NULL,
+  PRIMARY KEY ("id"),
+  "expense_id" integer NOT NULL,
+  "user_id" integer NOT NULL,
+  "amount" integer NOT NULL,
+  "currency" character varying(255) NOT NULL,
+  "is_income" boolean NOT NULL DEFAULT FALSE,
+  "created_at" date NOT NULL,
+  "updated_at" date NOT NULL
+);
+
+ALTER TABLE "transaction"
+ADD FOREIGN KEY ("user_id") REFERENCES "user" ("id") ON DELETE CASCADE ON UPDATE CASCADE;
--- a/migrations/20241019112255_create_expense_table.postgres.down.sql
+++ b/migrations/20241019112255_create_expense_table.postgres.down.sql
@ -0,0 +1 @@
+DROP TABLE "expense";
--- a/migrations/20241019112255_create_expense_table.postgres.up.sql
+++ b/migrations/20241019112255_create_expense_table.postgres.up.sql
@ -0,0 +1,14 @@
+CREATE TABLE "expense" (
+  "id" serial NOT NULL,
+  PRIMARY KEY ("id"),
+  "created_at" date NOT NULL,
+  "updated_at" date NOT NULL,
+  "amount" integer NOT NULL,
+  "currency" character varying NOT NULL,
+  "event_id" integer NOT NULL,
+  "name" character varying(255) NULL,
+  "place" character varying(1000) NULL
+);
+
+ALTER TABLE "expense"
+ADD FOREIGN KEY ("event_id") REFERENCES "event" ("id") ON DELETE CASCADE ON UPDATE CASCADE
--- a/migrations/20241019112421_fk_transaction_expense.postgres.down.sql
+++ b/migrations/20241019112421_fk_transaction_expense.postgres.down.sql
@ -0,0 +1 @@
+DROP TABLE transaction;
--- a/migrations/20241019112421_fk_transaction_expense.postgres.up.sql
+++ b/migrations/20241019112421_fk_transaction_expense.postgres.up.sql
@ -0,0 +1,2 @@
+ALTER TABLE "transaction"
+ADD FOREIGN KEY ("expense_id") REFERENCES "expense" ("id") ON DELETE CASCADE ON UPDATE CASCADE
--- a/sqlc.yml
+++ b/sqlc.yml
@ -28,3 +28,4 @@ sql:
    gen:
      go:
        out: "internal/howmuch/adapter/repo/sqlc"
+        emit_interface: true
--- a/web/package-lock.json
+++ b/web/package-lock.json
@ -8,6 +8,7 @@
      "name": "web",
      "version": "0.0.0",
      "dependencies": {
+        "axios": "^1.7.7",
        "vue": "^3.4.29",
        "vue-router": "^4.3.3"
      },
@ -2299,8 +2300,17 @@
    "node_modules/asynckit": {
      "version": "0.4.0",
      "resolved": "https://registry.npmjs.org/asynckit/-/asynckit-0.4.0.tgz",
-      "integrity": "sha512-Oei9OH4tRh0YqU3GxhX79dM/mwVgvbZJaSNaRk+bshkj0S5cfHcgYakreBjrHwatXKbz+IoIdYLxrKim2MjW0Q==",
-      "dev": true
+      "integrity": "sha512-Oei9OH4tRh0YqU3GxhX79dM/mwVgvbZJaSNaRk+bshkj0S5cfHcgYakreBjrHwatXKbz+IoIdYLxrKim2MjW0Q=="
+    },
+    "node_modules/axios": {
+      "version": "1.7.7",
+      "resolved": "https://registry.npmjs.org/axios/-/axios-1.7.7.tgz",
+      "integrity": "sha512-S4kL7XrjgBmvdGut0sN3yJxqYzrDOnivkBiN0OFs6hLiUam3UPvswUo0kqGyhqUZGEOytHyumEdXsAkgCOUf3Q==",
+      "dependencies": {
+        "follow-redirects": "^1.15.6",
+        "form-data": "^4.0.0",
+        "proxy-from-env": "^1.1.0"
+      }
    },
    "node_modules/balanced-match": {
      "version": "1.0.2",
@ -2497,7 +2507,6 @@
      "version": "1.0.8",
      "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.8.tgz",
      "integrity": "sha512-FQN4MRfuJeHf7cBbBMJFXhKSDq+2kAArBlmRBvcvFE5BB1HZKXtSFASDhdlz9zOYwxh8lDdnvmMOe/+5cdoEdg==",
-      "dev": true,
      "dependencies": {
        "delayed-stream": "~1.0.0"
      },
@ -2710,7 +2719,6 @@
      "version": "1.0.0",
      "resolved": "https://registry.npmjs.org/delayed-stream/-/delayed-stream-1.0.0.tgz",
