Setting un invoice pdf microservice

.gitignore

@@ -6,3 +6,4 @@ cred.txt
 dist/
 .air.toml
 tmp/
+invoices/

Makefile

@@ -5,7 +5,7 @@ API_PORT=4001
 DSN=vinchent:secret@tcp(localhost:3306)/widgets?parseTime=true&tls=false
 
 ## build: builds all binaries
-build: clean build_front build_back
+build: clean build_front build_back build_invoice
 	@printf "All binaries built!\n"
 
 ## clean: cleans all binaries and runs go clean
@@ -15,6 +15,12 @@ clean:
 	@go clean
 	@echo "Cleaned!"
 
+## build_invoice: builds the invoice microservice
+build_invoice:
+	@echo "Building invoice microservice..."
+	@go build -o dist/invoice ./cmd/micro/invoice
+	@echo "Invoice microservice built!"
+
 ## build_front: builds the front end
 build_front:
 	@echo "Building front end..."
@@ -28,8 +34,14 @@ build_back:
 	@echo "Back end built!"
 
 ## start: starts front and back end
-start: start_front start_back
+start: start_front start_back start_invoice
 	
+## start_invoice: starts the invoice microservice
+start_invoice: build_invoice
+	@echo "Starting the invoice microservice..."
+	@./dist/invoice &
+	@echo "invoice microservice running!"
+
 ## start_front: starts the front end
 start_front: build_front
 	@echo "Starting the front end..."
@@ -43,9 +55,15 @@ start_back: build_back
 	@echo "Back end running!"
 
 ## stop: stops the front and back end
-stop: stop_front stop_back
+stop: stop_front stop_back stop_invoice
 	@echo "All applications stopped"
 
+## stop_invoice: stops the invoice microservice
+stop_invoice:
+	@echo "Stopping the invoice microservice..."
+	@-pkill -SIGTERM -f "invoice"
+	@echo "Stopped invoice microservice"
+
 ## stop_front: stops the front end
 stop_front:
 	@echo "Stopping the front end..."

cmd/api/handlers-api.go

@@ -33,7 +33,7 @@ type stripePayload struct {
 	LastName      string `json:"last_name"`
 }
 
-type jsonResponse struct {
+type JSONResponse struct {
 	OK      bool   `json:"ok"`
 	Message string `json:"message,omitempty"`
 	Content string `json:"content,omitempty"`
@@ -63,7 +63,7 @@ func (app *application) GetPaymentIntent(w http.ResponseWriter, r *http.Request)
 
 	pi, msg, err := card.Charge(payload.Currency, amount)
 	if err != nil {
-		j := jsonResponse{
+		j := JSONResponse{
 			OK:      false,
 			Message: msg,
 			Content: "",
@@ -190,7 +190,7 @@ func (app *application) CreateCustomerAndSubscribeToPlan(w http.ResponseWriter,
 		}
 	}
 
-	resp := jsonResponse{
+	resp := JSONResponse{
 		OK:      okay,
 		Message: txnMsg,
 	}
@@ -340,7 +340,7 @@ func (app *application) CheckAuthentication(w http.ResponseWriter, r *http.Reque
 	}
 
 	// valid user
-	var payload jsonResponse
+	var payload JSONResponse
 	payload.OK = true
 	payload.Message = fmt.Sprintf("authenticated user %s", user.Email)
 	app.writeJSON(w, http.StatusOK, payload)
@@ -423,7 +423,7 @@ func (app *application) SendPasswordResetEmail(w http.ResponseWriter, r *http.Re
 	// verify that email exists
 	_, err = app.DB.GetUserByEmail(payload.Email)
 	if err != nil {
-		resp := jsonResponse{
+		resp := JSONResponse{
 			OK:      false,
 			Message: "No matching email found on our system",
 		}
@@ -458,7 +458,7 @@ func (app *application) SendPasswordResetEmail(w http.ResponseWriter, r *http.Re
 		return
 	}
 
-	resp := jsonResponse{
+	resp := JSONResponse{
 		OK: true,
 	}
 
@@ -509,7 +509,7 @@ func (app *application) ResetPassword(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	resp := jsonResponse{
+	resp := JSONResponse{
 		OK:      true,
 		Message: "Password reset.",
 	}
@@ -649,7 +649,7 @@ func (app *application) RefundCharge(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	var resp jsonResponse
+	var resp JSONResponse
 	resp.OK = true
 	resp.Message = "Charge refunded"
 
@@ -696,7 +696,7 @@ func (app *application) CancelSubscription(w http.ResponseWriter, r *http.Reques
 		return
 	}
 
-	var resp jsonResponse
+	var resp JSONResponse
 	resp.OK = true
 	resp.Message = "Subscription canceled"
 
