// Author: fruit.com.cn

import 'package:flutter/material.dart';

import '../../../core/data/models/drama.dart';
import '../../../core/data/models/home_feed.dart';
import '../../../core/theme/app_colors.dart';
import '../../../core/widgets/empty_state.dart';
import '../../../core/widgets/remote_image.dart';
import '../../../l10n/app_localizations.dart';
import '../ranking_logic.dart';

const int _topLimit = 5;
const double _rowHeight = 68;
const double _posterWidth = 40;
const double _posterHeight = 54;
const double _badgeSize = 24;

/// 发现页内嵌榜单区块：热播/新剧切换 + 前 5 名。
class RankingSection extends StatefulWidget {
  const RankingSection({
    super.key,
    required this.sections,
    required this.fallback,
    required this.onOpen,
  });

  final List<FeedSection> sections;
  final List<Drama> fallback;
  final ValueChanged<Drama> onOpen;

  @override
  State<RankingSection> createState() => _RankingSectionState();
}

class _RankingSectionState extends State<RankingSection> {
  late final RankingLogic logic = RankingLogic(
    sections: widget.sections,
    fallback: widget.fallback,
  );

  @override
  void didUpdateWidget(covariant RankingSection oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (!identical(oldWidget.sections, widget.sections) ||
        !identical(oldWidget.fallback, widget.fallback)) {
      logic.updateSources(sections: widget.sections, fallback: widget.fallback);
    }
  }

  @override
  void dispose() {
    logic.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => ListenableBuilder(
    listenable: logic,
    builder: (context, _) => _content(context),
  );

  Widget _content(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    final entries = logic.entries.take(_topLimit).toList();
    return Container(
      key: const Key('discover-ranking-section'),
      margin: const EdgeInsets.fromLTRB(14, 16, 14, 8),
      padding: const EdgeInsets.fromLTRB(12, 12, 12, 8),
      decoration: BoxDecoration(
        color: AppColors.card,
        borderRadius: BorderRadius.circular(14),
        border: Border.all(color: AppColors.border),
      ),
      child: Column(
        children: [
          _header(l10n),
          const SizedBox(height: 8),
          if (entries.isEmpty)
            EmptyState(
              key: const Key('ranking-empty'),
              icon: Icons.leaderboard_outlined,
              title: l10n.rankingEmptyTitle,
              subtitle: l10n.rankingEmptyBody,
              compact: true,
            )
          else
            for (final entry in entries) _row(entry, l10n),
        ],
      ),
    );
  }

  Widget _header(AppLocalizations l10n) {
    return Row(
      children: [
        const Icon(
          Icons.local_fire_department_rounded,
          color: AppColors.blue,
          size: 18,
        ),
        const SizedBox(width: 6),
        Expanded(
          child: Text(
            l10n.rankingTitle,
            maxLines: 1,
            overflow: TextOverflow.ellipsis,
            style: const TextStyle(
              color: AppColors.onSurface,
              fontSize: 13,
              fontWeight: FontWeight.w800,
            ),
          ),
        ),
        _boardChip(
          key: const Key('ranking-tab-hot'),
          label: l10n.rankingHot,
          board: RankingBoard.hot,
        ),
        const SizedBox(width: 6),
        _boardChip(
          key: const Key('ranking-tab-new'),
          label: l10n.rankingNew,
          board: RankingBoard.newReleases,
        ),
      ],
    );
  }

  Widget _boardChip({
    required Key key,
    required String label,
    required RankingBoard board,
  }) {
    final selected = logic.board == board;
    return Material(
      key: key,
      color: selected ? AppColors.blue : AppColors.card,
      borderRadius: BorderRadius.circular(999),
      clipBehavior: Clip.antiAlias,
      child: InkWell(
        onTap: () => logic.select(board),
        child: Padding(
          padding: const EdgeInsets.symmetric(horizontal: 9, vertical: 5),
          child: Text(
            label,
            style: TextStyle(
              color: selected ? AppColors.onPrimary : AppColors.onSurface,
              fontSize: 9,
              fontWeight: FontWeight.w700,
            ),
          ),
        ),
      ),
    );
  }

  Widget _row(RankingEntry entry, AppLocalizations l10n) {
    return _RankRow(
      entry: entry,
      subtitle: _subtitle(entry.drama, l10n),
      onTap: () => widget.onOpen(entry.drama),
    );
  }

  String _subtitle(Drama drama, AppLocalizations l10n) {
    final genre = drama.genre.isNotEmpty ? drama.genre : drama.category;
    final count = l10n.episodeCount(drama.episodeCount);
    return genre.isEmpty ? count : '$genre · $count';
  }
}

class _RankRow extends StatelessWidget {
  const _RankRow({
    required this.entry,
    required this.subtitle,
    required this.onTap,
  });

  final RankingEntry entry;
  final String subtitle;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    final drama = entry.drama;
    return Material(
      key: Key('ranking-entry-${drama.id}'),
      color: Colors.transparent,
      child: InkWell(
        onTap: onTap,
        borderRadius: BorderRadius.circular(10),
        child: SizedBox(height: _rowHeight, child: _content(drama)),
      ),
    );
  }

  Widget _content(Drama drama) {
    return Row(
      children: [
        _rankBadge(entry.rank),
        const SizedBox(width: 8),
        ClipRRect(
          borderRadius: BorderRadius.circular(7),
          child: RemoteImage(
            drama.posterUrl,
            width: _posterWidth,
            height: _posterHeight,
          ),
        ),
        const SizedBox(width: 10),
        Expanded(child: _text(drama)),
        const Icon(
          Icons.chevron_right_rounded,
          color: AppColors.subtle,
          size: 18,
        ),
      ],
    );
  }

  Widget _text(Drama drama) {
    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          drama.title,
          maxLines: 1,
          overflow: TextOverflow.ellipsis,
          style: const TextStyle(
            color: AppColors.onSurface,
            fontSize: 11,
            fontWeight: FontWeight.w700,
          ),
        ),
        const SizedBox(height: 3),
        Text(
          subtitle,
          maxLines: 1,
          overflow: TextOverflow.ellipsis,
          style: const TextStyle(color: AppColors.subtle, fontSize: 9),
        ),
      ],
    );
  }

  Widget _rankBadge(int rank) {
    final top = rank <= 3;
    return Container(
      width: _badgeSize,
      height: _badgeSize,
      alignment: Alignment.center,
      decoration: BoxDecoration(
        color: top ? AppColors.gold.withValues(alpha: 0.16) : AppColors.raised,
        borderRadius: BorderRadius.circular(7),
      ),
      child: Text(
        '$rank',
        style: TextStyle(
          color: top ? AppColors.gold : AppColors.muted,
          fontSize: 11,
          fontWeight: FontWeight.w900,
        ),
      ),
    );
  }
}