// Author: fruit.com.cn

import 'package:flutter/material.dart';

import '../../../l10n/app_localizations.dart';

const double _topIconSize = 36;
const double _topIconGlyph = 22;
const double _tabGap = 22;
const double _tabFontSize = 15;
const double _underlineWidth = 18;
const double _underlineHeight = 2;

/// 首页 feed 固定顶栏：刷新 / 漫剧·真人剧·推荐 / 搜索。
class HomeFeedHeader extends StatefulWidget {
  const HomeFeedHeader({
    super.key,
    required this.l10n,
    required this.onRefresh,
    required this.onSearch,
    required this.onMore,
  });

  final AppLocalizations l10n;
  final Future<bool> Function() onRefresh;
  final VoidCallback onSearch;
  final VoidCallback onMore;

  @override
  State<HomeFeedHeader> createState() => _HomeFeedHeaderState();
}

class _HomeFeedHeaderState extends State<HomeFeedHeader> {
  _FeedTab _tab = _FeedTab.recommend;
  bool _refreshing = false;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.fromLTRB(8, 6, 8, 4),
      child: Row(
        children: [
          _RefreshButton(
            tooltip: widget.l10n.retry,
            dimension: _topIconSize,
            glyphSize: _topIconGlyph,
            refreshing: _refreshing,
            onTap: _refresh,
            onLongPress: widget.onMore,
          ),
          Expanded(
            child: Center(
              child: SingleChildScrollView(
                scrollDirection: Axis.horizontal,
                child: Row(
                  children: [
                    for (var index = 0; index < _FeedTab.values.length; index++)
                      _tabSlot(_FeedTab.values[index], index),
                  ],
                ),
              ),
            ),
          ),
          _TopIconButton(
            key: const Key('home-feed-search'),
            tooltip: widget.l10n.search,
            icon: Icons.search_rounded,
            dimension: _topIconSize,
            glyphSize: _topIconGlyph,
            onPressed: widget.onSearch,
          ),
        ],
      ),
    );
  }

  Widget _tabSlot(_FeedTab tab, int index) {
    final item = _FeedTabItem(
      tab: tab,
      label: tab.label(widget.l10n),
      selected: _tab == tab,
      fontSize: _tabFontSize,
      underlineWidth: _underlineWidth,
      underlineHeight: _underlineHeight,
      onTap: () => _selectTab(tab),
    );
    if (index == 0) return item;
    return Padding(
      padding: const EdgeInsets.only(left: _tabGap),
      child: item,
    );
  }

  void _selectTab(_FeedTab tab) {
    if (tab.comingSoon) {
      _showComingSoon();
      return;
    }
    setState(() => _tab = tab);
  }

  Future<void> _refresh() async {
    if (_refreshing) return;
    setState(() => _refreshing = true);
    await widget.onRefresh();
    if (mounted) setState(() => _refreshing = false);
  }

  void _showComingSoon() {
    ScaffoldMessenger.of(
      context,
    ).showSnackBar(SnackBar(content: Text(widget.l10n.comingSoon)));
  }
}

/// 顶部频道 tab：漫剧点击提示即将上线。
enum _FeedTab {
  anime,
  real,
  recommend;

  bool get comingSoon => this == _FeedTab.anime;

  String get keyName => switch (this) {
    _FeedTab.anime => 'anime',
    _FeedTab.real => 'real',
    _FeedTab.recommend => 'recommend',
  };

  String label(AppLocalizations l10n) => switch (this) {
    _FeedTab.anime => l10n.feedTabAnime,
    _FeedTab.real => l10n.feedTabReal,
    _FeedTab.recommend => l10n.feedTabForYou,
  };
}

class _TopIconButton extends StatelessWidget {
  const _TopIconButton({
    super.key,
    required this.tooltip,
    required this.icon,
    required this.dimension,
    required this.glyphSize,
    required this.onPressed,
  });

  final String tooltip;
  final IconData icon;
  final double dimension;
  final double glyphSize;
  final VoidCallback onPressed;

  @override
  Widget build(BuildContext context) {
    return SizedBox.square(
      dimension: dimension,
      child: IconButton(
        tooltip: tooltip,
        onPressed: onPressed,
        padding: EdgeInsets.zero,
        icon: Icon(
          icon,
          size: glyphSize,
          color: Colors.white,
          shadows: const [Shadow(blurRadius: 6, color: Colors.black)],
        ),
      ),
    );
  }
}

/// 刷新入口：点击重新加载 feed，长按打开更多（清屏等）。
class _RefreshButton extends StatelessWidget {
  const _RefreshButton({
    required this.tooltip,
    required this.dimension,
    required this.glyphSize,
    required this.refreshing,
    required this.onTap,
    required this.onLongPress,
  });

  final String tooltip;
  final double dimension;
  final double glyphSize;
  final bool refreshing;
  final VoidCallback onTap;
  final VoidCallback onLongPress;

  @override
  Widget build(BuildContext context) {
    return Tooltip(
      message: tooltip,
      child: GestureDetector(
        key: const Key('home-feed-refresh'),
        behavior: HitTestBehavior.opaque,
        onTap: onTap,
        onLongPress: onLongPress,
        child: SizedBox.square(
          dimension: dimension,
          child: refreshing
              ? const Center(
                  child: SizedBox.square(
                    dimension: 18,
                    child: CircularProgressIndicator(
                      key: Key('home-feed-refreshing'),
                      strokeWidth: 2,
                      color: Colors.white,
                    ),
                  ),
                )
              : Icon(
                  Icons.refresh_rounded,
                  size: glyphSize,
                  color: Colors.white,
                  shadows: const [Shadow(blurRadius: 6, color: Colors.black)],
                ),
        ),
      ),
    );
  }
}

class _FeedTabItem extends StatelessWidget {
  const _FeedTabItem({
    required this.tab,
    required this.label,
    required this.selected,
    required this.fontSize,
    required this.underlineWidth,
    required this.underlineHeight,
    required this.onTap,
  });

  final _FeedTab tab;
  final String label;
  final bool selected;
  final double fontSize;
  final double underlineWidth;
  final double underlineHeight;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      key: Key('home-feed-tab-${tab.keyName}'),
      behavior: HitTestBehavior.opaque,
      onTap: onTap,
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          Text(
            label,
            maxLines: 1,
            style: TextStyle(
              color: selected ? Colors.white : Colors.white70,
              fontSize: fontSize,
              fontWeight: selected ? FontWeight.w800 : FontWeight.w600,
              shadows: const [Shadow(blurRadius: 6, color: Colors.black)],
            ),
          ),
          const SizedBox(height: 4),
          Container(
            width: underlineWidth,
            height: underlineHeight,
            decoration: BoxDecoration(
              color: selected ? Colors.white : Colors.transparent,
              borderRadius: BorderRadius.circular(1),
            ),
          ),
        ],
      ),
    );
  }
}