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

import '../../../common/config/shorebird_service.dart';
import '../../../common/router/app_router.dart';
import '../../../common/theme/app_text.dart';
import '../../../common/theme/spacing.dart';

class DebugShorebirdPage extends StatefulWidget {
  const DebugShorebirdPage({super.key});

  @override
  State<DebugShorebirdPage> createState() => _DebugShorebirdPageState();
}

class _DebugShorebirdPageState extends State<DebugShorebirdPage> {
  final ShorebirdService _shorebird = ShorebirdService.instance;
  late final bool _isUpdaterAvailable;
  var _currentTrack = UpdateTrack.stable;
  var _isCheckingForUpdates = false;
  Patch? _currentPatch;

  @override
  void initState() {
    super.initState();
    _isUpdaterAvailable = _shorebird.isAvailable;
    _loadCurrentPatch();
  }

  Future<void> _loadCurrentPatch() async {
    try {
      await _shorebird.initCurrentPatch();
      if (!mounted) return;
      setState(() => _currentPatch = _shorebird.currentPatch);
    } catch (error) {
      debugPrint('Error reading current patch: $error');
    }
  }

  Future<void> _checkForUpdate() async {
    if (_isCheckingForUpdates) return;

    try {
      setState(() => _isCheckingForUpdates = true);
      final status = await _shorebird.checkForUpdate(track: _currentTrack);
      if (!mounted) return;
      switch (status) {
        case UpdateStatus.upToDate:
          _showNoUpdateAvailableBanner();
          break;
        case UpdateStatus.outdated:
          _showUpdateAvailableBanner();
          break;
        case UpdateStatus.restartRequired:
          _showRestartBanner();
          break;
        case UpdateStatus.unavailable:
          _showUnavailableBanner();
          break;
      }
    } catch (error) {
      debugPrint('Error checking for update: $error');
      _showErrorBanner(error);
    } finally {
      if (mounted) {
        setState(() => _isCheckingForUpdates = false);
      }
    }
  }

  void _showDownloadingBanner() {
    ScaffoldMessenger.of(context)
      ..hideCurrentMaterialBanner()
      ..showMaterialBanner(
        const MaterialBanner(
          content: Text('正在下载更新...'),
          actions: [
            SizedBox(height: 14, width: 14, child: CircularProgressIndicator()),
          ],
        ),
      );
  }

  void _showUpdateAvailableBanner() {
    ScaffoldMessenger.of(context)
      ..hideCurrentMaterialBanner()
      ..showMaterialBanner(
        MaterialBanner(
          content: Text('当前 ${_currentTrack.name} track 有可用更新。'),
          actions: [
            TextButton(
              onPressed: () async {
                ScaffoldMessenger.of(context).hideCurrentMaterialBanner();
                await _downloadUpdate();
                if (!mounted) return;
                ScaffoldMessenger.of(context).hideCurrentMaterialBanner();
              },
              child: const Text('Download'),
            ),
          ],
        ),
      );
  }

  void _showNoUpdateAvailableBanner() {
    ScaffoldMessenger.of(context)
      ..hideCurrentMaterialBanner()
      ..showMaterialBanner(
        MaterialBanner(
          content: Text('当前 ${_currentTrack.name} track 没有可用更新。'),
          actions: [
            TextButton(
              onPressed: () {
                ScaffoldMessenger.of(context).hideCurrentMaterialBanner();
              },
              child: const Text('Dismiss'),
            ),
          ],
        ),
      );
  }

  void _showRestartBanner() {
    ScaffoldMessenger.of(context)
      ..hideCurrentMaterialBanner()
      ..showMaterialBanner(
        MaterialBanner(
          content: const Text('新的 patch 已准备好，请重启应用。'),
          actions: [
            TextButton(
              onPressed: () {
                ScaffoldMessenger.of(context).hideCurrentMaterialBanner();
              },
              child: const Text('Dismiss'),
            ),
          ],
        ),
      );
  }

  void _showUnavailableBanner() {
    ScaffoldMessenger.of(context)
      ..hideCurrentMaterialBanner()
      ..showMaterialBanner(
        MaterialBanner(
          content: const Text('当前构建不可用 Shorebird。'),
          actions: [
            TextButton(
              onPressed: () {
                ScaffoldMessenger.of(context).hideCurrentMaterialBanner();
              },
              child: const Text('Dismiss'),
            ),
          ],
        ),
      );
  }

  void _showErrorBanner(Object error) {
    ScaffoldMessenger.of(context)
      ..hideCurrentMaterialBanner()
      ..showMaterialBanner(
        MaterialBanner(
          content: Text('检查更新时发生错误：$error'),
          actions: [
            TextButton(
              onPressed: () {
                ScaffoldMessenger.of(context).hideCurrentMaterialBanner();
              },
              child: const Text('Dismiss'),
            ),
          ],
        ),
      );
  }

  Future<void> _downloadUpdate() async {
    _showDownloadingBanner();
    try {
      await _shorebird.downloadUpdate(track: _currentTrack);
      if (!mounted) return;
      setState(() => _currentPatch = _shorebird.currentPatch);
      _showRestartBanner();
    } on UpdateException catch (error) {
      _showErrorBanner(error.message);
    } catch (error) {
      _showErrorBanner(error);
    }
  }