      "integrity": "sha512-ZySD7Nf91aLB0RxL4KGrKHBXl7Eds1DAmEdcoVawXnLD7SDhpNgtuII2aAkg7a7QS41jxPSZ17p4VdGnMHk3MQ==",
-      "dev": true,
      "engines": {
        "node": ">=0.4.0"
      }
@ -3256,6 +3264,25 @@
      "integrity": "sha512-X8cqMLLie7KsNUDSdzeN8FYK9rEt4Dt67OsG/DNGnYTSDBG4uFAJFBnUeiV+zCVAvwFy56IjM9sH51jVaEhNxw==",
      "dev": true
    },
+    "node_modules/follow-redirects": {
+      "version": "1.15.9",
+      "resolved": "https://registry.npmjs.org/follow-redirects/-/follow-redirects-1.15.9.tgz",
+      "integrity": "sha512-gew4GsXizNgdoRyqmyfMHyAmXsZDk6mHkSxZFCzW9gwlbtOW44CDtYavM+y+72qD/Vq2l550kMF52DT8fOLJqQ==",
+      "funding": [
+        {
+          "type": "individual",
+          "url": "https://github.com/sponsors/RubenVerborgh"
+        }
+      ],
+      "engines": {
+        "node": ">=4.0"
+      },
+      "peerDependenciesMeta": {
+        "debug": {
+          "optional": true
+        }
+      }
+    },
    "node_modules/foreground-child": {
      "version": "3.3.0",
      "resolved": "https://registry.npmjs.org/foreground-child/-/foreground-child-3.3.0.tgz",
@ -3276,7 +3303,6 @@
      "version": "4.0.0",
      "resolved": "https://registry.npmjs.org/form-data/-/form-data-4.0.0.tgz",
      "integrity": "sha512-ETEklSGi5t0QMZuiXoA/Q6vcnxcLQP5vdugSpuAyi6SVGi2clPPp+xgEhuMaHC+zGgn31Kd235W35f7Hykkaww==",
-      "dev": true,
      "dependencies": {
        "asynckit": "^0.4.0",
        "combined-stream": "^1.0.8",
@ -4041,7 +4067,6 @@
      "version": "1.52.0",
      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.52.0.tgz",
      "integrity": "sha512-sPU4uV7dYlvtWJxwwxHD0PuihVNiE7TyAbQ5SWxDCB9mUYvOgroQOwYQQOKPJ8CIbE+1ETVlOoK1UC2nU3gYvg==",
-      "dev": true,
      "engines": {
        "node": ">= 0.6"
      }
@ -4050,7 +4075,6 @@
      "version": "2.1.35",
      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.35.tgz",
      "integrity": "sha512-ZDY+bPm5zTTF+YpCrAU9nK0UgICYPT0QtT1NZWFv4s++TNkcgVaT0g6+4R2uI4MjQjzysHB1zxuWL50hzaeXiw==",
-      "dev": true,
      "dependencies": {
        "mime-db": "1.52.0"
      },
@ -4614,6 +4638,11 @@
      "integrity": "sha512-vtK/94akxsTMhe0/cbfpR+syPuszcuwhqVjJq26CuNDgFGj682oRBXOP5MJpv2r7JtE8MsiepGIqvvOTBwn2vA==",
      "dev": true
    },
+    "node_modules/proxy-from-env": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/proxy-from-env/-/proxy-from-env-1.1.0.tgz",
+      "integrity": "sha512-D+zkORCbA9f1tdWRK0RaCR3GPv50cMxcrz4X8k5LTSUD1Dkw47mKJEZQNunItRTkWwgtaUSo1RVFRIG9ZXiFYg=="
+    },
    "node_modules/psl": {
      "version": "1.9.0",
      "resolved": "https://registry.npmjs.org/psl/-/psl-1.9.0.tgz",
--- a/web/package.json
+++ b/web/package.json
@ -14,6 +14,7 @@
    "format": "prettier --write src/"
  },
  "dependencies": {
+    "axios": "^1.7.7",
    "vue": "^3.4.29",
    "vue-router": "^4.3.3"
  },
--- a/web/src/App.vue
+++ b/web/src/App.vue
@ -37,6 +37,8 @@ import HelloWorld from './components/HelloWorld.vue'
      <nav>
        <RouterLink to="/">Home</RouterLink>
        <RouterLink to="/about">About</RouterLink>
+        <RouterLink to="/login">Login</RouterLink>
+        <RouterLink to="/Signup">Signup</RouterLink>
      </nav>
    </div>
  </header>
--- a/web/src/router/index.ts
+++ b/web/src/router/index.ts
@ -40,6 +40,16 @@ const router = createRouter({
      // this generates a separate chunk (About.[hash].js) for this route
      // which is lazy-loaded when the route is visited.
