package handler

import (
	"dianshang/internal/service"
	"dianshang/pkg/response"
	"dianshang/pkg/utils"
	"fmt"
	"net/http"

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

// CartHandler 购物车处理器
type CartHandler struct {
	cartService *service.CartService
}

// NewCartHandler 创建购物车处理器
func NewCartHandler(cartService *service.CartService) *CartHandler {
	return &CartHandler{
		cartService: cartService,
	}
}

// GetCart 获取购物车
func (h *CartHandler) GetCart(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		response.Unauthorized(c)
		return
	}

	cart, err := h.cartService.GetCart(userID.(uint))
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	// 计算购物车统计信息
	count, _ := h.cartService.GetCartCount(userID.(uint))
	total, _ := h.cartService.GetCartTotal(userID.(uint))

	result := map[string]interface{}{
		"items": cart,
		"count": count,
		"total": fmt.Sprintf("%.2f", total),
	}

	response.Success(c, result)
}

// AddToCart 添加到购物车
func (h *CartHandler) AddToCart(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		response.Unauthorized(c)
		return
	}

	var req struct {
		ProductID uint `json:"product_id" binding:"required"`
		SKUID     uint `json:"sku_id"`
		Quantity  uint `json:"quantity" binding:"required,min=1"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误: "+err.Error())
		return
	}

	if err := h.cartService.AddToCart(userID.(uint), req.ProductID, req.SKUID, int(req.Quantity)); err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, nil)
}

// UpdateCartItem 更新购物车项
func (h *CartHandler) UpdateCartItem(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		response.Unauthorized(c)
		return
	}

	productIDStr := c.Param("product_id")
	productID := utils.StringToUint(productIDStr)
	if productID == 0 {
		response.BadRequest(c, "无效的产品ID")
		return
	}

	var req struct {
		Quantity uint `json:"quantity" binding:"required"`
		SKUID    uint `json:"sku_id"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误: "+err.Error())
		return
	}

	// 添加调试日志
	fmt.Printf("🔍 [UpdateCartItem] 用户ID: %d, 产品ID: %d, SKU ID: %d, 数量: %d\n", 
		userID.(uint), productID, req.SKUID, req.Quantity)

	if err := h.cartService.UpdateCartItemBySKU(userID.(uint), productID, req.SKUID, int(req.Quantity)); err != nil {
		fmt.Printf("❌ [UpdateCartItem] 服务层错误: %v\n", err)
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, nil)
}

// RemoveFromCart 从购物车移除
func (h *CartHandler) RemoveFromCart(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		response.Unauthorized(c)
		return
	}

	productIDStr := c.Param("product_id")
	productID := utils.StringToUint(productIDStr)
	if productID == 0 {
		response.BadRequest(c, "无效的产品ID")
		return
	}

	// 从查询参数获取sku_id
	skuIDStr := c.Query("sku_id")
	skuID := utils.StringToUint(skuIDStr)

	if err := h.cartService.RemoveFromCartBySKU(userID.(uint), productID, skuID); err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, nil)
}

// ClearCart 清空购物车
func (h *CartHandler) ClearCart(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		response.Unauthorized(c)
		return
	}

	if err := h.cartService.ClearCart(userID.(uint)); err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, nil)
}

// GetCartCount 获取购物车商品数量
func (h *CartHandler) GetCartCount(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		response.Unauthorized(c)
		return
	}

	count, err := h.cartService.GetCartCount(userID.(uint))
	if err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, map[string]interface{}{"count": count})
}

// SelectCartItem 选择/取消选择购物车项
func (h *CartHandler) SelectCartItem(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		response.Unauthorized(c)
		return
	}

	cartIDStr := c.Param("id")
	cartID := utils.StringToUint(cartIDStr)
	if cartID == 0 {
		response.BadRequest(c, "无效的购物车ID")
		return
	}

	var req struct {
		Selected bool `json:"selected"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误: "+err.Error())
		return
	}

	if err := h.cartService.SelectCartItem(userID.(uint), cartID, req.Selected); err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, nil)
}

// SelectAllCartItems 全选/取消全选购物车
func (h *CartHandler) SelectAllCartItems(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		response.Unauthorized(c)
		return
	}

	var req struct {
		Selected bool `json:"selected"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误: "+err.Error())
		return
	}

	if err := h.cartService.SelectAllCartItems(userID.(uint), req.Selected); err != nil {
		response.ErrorWithMessage(c, response.ERROR, err.Error())
		return
	}

	response.Success(c, nil)
}

// BatchAddToCartRequest 批量添加到购物车请求
type BatchAddToCartRequest struct {
	Items []struct {
		ProductID uint `json:"product_id" binding:"required"`
		SKUID     uint `json:"sku_id"`
		Quantity  int  `json:"quantity" binding:"required,min=1"`
	} `json:"items" binding:"required"`
}