  @override
  Widget build(BuildContext context) {
    final cs = ShadTheme.of(context).colorScheme;
    return Scaffold(
      appBar: AppBar(
        backgroundColor: cs.background,
        surfaceTintColor: Colors.transparent,
        elevation: 0,
        scrolledUnderElevation: 0,
        title: Text(
          'Shorebird',
          style: TextStyle(
            fontSize: 17,
            fontWeight: FontWeight.w700,
            color: cs.foreground,
          ),
        ),
        leading: IconButton(
          icon: Icon(Icons.arrow_back_ios_new, color: cs.foreground, size: 18),
          onPressed: () {
            if (context.canPop()) {
              context.pop();
            } else {
              context.go(AppRoutes.debug);
            }
          },
        ),
      ),
      body: ListView(
        padding: const EdgeInsets.fromLTRB(Spacing.page, 8, Spacing.page, 24),
        children: [
          if (!_isUpdaterAvailable) ...[
            _Card(
              child: Text(
                '当前构建未接入 Shorebird。请确认应用是通过 `shorebird release` 生成的 release 包，然后再检查更新与 patch 状态。',
                style: AppText.body.copyWith(color: cs.mutedForeground),
              ),
            ),
            const SizedBox(height: Spacing.cardGap),
          ],
          _Section(
            title: '当前状态',
            child: _Card(
              child: Column(
                children: [
                  _InfoTile(
                    title: '当前 patch 版本',
                    value: _currentPatch != null
                        ? '${_currentPatch!.number}'
                        : '未安装 patch',
                  ),
                  Divider(height: 1, thickness: 1, color: cs.border),
                  _InfoTile(
                    title: '更新器可用',
                    value: _isUpdaterAvailable ? '是' : '否',
                  ),
                ],
              ),
            ),
          ),
          _Section(
            title: 'Track 选择',
            child: _Card(
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      '选择要检查和下载的 track。',
                      style: AppText.body.copyWith(color: cs.mutedForeground),
                    ),
                    const SizedBox(height: 12),
                    SegmentedButton<UpdateTrack>(
                      segments: const [
                        ButtonSegment(
                          label: Text('Stable'),
                          value: UpdateTrack.stable,
                        ),
                        ButtonSegment(
                          label: Text('Beta'),
                          value: UpdateTrack.beta,
                        ),
                        ButtonSegment(
                          label: Text('Staging'),
                          value: UpdateTrack.staging,
                        ),
                      ],
                      selected: {_currentTrack},
                      onSelectionChanged: (tracks) {
                        setState(() => _currentTrack = tracks.single);
                      },
                    ),
                  ],
                ),
              ),
            ),
          ),
          _Section(
            title: '操作',
            child: _Card(
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Row(
                  children: [
                    Expanded(
                      child: FilledButton(
                        onPressed: _isCheckingForUpdates
                            ? null
                            : _checkForUpdate,
                        child: _isCheckingForUpdates
                            ? const SizedBox(
                                width: 16,
                                height: 16,
                                child: CircularProgressIndicator(
                                  strokeWidth: 2,
                                ),
                              )
                            : const Text('检查更新'),
                      ),
                    ),
                    const SizedBox(width: 12),
                    Expanded(
                      child: OutlinedButton(
                        onPressed: _downloadUpdate,
                        child: const Text('下载更新'),
                      ),
                    ),
                  ],
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }
}

class _Section extends StatelessWidget {
  const _Section({required this.title, required this.child});

  final String title;
  final Widget child;

  @override
  Widget build(BuildContext context) {
    final cs = ShadTheme.of(context).colorScheme;
    return Padding(
      padding: const EdgeInsets.only(bottom: Spacing.sectionGap),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Padding(
            padding: const EdgeInsets.only(left: 4, bottom: 10),
            child: Text(
              title,
              style: AppText.meta.copyWith(
                fontSize: 13,
                fontWeight: FontWeight.w600,
                color: cs.mutedForeground,
              ),
            ),
          ),
          child,
        ],
      ),
    );
  }
}

class _Card extends StatelessWidget {
  const _Card({required this.child});

  final Widget child;

  @override
  Widget build(BuildContext context) {
    final cs = ShadTheme.of(context).colorScheme;
    return Container(
      decoration: BoxDecoration(
        color: cs.card,
        border: Border.all(color: cs.border),
        borderRadius: BorderRadius.circular(Spacing.radiusBase),
      ),
      clipBehavior: Clip.antiAlias,
      child: child,
    );
  }
}

class _InfoTile extends StatelessWidget {
  const _InfoTile({required this.title, required this.value});

  final String title;
  final String value;

  @override
  Widget build(BuildContext context) {
    final cs = ShadTheme.of(context).colorScheme;
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 14),
      child: Row(
        children: [
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  title,
                  style: AppText.meta.copyWith(color: cs.mutedForeground),
                ),
                const SizedBox(height: 4),
                Text(
                  value,
                  style: AppText.body.copyWith(
                    color: cs.foreground,
                    fontWeight: FontWeight.w600,
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}