import React, { useState, useEffect, useCallback } from "react";
import {
  View,
  Text,
  StyleSheet,
  FlatList,
  Image,
  TouchableOpacity,
  TextInput,
  SafeAreaView,
  StatusBar,
  ActivityIndicator,
  KeyboardAvoidingView,
  Platform,
  Keyboard,
  ScrollView,
} from "react-native";
import Ionicons from "@expo/vector-icons/Ionicons";
import { useNavigation, useRoute } from "@react-navigation/native";
import { NativeStackNavigationProp } from "@react-navigation/native-stack";
import { RouteProp } from "@react-navigation/native";
import {
  productApi,
  ProductParams,
  type Product,
} from "../services/api/productApi";
import { useTranslation } from 'react-i18next';

// 图标组件 - 使用React.memo优化渲染
const IconComponent = React.memo(
  ({ name, size, color }: { name: string; size: number; color: string }) => {
    const Icon = Ionicons as any;
    return <Icon name={name} size={size} color={color} />;
  }
);

// 路由参数类型
type SearchResultRouteParams = {
  keyword: string;
};

// 产品项组件 - 使用React.memo优化渲染
const ProductItem = React.memo(
  ({
    product,
    onPress,
    t,
  }: {
    product: Product;
    onPress: (product: Product) => void;
    t: any;
  }) => (
    <TouchableOpacity
      style={styles.productCard}
      onPress={() => onPress(product)}
      activeOpacity={0.7}
    >
      <View style={styles.productImageContainer}>
        {product.product_image_urls[0] ? (
          <Image
            source={{ uri: product.product_image_urls[0] }}
            style={styles.productImage}
            resizeMode="cover"
          />
        ) : (
          <Text style={styles.placeholderText}>product picture</Text>
        )}
      </View>
      {/* 价格 */}
      <View style={styles.productInfo}>
        <Text style={styles.productPrice}>
          {product?.min_price?.toFixed(2)}
        </Text>
        {/* 产品标题 */}
        <Text style={styles.productTitle} numberOfLines={2}>
          {product.subject}
        </Text>
        {/* 销售量 */}
        <Text style={styles.productSales}>
          {t('monthlySales')}: {product.sold_out}
        </Text>
      </View>
    </TouchableOpacity>
  )
);

export const SearchResultScreen = () => {
  const { t } = useTranslation();
  const navigation = useNavigation<NativeStackNavigationProp<any>>();
  const route =
    useRoute<RouteProp<Record<string, SearchResultRouteParams>, string>>();
  const [searchText, setSearchText] = useState("");
  const [products, setProducts] = useState<Product[]>([]);
  const [loading, setLoading] = useState(true);
  const [hasMore, setHasMore] = useState(true);
  const [loadingMore, setLoadingMore] = useState(false);
  const [minPrice, setMinPrice] = useState<string>("");
  const [maxPrice, setMaxPrice] = useState<string>("");
  const [isFilterVisible, setIsFilterVisible] = useState(false);
  const [sortOrder, setSortOrder] = useState<"asc" | "desc" | null>(null);
  const [sortField, setSortField] = useState<"price" | "time">("price");
  const [showBackToTop, setShowBackToTop] = useState(false);
  const flatListRef = React.useRef<FlatList>(null);

  const [searchParams, setSearchParams] = useState<ProductParams>({
    keyword: route.params?.keyword || "",
    page: 1,
    page_size: 20,
    sort_order: "desc",
    max_price: null,
    min_price: null,
    category_id: null,
    sort_by: "create_date",
  });

  // 初始化搜索关键字
  useEffect(() => {
    if (route.params?.keyword) {
      setSearchText(route.params.keyword);
      const newParams = {
        ...searchParams,
        keyword: route.params.keyword,
      };
      setSearchParams(newParams);
      searchProducts(newParams);
    }
  }, [route.params?.keyword]);

