backend-service/internal/handlers/auth.go

package handlers

import (
	"net/http"

	"attune-heart-therapy/internal/middleware"
	"attune-heart-therapy/internal/services"

	"github.com/gin-gonic/gin"
)

type AuthHandler struct {
	userService services.UserService
}

func NewAuthHandler(userService services.UserService) *AuthHandler {
	return &AuthHandler{
		userService: userService,
	}
}

// Register handles POST /api/auth/register for new user registration
func (h *AuthHandler) Register(c *gin.Context) {
	var req services.RegisterRequest

	// Bind JSON request to struct
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{
			"error":   "Invalid request format",
			"details": err.Error(),
		})
		return
	}

	// Create new user
	user, err := h.userService.Register(req)
	if err != nil {
		// Check for specific error types
		if err.Error() == "validation failed" ||
			err.Error() == "password must be at least 8 characters long" {
			c.JSON(http.StatusBadRequest, gin.H{
				"error":   "Validation failed",
				"details": err.Error(),
			})
			return
		}

		if err.Error() == "user with email "+req.Email+" already exists" {
			c.JSON(http.StatusConflict, gin.H{
				"error":   "User already exists",
				"details": err.Error(),
			})
			return
		}

		c.JSON(http.StatusInternalServerError, gin.H{
			"error":   "Failed to create user",
			"details": err.Error(),
		})
		return
	}

	c.JSON(http.StatusCreated, gin.H{
		"message": "User registered successfully",
		"user":    user,
	})
}

// Login handles POST /api/auth/login for user authentication
func (h *AuthHandler) Login(c *gin.Context) {
	var loginReq struct {
		Email    string `json:"email" binding:"required,email"`
		Password string `json:"password" binding:"required"`
	}

	// Bind JSON request to struct
	if err := c.ShouldBindJSON(&loginReq); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{
			"error":   "Invalid request format",
			"details": err.Error(),
		})
		return
	}

	// Authenticate user
	user, token, err := h.userService.Login(loginReq.Email, loginReq.Password)
	if err != nil {
		if err.Error() == "invalid credentials" {
			c.JSON(http.StatusUnauthorized, gin.H{
				"error": "Invalid email or password",
			})
			return
		}

		c.JSON(http.StatusInternalServerError, gin.H{
			"error":   "Login failed",
			"details": err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"message": "Login successful",
		"user":    user,
		"token":   token,
	})
}

// GetProfile handles GET /api/auth/profile for retrieving user profile
func (h *AuthHandler) GetProfile(c *gin.Context) {
	// Get user ID from JWT token (set by auth middleware)
	userID, exists := middleware.GetUserIDFromContext(c)
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{
			"error": "User not authenticated",
		})
		return
	}

	// Get user profile
	user, err := h.userService.GetProfile(userID)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{
			"error":   "User not found",
			"details": err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"user": user,
	})
}

// UpdateProfile handles PUT /api/auth/profile for updating user profile
func (h *AuthHandler) UpdateProfile(c *gin.Context) {
	// Get user ID from JWT token (set by auth middleware)
	userID, exists := middleware.GetUserIDFromContext(c)
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{
			"error": "User not authenticated",
		})
		return
	}

	var req services.UpdateProfileRequest

	// Bind JSON request to struct
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{
			"error":   "Invalid request format",
			"details": err.Error(),
		})
		return
	}

	// Update user profile
	user, err := h.userService.UpdateProfile(userID, req)
	if err != nil {
		if err.Error() == "invalid user ID" {
			c.JSON(http.StatusBadRequest, gin.H{
				"error": "Invalid user ID",
			})
			return
		}

		c.JSON(http.StatusInternalServerError, gin.H{
			"error":   "Failed to update profile",
			"details": err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"message": "Profile updated successfully",
		"user":    user,
	})
}

// Logout handles POST /api/auth/logout for user logout
// Note: Since we're using stateless JWT tokens, logout is handled client-side
// by removing the token. This endpoint is provided for consistency.
func (h *AuthHandler) Logout(c *gin.Context) {
	c.JSON(http.StatusOK, gin.H{
		"message": "Logout successful",
	})
}