feat(auth): implement user authentication and authorization

.env.example

@@ -1,13 +1,13 @@
 APP_NAME=go-pos
-APP_ENV=local
-APP_URL=127.0.0.1
-APP_PORT=8080
+APP_ENV=development
+
+HTTP_URL=127.0.0.1
+HTTP_PORT=8080
+HTTP_ALLOWED_ORIGINS="http://localhost:3000,http://localhost:5173"
 
 DB_CONNECTION=postgres
 DB_HOST=127.0.0.1
 DB_PORT=5432
 DB_DATABASE=gopos
-DB_USERNAME=root
+DB_USERNAME=
 DB_PASSWORD=
-
-ALLOWED_ORIGINS="http://localhost:3000,http://localhost:5173"

cmd/http/main.go

@@ -7,6 +7,7 @@ import (
 
 	handler "github.com/bagashiz/go-pos/internal/adapter/handler/http"
 	repo "github.com/bagashiz/go-pos/internal/adapter/repository/postgres"
+	token "github.com/bagashiz/go-pos/internal/adapter/token/paseto"
 	"github.com/bagashiz/go-pos/internal/core/service"
 	"github.com/joho/godotenv"
 )
@@ -39,9 +40,10 @@ func main() {
 	appName := os.Getenv("APP_NAME")
 	env := os.Getenv("APP_ENV")
 	dbConn := os.Getenv("DB_CONNECTION")
-	url := os.Getenv("APP_URL")
-	port := os.Getenv("APP_PORT")
-	listenAddr := url + ":" + port
+	tokenSymmetricKey := os.Getenv("TOKEN_SYMMETRIC_KEY")
+	httpUrl := os.Getenv("HTTP_URL")
+	httpPort := os.Getenv("HTTP_PORT")
+	listenAddr := httpUrl + ":" + httpPort
 
 	slog.Info("Starting the application", "app", appName, "env", env)
 
@@ -54,12 +56,13 @@ func main() {
 	}
 	defer db.Close()
 
-	err = db.Ping(ctx)
+	slog.Info("Successfully connected to the database", "db", dbConn)
+
+	// Init token service
+	tokenService, err := token.NewToken(tokenSymmetricKey)
 	if err != nil {
-		slog.Error("Error connecting to database", "error", err)
+		slog.Error("Error initializing token service", "error", err)
 		os.Exit(1)
-	} else {
-		slog.Info("Successfully connected to the database", "db", dbConn)
 	}
 
 	// Dependency injection
@@ -68,6 +71,10 @@ func main() {
 	userService := service.NewUserService(userRepo)
 	userHandler := handler.NewUserHandler(userService)
 
+	// Auth
+	authService := service.NewAuthService(userRepo, tokenService)
+	authHandler := handler.NewAuthHandler(authService)
+
 	// Payment
 	paymentRepo := repo.NewPaymentRepository(db)
 	paymentService := service.NewPaymentService(paymentRepo)
@@ -89,9 +96,10 @@ func main() {
 	orderHandler := handler.NewOrderHandler(orderService)
 
 	// Init router
-	router := handler.NewRouter()
-	router.InitRoutes(
+	router := handler.NewRouter(
+		tokenService,
 		*userHandler,
+		*authHandler,
 		*paymentHandler,
 		*categoryHandler,
 		*productHandler,
@@ -100,7 +108,7 @@ func main() {
 
 	// Start server
 	slog.Info("Starting the HTTP server", "listen_address", listenAddr)
-	err = router.Run(listenAddr)
+	err = router.Serve(listenAddr)
 	if err != nil {
 		slog.Error("Error starting the HTTP server", "error", err)
 		os.Exit(1)

go.mod

@@ -12,6 +12,13 @@ require (
 	golang.org/x/crypto v0.9.0
 )
 
+require (
+	github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da // indirect
+	github.com/aead/chacha20poly1305 v0.0.0-20170617001512-233f39982aeb // indirect
+	github.com/aead/poly1305 v0.0.0-20180717145839-3fee0db0b635 // indirect
+	github.com/pkg/errors v0.8.0 // indirect
+)
+
 require (
 	github.com/bytedance/sonic v1.9.1 // indirect
 	github.com/chenzhuoyu/base64x v0.0.0-20221115062448-fe3a3abad311 // indirect
@@ -32,6 +39,7 @@ require (
 	github.com/mattn/go-isatty v0.0.19 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
+	github.com/o1egl/paseto v1.0.0
 	github.com/pelletier/go-toml/v2 v2.0.8 // indirect
 	github.com/rogpeppe/go-internal v1.11.0 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect

go.sum

@@ -1,5 +1,11 @@
 github.com/Masterminds/squirrel v1.5.4 h1:uUcX/aBc8O7Fg9kaISIUsHXdKuqehiXAMQTYX8afzqM=
 github.com/Masterminds/squirrel v1.5.4/go.mod h1:NNaOrjSoIDfDA40n7sr2tPNZRfjzjA400rg+riTZj10=
+github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da h1:KjTM2ks9d14ZYCvmHS9iAKVt9AyzRSqNU1qabPih5BY=
+github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da/go.mod h1:eHEWzANqSiWQsof+nXEI9bUVUyV6F53Fp89EuCh2EAA=
+github.com/aead/chacha20poly1305 v0.0.0-20170617001512-233f39982aeb h1:6Z/wqhPFZ7y5ksCEV/V5MXOazLaeu/EW97CU5rz8NWk=
+github.com/aead/chacha20poly1305 v0.0.0-20170617001512-233f39982aeb/go.mod h1:UzH9IX1MMqOcwhoNOIjmTQeAxrFgzs50j4golQtXXxU=
+github.com/aead/poly1305 v0.0.0-20180717145839-3fee0db0b635 h1:52m0LGchQBBVqJRyYYufQuIbVqRawmubW3OFGqK1ekw=
+github.com/aead/poly1305 v0.0.0-20180717145839-3fee0db0b635/go.mod h1:lmLxL+FV291OopO93Bwf9fQLQeLyt33VJRUg5VJ30us=
 github.com/bytedance/sonic v1.5.0/go.mod h1:ED5hyg4y6t3/9Ku1R6dU/4KyJ48DZ4jPhfY1O2AihPM=
 github.com/bytedance/sonic v1.9.1 h1:6iJ6NqdoxCDr6mbY8h18oSO+cShGSMRGCEo7F2h0x8s=
 github.com/bytedance/sonic v1.9.1/go.mod h1:i736AoUSYt75HyZLoJW9ERYxcy6eaN6h4BZXU064P/U=
@@ -78,10 +84,14 @@ github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd h1:TRLaZ9cD/w
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9Gz0M=
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
+github.com/o1egl/paseto v1.0.0 h1:bwpvPu2au176w4IBlhbyUv/S5VPptERIA99Oap5qUd0=
+github.com/o1egl/paseto v1.0.0/go.mod h1:5HxsZPmw/3RI2pAwGo1HhOOwSdvBpcuVzO7uDkm+CLU=
 github.com/pelletier/go-toml/v2 v2.0.1/go.mod h1:r9LEWfGN8R5k0VXJ+0BkIe7MYkRdwZOjgMj2KwnJFUo=
 github.com/pelletier/go-toml/v2 v2.0.8 h1:0ctb6s9mE31h0/lhu+J6OPmVeDxJn+kYnJc2jZR9tGQ=
 github.com/pelletier/go-toml/v2 v2.0.8/go.mod h1:vuYfssBdrU2XDZ9bYydBu6t+6a6PYNcZljzZR9VXg+4=
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
+github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
+github.com/pkg/errors v0.8.0/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/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
@@ -110,6 +120,7 @@ github.com/ugorji/go/codec v1.2.11/go.mod h1:UNopzCgEMSXjBc6AOMqYvWC1ktqTAfzJZUZ
 golang.org/x/arch v0.0.0-20210923205945-b76863e36670/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=
 golang.org/x/arch v0.3.0 h1:02VY4/ZcO/gBOH6PUaoiptASxtXU10jazRCP865E97k=
 golang.org/x/arch v0.3.0/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=
+golang.org/x/crypto v0.0.0-20181025213731-e84da0312774/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/crypto v0.9.0 h1:LF6fAI+IutBocDJ2OT0Q1g8plpYljMZ4+lty+dsqw3g=
 golang.org/x/crypto v0.9.0/go.mod h1:yrmDGqONDYtNj3tH8X9dzUun2m2lzPa9ngI6/RUPGR0=
@@ -118,6 +129,7 @@ golang.org/x/net v0.10.0 h1:X2//UzNDwYmtCLn7To6G58Wr6f5ahEAQgKNzv9Y951M=
 golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
 golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20181026203630-95b1ffbd15a5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

internal/adapter/handler/http/auth.go

@@ -0,0 +1,63 @@
+package handler
+
+import (
+	"net/http"
+
+	"github.com/bagashiz/go-pos/internal/core/domain"
+	"github.com/bagashiz/go-pos/internal/core/port"
+	"github.com/gin-gonic/gin"
+)
+
+// AuthHandler represents the HTTP handler for authentication-related requests
+type AuthHandler struct {
+	svc port.AuthService
+}
+
+// NewAuthHandler creates a new AuthHandler instance
+func NewAuthHandler(svc port.AuthService) *AuthHandler {
+	return &AuthHandler{
+		svc,
+	}
+}
+
+// authResponse represents an authentication response body
+type authResponse struct {
+	AccessToken string `json:"token"`
+}
+
+// newAuthResponse is a helper function to create a response body for handling authentication data
+func newAuthResponse(token string) authResponse {
+	return authResponse{
+		AccessToken: token,
+	}
+}
+
+// loginRequest represents the request body for logging in a user
+type loginRequest struct {
+	Email    string `json:"email" binding:"required,email"`
+	Password string `json:"password" binding:"required,min=8"`
+}
+
+// Login gives a registered user an access token if the credentials are valid
+func (ah *AuthHandler) Login(ctx *gin.Context) {
+	var req loginRequest
+	if err := ctx.ShouldBindJSON(&req); err != nil {
+		errorResponse(ctx, http.StatusBadRequest, err)
+		return
+	}
+
+	token, err := ah.svc.Login(ctx, req.Email, req.Password)
+	if err != nil {
+		if err == domain.ErrInvalidCredentials {
+			errorResponse(ctx, http.StatusUnauthorized, err)
+			return
+		}
+
+		errorResponse(ctx, http.StatusInternalServerError, err)
+		return
+	}
+
+	rsp := newAuthResponse(token)
+
+	successResponse(ctx, http.StatusOK, rsp)
+}