  // 搜索产品的API调用
  const searchProducts = useCallback(
    async (params: ProductParams, isLoadMore = false) => {
      if (!isLoadMore) setLoading(true);
      try {
        const res = await productApi.getSearchProducts(params);
        if (isLoadMore) {
          setProducts((prev) => [...prev, ...res.products]);
        } else {
          setProducts(res.products);
        }
        // 如果返回的数据少于页面大小，说明没有更多数据了
        setHasMore(res.products.length === params.page_size);
      } catch (error) {
        console.error("Error searching products:", error);
      } finally {
        setLoading(false);
        setLoadingMore(false);
      }
    },
    []
  );

  // 处理搜索提交
  const handleSearch = useCallback(() => {
    if (searchText.trim()) {
      // 重置排序状态
      setSortField("price");
      setSortOrder(null);
      
      const newParams = {
        ...searchParams,
        keyword: searchText.trim(),
        page: 1, // 重置到第一页
      };
      setSearchParams(newParams);
      searchProducts(newParams);
    }
  }, [searchText, searchParams, searchProducts]);

  // 处理价格筛选
  const handlePriceFilter = useCallback(() => {
    Keyboard.dismiss();
    const newParams = { ...searchParams };

    if (minPrice.trim()) {
      newParams.min_price = parseFloat(minPrice);
    } else {
      newParams.min_price = null;
    }

    if (maxPrice.trim()) {
      newParams.max_price = parseFloat(maxPrice);
    } else {
      newParams.max_price = null;
    }

    newParams.page = 1; // 重置到第一页
    setSearchParams(newParams);
    searchProducts(newParams);
    console.log(newParams);
  }, [minPrice, maxPrice, searchParams, searchProducts]);

  // 重置价格筛选
  const resetPriceFilter = useCallback(() => {
    setMinPrice("");
    setMaxPrice("");
    const newParams = {
      ...searchParams,
      min_price: null,
      max_price: null,
      page: 1,
    };
    setSearchParams(newParams);
    searchProducts(newParams);
  }, [searchParams, searchProducts]);

  // 切换筛选器显示状态
  const toggleFilter = useCallback(() => {
    setIsFilterVisible(!isFilterVisible);
  }, [isFilterVisible]);

  // 处理点击产品
  const handleProductPress = useCallback(
    (product: Product) => {
      // 导航到产品详情页，并传递产品信息
      navigation.navigate("ProductDetail", {
        offer_id: product.offer_id,
        searchKeyword: searchText,
        price: product.min_price,
      });
    },
    [navigation, searchText]
  );

  // 返回上一页
  const goBack = useCallback(() => {
    navigation.goBack();
  }, [navigation]);

  // 渲染列表为空时的组件
  const renderEmptyList = useCallback(
    () => (
      <View style={styles.emptyContainer}>
        <IconComponent name="search-outline" size={48} color="#ccc" />
        <Text style={styles.emptyText}>
          {t('noResults')} "{searchText}"
        </Text>
        <Text style={styles.emptySubtext}>
          {t('tryDifferentKeywords')}
        </Text>
      </View>
    ),
    [searchText, t]
  );

  // 渲染产品项
  const renderProductItem = useCallback(
    ({ item }: { item: Product }) => (
      <ProductItem product={item} onPress={handleProductPress} t={t} />
    ),
    [handleProductPress, t]
  );

  // 处理排序
  const handleSort = useCallback(
    (field: "price" | "time", order: "asc" | "desc") => {
      setSortField(field);
      setSortOrder(order);

      // 本地排序，不发送API请求
      setProducts((prevProducts) => {
        const sortedProducts = [...prevProducts];

        if (field === "price") {
          sortedProducts.sort((a, b) => {
            const priceA = a.min_price || 0;
            const priceB = b.min_price || 0;
            return order === "asc" ? priceA - priceB : priceB - priceA;
          });
        } else if (field === "time") {
          sortedProducts.sort((a, b) => {
            // 假设产品有create_time字段，如果没有可以使用其他时间相关字段
            const timeA = new Date(a.create_date || 0).getTime();
            const timeB = new Date(b.create_date || 0).getTime();
            return order === "asc" ? timeA - timeB : timeB - timeA;
          });
        }

        return sortedProducts;
      });
    },
    []
  );

