import 'dart:math';

import 'package:flutter/material.dart';
import 'package:flutter_infinite_marquee/flutter_infinite_marquee.dart';
import 'package:jydj/hj_utils/screen.dart';
import 'package:jydj/tools_base/ad_manager.dart';

import '../../hj_model/splash/ads_model.dart';
import 'ads_banner.dart';
import 'ads_item.dart';

/// 广告位展示样式，由广告的 coverImgSize 映射而来（见 AdsInfoModel.adStyle）
enum AdStyle {
  normal, //两排共 10 个（固定样式时用）
  banner, //大 banner 轮播
  twoAutoScroll, //双排：上排固定，下排自动滚动
  oneScrollBig, //单排自动滚动的大图
}

/// 广告位通用容器：按 [AdStyle] 切换九宫格 / banner / 双排滚动 / 大图滚动
class AdsGridView extends StatelessWidget {
  final int position; //广告位标识，ads 为空时按此取本地缓存广告
  final List<AdsInfoModel>? ads; //外部直接传入的广告，优先于 position
  final bool autoStyle; //true：按第一个广告的 coverImgSize 选样式；false：固定两排九宫格
  final EdgeInsetsGeometry? padding;

  const AdsGridView(
    this.position, {
    super.key,
    this.ads,
    this.autoStyle = false,
    this.padding,
  });

  @override
  Widget build(BuildContext context) {
    //一次 build 只取一次，自动滚动的 itemBuilder 复用同一份，避免反复全表 filter
    final list = ads ?? AdManager().adsByType(position);
    //无数据或 ab 测未命中广告，直接占位不渲染
    if (list.isEmpty || !AdManager().showAbTestAd) return const SizedBox();
    final style = autoStyle ? list.first.adStyle : AdStyle.normal;
    return switch (style) {
      AdStyle.normal => _normal(list),
      AdStyle.banner => _banner(list),
      AdStyle.twoAutoScroll => _twoAutoScroll(list),
      AdStyle.oneScrollBig => _oneScrollBig(list),
    };
  }

  //统一构造广告项
  Widget _item(AdsInfoModel model, {double? aspectRatio}) {
    return AdsItem(adInfo: model, aspectRatio: aspectRatio);
  }

  //两排共 10 个
  Widget _normal(List<AdsInfoModel> list) {
    return GridView.builder(
      padding: padding,
      physics: const NeverScrollableScrollPhysics(),
      shrinkWrap: true,
      gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
        crossAxisCount: 5,
        mainAxisSpacing: 12,
        crossAxisSpacing: 10,
        childAspectRatio: 60 / 82,
      ),
      itemCount: min(10, list.length),
      itemBuilder: (_, index) => _item(list[index]),
    );
  }

  //大 banner：单张轮播，最多 20 张
  Widget _banner(List<AdsInfoModel> list) {
    return Container(
      padding: padding,
      alignment: Alignment.center,
      child: ClipRRect(
        borderRadius: BorderRadius.circular(8),
        child: AspectRatio(
          aspectRatio: 720 / 150,
          child: AdsBanner(
            list.length > 20 ? list.take(20).toList() : list,
            autoPlayMs: 2000,
          ),
        ),
      ),
    );
  }

  //双排：不足 11 个全放九宫格；否则上排固定 5 个，其余在下排自动滚动
  Widget _twoAutoScroll(List<AdsInfoModel> list) {
    if (list.length < 11) {
      return GridView.builder(
        padding: const EdgeInsets.fromLTRB(16, 12, 16, 12),
        physics: const NeverScrollableScrollPhysics(),
        shrinkWrap: true,
        gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
          crossAxisCount: 5,
          mainAxisSpacing: 12,
          crossAxisSpacing: 10,
          childAspectRatio: 60 / 82,
        ),
        itemCount: list.length,
        itemBuilder: (_, index) => _item(list[index]),
      );
    }
    final head = list.take(5).toList();
    final foot = list.sublist(5);
    return LayoutBuilder(
      builder: (_, constraints) {
        //下排一格和上排九宫格一样宽：4 个列间距共 40 + 左右边距各 16
        final itemWidth = ((constraints.maxWidth - 40 - 16 * 2) / 5);
        return Column(
          children: [
            GridView.builder(
              padding: const EdgeInsets.fromLTRB(16, 12, 16, 0),
              physics: const NeverScrollableScrollPhysics(),
              shrinkWrap: true,
              gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
                crossAxisCount: 5,
                mainAxisSpacing: 12,
                crossAxisSpacing: 10,
                childAspectRatio: 60 / 82,
              ),
              itemCount: head.length,
              itemBuilder: (_, index) => _item(head[index]),
            ),
            12.sizeBoxH,
            SizedBox(
              height: itemWidth / (60 / 82), //宽高比和上排一致
              child: InfiniteMarquee(
                frequency: const Duration(milliseconds: 20),
                itemBuilder: (_, index) => Container(
                  width: itemWidth,
                  margin: const EdgeInsets.only(right: 7),
                  child: _item(foot[index % foot.length]),
                ),
              ),
            ),
            12.sizeBoxH,
          ],
        );
      },
    );
  }

  //单排自动滚动的大图，最多 20 个；一屏 3.2 个，露出下一张引导滑动
  Widget _oneScrollBig(List<AdsInfoModel> list) {
    return LayoutBuilder(
      builder: (_, constraints) {
        final data = list.length > 20 ? list.take(20).toList() : list;
        final itemWidth = ((constraints.maxWidth - 7 * 2 - 16 * 2) / 3.2);
        return Container(
          margin: padding,
          height: itemWidth / (104 / 176),
          child: InfiniteMarquee(
            frequency: const Duration(milliseconds: 20),
            itemBuilder: (_, index) => Container(
              width: itemWidth,
              margin: const EdgeInsets.only(right: 7),
              child: _item(data[index % data.length], aspectRatio: 104 / 152),
            ),
          ),
        );
      },
    );
  }
}