      component: () => import('../views/AboutView.vue')
+    },
+    {
+      path: '/login',
+      name: 'login',
+      component: () => import('../views/LoginView.vue')
+    },
+    {
+      path: '/signup',
+      name: 'signup',
+      component: () => import('../views/SignupView.vue')
    }
  ]
 })
--- a/web/src/views/LoginView.vue
+++ b/web/src/views/LoginView.vue
@ -0,0 +1,83 @@
+<!--
+ MIT License
+
+ Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included in all
+ copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ SOFTWARE.
+-->
+<template>
+  <div class="login-container">
+    <h2>Login</h2>
+    <form @submit.prevent="handleLogin">
+      <div class="form-group">
+        <label for="email">Email:</label>
+        <input type="text" id="email" v-model="email" required />
+      </div>
+      <div class="form-group">
+        <label for="password">Password:</label>
+        <input type="password" id="password" v-model="password" required />
+      </div>
+      <button type="submit">Login</button>
+    </form>
+    <p v-if="error" class="error">{{ error }}</p>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { ref } from 'vue'
+import { useRouter } from 'vue-router'
+import axios from 'axios'
+
+const email = ref('')
+const password = ref('')
+const error = ref('')
+
+const router = useRouter()
+
+const handleLogin = async () => {
+  try {
+    const response = await axios.post('http://localhost:8000/v1/session/create', {
+      email: email.value,
+      password: password.value
+    })
+
+    if (response.status === 200) {
+      // Clear error message
+      error.value = ''
+      // Redirect to dashboard or another route
+      router.push('/about')
+    } else {
+      error.value = 'Invalid email or password'
+    }
+  } catch (err) {
+    error.value = 'An error occurred. Please try again.'
+    console.error(err)
+  }
+}
+</script>
+
+<style>
+@media (min-width: 1024px) {
+  .about {
+    min-height: 100vh;
+    display: flex;
+    align-items: center;
+  }
+}
+</style>
--- a/web/src/views/SignupView.vue
+++ b/web/src/views/SignupView.vue
@ -0,0 +1,95 @@
+<!--
+ MIT License
+
+ Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included in all
+ copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ SOFTWARE.
+-->
+<template>
+  <div class="signup-container">
+    <h2>Signup</h2>
+    <form @submit.prevent="handleSignup">
+      <div class="form-group">
+        <label for="email">Email:</label>
+        <input type="text" id="email" v-model="email" required />
+      </div>
+      <div class="form-group">
+        <label for="password">Password:</label>
+        <input type="password" id="password" v-model="password" required />
+      </div>
+      <div class="form-group">
+        <label for="first_name">First Name:</label>
+        <input type="first_name" id="first_name" v-model="first_name" required />
+      </div>
+      <div class="form-group">
+        <label for="last_name">Last Name:</label>
+        <input type="last_name" id="last_name" v-model="last_name" required />
+      </div>
+      <button type="submit">Signup</button>
+    </form>
+    <p v-if="error" class="error">{{ error }}</p>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { ref } from 'vue'
+import { useRouter } from 'vue-router'
+import axios from 'axios'
+
+const first_name = ref('')
+const last_name = ref('')
+const email = ref('')
+const password = ref('')
+const error = ref('')
+
+const router = useRouter()
+
+const handleSignup = async () => {
+  try {
+    const response = await axios.post('http://localhost:8000/v1/user/create', {
+      email: email.value,
+      password: password.value,
+      first_name: first_name.value,
+      last_name: last_name.value
+    })
+
+    if (response.status === 200) {
+      // Clear error message
+      error.value = ''
+      // Redirect to dashboard or another route
+      router.push('/login')
+    } else {
+      error.value = 'Failed to signup'
+    }
+  } catch (err) {
+    error.value = 'An error occurred. Please try again.'