  // 处理加载更多
  const handleLoadMore = useCallback(() => {
    if (loading || !hasMore || loadingMore) return;

    setLoadingMore(true);

    const newParams = {
      ...searchParams,
      page: searchParams.page + 1,
    };
    setSearchParams(newParams);
    searchProducts(newParams, true);
  }, [loading, hasMore, loadingMore, searchParams, searchProducts]);

  // 渲染底部加载指示器
  const renderFooter = useCallback(() => {
    if (!hasMore)
      return (
        <View style={styles.footerContainer}>
          <Text style={styles.footerText}>{t('noMoreData')}</Text>
        </View>
      );

    if (loadingMore)
      return (
        <View style={styles.footerContainer}>
          <ActivityIndicator size="small" color="#0066FF" />
          <Text style={styles.footerText}>{t('loadingMore')}</Text>
        </View>
      );

    return <View style={styles.footerSpace} />;
  }, [loadingMore, hasMore, t]);

  // 处理滚动事件
  const handleScroll = useCallback((event: any) => {
    const offsetY = event.nativeEvent.contentOffset.y;
    // 当滚动超过屏幕高度的一半时显示回到顶部按钮
    setShowBackToTop(offsetY > 300);
  }, []);

  // 回到顶部
  const scrollToTop = useCallback(() => {
    flatListRef.current?.scrollToOffset({ offset: 0, animated: true });
  }, []);

  return (
    <SafeAreaView style={styles.safeArea}>
      <StatusBar barStyle="dark-content" backgroundColor="#fff" />
      <KeyboardAvoidingView
        behavior={Platform.OS === "ios" ? "padding" : "height"}
        style={styles.container}
      >
        {/* 搜索栏 */}
        <View style={styles.searchHeader}>
          <TouchableOpacity style={styles.backButton} onPress={goBack}>
            <IconComponent name="arrow-back" size={24} color="#333" />
          </TouchableOpacity>
          <View style={styles.searchBar}>
            <IconComponent name="search-outline" size={20} color="#999" />
            <TextInput
              style={styles.searchInput}
              placeholder={t('searchProducts')}
              placeholderTextColor="#999"
              value={searchText}
              onChangeText={setSearchText}
              returnKeyType="search"
              onSubmitEditing={handleSearch}
            />
            {searchText.length > 0 && (
              <TouchableOpacity onPress={() => setSearchText("")}>
                <IconComponent name="close-circle" size={20} color="#999" />
              </TouchableOpacity>
            )}
          </View>
          <TouchableOpacity style={styles.filterButton} onPress={toggleFilter}>
            <IconComponent
              name={isFilterVisible ? "options" : "options-outline"}
              size={24}
              color="#333"
            />
          </TouchableOpacity>
        </View>

        {/* 搜索结果 */}
        <View style={styles.resultsContainer}>
          {/* 价格筛选器 */}
          {isFilterVisible && (
            <View style={styles.filterContainer}>
              <View style={styles.priceFilterRow}>
                <Text style={styles.filterLabel}>{t('priceRange')}：</Text>
                <View style={styles.priceInputContainer}>
                  <TextInput
                    style={styles.priceInput}
                    placeholder={t('minPrice')}
                    placeholderTextColor="#999"
                    value={minPrice}
                    onChangeText={setMinPrice}
                    keyboardType="numeric"
                    returnKeyType="done"
                  />
                  <Text style={styles.priceDivider}>-</Text>
                  <TextInput
                    style={styles.priceInput}
                    placeholder={t('maxPrice')}
                    placeholderTextColor="#999"
                    value={maxPrice}
                    onChangeText={setMaxPrice}
                    keyboardType="numeric"
                    returnKeyType="done"
                  />
                </View>
              </View>
              <View style={styles.filterButtons}>
                <TouchableOpacity
                  style={styles.resetButton}
                  onPress={resetPriceFilter}
                >
                  <Text style={styles.resetButtonText}>{t('reset')}</Text>
                </TouchableOpacity>
                <TouchableOpacity
                  style={styles.applyButton}
                  onPress={handlePriceFilter}
                >
                  <Text style={styles.applyButtonText}>{t('apply')}</Text>
                </TouchableOpacity>
              </View>
            </View>
          )}