// BatchAddToCart 批量添加到购物车
func (h *CartHandler) BatchAddToCart(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
		return
	}

	var req BatchAddToCartRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// 转换请求参数类型
	items := make([]struct {
		ProductID uint `json:"product_id"`
		SKUID     uint `json:"sku_id"`
		Quantity  int  `json:"quantity"`
	}, len(req.Items))
	
	for i, item := range req.Items {
		items[i] = struct {
			ProductID uint `json:"product_id"`
			SKUID     uint `json:"sku_id"`
			Quantity  int  `json:"quantity"`
		}{
			ProductID: item.ProductID,
			SKUID:     item.SKUID,
			Quantity:  item.Quantity,
		}
	}
	
	err := h.cartService.BatchAddToCart(userID.(uint), items)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "批量添加成功"})
}

// BatchRemoveFromCartRequest 批量移除购物车请求
type BatchRemoveFromCartRequest struct {
	CartIDs []uint `json:"cart_ids" binding:"required"`
}

// BatchRemoveFromCart 批量从购物车移除
func (h *CartHandler) BatchRemoveFromCart(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
		return
	}

	var req BatchRemoveFromCartRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	err := h.cartService.BatchRemoveFromCart(userID.(uint), req.CartIDs)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "批量删除成功"})
}

// BatchUpdateCartItemsRequest 批量更新购物车项请求
type BatchUpdateCartItemsRequest struct {
	Updates []struct {
		CartID   uint `json:"cart_id" binding:"required"`
		Quantity int  `json:"quantity" binding:"min=0"`
	} `json:"updates" binding:"required"`
}

// BatchUpdateCartItems 批量更新购物车项
func (h *CartHandler) BatchUpdateCartItems(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
		return
	}

	var req BatchUpdateCartItemsRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// 转换请求参数类型
	updates := make([]struct {
		CartID   uint `json:"cart_id"`
		Quantity int  `json:"quantity"`
	}, len(req.Updates))
	
	for i, update := range req.Updates {
		updates[i] = struct {
			CartID   uint `json:"cart_id"`
			Quantity int  `json:"quantity"`
		}{
			CartID:   update.CartID,
			Quantity: update.Quantity,
		}
	}
	
	err := h.cartService.BatchUpdateCartItems(userID.(uint), updates)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "批量更新成功"})
}

// GetCartWithDetails 获取购物车详细信息
func (h *CartHandler) GetCartWithDetails(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
		return
	}

	details, err := h.cartService.GetCartWithDetails(userID.(uint))
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"code": 200,
		"data": details,
	})
}

// ValidateCartItems 验证购物车商品有效性
func (h *CartHandler) ValidateCartItems(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
		return
	}

	validation, err := h.cartService.ValidateCartItems(userID.(uint))
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"code": 200,
		"data": validation,
	})
}

// CleanInvalidCartItems 清理无效的购物车项
func (h *CartHandler) CleanInvalidCartItems(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
		return
	}

	err := h.cartService.CleanInvalidCartItems(userID.(uint))
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "清理完成"})
}

// GetCartSummary 获取购物车摘要信息
func (h *CartHandler) GetCartSummary(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
		return
	}

	summary, err := h.cartService.GetCartSummary(userID.(uint))
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"code": 200,
		"data": summary,
	})
}

// MergeCartRequest 合并购物车请求
type MergeCartRequest struct {
	GuestCartItems []struct {
		ProductID uint `json:"product_id" binding:"required"`
		SKUID     uint `json:"sku_id"`
		Quantity  int  `json:"quantity" binding:"required,min=1"`
	} `json:"guest_cart_items" binding:"required"`
}

// MergeCart 合并购物车
func (h *CartHandler) MergeCart(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
		return
	}

	var req MergeCartRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// 转换请求参数类型
	guestCartItems := make([]struct {
		ProductID uint `json:"product_id"`
		SKUID     uint `json:"sku_id"`
		Quantity  int  `json:"quantity"`
	}, len(req.GuestCartItems))
	
	for i, item := range req.GuestCartItems {
		guestCartItems[i] = struct {
			ProductID uint `json:"product_id"`
			SKUID     uint `json:"sku_id"`
			Quantity  int  `json:"quantity"`
		}{
			ProductID: item.ProductID,
			SKUID:     item.SKUID,
			Quantity:  item.Quantity,
		}
	}
	
	err := h.cartService.MergeCart(userID.(uint), guestCartItems)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "购物车合并成功"})
}

// GetSelectedCartItems 获取选中的购物车项
func (h *CartHandler) GetSelectedCartItems(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
		return
	}

	items, err := h.cartService.GetSelectedCartItems(userID.(uint))
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"code": 200,
		"data": items,
	})
}

// CalculateCartDiscountRequest 计算购物车优惠请求
type CalculateCartDiscountRequest struct {
	CouponID uint `json:"coupon_id"`
}

// CalculateCartDiscount 计算购物车优惠
func (h *CartHandler) CalculateCartDiscount(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
		return
	}

	var req CalculateCartDiscountRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	discount, err := h.cartService.CalculateCartDiscount(userID.(uint), req.CouponID)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"code": 200,
		"data": discount,
	})
}