@@ -775,7 +775,7 @@ func (app *application) EditUser(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	var resp jsonResponse
+	var resp JSONResponse
 	resp.OK = true
 	app.writeJSON(w, http.StatusOK, resp)
 }
@@ -789,7 +789,7 @@ func (app *application) DeleteUser(w http.ResponseWriter, r *http.Request) {
 		app.badRequest(w, r, err)
 		return
 	}
-	var resp jsonResponse
+	var resp JSONResponse
 	resp.OK = true
 	app.writeJSON(w, http.StatusOK, resp)
 }

cmd/micro/invoice/helpers.go

@@ -0,0 +1,86 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"os"
+)
+
+type JSONResponse struct {
+	OK      bool   `json:"ok"`
+	Message string `json:"message,omitempty"`
+}
+
+func (app *application) readJSON(w http.ResponseWriter, r *http.Request, data interface{}) error {
+	maxBytes := 1048576
+
+	r.Body = http.MaxBytesReader(w, r.Body, int64(maxBytes))
+
+	dec := json.NewDecoder(r.Body)
+	err := dec.Decode(data)
+	if err != nil {
+		return err
+	}
+
+	// Make sure there is only one entry.
+	err = dec.Decode(&struct{}{})
+	if err != io.EOF {
+		return errors.New("body must only have a single JSON value")
+	}
+
+	return nil
+}
+
+// writeJSON writes arbitrary data out as JSON
+func (app *application) writeJSON(
+	w http.ResponseWriter,
+	status int, data interface{},
+	headers ...http.Header,
+) error {
+	out, err := json.MarshalIndent(data, "", "\t")
+	if err != nil {
+		return err
+	}
+
+	if len(headers) > 0 {
+		for k, v := range headers[0] {
+			w.Header()[k] = v
+		}
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	w.Write(out)
+	return nil
+}
+
+func (app *application) badRequest(w http.ResponseWriter, r *http.Request, err error) error {
+	var payload JSONResponse
+
+	payload.OK = false
+	payload.Message = err.Error()
+
+	out, err := json.MarshalIndent(payload, "", "\t")
+	if err != nil {
+		return err
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusBadGateway)
+	w.Write(out)
+	return nil
+}
+
+func (app *application) CreateDirIfNotExist(path string) error {
+	const mode = 0755
+	if _, err := os.Stat(path); os.IsNotExist(err) {
+		err := os.Mkdir(path, mode)
+		if err != nil {
+			app.errorLog.Println(err)
+			return err
+		}
+	}
+	return nil
+}

cmd/micro/invoice/invoice-handlers.go

@@ -0,0 +1,145 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/phpdave11/gofpdf"
+	"github.com/phpdave11/gofpdf/contrib/gofpdi"
+)
+
+type Order struct {
+	ID        int       `json:"id"`
+	Quantity  int       `json:"quantity"`
+	Amount    int       `json:"amount"`
+	Product   string    `json:"product"`
+	FirstName string    `json:"first_name"`
+	LastName  string    `json:"last_name"`
+	Email     string    `json:"email"`
+	CreatedAt time.Time `json:"-"`
+}
+
+func (app *application) CreateAndSendInvoice(w http.ResponseWriter, r *http.Request) {
+	// receive json
+	var order Order
+
+	err := app.readJSON(w, r, &order)
+	if err != nil {
+		app.badRequest(w, r, err)
+		return
+	}
+
+	// generate a pdf invoice
+
+	// create mail
+
+	// send mail with attachment
+
+	// send response
+	var resp JSONResponse
+	resp.OK = true
+	resp.Message = fmt.Sprintf("Invoice %d.pdf created and sent to %s", order.ID, order.Email)
+	app.writeJSON(w, http.StatusCreated, resp)
+}
+
+func (app *application) createInvoicePDF(order Order) error {
+	pdf := gofpdf.New("P", "mm", "Letter", "")
+	pdf.SetMargins(10, 13, 10)
+	pdf.SetAutoPageBreak(true, 0)
+
+	importer := gofpdi.NewImporter()
+
+	t := importer.ImportPage(pdf, "./pdf-templates/invoice.pdf", q, "/MediaBox")
+
+	pdf.AddPage()
+	importer.UseImportedTemplate(pdf, t, 0, 0, 215.9, 0)
+
+	pdf.SetY(20)
+
+	// write info
+	pdf.SetY(50)
+	pdf.SetX(10)
+	pdf.SetFont("Times", "", 11)
+	pdf.CellFormat(
+		97,
+		8,
+		fmt.Sprintf("Attention: %s %s", order.FirstName, order.LastName),
+		"",
+		0,
+		"L",
+		false,
+		0,
+		"",
+	)
+	pdf.Ln(5)
+	pdf.CellFormat(
+		97,
+		8,
+		order.Email,
+		"",
+		0,
+		"L",
+		false,
+		0,
+		"",
+	)
+	pdf.Ln(5)
+	pdf.CellFormat(
+		97,
+		8,
+		order.CreatedAt.Format("2005-01-02"),
+		"",
+		0,
+		"L",
+		false,
+		0,
+		"",
+	)
+
+	pdf.SetX(58)
+	pdf.SetY(93)
+	pdf.CellFormat(
+		155,
+		8,
+		order.Product,
+		"",
+		0,
+		"L",
+		false,
+		0,
+		"",
+	)
+	pdf.SetX(166)
+	pdf.CellFormat(
+		20,
+		8,
+		fmt.Sprintf("%d", order.Quantity),
+		"",
+		0,
+		"C",
+		false,
+		0,
+		"",
+	)
+
+	pdf.SetX(185)
+	pdf.CellFormat(
+		155,
+		8,
+		fmt.Sprintf("€%.2f", float32(order.Amount/100.0)),
+		"",
+		0,
+		"R",
+		false,
+		0,
+		"",
+	)
+
+	invoicePath := fmt.Sprintf("./invoices/%d.pdf", order.ID)
+	err := pdf.OutputFileAndClose(invoicePath)
+	if err != nil {
+		return err
+	}
+	return nil
+}