          {/* 搜索结果标题栏和排序选项 */}
          <View style={styles.resultsHeader}>
            <ScrollView
              horizontal
              showsHorizontalScrollIndicator={false}
              style={styles.sortScrollView}
            >
              <View style={styles.sortGroup}>
                <Text style={styles.sortLabel}>{t('price')}:</Text>
                <View style={styles.sortButtons}>
                  <TouchableOpacity
                    style={[
                      styles.sortButton,
                      sortField === "price" && sortOrder === "asc"
                        ? styles.sortButtonActive
                        : {},
                    ]}
                    onPress={() => handleSort("price", "asc")}
                  >
                    <Text
                      style={[
                        styles.sortButtonText,
                        sortField === "price" && sortOrder === "asc"
                          ? styles.sortButtonTextActive
                          : {},
                      ]}
                    >
                      {t('lowToHigh')}
                    </Text>
                    {sortField === "price" && sortOrder === "asc" && (
                      <IconComponent
                        name="chevron-up"
                        size={16}
                        color="#ff6600"
                      />
                    )}
                  </TouchableOpacity>
                  <TouchableOpacity
                    style={[
                      styles.sortButton,
                      sortField === "price" && sortOrder === "desc"
                        ? styles.sortButtonActive
                        : {},
                    ]}
                    onPress={() => handleSort("price", "desc")}
                  >
                    <Text
                      style={[
                        styles.sortButtonText,
                        sortField === "price" && sortOrder === "desc"
                          ? styles.sortButtonTextActive
                          : {},
                      ]}
                    >
                      {t('highToLow')}
                    </Text>
                    {sortField === "price" && sortOrder === "desc" && (
                      <IconComponent
                        name="chevron-down"
                        size={16}
                        color="#ff6600"
                      />
                    )}
                  </TouchableOpacity>
                </View>
              </View>

              <View style={styles.sortDivider} />

              <View style={styles.sortGroup}>
                <Text style={styles.sortLabel}>{t('time')}:</Text>
                <View style={styles.sortButtons}>
                  <TouchableOpacity
                    style={[
                      styles.sortButton,
                      sortField === "time" && sortOrder === "asc"
                        ? styles.sortButtonActive
                        : {},
                    ]}
                    onPress={() => handleSort("time", "asc")}
                  >
                    <Text
                      style={[
                        styles.sortButtonText,
                        sortField === "time" && sortOrder === "asc"
                          ? styles.sortButtonTextActive
                          : {},
                      ]}
                    >
                      {t('oldest')}
                    </Text>
                    {sortField === "time" && sortOrder === "asc" && (
                      <IconComponent
                        name="chevron-up"
                        size={16}
                        color="#ff6600"
                      />
                    )}
                  </TouchableOpacity>
                  <TouchableOpacity
                    style={[
                      styles.sortButton,
                      sortField === "time" && sortOrder === "desc"
                        ? styles.sortButtonActive
                        : {},
                    ]}
                    onPress={() => handleSort("time", "desc")}
                  >
                    <Text
                      style={[
                        styles.sortButtonText,
                        sortField === "time" && sortOrder === "desc"
                          ? styles.sortButtonTextActive
                          : {},
                      ]}
                    >
                      {t('newest')}
                    </Text>
                    {sortField === "time" && sortOrder === "desc" && (
                      <IconComponent
                        name="chevron-down"
                        size={16}
                        color="#ff6600"
                      />
                    )}
                  </TouchableOpacity>
                </View>
              </View>
            </ScrollView>
          </View>

