searching for availability for all rooms

internal/repository/dbrepo/postgres.go

@@ -64,3 +64,65 @@ func (m *postgresDBRepo) InsertRoomRestriction(r models.RoomRestriction) error {
 
 	return nil
 }
+
+// SearchAvailabilityByDatesByRoomID returns true if availability exists for roomID, and false if no availability
+func (m *postgresDBRepo) SearchAvailabilityByDatesByRoomID(start, end time.Time, roomID int) (bool, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	var numRows int
+	stmt := `select count(id) from room_restrictions
+             where room_id = $1 and
+             $2 < end_date and $3> start_date`
+
+	row := m.DB.QueryRowContext(ctx, stmt, roomID, start, end)
+	err := row.Scan(&numRows)
+	if err != nil {
+		return false, err
+	}
+
+	if numRows == 0 {
+		return true, nil
+	}
+
+	return false, nil
+}
+
+// SearchAvailabilityForAllRooms returns a slice of rooms, if any, for given date range
+func (m *postgresDBRepo) SearchAvailabilityForAllRooms(start, end time.Time) ([]models.Room, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	var rooms []models.Room
+	stmt := `select
+                r.id, r.room_name
+            from
+                rooms r
+            where r.id not in
+                (select
+                    roomId
+                from
+                    room_restrictions rr
+                where
+                    $1 < rr.end_date and $2> rr.start_date)`
+
+	rows, err := m.DB.QueryContext(ctx, stmt, start, end)
+	if err != nil {
+		return nil, err
+	}
+	for rows.Next() {
+		var room models.Room
+
+		err := rows.Scan(&room.ID, &room.RoomName)
+		if err != nil {
+			return rooms, err
+		}
+		rooms = append(rooms, room)
+	}
+
+	if err = rows.Err(); err != nil {
+		return rooms, err
+	}
+
+	return rooms, nil
+}

internal/repository/repository.go

@@ -1,10 +1,15 @@
 package repository
 
-import "go-udemy-web-1/internal/models"
+import (
+	"go-udemy-web-1/internal/models"
+	"time"
+)
 
 type DatabaseRepo interface {
 	AllUsers() bool
 
 	InsertReservation(res models.Reservation) (int, error)
 	InsertRoomRestriction(res models.RoomRestriction) error
+	SearchAvailabilityByDatesByRoomID(start, end time.Time, roomID int) (bool, error)
+	SearchAvailabilityForAllRooms(start, end time.Time) ([]models.Room, error)
 }

migrations/20240709213207_add_not_null_to_reservation_id_for_restrictions.down.fizz

@@ -0,0 +1,2 @@
+change_column("room_restrictions", "reservation_id", "integer", {"null": false})
+

migrations/20240709213207_add_not_null_to_reservation_id_for_restrictions.up.fizz

@@ -0,0 +1 @@
+change_column("room_restrictions", "reservation_id", "integer", {"null": true})

migrations/schema.sql

@@ -107,7 +107,7 @@ CREATE TABLE public.room_restrictions (
     start_date date NOT NULL,
     end_date date NOT NULL,
     room_id integer NOT NULL,
-    reservation_id integer NOT NULL,
+    reservation_id integer,
     restriction_id integer NOT NULL,
     created_at timestamp without time zone NOT NULL,
     updated_at timestamp without time zone NOT NULL