/**
 * 轮播图组件
 *
 * 展示首页轮播图，支持自动播放和手动滑动
 * 使用真实数据
 */

import React, { useState, useEffect, useRef, useCallback } from 'react';
import {
  View,
  Image,
  TouchableOpacity,
  ScrollView,
  NativeScrollEvent,
  NativeSyntheticEvent,
  ActivityIndicator,
  Dimensions,
  Alert,
} from 'react-native';
import Colors from '@/constants/Colors';
// import type { Banner } from '@/types/home';
import { styles } from './styles';
import useMsgStore from '@/stores/msgStore';


interface BannerSwiperProps {
  theme: 'light' | 'dark';
}

const { width } = Dimensions.get('window');

/**
 * 轮播图组件
 */
export default function BannerSwiper({ theme }: BannerSwiperProps) {
  const s = styles[theme];
  const [currentIndex, setCurrentIndex] = useState(0);
  const [loading, setLoading] = useState(true);
  const scrollViewRef = useRef<ScrollView>(null);
  const autoPlayTimerRef = useRef<any>(null);
  const { homeBanner } = useMsgStore();


  // 加载轮播图数据
  useEffect(() => {
    // 如果有传入的 banners 数据，直接使用
    if (homeBanner.length > 0) {
      setLoading(false);
      return;
    }
    // 如果没有数据，保持 loading 状态显示骨架屏
  }, [homeBanner]);

  // 处理 Banner 点击
  const onBannerPress = useCallback((banner: Record<string, any>) => {
    Alert.alert('轮播图', `点击了: ${banner.title || banner.id}`);
    // 这里可以添加导航逻辑
  }, []);

  // 处理滚动事件
  const handleScroll = (event: NativeSyntheticEvent<NativeScrollEvent>) => {
    const contentOffsetX = event.nativeEvent.contentOffset.x;
    const index = Math.round(contentOffsetX / (width - 24));
    setCurrentIndex(Math.min(index, homeBanner.length - 1));
  };

  // 启动自动播放
  const startAutoPlay = useCallback(() => {
    if (homeBanner.length <= 1) return;
    autoPlayTimerRef.current = setInterval(() => {
      setCurrentIndex((prev) => {
        const nextIndex = (prev + 1) % homeBanner.length;
        scrollViewRef.current?.scrollTo({
          x: nextIndex * (width - 24),
          animated: true,
        });
        return nextIndex;
      });
    }, 5000);
  }, [homeBanner.length]);

  // 停止自动播放
  const stopAutoPlay = useCallback(() => {
    if (autoPlayTimerRef.current) {
      clearInterval(autoPlayTimerRef.current);
    }
  }, []);

  // 自动播放
  useEffect(() => {
    if (!loading && homeBanner.length > 0) {
      startAutoPlay();
    }
    return () => stopAutoPlay();
  }, [loading, homeBanner.length, startAutoPlay, stopAutoPlay]);

  // 骨架屏 - 加载中显示占位符
  if (loading || homeBanner.length === 0) {
    return (
      <View style={s.container}>
        <View
          style={[
            s.image,
            {
              backgroundColor: theme === 'dark' ? '#333' : '#e0e0e0',
            },
          ]}
        />
      </View>
    );
  }

  return (
    <View style={s.container}>
      <ScrollView
        ref={scrollViewRef}
        style={s.scrollView}
        horizontal
        pagingEnabled
        scrollEventThrottle={16}
        onScroll={handleScroll}
        showsHorizontalScrollIndicator={false}
        onMomentumScrollBegin={stopAutoPlay}
        onMomentumScrollEnd={startAutoPlay}
      >
        {homeBanner.map((banner) => (
          <TouchableOpacity
            key={banner.id}
            onPress={() => onBannerPress(banner)}
            activeOpacity={0.9}
          >
            <Image
              source={{ uri: banner.subject }}
              style={s.image}
              resizeMode="cover"
            />
          </TouchableOpacity>
        ))}
      </ScrollView>

      {/* 指示器 */}
      <View style={s.indicatorContainer}>
        {homeBanner.map((_, index) => (
          <View
            key={index}
            style={[
              s.indicator,
              index === currentIndex && s.indicatorActive,
            ]}
          />
        ))}
      </View>
    </View>
  );
}