<template>
  <div class="shop-page">
    <!-- 导航栏 -->
    <nav class="navbar">
      <div class="nav-center">
        <h1 class="nav-title">积分商城</h1>
      </div>
      <div class="nav-right">
        <el-button 
          type="text" 
          @click="$router.push('/points')"
          class="points-btn"
        >
          <el-icon><Coin /></el-icon>
          {{ userPoints }}
        </el-button>
      </div>
    </nav>

    <!-- 搜索栏 -->
    <div class="search-section">
      <el-input
        v-model="searchKeyword"
        placeholder="搜索商品"
        class="search-input"
        @input="handleSearch"
      >
        <template #prefix>
          <el-icon><Search /></el-icon>
        </template>
      </el-input>
    </div>

    <!-- 分类筛选 -->
    <div class="category-section">
      <el-scrollbar>
        <div class="category-list">
          <div 
            v-for="category in categories" 
            :key="category.id"
            :class="['category-item', { active: selectedCategory === category.id }]"
            @click="selectCategory(category.id)"
          >
            <el-icon>{{ category.icon }}</el-icon>
            <span>{{ category.name }}</span>
          </div>
        </div>
      </el-scrollbar>
    </div>

    <!-- 商品列表 -->
    <div class="products-section">
      <div class="section-header">
        <h3>热门商品</h3>
        <el-dropdown @command="handleSort">
          <span class="sort-btn">
            {{ sortText }}
            <el-icon><ArrowDown /></el-icon>
          </span>
          <template #dropdown>
            <el-dropdown-menu>
              <el-dropdown-item command="default">默认排序</el-dropdown-item>
              <el-dropdown-item command="price_asc">价格从低到高</el-dropdown-item>
              <el-dropdown-item command="price_desc">价格从高到低</el-dropdown-item>
              <el-dropdown-item command="sales">销量优先</el-dropdown-item>
            </el-dropdown-menu>
          </template>
        </el-dropdown>
      </div>

      <div v-loading="loading" class="products-grid">
        <div 
          v-for="product in filteredProducts" 
          :key="product.id"
          class="product-card"
          @click="goToProduct(product.id)"
        >
          <div class="product-image">
            <img :src="product.image" :alt="product.name" />
            <div v-if="product.discount" class="discount-badge">
              {{ product.discount }}折
            </div>
          </div>
          <h4 class="product-name">{{ product.name }}</h4>
          <div class="product-price">
            <span class="current-price">
              <el-icon><Coin /></el-icon>
              {{ product.points }}
            </span>
            <span v-if="product.originalPoints" class="original-price">
              {{ product.originalPoints }}
            </span>
          </div>
        </div>
      </div>

      <!-- 空状态 -->
      <div v-if="!loading && filteredProducts.length === 0" class="empty-state">
        <el-icon size="60"><Box /></el-icon>
        <p>暂无商品</p>
      </div>

      <!-- 加载更多 -->
      <div v-if="hasMore" class="load-more">
        <el-button @click="loadMore" :loading="loadingMore">
          加载更多
        </el-button>
      </div>
    </div>

    <!-- 购物车悬浮按钮 -->
    <div class="cart-fab" @click="showCart = true">
      <el-badge :value="cartCount" :hidden="cartCount === 0">
        <el-icon size="24"><ShoppingCart /></el-icon>
      </el-badge>
    </div>

    <!-- 购物车抽屉 -->
    <el-drawer
      v-model="showCart"
      title="购物车"
      direction="rtl"
      size="80%"
    >
      <div class="cart-content">
        <div v-if="cartItems.length === 0" class="empty-cart">
          <el-icon size="60"><ShoppingCart /></el-icon>
          <p>购物车是空的</p>
        </div>
        <div v-else>
          <div v-for="item in cartItems" :key="item.id" class="cart-item">
            <img :src="item.image" :alt="item.name" class="item-image" />
            <div class="item-info">
              <h4>{{ item.name }}</h4>
              <p class="item-price">
                <el-icon><Coin /></el-icon>
                {{ item.points }}
              </p>
            </div>
            <div class="item-actions">
              <el-input-number
                v-model="item.quantity"
                :min="1"
                :max="item.stock"
                size="small"
                @change="updateCartItem(item)"
              />
              <el-button 
                type="danger" 
                size="small" 
                @click="removeFromCart(item.id)"
              >
                删除
              </el-button>
            </div>
          </div>
          <div class="cart-footer">
            <div class="total-points">
              总计：<el-icon><Coin /></el-icon>{{ totalPoints }}
            </div>
            <el-button 
              type="primary" 
              size="large"
              @click="checkout"
              :disabled="totalPoints > userPoints"
            >
              {{ totalPoints > userPoints ? '积分不足' : '立即兑换' }}
            </el-button>
          </div>
        </div>
      </div>
    </el-drawer>
  </div>
</template>