          {/* 加载指示器 */}
          {loading ? (
            <View style={styles.loadingContainer}>
              <ActivityIndicator size="large" color="#0066FF" />
            </View>
          ) : (
            <>
              <FlatList
                ref={flatListRef}
                data={products}
                renderItem={renderProductItem}
                keyExtractor={(item) => String(item.offer_id)}
                numColumns={2}
                contentContainerStyle={styles.productGrid}
                ListEmptyComponent={renderEmptyList}
                ListFooterComponent={renderFooter}
                showsVerticalScrollIndicator={false}
                initialNumToRender={8}
                maxToRenderPerBatch={10}
                windowSize={5}
                removeClippedSubviews={true}
                onEndReached={handleLoadMore}
                onEndReachedThreshold={0.2}
                onScroll={handleScroll}
                scrollEventThrottle={16}
              />
              {showBackToTop && (
                <TouchableOpacity
                  style={styles.backToTopButton}
                  onPress={scrollToTop}
                  activeOpacity={0.7}
                >
                  <IconComponent name="arrow-up" size={24} color="#fff" />
                </TouchableOpacity>
              )}
            </>
          )}
        </View>
      </KeyboardAvoidingView>
    </SafeAreaView>
  );
};

const styles = StyleSheet.create({
  safeArea: {
    flex: 1,
    backgroundColor: "#ffffff",
  },
  container: {
    flex: 1,
    backgroundColor: "#f5f5f5",
  },
  searchHeader: {
    flexDirection: "row",
    alignItems: "center",
    paddingHorizontal: 15,
    paddingVertical: 10,
    backgroundColor: "#fff",
    borderBottomWidth: 1,
    borderBottomColor: "#f0f0f0",
  },
  backButton: {
    marginRight: 10,
    padding: 5,
  },
  searchBar: {
    flex: 1,
    flexDirection: "row",
    alignItems: "center",
    backgroundColor: "#f5f5f5",
    borderRadius: 20,
    paddingHorizontal: 15,
    height: 40,
  },
  searchInput: {
    flex: 1,
    marginLeft: 8,
    fontSize: 16,
    color: "#333",
    height: 40,
  },
  resultsContainer: {
    flex: 1,
  },
  resultsHeader: {
    backgroundColor: "#fff",
    borderBottomWidth: 1,
    borderBottomColor: "#f0f0f0",
    paddingVertical: 10,
  },
  resultsTitle: {
    fontSize: 16,
    fontWeight: "bold",
    color: "#333",
    flex: 1,
  },
  resultsCount: {
    fontSize: 14,
    color: "#999",
  },
  loadingContainer: {
    flex: 1,
    justifyContent: "center",
    alignItems: "center",
  },
  productGrid: {
    padding: 8,
  },
  productCard: {
    flex: 1,
    margin: 8,
    backgroundColor: "#fff",
    borderRadius: 8,
    overflow: "hidden",
    elevation: 2, // Android shadow
    shadowColor: "#000", // iOS shadow
    shadowOffset: { width: 0, height: 1 },
    shadowOpacity: 0.1,
    shadowRadius: 2,
  },
  productImageContainer: {
    height: 150,
    backgroundColor: "#f9f9f9",
    alignItems: "center",
    justifyContent: "center",
  },
  productImage: {
    width: "100%",
    height: "100%",
  },
  placeholderText: {
    color: "#999",
    fontSize: 16,
  },
  productInfo: {
    padding: 10,
  },
  productPrice: {
