import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../../models/media_asset.dart';
import '../../../services/media_service.dart';
import '../../../services/api_client.dart';

/// 媒资排行榜 Top10 管理页。
class MediaRankPage extends ConsumerStatefulWidget {
  const MediaRankPage({super.key});

  @override
  ConsumerState<MediaRankPage> createState() => _MediaRankPageState();
}

class _MediaRankPageState extends ConsumerState<MediaRankPage> {
  List<MediaRankItem> _items = [];
  bool _loading = false;
  String? _error;

  @override
  void initState() {
    super.initState();
    _loadData();
  }

  Future<void> _loadData() async {
    setState(() {
      _loading = true;
      _error = null;
    });
    try {
      final list = await MediaService().getMediaAssetRankTop10();
      if (!mounted) return;
      setState(() {
        _items = list;
        _loading = false;
      });
    } catch (e) {
      if (!mounted) return;
      setState(() {
        _loading = false;
        _error = e is ApiException ? e.message : '加载失败';
      });
    }
  }

  Future<void> _moveUp(String code) async {
    try {
      await MediaService().moveUpMediaAssetRank(code);
      _loadData();
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text(e is ApiException ? e.message : '操作失败')),
      );
    }
  }

  Future<void> _moveDown(String code) async {
    try {
      await MediaService().moveDownMediaAssetRank(code);
      _loadData();
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text(e is ApiException ? e.message : '操作失败')),
      );
    }
  }

  Future<void> _remove(String code) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('确认移除'),
        content: const Text('确定要从排行榜移除此媒资吗？'),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text('取消')),
          TextButton(onPressed: () => Navigator.pop(ctx, true), child: const Text('移除')),
        ],
      ),
    );
    if (confirmed != true) return;
    try {
      await MediaService().removeMediaAssetRank(code);
      _loadData();
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('移除成功')));
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text(e is ApiException ? e.message : '移除失败')),
      );
    }
  }

  Future<void> _clearAll() async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('确认清空'),
        content: const Text('确定要清空整个排行榜吗？此操作不可撤销。'),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text('取消')),
          TextButton(onPressed: () => Navigator.pop(ctx, true), child: const Text('清空')),
        ],
      ),
    );
    if (confirmed != true) return;
    try {
      await MediaService().clearMediaAssetRank();
      _loadData();
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('已清空')));
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text(e is ApiException ? e.message : '操作失败')),
      );
    }
  }

  void _showAddDialog() {
    final searchCtrl = TextEditingController();
    List<MediaAsset> allMedia = [];
    bool searching = false;

    showModalBottomSheet<void>(
          useSafeArea: true,
      context: context,
      isScrollControlled: true,
      builder: (sheetCtx) {
        return StatefulBuilder(
          builder: (ctx, setSheet) {
            Future<void> doSearch() async {
              setSheet(() => searching = true);
              try {
                allMedia = await MediaService().getMediaAssetList(page: 1, limit: 50);
              } catch (_) {
                allMedia = [];
              } finally {
                setSheet(() => searching = false);
              }
            }

            if (allMedia.isEmpty && !searching) {
              doSearch();
            }

            final kw = searchCtrl.text.trim().toLowerCase();
            final filtered = kw.isEmpty
                ? allMedia
                : allMedia.where((m) => m.name.toLowerCase().contains(kw)).toList();
            final existingCodes = _items.map((e) => e.code).toSet();
            final available = filtered.where((m) => !existingCodes.contains(m.code)).toList();

            return SizedBox(
              height: MediaQuery.of(ctx).size.height * 0.7,
              child: Column(
                children: [
                  Padding(
                    padding: const EdgeInsets.all(16),
                    child: Row(
                      children: [
                        Text('选择媒资', style: Theme.of(ctx).textTheme.titleLarge),
                        const Spacer(),
                        IconButton(
                          icon: const Icon(Icons.close),
                          onPressed: () => Navigator.of(ctx).pop(),
                        ),
                      ],
                    ),
                  ),
                  Padding(
                    padding: const EdgeInsets.symmetric(horizontal: 16),
                    child: TextField(
                      controller: searchCtrl,
                      decoration: const InputDecoration(
                        hintText: '搜索媒资名称',
                        prefixIcon: Icon(Icons.search),
                        border: OutlineInputBorder(),
                      ),
                      onChanged: (_) => setSheet(() {}),
                    ),
                  ),
                  const SizedBox(height: 8),
                  Expanded(
                    child: searching
                        ? const Center(child: CircularProgressIndicator())
                        : available.isEmpty
                            ? const Center(child: Text('无可选媒资'))
                            : ListView.builder(
                                itemCount: available.length,
                                itemBuilder: (_, index) {
                                  final media = available[index];
                                  return ListTile(
                                    leading: media.coverUrl.isNotEmpty
                                        ? ClipRRect(
                                            borderRadius: BorderRadius.circular(4),
                                            child: Image.network(
                                              media.coverUrl,
                                              width: 40,
                                              height: 56,
                                              fit: BoxFit.cover,
                                              errorBuilder: (_, __, ___) =>
                                                  const SizedBox(
                                                      width: 40,
                                                      height: 56,
                                                      child: Icon(Icons.video_library)),
                                            ),
                                          )
                                        : const SizedBox(
                                            width: 40,
                                            height: 56,
                                            child: Icon(Icons.video_library),
                                          ),
                                    title: Text(media.name),
                                    subtitle: Text(media.code),
                                    trailing: FilledButton.tonal(
                                      onPressed: () => _addToRank(ctx, media.code, media.name),
                                      child: const Text('添加'),
                                    ),
                                  );
                                },
                              ),
                  ),
                ],
              ),
            );
          },
        );
      },
    );
  }

