Reapply "feat(loyalty): EnakPoint & EnakCoin" (#32)

This reverts commit 4e24f9bbb0.

internal/repository/customer_device_repository.go

@@ -0,0 +1,84 @@
+package repository
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+	"gorm.io/gorm"
+)
+
+// CustomerDevice is one install of the customer app that can receive push
+// notifications.
+type CustomerDevice struct {
+	CustomerID uuid.UUID
+	DeviceID   string
+	Platform   *string
+	FCMToken   string
+	AppVersion *string
+}
+
+// CustomerDeviceRepository keeps the FCM tokens of the customer app.
+type CustomerDeviceRepository interface {
+	// Register saves the device's current token. A token is only ever one customer's:
+	// registering it takes it away from whoever had it before on that phone, so they
+	// stop getting this customer's notifications.
+	Register(ctx context.Context, device CustomerDevice, now time.Time) error
+	// Unregister forgets a device, for instance on logout. An unknown device is not an error.
+	Unregister(ctx context.Context, customerID uuid.UUID, deviceID string) error
+	ListTokens(ctx context.Context, customerID uuid.UUID) ([]string, error)
+}
+
+type customerDeviceRepository struct {
+	db *gorm.DB
+}
+
+func NewCustomerDeviceRepository(db *gorm.DB) CustomerDeviceRepository {
+	return &customerDeviceRepository{db: db}
+}
+
+func (r *customerDeviceRepository) Register(ctx context.Context, d CustomerDevice, now time.Time) error {
+	return DBFromContext(ctx, r.db).WithContext(ctx).Transaction(func(tx *gorm.DB) error {
+		err := tx.Exec(`DELETE FROM customer_devices WHERE fcm_token = ? AND NOT (customer_id = ? AND device_id = ?)`,
+			d.FCMToken, d.CustomerID, d.DeviceID).Error
+		if err != nil {
+			return fmt.Errorf("failed to release FCM token: %w", err)
+		}
+		err = tx.Exec(`INSERT INTO customer_devices (customer_id, device_id, platform, fcm_token, app_version, last_active_at)
+			VALUES (?, ?, ?, ?, ?, ?)
+			ON CONFLICT (customer_id, device_id) DO UPDATE SET
+				platform = EXCLUDED.platform,
+				fcm_token = EXCLUDED.fcm_token,
+				app_version = EXCLUDED.app_version,
+				last_active_at = EXCLUDED.last_active_at,
+				updated_at = NOW()`,
+			d.CustomerID, d.DeviceID, d.Platform, d.FCMToken, d.AppVersion, now).Error
+		if err != nil {
+			return fmt.Errorf("failed to register customer device: %w", err)
+		}
+		return nil
+	})
+}
+
+func (r *customerDeviceRepository) Unregister(ctx context.Context, customerID uuid.UUID, deviceID string) error {
+	err := DBFromContext(ctx, r.db).WithContext(ctx).
+		Exec(`DELETE FROM customer_devices WHERE customer_id = ? AND device_id = ?`, customerID, deviceID).Error
+	if err != nil {
+		return fmt.Errorf("failed to unregister customer device: %w", err)
+	}
+	return nil
+}
+
+func (r *customerDeviceRepository) ListTokens(ctx context.Context, customerID uuid.UUID) ([]string, error) {
+	var tokens []string
+	err := DBFromContext(ctx, r.db).WithContext(ctx).
+		Table("customer_devices").
+		Where("customer_id = ? AND fcm_token <> ''", customerID).
+		Order("last_active_at DESC NULLS LAST").
+		Pluck("fcm_token", &tokens).Error
+	if err != nil {
+		return nil, fmt.Errorf("failed to list customer FCM tokens: %w", err)
+	}
+	return tokens, nil
+}