class CartStore {
  constructor() {
    this.storageKey = 'shopping_cart';
    this.currentShopId = ''; // 当前店铺ID
  }
  
  // 设置当前店铺ID
  setShopId() {
    this.currentShopId = uni.getStorageSync('shop_id');
  }
  
  // 获取购物车数据
  getCart() {
    try {
      const cartStr = uni.getStorageSync(this.storageKey);
      if (!cartStr) {
        return {};
      }
      return JSON.parse(cartStr);
    } catch (e) {
      console.error('获取购物车失败:', e);
      return {};
    }
  }
  
  // 保存购物车数据
  saveCart(cartData) {
    try {
      uni.setStorageSync(this.storageKey, JSON.stringify(cartData));
    } catch (e) {
      console.error('保存购物车失败:', e);
    }
  }
  
  // 获取指定店铺的购物车
  getShopCart(shopId = null) {
    const cart = this.getCart();
    const targetShopId = shopId || this.currentShopId;
    if (!targetShopId) return null;
    
    if (!cart[targetShopId]) {
      cart[targetShopId] = {
        total_price: 0,
        total_num: 0,
        goods_list: [],
        shop_info: null
      };
      this.saveCart(cart);
    }
    
    return cart[targetShopId];
  }
  
  // 添加商品到购物车
  addToCart(goods, goodsSpec = [], quantity = 1) {
    if (!this.currentShopId) {
      console.error('未设置店铺ID');
      return false;
    }
    
    const cart = this.getCart();
    if (!cart[this.currentShopId]) {
      cart[this.currentShopId] = {
        total_price: 0,
        total_num: 0,
        goods_list: [],
        shop_info: null
      };
    }
    
    const shopCart = cart[this.currentShopId];
    
    // 生成商品唯一标识（结合商品ID和规格ID）
    const specIdStr = goodsSpec.length > 0 
      ? goodsSpec.map(spec => `${spec.id}_${spec.number}`).sort().join('_')
      : 'no_spec';
    
    const goodsKey = `${goods.goods_id}_${specIdStr}`;
    
    // 查找是否已存在相同商品
    const existingIndex = shopCart.goods_list.findIndex(
      item => this.getGoodsKey(item) === goodsKey
    );
    
    if (existingIndex > -1) {
      // 已存在，更新数量
      shopCart.goods_list[existingIndex].goods_number += quantity;
    } else {
      // 新商品，添加到列表
      shopCart.goods_list.push({
        goods_id: goods.goods_id,
        goods_name: goods.goods_name || '',
        goods_image: goods.goods_image || '',
        price: this.calculatePrice(goods, goodsSpec),
        goods_number: quantity,
        goods_attr: this.getSpecAttr(goodsSpec),
        goods_spec: goodsSpec,
        category_id: goods.category_id,
        goods_desc: goods.goods_desc || '',
        spec_type: goods.spec_type || 1
      });
    }
    
    // 重新计算总计
    this.calculateTotals(shopCart);
    
    // 保存到本地存储
    this.saveCart(cart);
    
    return true;
  }
  
  // 更新商品数量
  updateQuantity(goodsId, goodsSpec = [], quantity) {
    if (!this.currentShopId) return false;
    
    const cart = this.getCart();
    const shopCart = cart[this.currentShopId];
    if (!shopCart) return false;
    
    const specIdStr = goodsSpec.length > 0 
      ? goodsSpec.map(spec => `${spec.id}_${spec.number}`).sort().join('_')
      : 'no_spec';
    
    const goodsKey = `${goodsId}_${specIdStr}`;
    
    const goodsIndex = shopCart.goods_list.findIndex(
      item => this.getGoodsKey(item) === goodsKey
    );
    
    if (goodsIndex > -1) {
      if (quantity <= 0) {
        // 数量为0，移除商品
        shopCart.goods_list.splice(goodsIndex, 1);
      } else {
        // 更新数量
        shopCart.goods_list[goodsIndex].goods_number = quantity;
      }
      
      // 重新计算总计
      this.calculateTotals(shopCart);
      this.saveCart(cart);
      return true;
    }
    
    return false;
  }
  
  // 从购物车移除商品
  removeFromCart(goodsId, goodsSpec = []) {
    return this.updateQuantity(goodsId, goodsSpec, 0);
  }
  
  // 清空当前店铺购物车
  clearCurrentShopCart() {
    if (!this.currentShopId) return false;
    
    const cart = this.getCart();
    cart[this.currentShopId] = {
      total_price: 0,
      total_num: 0,
      goods_list: []
    };
    
    this.saveCart(cart);
    return true;
  }
  
  // 计算商品价格
  calculatePrice(goods, goodsSpec = []) {
    let price = goods.seckill_money > 0 ? Number(goods.seckill_money) : Number(goods.price);
    // 如果有规格，累加规格价格
    if (goodsSpec.length > 0) {
      goodsSpec.forEach(spec => {
        // 这里需要根据实际情况获取规格价格
        // 假设规格信息中包含价格
        if (spec.price) {
          price += Number(spec.price) * (spec.number || 1);
        }
      });
    }
    
    return Number(price).toFixed(2);
  }
  
  // 获取规格描述
  getSpecAttr(goodsSpec = []) {
    if (goodsSpec.length === 0) return '';
    return goodsSpec.map(spec => spec.name || '').join('、');
  }
  
  // 生成商品唯一键
  getGoodsKey(goodsItem) {
    const specIdStr = goodsItem.goods_spec && goodsItem.goods_spec.length > 0
      ? goodsItem.goods_spec.map(spec => `${spec.id}_${spec.number}`).sort().join('_')
      : 'no_spec';
    
    return `${goodsItem.goods_id}_${specIdStr}`;
  }
  
  // 计算购物车总计
  calculateTotals(shopCart) {
    let total_price = 0;
    let total_num = 0;
    
    shopCart.goods_list.forEach(item => {
      total_price += item.price * item.goods_number;
      total_num += item.goods_number;
    });
    
    shopCart.total_price = parseFloat(total_price.toFixed(2));
    shopCart.total_num = total_num;
  }
  
  // 获取商品在购物车中的数量
  getGoodsQuantity(goodsId, goodsSpec = []) {
    if (!this.currentShopId) return 0;
    
    const cart = this.getCart();
    const shopCart = cart[this.currentShopId];
    if (!shopCart) return 0;
    
    const specIdStr = goodsSpec.length > 0 
      ? goodsSpec.map(spec => `${spec.id}_${spec.number}`).sort().join('_')
      : 'no_spec';
    
    const goodsKey = `${goodsId}_${specIdStr}`;
    
    const goodsItem = shopCart.goods_list.find(
      item => this.getGoodsKey(item) === goodsKey
    );
    
    return goodsItem ? goodsItem.goods_number : 0;
  }
  
  // 获取指定店铺购物车中某商品的总数量（所有规格合并）
  getGoodsTotalQuantity(goodsId) {
    if (!this.currentShopId) return 0;
    
    const cart = this.getCart();
    const shopCart = cart[this.currentShopId];
    if (!shopCart) return 0;
    
    let total = 0;
    shopCart.goods_list.forEach(item => {
      if (item.goods_id === goodsId) {
        total += item.goods_number;
      }
    });
    
    return total;
  }
}

// 创建单例
const cartStore = new CartStore();
export default cartStore;