cmd/micro/invoice/invoice-routes.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/cors"
+)
+
+func (app *application) routes() http.Handler {
+	mux := chi.NewRouter()
+
+	mux.Use(cors.Handler(cors.Options{
+		AllowedOrigins:   []string{"https://*", "http://*"},
+		AllowedMethods:   []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
+		AllowedHeaders:   []string{"Accept", "Authorization", "Content-Type", "X-CSRF-Token"},
+		AllowCredentials: false,
+		MaxAge:           300,
+	}))
+
+	mux.Post("/invoice/create-and-send", app.CreateAndSendInvoice)
+	return mux
+}

cmd/micro/invoice/invoice.go

@@ -0,0 +1,79 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"time"
+)
+
+const (
+	version = "1.0.0"
+)
+
+type config struct {
+	port int
+	smtp struct {
+		host     string
+		port     int
+		username string
+		password string
+	}
+	frontend string
+}
+
+type application struct {
+	config   config
+	infoLog  *log.Logger
+	errorLog *log.Logger
+	version  string
+}
+
+func (app *application) serve() error {
+	srv := &http.Server{
+		Addr:              fmt.Sprintf(":%d", app.config.port),
+		Handler:           app.routes(),
+		IdleTimeout:       30 * time.Second,
+		ReadTimeout:       10 * time.Second,
+		ReadHeaderTimeout: 5 * time.Second,
+		WriteTimeout:      5 * time.Second,
+	}
+
+	app.infoLog.Printf(
+		"Starting invoice microservice on port %d",
+		app.config.port,
+	)
+	return srv.ListenAndServe()
+}
+
+func main() {
+	var cfg config
+
+	flag.IntVar(&cfg.port, "port", 5000, "Server port to listen on")
+	flag.StringVar(&cfg.smtp.host, "smtphost", "0.0.0.0", "smtp host")
+	flag.IntVar(&cfg.smtp.port, "smtpport", 1025, "smtp host")
+	flag.StringVar(&cfg.smtp.username, "smtpuser", "user", "smtp user")
+	flag.StringVar(&cfg.smtp.password, "smtppwd", "password", "smtp password")
+	flag.StringVar(&cfg.frontend, "frontend", "http://localhost:4000", "frontend address")
+
+	flag.Parse()
+
+	infoLog := log.New(os.Stdout, "INFO\t", log.Ldate|log.Ltime)
+	errorLog := log.New(os.Stdout, "ERROR\t", log.Ldate|log.Ltime|log.Lshortfile)
+
+	app := &application{
+		version:  version,
+		config:   cfg,
+		infoLog:  infoLog,
+		errorLog: errorLog,
+	}
+
+	app.CreateDirIfNotExist("./invoices")
+
+	err := app.serve()
+	if err != nil {
+		log.Fatal(err)
+	}
+}

go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/go-chi/cors v1.2.1
 	github.com/go-sql-driver/mysql v1.8.1
 	github.com/gorilla/websocket v1.5.3
+	github.com/phpdave11/gofpdf v1.4.2
 	github.com/stripe/stripe-go/v79 v79.6.0
 	github.com/xhit/go-simple-mail/v2 v2.16.0
 	golang.org/x/crypto v0.26.0
@@ -18,6 +19,8 @@ require (
 require (
 	filippo.io/edwards25519 v1.1.0 // indirect
 	github.com/go-test/deep v1.1.1 // indirect
+	github.com/phpdave11/gofpdi v1.0.12 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
 	github.com/toorop/go-dkim v0.0.0-20201103131630-e1cd1a0a5208 // indirect
 	golang.org/x/sys v0.23.0 // indirect
 )