internal/adapter/handler/http/category.go

@@ -14,9 +14,9 @@ type CategoryHandler struct {
 }
 
 // NewCategoryHandler creates a new CategoryHandler instance
-func NewCategoryHandler(CategoryService port.CategoryService) *CategoryHandler {
+func NewCategoryHandler(svc port.CategoryService) *CategoryHandler {
 	return &CategoryHandler{
-		svc: CategoryService,
+		svc,
 	}
 }
 
@@ -53,6 +53,11 @@ func (ch *CategoryHandler) CreateCategory(ctx *gin.Context) {
 
 	_, err := ch.svc.CreateCategory(ctx, &category)
 	if err != nil {
+		if err == domain.ErrConflictingData {
+			errorResponse(ctx, http.StatusConflict, err)
+			return
+		}
+
 		errorResponse(ctx, http.StatusInternalServerError, err)
 		return
 	}
@@ -77,7 +82,7 @@ func (ch *CategoryHandler) GetCategory(ctx *gin.Context) {
 
 	category, err := ch.svc.GetCategory(ctx, req.ID)
 	if err != nil {
-		if err.Error() == "category not found" {
+		if err == domain.ErrDataNotFound {
 			errorResponse(ctx, http.StatusNotFound, err)
 			return
 		}
@@ -138,7 +143,7 @@ func (ch *CategoryHandler) UpdateCategory(ctx *gin.Context) {
 	}
 
 	idStr := ctx.Param("id")
-	id, err := convertStringToUint64(idStr)
+	id, err := stringToUint64(idStr)
 	if err != nil {
 		errorResponse(ctx, http.StatusBadRequest, err)
 		return
@@ -151,16 +156,21 @@ func (ch *CategoryHandler) UpdateCategory(ctx *gin.Context) {
 
 	_, err = ch.svc.UpdateCategory(ctx, &category)
 	if err != nil {
-		if err.Error() == "category not found" {
+		if err == domain.ErrDataNotFound {
 			errorResponse(ctx, http.StatusNotFound, err)
 			return
 		}
 
-		if err.Error() == "no data to update" {
+		if err == domain.ErrNoUpdatedData {
 			errorResponse(ctx, http.StatusBadRequest, err)
 			return
 		}
 
+		if err == domain.ErrConflictingData {
+			errorResponse(ctx, http.StatusConflict, err)
+			return
+		}
+
 		errorResponse(ctx, http.StatusInternalServerError, err)
 		return
 	}
@@ -185,7 +195,7 @@ func (ch *CategoryHandler) DeleteCategory(ctx *gin.Context) {
 
 	err := ch.svc.DeleteCategory(ctx, req.ID)
 	if err != nil {
-		if err.Error() == "category not found" {
+		if err == domain.ErrDataNotFound {
 			errorResponse(ctx, http.StatusNotFound, err)
 			return
 		}

internal/adapter/handler/http/helper.go

@@ -3,9 +3,22 @@ package handler
 import (
 	"strconv"
 
+	"github.com/bagashiz/go-pos/internal/core/domain"
 	"github.com/gin-gonic/gin"
 )
 
+// stringToUint64 is a helper function to convert a string to uint64
+func stringToUint64(str string) (uint64, error) {
+	num, err := strconv.ParseUint(str, 10, 64)
+
+	return num, err
+}
+
+// getAuthPayload is a helper function to get the auth payload from the context
+func getAuthPayload(ctx *gin.Context, key string) *domain.TokenPayload {
+	return ctx.MustGet(key).(*domain.TokenPayload)
+}
+
 // meta represents metadata for a paginated response
 type meta struct {
 	Total uint64 `json:"total"`
@@ -22,13 +35,6 @@ func newMeta(total, limit, skip uint64) meta {
 	}
 }
 
-// convertStringToUint64 is a helper function to convert a string to uint64
-func convertStringToUint64(str string) (uint64, error) {
-	num, err := strconv.ParseUint(str, 10, 64)
-
-	return num, err
-}
-
 // toMap is a helper function to add meta and data to a map
 func toMap(m meta, data any, key string) map[string]any {
 	return map[string]any{
@@ -45,6 +51,14 @@ func errorResponse(ctx *gin.Context, statusCode int, err error) {
 	})
 }
 
+// abortResponse returns an abort JSON response with the error message and status code
+func abortResponse(ctx *gin.Context, statusCode int, err error) {
+	ctx.AbortWithStatusJSON(statusCode, gin.H{
+		"success": false,
+		"error":   err.Error(),
+	})
+}
+
 // successResponse returns a JSON response with the success message and data
 func successResponse(ctx *gin.Context, statusCode int, data any) {
 	if data == nil {