yanting/lib/features/shell_page.dart

import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';
import 'package:shadcn_ui/shadcn_ui.dart';

import '../data/providers.dart';
import '../routing/app_routes.dart';
import '../theme/yanting_text.dart';
import '../widgets/bottom_tab_bar.dart';
import '../widgets/mini_player.dart';

class ShellPage extends ConsumerStatefulWidget {
  const ShellPage({required this.child, required this.currentPath, super.key});

  final Widget child;
  final String currentPath;

  @override
  ConsumerState<ShellPage> createState() => _ShellPageState();
}

class _ShellPageState extends ConsumerState<ShellPage> {
  static const double _compactHeaderThreshold = 34;

  bool _showCompactHeader = false;

  @override
  void didUpdateWidget(covariant ShellPage oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (oldWidget.currentPath != widget.currentPath && _showCompactHeader) {
      _showCompactHeader = false;
    }
  }

  @override
  Widget build(BuildContext context) {
    final theme = ShadTheme.of(context);
    final player = ref.watch(audioPlayerControllerProvider);
    final controller = ref.read(audioPlayerControllerProvider.notifier);
    final canPop = GoRouter.of(context).canPop();
    final selectedIndex = _tabs.indexWhere(
      (tab) => tab.path == widget.currentPath,
    );
    final safeIndex = selectedIndex < 0 ? 0 : selectedIndex;
    final header = _headerForPath(widget.currentPath);

    return Scaffold(
      backgroundColor: theme.colorScheme.background,
      appBar: AppBar(
        backgroundColor: theme.colorScheme.background,
        surfaceTintColor: Colors.transparent,
        elevation: 0,
        scrolledUnderElevation: 0,
        centerTitle: true,
        leading: canPop
            ? ShadIconButton.ghost(
                onPressed: () => context.pop(),
                icon: const Icon(LucideIcons.chevronLeft, size: 18),
              )
            : null,
        title: AnimatedOpacity(
          opacity: _showCompactHeader ? 1 : 0,
          duration: const Duration(milliseconds: 160),
          curve: Curves.easeOut,
          child: Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.center,
            children: [
              Text(
                header.title,
                textAlign: TextAlign.center,
                style: YantingText.listTitle,
              ),
              if (header.subtitle.isNotEmpty)
                Text(
                  header.subtitle,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  textAlign: TextAlign.center,
                  style: YantingText.meta.copyWith(fontSize: 12),
                ),
            ],
          ),
        ),
      ),
      body: ColoredBox(
        color: theme.colorScheme.background,
        child: NotificationListener<ScrollNotification>(
          onNotification: _handleScrollNotification,
          child: Stack(children: [Positioned.fill(child: widget.child)]),
        ),
      ),
      bottomNavigationBar: SafeArea(
        top: false,
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            MiniPlayer(player: player, onToggle: controller.toggleAudio),
            BottomTabBar(
              items: yantingBottomTabItems,
              selectedIndex: safeIndex,
              onSelected: (index) => context.go(_tabs[index].path),
            ),
          ],
        ),
      ),
    );
  }

  bool _handleScrollNotification(ScrollNotification notification) {
    if (notification.metrics.axis != Axis.vertical) {
      return false;
    }
    final next = notification.metrics.pixels > _compactHeaderThreshold;
    if (next != _showCompactHeader && mounted) {
      setState(() => _showCompactHeader = next);
    }
    return false;
  }
}

_ShellHeader _headerForPath(String path) {
  return switch (path) {
    AppRoutes.reports => const _ShellHeader('研报', '全部已发布研报解读'),
    AppRoutes.institutions => const _ShellHeader('机构', '可获取研报的机构'),
    AppRoutes.listen => const _ShellHeader('听单', '已转音频的研报解读'),
    AppRoutes.profile => const _ShellHeader('我的', ''),
    _ => const _ShellHeader('研听', '全球机构研报中文解读'),
  };
}

class _ShellHeader {
  const _ShellHeader(this.title, this.subtitle);

  final String title;
  final String subtitle;
}

class _TabItem {
  const _TabItem({required this.path});

  final String path;
}

const List<_TabItem> _tabs = [
  _TabItem(path: AppRoutes.home),
  _TabItem(path: AppRoutes.reports),
  _TabItem(path: AppRoutes.institutions),
  _TabItem(path: AppRoutes.listen),
  _TabItem(path: AppRoutes.profile),
];