// Author: fruit.com.cn

import 'package:flutter/material.dart';

import '../../../core/config/app_config.dart';
import '../../../core/data/models/drama.dart';
import '../../../core/formatting/count_format.dart';
import '../../../core/theme/app_colors.dart';
import '../../../core/theme/app_dimens.dart';
import '../../../l10n/app_localizations.dart';

const int _columns = 2;
const double _columnGap = 8;
const double _cardGap = 14;
const double _gridHorizontalPadding = 12;
const double _coverAspectRatio = 3 / 4;
const double _coverRadius = 10;
const double _titleGap = 8;
const double _tagsGap = 6;
const double _titleFontSize = 15;
const double _tagChipRadius = 6;
const double _tagChipFontSize = 11;
const double _heatFontSize = 9;
const double _heatIconSize = 11;
const int _maxTags = 3;
const Color _heatBackground = Color(0x99000000);
const Color _tagChipBackground = Color(0xFFF4F1EE);
final RegExp _tagSplitter = RegExp(r'[,/、·]');

/// 剧场/分类页共用的双列剧目网格。
class DramaGrid extends StatelessWidget {
  const DramaGrid({
    super.key,
    required this.l10n,
    required this.dramas,
    required this.onOpen,
  });

  final AppLocalizations l10n;
  final List<Drama> dramas;
  final ValueChanged<Drama> onOpen;

  @override
  Widget build(BuildContext context) {
    return Padding(
      key: const Key('home-all-dramas-section'),
      padding: const EdgeInsets.symmetric(horizontal: _gridHorizontalPadding),
      child: Row(
        key: const Key('home-all-dramas-grid'),
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Expanded(child: _column(0)),
          const SizedBox(width: _columnGap),
          Expanded(child: _column(1)),
        ],
      ),
    );
  }

  Widget _column(int start) {
    final children = <Widget>[];
    for (var index = start; index < dramas.length; index += _columns) {
      final drama = dramas[index];
      children.add(
        DramaGridCard(l10n: l10n, drama: drama, onTap: () => onOpen(drama)),
      );
      if (index + _columns < dramas.length) {
        children.add(const SizedBox(height: _cardGap));
      }
    }
    return Column(children: children);
  }
}

/// 双列网格中的剧目卡片：海报 + 标题 + 题材标签。
class DramaGridCard extends StatelessWidget {
  const DramaGridCard({
    super.key,
    required this.l10n,
    required this.drama,
    required this.onTap,
  });

  final AppLocalizations l10n;
  final Drama drama;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      key: Key('home-drama-card-${drama.id}'),
      behavior: HitTestBehavior.opaque,
      onTap: onTap,
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          _cover(),
          const SizedBox(height: _titleGap),
          _title(),
          const SizedBox(height: _tagsGap),
          _tags(),
        ],
      ),
    );
  }

  Widget _cover() {
    return ClipRRect(
      key: Key('home-drama-cover-${drama.id}'),
      borderRadius: BorderRadius.circular(_coverRadius),
      child: AspectRatio(
        aspectRatio: _coverAspectRatio,
        child: Stack(
          fit: StackFit.expand,
          children: [
            _DiscoverCoverImage(path: drama.posterUrl),
            Positioned(left: 8, bottom: 8, child: _heatBadge()),
          ],
        ),
      ),
    );
  }

  Widget _heatBadge() {
    return Container(
      key: Key('drama-heat-${drama.id}'),
      padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 3),
      decoration: BoxDecoration(
        color: _heatBackground,
        borderRadius: BorderRadius.circular(AppDimens.pillRadius),
      ),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          const Icon(
            Icons.local_fire_department_rounded,
            color: AppColors.onPrimary,
            size: _heatIconSize,
          ),
          const SizedBox(width: 2),
          Text(
            l10n.heatLabel(formatInteractionCount(drama.viewCount)),
            style: const TextStyle(
              color: AppColors.onPrimary,
              fontSize: _heatFontSize,
              fontWeight: FontWeight.w600,
            ),
          ),
        ],
      ),
    );
  }

  Widget _title() {
    return Text(
      drama.title,
      key: Key('home-drama-title-${drama.id}'),
      maxLines: 2,
      overflow: TextOverflow.ellipsis,
      style: const TextStyle(
        color: AppColors.onSurface,
        fontSize: _titleFontSize,
        fontWeight: FontWeight.w700,
        height: 1.25,
      ),
    );
  }

  Widget _tags() {
    final tags = _tagValues();
    if (tags.isEmpty) return const SizedBox.shrink();
    return Wrap(
      spacing: 6,
      runSpacing: 4,
      children: [
        for (var index = 0; index < tags.length; index++)
          Container(
            key: Key('drama-tag-chip-${drama.id}-$index'),
            padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
            decoration: BoxDecoration(
              color: _tagChipBackground,
              borderRadius: BorderRadius.circular(_tagChipRadius),
            ),
            child: Text(
              tags[index],
              style: const TextStyle(
                color: AppColors.muted,
                fontSize: _tagChipFontSize,
              ),
            ),
          ),
      ],
    );
  }

  List<String> _tagValues() {
    final result = <String>[];
    for (final value in [drama.genre, drama.category]) {
      for (final part in value.split(_tagSplitter)) {
        final tag = part.trim();
        if (tag.isEmpty || result.contains(tag)) continue;
        result.add(tag);
        if (result.length == _maxTags) return result;
      }
    }
    return result;
  }
}

class _DiscoverCoverImage extends StatelessWidget {
  const _DiscoverCoverImage({required this.path});

  final String path;

  @override
  Widget build(BuildContext context) {
    final url = AppConfig.mediaUrl(path);
    if (url.isEmpty) return _placeholder();
    return Image.network(
      url,
      width: double.infinity,
      height: double.infinity,
      fit: BoxFit.cover,
      loadingBuilder: (context, child, progress) {
        if (progress == null) return child;
        return _placeholder();
      },
      errorBuilder: (_, _, _) => _placeholder(),
    );
  }

  Widget _placeholder() {
    return const ColoredBox(
      color: AppColors.card,
      child: Center(
        child: Icon(
          Icons.image_not_supported_outlined,
          color: AppColors.muted,
          size: 32,
        ),
      ),
    );
  }
}