package auth

import (
	"errors"
	"net/http"

	"github.com/gin-gonic/gin"

	"backend/internal/modules/users"
	"backend/internal/platform/middleware"
	"backend/internal/platform/security"
)

// customer cookie name/path are intentionally distinct from the admin ones
// (see admin_handler.go) so the two spaces never share a session cookie.
const (
	customerRefreshCookieName = "customer_refresh_token"
	customerRefreshCookiePath = "/api/auth/customer"
)

// CustomerHandler mirrors AdminHandler but issues/accepts only
// customer-audience tokens. Not mounted by main.go in this phase (no
// customer-facing module needs it yet) — it exists so the future
// cart/orders module can activate customer auth without touching the admin
// code path at all.
type CustomerHandler struct {
	service      *Service
	cookieSecure bool
}

func NewCustomerHandler(service *Service, cookieSecure bool) *CustomerHandler {
	return &CustomerHandler{service: service, cookieSecure: cookieSecure}
}

func (h *CustomerHandler) Login(c *gin.Context) {
	var req loginRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "validation error", "details": err.Error()})
		return
	}

	pair, user, err := h.service.Login(c.Request.Context(), security.AudienceCustomer, users.RoleCustomer, req.Email, req.Password)
	if err != nil {
		switch {
		case errors.Is(err, ErrInvalidCredentials), errors.Is(err, ErrAccountDisabled):
			c.JSON(http.StatusUnauthorized, gin.H{"error": "invalid credentials"})
		default:
			c.JSON(http.StatusInternalServerError, gin.H{"error": "login failed"})
		}
		return
	}

	h.setRefreshCookie(c, pair.RefreshToken)
	c.JSON(http.StatusOK, accessTokenResponse{
		AccessToken: pair.AccessToken,
		User:        &authUserResponse{ID: user.ID, Email: user.Email, Role: user.Role},
	})
}

func (h *CustomerHandler) Refresh(c *gin.Context) {
	token, err := c.Cookie(customerRefreshCookieName)
	if err != nil || token == "" {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "missing refresh token"})
		return
	}

	pair, err := h.service.Refresh(c.Request.Context(), security.AudienceCustomer, token)
	if err != nil {
		h.clearRefreshCookie(c)
		c.JSON(http.StatusUnauthorized, gin.H{"error": "invalid or expired refresh token"})
		return
	}

	h.setRefreshCookie(c, pair.RefreshToken)
	c.JSON(http.StatusOK, accessTokenResponse{AccessToken: pair.AccessToken})
}

func (h *CustomerHandler) Logout(c *gin.Context) {
	if token, err := c.Cookie(customerRefreshCookieName); err == nil && token != "" {
		_ = h.service.Logout(c.Request.Context(), security.AudienceCustomer, token)
	}
	h.clearRefreshCookie(c)
	c.JSON(http.StatusOK, gin.H{"message": "logged out"})
}

func (h *CustomerHandler) Me(c *gin.Context) {
	userID, ok := middleware.GetUserID(c)
	if !ok {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "unauthorized"})
		return
	}
	user, err := h.service.Me(c.Request.Context(), userID)
	if err != nil {
		if errors.Is(err, users.ErrNotFound) {
			c.JSON(http.StatusNotFound, gin.H{"error": "user not found"})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to load user"})
		return
	}
	c.JSON(http.StatusOK, authUserResponse{ID: user.ID, Email: user.Email, Role: user.Role})
}

func (h *CustomerHandler) setRefreshCookie(c *gin.Context, token string) {
	c.SetSameSite(http.SameSiteStrictMode)
	c.SetCookie(customerRefreshCookieName, token, int(h.service.RefreshTTL().Seconds()), customerRefreshCookiePath, "", h.cookieSecure, true)
}

func (h *CustomerHandler) clearRefreshCookie(c *gin.Context) {
	c.SetSameSite(http.SameSiteStrictMode)
	c.SetCookie(customerRefreshCookieName, "", -1, customerRefreshCookiePath, "", h.cookieSecure, true)
}