+    console.error(err)
+  }
+}
+</script>
+
+<style>
+@media (min-width: 1024px) {
+  .about {
+    min-height: 100vh;
+    display: flex;
+    align-items: center;
+  }
+}
+</style>
Author	SHA1	Message	Date
Muyao CHEN	dd999b9355	refacto: refacto repo layer code while adding new usecase methods All checks were successful Build and test / Build (push) Successful in 2m19s Details	2024-10-26 17:27:33 +02:00
Muyao CHEN	14ee642aab	refacto: add db tx as a possible input for repo methods All checks were successful Build and test / Build (push) Successful in 2m22s Details	2024-10-25 23:52:43 +02:00
Muyao CHEN	b30a5c5c2d	feat: implement repo expense methods All checks were successful Build and test / Build (push) Successful in 2m28s Details	2024-10-24 23:39:13 +02:00
Muyao CHEN	58cff774e6	feat: add expense repo type conversion	2024-10-24 22:33:24 +02:00
Muyao CHEN	716a58d44c	fix: use simple slices instead of []*T	2024-10-24 22:32:57 +02:00
Muyao CHEN	de7c6f7223	test: add event repo tests	2024-10-23 23:29:44 +02:00
Muyao CHEN	0258ff6620	web: add test login and signup page All checks were successful Build and test / Build (push) Successful in 2m28s Details	2024-10-23 22:39:19 +02:00
Muyao CHEN	0da8b29507	test: try to test user repo and event repo All checks were successful Build and test / Build (push) Successful in 2m27s Details	2024-10-23 09:54:00 +02:00
Muyao CHEN	304651e7ff	feat: implement event repo methods	2024-10-20 23:27:17 +02:00
Muyao CHEN	74ae6b7877	doc: add readme	2024-10-20 23:26:45 +02:00
Muyao CHEN	b4259e9a51	doc: add licence for event.go	2024-10-20 21:27:26 +02:00
Muyao CHEN	46c14b63ea	feat: add a method for event. And introduce the mock All checks were successful Build and test / Build (push) Successful in 2m27s Details	2024-10-20 21:26:12 +02:00
Muyao CHEN	c27dfc687f	minor: cleanup	2024-10-19 17:14:08 +02:00
Muyao CHEN	3d616bff50	db: finish sql commands All checks were successful Build and test / Build (push) Successful in 2m23s Details	2024-10-19 17:08:05 +02:00
Muyao CHEN	dac36db284	db: add more tables	2024-10-19 13:28:02 +02:00
Muyao CHEN	80a5f1f8a8	fix: CHANGE NAMES AGAIN. Just want to be clearer All checks were successful Build and test / Build (push) Successful in 2m20s Details	2024-10-18 23:24:31 +02:00
Muyao CHEN	a55fd26f90	repo: add some more sql for events	2024-10-18 21:41:53 +02:00
Muyao CHEN	dde4eb337c	repo: add some sql for events All checks were successful Build and test / Build (push) Successful in 2m29s Details	2024-10-18 21:15:27 +02:00
Muyao CHEN	39eaae46d8	db: add migrations	2024-10-18 19:36:31 +02:00
Muyao CHEN	86832cf1f9	test: add wrong params test cases for session create	2024-10-17 22:12:31 +02:00
Muyao CHEN	350a6f86d9	doc: add diary for use cases All checks were successful Build and test / Build (push) Successful in 2m21s Details	2024-10-17 21:56:23 +02:00
Muyao CHEN	a7a915d825	feat: Impl event while refactoring user domain All checks were successful Build and test / Build (push) Successful in 2m21s Details	2024-10-16 23:47:06 +02:00
Muyao CHEN	29633e0e95	feat: use PO for repo layer All checks were successful Build and test / Build (push) Successful in 2m26s Details	2024-10-16 09:59:03 +02:00
Muyao CHEN	0e05924585	feat: rework entities design	2024-10-16 09:49:07 +02:00
Muyao CHEN	dfc2d1b2eb	feat: add transaction and participation associations	2024-10-16 09:23:32 +02:00