  Future<void> _addToRank(BuildContext sheetCtx, String code, String name) async {
    try {
      await MediaService().setMediaAssetRank([code]);
      if (!mounted) return;
      Navigator.of(sheetCtx).pop();
      _loadData();
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('已添加「$name」到排行榜')),
      );
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text(e is ApiException ? e.message : '添加失败')),
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        automaticallyImplyLeading: false,
        title: const Text('媒资排行榜 Top10'),
        actions: [
          if (_items.isNotEmpty)
            IconButton(
              icon: const Icon(Icons.delete_sweep),
              onPressed: _clearAll,
              tooltip: '清空排行榜',
            ),
        ],
      ),
      body: _loading
          ? const Center(child: CircularProgressIndicator())
          : _error != null
              ? Center(child: Column(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Text(_error!),
                    const SizedBox(height: 8),
                    FilledButton.tonal(onPressed: _loadData, child: const Text('重试')),
                  ],
                ))
              : _items.isEmpty
                  ? const Center(child: Text('排行榜为空，点击+添加'))
                  : ListView.builder(
                      padding: const EdgeInsets.all(8),
                      itemCount: _items.length,
                      itemBuilder: (ctx, i) {
                        final item = _items[i];
                        final rank = i + 1;
                        return Card(
                          child: ListTile(
                            leading: Row(
                              mainAxisSize: MainAxisSize.min,
                              children: [
                                Container(
                                  width: 36,
                                  height: 48,
                                  alignment: Alignment.center,
                                  decoration: BoxDecoration(
                                    color: rank <= 3
                                        ? [Colors.amber, Colors.grey, Colors.brown][rank - 1]
                                        : Theme.of(ctx).colorScheme.primaryContainer,
                                    borderRadius: BorderRadius.circular(6),
                                  ),
                                  child: Text(
                                    '$rank',
                                    style: TextStyle(
                                      fontWeight: FontWeight.bold,
                                      color: rank <= 3 ? Colors.white : null,
                                    ),
                                  ),
                                ),
                                const SizedBox(width: 8),
                                if (item.coverUrl.isNotEmpty)
                                  ClipRRect(
                                    borderRadius: BorderRadius.circular(4),
                                    child: Image.network(
                                      item.coverUrl,
                                      width: 36,
                                      height: 48,
                                      fit: BoxFit.cover,
                                      errorBuilder: (_, __, ___) =>
                                          const SizedBox(
                                              width: 36,
                                              height: 48,
                                              child: Icon(Icons.video_library, size: 20)),
                                    ),
                                  )
                                else
                                  const SizedBox(
                                    width: 36,
                                    height: 48,
                                    child: Icon(Icons.video_library, size: 20),
                                  ),
                              ],
                            ),
                            title: Text(item.mediaName.isNotEmpty
                                ? item.mediaName
                                : item.code),
                            subtitle: Text(item.code),
                            trailing: Row(
                              mainAxisSize: MainAxisSize.min,
                              children: [
                                IconButton(
                                  icon: const Icon(Icons.arrow_upward),
                                  onPressed: i > 0 ? () => _moveUp(item.code) : null,
                                ),
                                IconButton(
                                  icon: const Icon(Icons.arrow_downward),
                                  onPressed: i < _items.length - 1
                                      ? () => _moveDown(item.code)
                                      : null,
                                ),
                                IconButton(
                                  icon: const Icon(Icons.close),
                                  onPressed: () => _remove(item.code),
                                ),
                              ],
                            ),
                          ),
                        );
                      },
                    ),
      floatingActionButton: FloatingActionButton(
        onPressed: _showAddDialog,
        child: const Icon(Icons.add),
      ),
    );
  }
}