<script setup>
import { ref, reactive, computed, onMounted } from 'vue'
import { useRouter, useRoute } from 'vue-router'
import { useUserStore } from '@/stores/user'
import { ElMessage, ElMessageBox } from 'element-plus'
import { 
  ArrowLeft,
  Coin,
  Search,
  ArrowDown,
  Box,
  ShoppingCart
} from '@element-plus/icons-vue'
import api from '@/utils/api'
import { debounce } from 'lodash-es'

const router = useRouter()
const route = useRoute()
const userStore = useUserStore()

// 响应式数据
const loading = ref(false)
const loadingMore = ref(false)
const searchKeyword = ref('')
const selectedCategory = ref('all')
const sortBy = ref('default')
const products = ref([])
const page = ref(1)
const hasMore = ref(true)
const showCart = ref(false)
const cartItems = ref([])

// 用户积分
const userPoints = ref(0)

// 分类数据
const categories = ref([
  { id: 'all', name: '全部', icon: '🛍️' },
  { id: '数码产品', name: '数码产品', icon: '📱' },
  { id: '图书文具', name: '图书文具', icon: '📚' },
  { id: '生活用品', name: '生活用品', icon: '🏠' },
  { id: '食品饮料', name: '食品饮料', icon: '🍔' },
  { id: '服装配饰', name: '服装配饰', icon: '👕' },
  { id: '其他', name: '其他', icon: '📦' }
])

// 计算属性
const filteredProducts = computed(() => {
  let result = products.value
  
  // 分类筛选
  if (selectedCategory.value !== 'all') {
    result = result.filter(p => p.category === selectedCategory.value)
  }
  
  // 搜索筛选
  if (searchKeyword.value) {
    result = result.filter(p => 
      p.name.toLowerCase().includes(searchKeyword.value.toLowerCase()) ||
      p.description.toLowerCase().includes(searchKeyword.value.toLowerCase())
    )
  }
  
  // 排序
  switch (sortBy.value) {
    case 'price_asc':
      result.sort((a, b) => a.points - b.points)
      break
    case 'price_desc':
      result.sort((a, b) => b.points - a.points)
      break
    case 'sales':
      result.sort((a, b) => b.sales - a.sales)
      break
  }
  
  return result
})

const sortText = computed(() => {
  const sortMap = {
    default: '默认排序',
    price_asc: '价格从低到高',
    price_desc: '价格从高到低',
    sales: '销量优先'
  }
  return sortMap[sortBy.value]
})

const cartCount = computed(() => {
  return cartItems.value.reduce((sum, item) => sum + item.quantity, 0)
})

const totalPoints = computed(() => {
  return cartItems.value.reduce((sum, item) => sum + (item.points * item.quantity), 0)
})

// 方法
const selectCategory = (categoryId) => {
  selectedCategory.value = categoryId
}

const handleSort = (command) => {
  sortBy.value = command
}

const handleSearch = debounce(() => {
  // 搜索逻辑已在计算属性中处理
}, 300)

const goToProduct = (productId) => {
  router.push(`/product/${productId}`)
}

const addToCart = (product) => {
  const existingItem = cartItems.value.find(item => item.id === product.id)
  
  if (existingItem) {
    if (existingItem.quantity < product.stock) {
      existingItem.quantity++
      ElMessage.success('已添加到购物车')
    } else {
      ElMessage.warning('库存不足')
    }
  } else {
    cartItems.value.push({
      ...product,
      quantity: 1
    })
    ElMessage.success('已添加到购物车')
  }
}

const updateCartItem = (item) => {
  // 数量更新逻辑
}

const removeFromCart = (productId) => {
  const index = cartItems.value.findIndex(item => item.id === productId)
  if (index > -1) {
    cartItems.value.splice(index, 1)
    ElMessage.success('已从购物车移除')
  }
}

const checkout = async () => {
  try {
    await ElMessageBox.confirm(
      `确定要花费 ${totalPoints.value} 积分兑换这些商品吗？`,
      '确认兑换',
      {
        confirmButtonText: '确定',
        cancelButtonText: '取消',
        type: 'warning'
      }
    )
    
    const orderData = {
      items: cartItems.value.map(item => ({
        productId: item.id,
        quantity: item.quantity,
        points: item.points
      })),
      totalPoints: totalPoints.value
    }
    
    await api.post('/orders', orderData)
    
    // 清空购物车
    cartItems.value = []
    showCart.value = false
    
    // 更新用户积分
    userPoints.value -= totalPoints.value
    
    ElMessage.success('兑换成功！')
    router.push('/orders')
  } catch (error) {
    if (error !== 'cancel') {
      ElMessage.error('兑换失败，请重试')
    }
  }
}

const getProducts = async (isLoadMore = false) => {
  try {
    if (!isLoadMore) {
      loading.value = true
      page.value = 1
    } else {
      loadingMore.value = true
    }
    
    const {data} = await api.get('/products', {
      params: {
        page: page.value,
        limit: 20,
        category: selectedCategory.value === 'all' ? '' : selectedCategory.value,
        keyword: searchKeyword.value,
        sort: sortBy.value
      }
    })
    console.log(data,'response');
    