    fontSize: 18,
    fontWeight: "bold",
    color: "#ff6600",
    marginBottom: 5,
  },
  productTitle: {
    fontSize: 14,
    color: "#333",
    marginBottom: 5,
  },
  productSales: {
    fontSize: 12,
    color: "#999",
  },
  emptyContainer: {
    flex: 1,
    minHeight: 300,
    justifyContent: "center",
    alignItems: "center",
    padding: 20,
  },
  emptyText: {
    fontSize: 16,
    fontWeight: "bold",
    color: "#333",
    marginTop: 15,
    marginBottom: 8,
  },
  emptySubtext: {
    fontSize: 14,
    color: "#999",
    textAlign: "center",
  },
  filterButton: {
    marginLeft: 10,
    padding: 5,
  },
  filterContainer: {
    backgroundColor: "#fff",
    paddingHorizontal: 15,
    paddingVertical: 10,
    borderBottomWidth: 1,
    borderBottomColor: "#f0f0f0",
  },
  priceFilterRow: {
    flexDirection: "row",
    alignItems: "center",
    marginBottom: 10,
  },
  filterLabel: {
    fontSize: 14,
    fontWeight: "bold",
    color: "#333",
    marginRight: 10,
  },
  priceInputContainer: {
    flex: 1,
    flexDirection: "row",
    alignItems: "center",
  },
  priceInput: {
    flex: 1,
    height: 36,
    backgroundColor: "#f5f5f5",
    borderRadius: 4,
    paddingHorizontal: 10,
    fontSize: 14,
    color: "#333",
  },
  priceDivider: {
    marginHorizontal: 8,
    color: "#333",
  },
  filterButtons: {
    flexDirection: "row",
    justifyContent: "flex-end",
  },
  resetButton: {
    paddingHorizontal: 15,
    paddingVertical: 6,
    borderRadius: 4,
    backgroundColor: "#f5f5f5",
    marginRight: 10,
  },
  resetButtonText: {
    fontSize: 14,
    color: "#666",
  },
  applyButton: {
    paddingHorizontal: 15,
    paddingVertical: 6,
    borderRadius: 4,
    backgroundColor: "#0066FF",
  },
  applyButtonText: {
    fontSize: 14,
    color: "#fff",
    fontWeight: "bold",
  },
  sortScrollView: {
    flexGrow: 0,
  },
  sortGroup: {
    flexDirection: "row",
    alignItems: "center",
    paddingHorizontal: 15,
  },
  sortLabel: {
    fontSize: 14,
    color: "#666",
    marginRight: 8,
  },
  sortButtons: {
    flexDirection: "row",
    alignItems: "center",
  },
  sortButton: {
    flexDirection: "row",
    alignItems: "center",
    paddingVertical: 4,
    paddingHorizontal: 8,
    borderRadius: 4,
    marginLeft: 6,
    borderWidth: 1,
    borderColor: "#e0e0e0",
  },
  sortButtonActive: {
    borderColor: "#ff6600",
    backgroundColor: "#fff8f5",
  },
  sortButtonText: {
    fontSize: 12,
    color: "#666",
  },
  sortButtonTextActive: {
    color: "#ff6600",
    fontWeight: "bold",
  },
  sortDivider: {
    width: 1,
    height: 20,
    backgroundColor: "#e0e0e0",
    marginHorizontal: 15,
  },
  footerContainer: {
    padding: 15,
    alignItems: "center",
    flexDirection: "row",
    justifyContent: "center",
  },
  footerText: {
    fontSize: 14,
    color: "#666",
    marginLeft: 8,
  },
  footerSpace: {
    height: 20,
  },
  backToTopButton: {
    position: "absolute",
    bottom: 20,
    right: 20,
    width: 44,
    height: 44,
    borderRadius: 22,
    backgroundColor: "#0066FF",
    justifyContent: "center",
    alignItems: "center",
    elevation: 5,
    shadowColor: "#000",
    shadowOffset: { width: 0, height: 2 },
    shadowOpacity: 0.3,
    shadowRadius: 3,
  },
});