6 files changed, 269 insertions, 0 deletions
diff --git a/api/auth/auth.go b/api/auth/auth.go
new file mode 100644
index 0000000..23b4f53
--- /dev/null
+++ b/api/auth/auth.go
@@ -0,0 +1,48 @@
+package auth
+
+import (
+	"github.com/golang-jwt/jwt/v5"
+	"os"
+	"time"
+)
+
+var jwtKey = []byte(os.Getenv("JWT_SECRET"))
+
+type Claims struct {
+	UserID int `json:"user_id"`
+	jwt.RegisteredClaims
+}
+
+func GenerateJWT(userID int) (string, error) {
+	expirationTime := time.Now().Add(5 * time.Hour)
+	claims := &Claims{
+		UserID: userID,
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(expirationTime),
+		},
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	tokenString, err := token.SignedString(jwtKey)
+	if err != nil {
+		return "", err
+	}
+	return tokenString, nil
+}
+
+func ValidateJWT(tokenString string) (*Claims, error) {
+	claims := &Claims{}
+	token, err := jwt.ParseWithClaims(tokenString, claims, func(token *jwt.Token) (interface{}, error) {
+		return jwtKey, nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	if !token.Valid {
+		return nil, err
+	}
+
+	return claims, nil
+}
diff --git a/api/auth/auth_test.go b/api/auth/auth_test.go
new file mode 100644
index 0000000..50b6c9b
--- /dev/null
+++ b/api/auth/auth_test.go
@@ -0,0 +1,74 @@
+package auth
+
+import (
+	"os"
+	"testing"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGenerateAndValidateJWT(t *testing.T) {
+	// Set up the JWT secret for the test.
+	os.Setenv("JWT_SECRET", "testsecret")
+	jwtKey = []byte(os.Getenv("JWT_SECRET"))
+
+	userID := 123
+	tokenString, err := GenerateJWT(userID)
+	assert.NoError(t, err)
+	assert.NotEmpty(t, tokenString)
+
+	claims, err := ValidateJWT(tokenString)
+	assert.NoError(t, err)
+	assert.NotNil(t, claims)
+	assert.Equal(t, userID, claims.UserID)
+	assert.True(t, claims.ExpiresAt.After(time.Now()))
+}
+
+func TestValidateJWT_InvalidToken(t *testing.T) {
+	os.Setenv("JWT_SECRET", "testsecret")
+	jwtKey = []byte(os.Getenv("JWT_SECRET"))
+
+	_, err := ValidateJWT("invalid_token")
+	assert.Error(t, err)
+}
+
+func TestValidateJWT_ExpiredToken(t *testing.T) {
+	os.Setenv("JWT_SECRET", "testsecret")
+	jwtKey = []byte(os.Getenv("JWT_SECRET"))
+
+	// Create a token that has already expired.
+	claims := &Claims{
+		UserID: 123,
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(time.Now().Add(-1 * time.Hour)),
+		},
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	tokenString, err := token.SignedString(jwtKey)
+	assert.NoError(t, err)
+
+	_, err = ValidateJWT(tokenString)
+	assert.Error(t, err)
+}
+
+func TestValidateJWT_WrongSecret(t *testing.T) {
+	os.Setenv("JWT_SECRET", "testsecret")
+	jwtKey = []byte(os.Getenv("JWT_SECRET"))
+
+	userID := 123
+	tokenString, err := GenerateJWT(userID)
+	assert.NoError(t, err)
+
+	// Set a different secret for validation.
+	wrongKey := []byte("wrongsecret")
+
+	claims := &Claims{}
+	_, err = jwt.ParseWithClaims(tokenString, claims, func(token *jwt.Token) (interface{}, error) {
+		return wrongKey, nil
+	})
+
+	assert.Error(t, err)
+}
diff --git a/api/database/database.go b/api/database/database.go
new file mode 100644
index 0000000..e5ecca8
--- /dev/null
+++ b/api/database/database.go
@@ -0,0 +1,32 @@
+package database
+
+import (
+	"gorm.io/driver/postgres"
+	"gorm.io/gorm"
+
+	"errors"
+)
+
+// Global variable but private
+var db *gorm.DB = nil
+
+// Init the database from a DSN string which must be a valid PostgreSQL dsn.
+// Also, auto migrate all the models.
+func InitDb(dsn string) (*gorm.DB, error) {
+	var err error
+	db, err = gorm.Open(postgres.Open(dsn), &gorm.Config{})
+
+	if err == nil {
+		db.AutoMigrate(&User{})
+	}
+
+	return db, err
+}
+
+// Return the instance or error if the config is not laoded yet
+func GetDb() (*gorm.DB, error) {
+	if db == nil {
+		return nil, errors.New("You must call `InitDb()` first.")
+	}
+	return db, nil
+}
diff --git a/api/database/models.go b/api/database/models.go
new file mode 100644
index 0000000..e309a36
--- /dev/null
+++ b/api/database/models.go
@@ -0,0 +1,11 @@
+package database
+
+import "time"
+
+type User struct {
+	ID        int       `json:"id"`
+	Username  string    `json:"username"`
+	Password  string    `json:"password"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+}
diff --git a/api/handlers/handlers.go b/api/handlers/handlers.go
new file mode 100644
index 0000000..7d5fd10
--- /dev/null
+++ b/api/handlers/handlers.go
@@ -0,0 +1,68 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/boozec/rahanna/api/auth"
+	"github.com/boozec/rahanna/api/database"
+	"golang.org/x/crypto/bcrypt"
+)
+
+func RegisterUser(w http.ResponseWriter, r *http.Request) {
+	var user database.User
+	err := json.NewDecoder(r.Body).Decode(&user)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(user.Password), bcrypt.DefaultCost)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	user.Password = string(hashedPassword)
+
+	db, _ := database.GetDb()
+
+	result := db.Create(&user)
+	if result.Error != nil {
+		http.Error(w, result.Error.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	w.WriteHeader(http.StatusCreated)
+}
+
+func LoginUser(w http.ResponseWriter, r *http.Request) {
+	var inputUser database.User
+	err := json.NewDecoder(r.Body).Decode(&inputUser)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	var storedUser database.User
+
+	db, _ := database.GetDb()
+	result := db.Where("username = ?", inputUser.Username).First(&storedUser)
+	if result.Error != nil {
+		http.Error(w, "Invalid credentials", http.StatusUnauthorized)
+		return
+	}
+
+	err = bcrypt.CompareHashAndPassword([]byte(storedUser.Password), []byte(inputUser.Password))
+	if err != nil {
+		http.Error(w, "Invalid credentials", http.StatusUnauthorized)
+		return
+	}
+
+	token, err := auth.GenerateJWT(storedUser.ID)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	json.NewEncoder(w).Encode(map[string]string{"token": token})
+}
diff --git a/api/middleware/middleware.go b/api/middleware/middleware.go
new file mode 100644
index 0000000..29ed8b6
--- /dev/null
+++ b/api/middleware/middleware.go
@@ -0,0 +1,36 @@
+package middleware
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/boozec/rahanna/api/auth"
+)
+
+func AuthMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		tokenString := r.Header.Get("Authorization")
+
+		payloadMap := map[string]string{"error": "unauthorized"}
+		payload, _ := json.Marshal(payloadMap)
+
+		if tokenString == "" {
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusUnauthorized)
+
+			w.Write([]byte(payload))
+			return
+		}
+
+		_, err := auth.ValidateJWT(tokenString)
+		if err != nil {
+			w.WriteHeader(http.StatusUnauthorized)
+
+			payload, _ := json.Marshal(payloadMap)
+
+			w.Write([]byte(payload))
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}