    if (isLoadMore) {
      products.value.push(...data.data.products)
    } else {
      products.value = data.data.products
    }
    
    hasMore.value = data.data.hasMore
    page.value++
  } catch (error) {
    ElMessage.error('获取商品列表失败')
  } finally {
    loading.value = false
    loadingMore.value = false
  }
}

const loadMore = () => {
  getProducts(true)
}

const getUserPoints = async () => {
  try {
    const {data} = await api.get('/user/points')
    console.log(data,'points');
    
    userPoints.value = data.points
  } catch (error) {
    console.error('获取用户积分失败:', error)
  }
}

const truncateText = (text, maxLength) => {
  if (text.length <= maxLength) return text
  return text.substring(0, maxLength) + '...'
}

// 生命周期
onMounted(() => {
  // 检查URL参数中是否有分类
  const categoryFromQuery = route.query.category
  if (categoryFromQuery && categories.value.some(cat => cat.id === categoryFromQuery)) {
    selectedCategory.value = categoryFromQuery
  }
  
  getProducts()
  getUserPoints()
})
</script>

<style scoped>
.shop-page {
  min-height: 100vh;
  background-color: #f5f5f5;
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  height: 56px;
  background: white;
  border-bottom: 1px solid #eee;
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-left,
.nav-right {
  flex: 1;
}

.nav-right {
  display: flex;
  justify-content: flex-end;
}

.back-btn,
.points-btn {
  color: #409eff;
  font-size: 14px;
}

.nav-title {
  margin: 0;
  font-size: 18px;
  font-weight: 500;
  color: #333;
}

.search-section {
  padding: 16px;
  background: white;
  border-bottom: 1px solid #eee;
}

.search-input {
  width: 100%;
}

.category-section {
  background: white;
  padding: 16px 0;
  border-bottom: 1px solid #eee;
}

.category-list {
  display: flex;
  gap: 16px;
  padding: 0 16px;
  white-space: nowrap;
}

.category-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 8px 12px;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s;
  min-width: 60px;
}

.category-item:hover {
  background: #f0f9ff;
}

.category-item.active {
  background: #409eff;
  color: white;
}

.category-item span {
  font-size: 12px;
}

.products-section {
  padding: 16px;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.section-header h3 {
  margin: 0;
  font-size: 16px;
  color: #333;
}

.sort-btn {
  display: flex;
  align-items: center;
  gap: 4px;
  color: #666;
  font-size: 14px;
  cursor: pointer;
}

.products-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-bottom: 20px;
}

.product-card {
  width: 163px;
  height: 217px;
  background: white;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  cursor: pointer;
  transition: all 0.3s;
  display: flex;
  flex-direction: column;
}

.product-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);
}

.product-image {
  position: relative;
  width: 100%;
  height: 163px;
  overflow: hidden;
  flex-shrink: 0;
}

.product-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.discount-badge {
  position: absolute;
  top: 8px;
  right: 8px;
  background: #ff4757;
  color: white;
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 12px;
}

.product-name {
  margin: 8px 8px 4px;
  font-size: 14px;
  font-weight: 500;
  color: #333;
  line-height: 1.4;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.product-price {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 8px;
  padding-bottom: 8px;
}

.current-price {
  display: flex;
  align-items: center;
  gap: 2px;
  color: #ff6b35;
  font-weight: 600;
  font-size: 14px;
}

.original-price {
  color: #999;
  font-size: 12px;
  text-decoration: line-through;
}

.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: #999;
}

.load-more {
  text-align: center;
  padding: 20px;
}

.cart-fab {
  position: fixed;
  bottom: 80px;
  right: 20px;
  width: 56px;
  height: 56px;
  background: #409eff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(64, 158, 255, 0.4);
  z-index: 1000;
}

.cart-content {
  height: 100%;
  display: flex;
  flex-direction: column;
}

.empty-cart {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: #999;
}

.cart-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 0;
  border-bottom: 1px solid #eee;
}

.item-image {
  width: 60px;
  height: 60px;
  border-radius: 8px;
  object-fit: cover;
}

.item-info {
  flex: 1;
}

.item-info h4 {
  margin: 0 0 4px 0;
  font-size: 14px;
  color: #333;
}

.item-price {
  display: flex;
  align-items: center;
  gap: 2px;
  color: #ff6b35;
  font-weight: 600;
  margin: 0;
}

.item-actions {
  display: flex;
  flex-direction: column;
  gap: 8px;
  align-items: flex-end;
}

.cart-footer {
  margin-top: auto;
  padding: 20px 0;
  border-top: 1px solid #eee;
}

.total-points {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 18px;
  font-weight: 600;
  color: #ff6b35;
  margin-bottom: 16px;
}

/* 响应式设计 */
@media (max-width: 480px) {
  .products-grid {
    grid-template-columns: repeat(2, 1fr);
    justify-items: center;
  }
  
  .product-card {
    width: calc(50vw - 24px);
    max-width: 163px;
  }
}
</style>