go.sum

@@ -4,6 +4,7 @@ github.com/alexedwards/scs/mysqlstore v0.0.0-20240316134038-7e11d57e8885 h1:C7QA
 github.com/alexedwards/scs/mysqlstore v0.0.0-20240316134038-7e11d57e8885/go.mod h1:p8jK3D80sw1PFrCSdlcJF1O75bp55HqbgDyyCLM0FrE=
 github.com/alexedwards/scs/v2 v2.8.0 h1:h31yUYoycPuL0zt14c0gd+oqxfRwIj6SOjHdKRZxhEw=
 github.com/alexedwards/scs/v2 v2.8.0/go.mod h1:ToaROZxyKukJKT/xLcVQAChi5k6+Pn1Gvmdl7h3RRj8=
+github.com/boombuler/barcode v1.0.0/go.mod h1:paBWMcWSl3LHKBqUq+rly7CNSldXjb2rDl3JlRe0mD8=
 github.com/bwmarrin/go-alone v0.0.0-20190806015146-742bb55d1631 h1:Xb5rra6jJt5Z1JsZhIMby+IP5T8aU+Uc2RC9RzSxs9g=
 github.com/bwmarrin/go-alone v0.0.0-20190806015146-742bb55d1631/go.mod h1:P86Dksd9km5HGX5UMIocXvX87sEp2xUARle3by+9JZ4=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
@@ -19,9 +20,19 @@ github.com/go-test/deep v1.1.1 h1:0r/53hagsehfO4bzD2Pgr/+RgHqhmf+k1Bpse2cTu1U=
 github.com/go-test/deep v1.1.1/go.mod h1:5C2ZWiW0ErCdrYzpqxLbTX7MG14M9iiw8DgHncVwcsE=
 github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
 github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/jung-kurt/gofpdf v1.0.0/go.mod h1:7Id9E/uU8ce6rXgefFLlgrJj/GYY22cpxn+r32jIOes=
+github.com/phpdave11/gofpdf v1.4.2 h1:KPKiIbfwbvC/wOncwhrpRdXVj2CZTCFlw4wnoyjtHfQ=
+github.com/phpdave11/gofpdf v1.4.2/go.mod h1:zpO6xFn9yxo3YLyMvW8HcKWVdbNqgIfOOp2dXMnm1mY=
+github.com/phpdave11/gofpdi v1.0.12 h1:RZb9NG62cw/RW0rHAduVRo+98R8o/G1krcg2ns7DakQ=
+github.com/phpdave11/gofpdi v1.0.12/go.mod h1:vBmVV0Do6hSBHC8uKUQ71JGW+ZGQq74llk/7bXwjDoI=
+github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/ruudk/golang-pdf417 v0.0.0-20181029194003-1af4ab5afa58/go.mod h1:6lfFZQK844Gfx8o5WFuvpxWRwnSoipWe/p622j1v06w=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stripe/stripe-go/v79 v79.6.0 h1:qSBV2f2rpLEEZTdTlVLzdmQJZNmfoo2E3hUEkFT8GBc=
@@ -32,6 +43,7 @@ github.com/xhit/go-simple-mail/v2 v2.16.0 h1:ouGy/Ww4kuaqu2E2UrDw7SvLaziWTB60ICL
 github.com/xhit/go-simple-mail/v2 v2.16.0/go.mod h1:b7P5ygho6SYE+VIqpxA6QkYfv4teeyG4MKqB3utRu98=
 golang.org/x/crypto v0.26.0 h1:RrRspgV4mU+YwB4FYnuBoKsUapNIL5cohGAmSH3azsw=
 golang.org/x/crypto v0.26.0/go.mod h1:GY7jblb9wI+FOo5y8/S2oY4zWP07AkOJ4+jxCqdqn54=
+golang.org/x/image v0.0.0-20190910094157-69e4b8554b2a/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/net v0.0.0-20210520170846-37e1c6afe023/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.21.0 h1:AQyQV4dYCvJ7vGmJyKki9+PBdyvhkSd8EIx/qb0AYv4=
 golang.org/x/net v0.21.0/go.mod h1:bIjVDfnllIU7BJ2DNgfnXvpSvtn8VRwhlsaeUTyUS44=
@@ -40,6 +52,7 @@ golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.23.0 h1:YfKFowiIMvtgl1UERQoTPPToxltDeZfbj4H7dVUCwmM=
 golang.org/x/sys v0.23.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.17.0 h1:XtiM5bkSOt+ewxlOE/aE/AKEHibwj/6gvWMl9Rsh0Qc=
 golang.org/x/text v0.17.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=