import 'package:flutter/material.dart';

import '../../core/app_state.dart';
import '../../core/assessment_bank.dart';
import '../../core/ai_service.dart';
import '../../core/app_theme.dart';
import '../../core/models.dart';
import '../../core/voice_service.dart';
import '../../widgets/app_widgets.dart';
import '../../core/sync/sync_coordinator.dart';
import 'sync_settings_sheet.dart';

class ProgressPage extends StatelessWidget {
  const ProgressPage({
    super.key,
    required this.state,
    required this.onSettings,
    required this.onOpenAssessment,
  });
  final AppState state;
  final VoidCallback onSettings;
  final ValueChanged<AssessmentPack> onOpenAssessment;

  @override
  Widget build(BuildContext context) {
    final recall = state.mastery.values
        .where((item) => item.status == MasteryStatus.recall)
        .length;
    final recentEvidence = state.attemptEvidence.reversed.take(5).toList();
    return AppPage(
      child: SpacedColumn(
        children: [
          const Eyebrow('当前：A0 起步'),
          Text('进度来自掌握证据。', style: Theme.of(context).textTheme.headlineMedium),
          const Text('不是上完固定课数就升级。核心表达需要在不同时间、不同情境中独立用出。'),
          _AbilityRow(
            icon: Icons.psychology_outlined,
            title: '已接触',
            note: '${state.knownItemCount} 个词句或任务',
            completed: state.knownItemCount > 0,
          ),
          _AbilityRow(
            icon: Icons.replay_outlined,
            title: '能回忆',
            note: '$recall 项正在巩固',
            completed: recall > 0,
          ),
          _AbilityRow(
            icon: Icons.record_voice_over_outlined,
            title: '可使用',
            note: '${state.coreUsableCount} / 48 项核心内容已获得独立使用证据',
            completed: state.coreUsableCount >= 48,
          ),
          _AbilityRow(
            icon: Icons.verified_outlined,
            title: '已掌握（间隔复习）',
            note: '${state.coreMasteredCount} / 30 项达到四次间隔复习要求',
            completed: state.coreMasteredCount >= 30,
          ),
          _AbilityRow(
            icon: Icons.assignment_turned_in_outlined,
            title: '两套四技能评估',
            note: state.hasTwoValidAssessmentPasses
                ? '两套不同题组已在有效时间内通过'
                : '尚需两套不同题组通过，间隔至少 24 小时',
            completed: state.hasTwoValidAssessmentPasses,
          ),
          SectionCard(
            tint: state.dueReviewCount > 0
                ? AppColors.warm
                : AppColors.softGreen,
            child: Row(
              children: [
                Icon(
                  state.dueReviewCount > 0
                      ? Icons.schedule
                      : Icons.check_circle_outline,
                  color: state.dueReviewCount > 0
                      ? AppColors.warmInk
                      : AppColors.green,
                ),
                const SizedBox(width: 10),
                Expanded(
                  child: Text(
                    state.dueReviewCount > 0
                        ? '有 ${state.dueReviewCount} 项到期复习，完成后会更新掌握证据。'
                        : '目前没有到期复习。',
                  ),
                ),
              ],
            ),
          ),
          const SectionCard(
            child: Text(
              '进入下一阶段条件：60 项固定核心内容中至少 48 项可使用、30 项已掌握，且两套不同题组的听说读写评估都通过并间隔至少 24 小时。',
            ),
          ),
          AnimatedBuilder(
            animation: SyncCoordinator.instance,
            builder: (context, _) {
              final loggedIn = SyncCoordinator.instance.isLoggedIn;
              return SectionCard(
                onTap: () => SyncSettingsSheet.show(context, state),
                child: Row(
                  children: [
                    Icon(
                      loggedIn
                          ? Icons.cloud_done_outlined
                          : Icons.cloud_queue_outlined,
                      color: loggedIn ? AppColors.green : AppColors.muted,
                    ),
                    const SizedBox(width: 10),
                    Expanded(
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Text(
                            loggedIn
                                ? '云同步：${SyncCoordinator.instance.username}'
                                : '云端同步与多端备份',
                            style: const TextStyle(fontWeight: FontWeight.w600),
                          ),
                          Text(
                            loggedIn
                                ? '多端学习进度与复习状态已连接 · 点击管理'
                                : '未登录 · 点击配置自建服务器，在手机与电脑间同步',
                            style: Theme.of(context).textTheme.bodyMedium,
                          ),
                        ],
                      ),
                    ),
                    const Icon(Icons.chevron_right, color: AppColors.muted),
                  ],
                ),
              );
            },
          ),
          if (state.a0Passed)
            const SectionCard(
              tint: AppColors.softGreen,
              child: Text('A0 已通过。A1 主线内容尚未提供，可继续进行 A0 巩固。'),
            ),
          if (recentEvidence.isNotEmpty) ...[
            const Text(
              '最近学习证据',
              style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600),
            ),
            const Text('用于解释进度，不是公开记录。'),
            for (final evidence in recentEvidence)
              SectionCard(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      '${_evidenceLabel(evidence.outcome)} · ${evidence.skill}',
                      style: const TextStyle(fontWeight: FontWeight.w600),
                    ),
                    if (evidence.rawAnswer?.isNotEmpty == true) ...[
                      const SizedBox(height: 4),
                      Text('你的回答：${evidence.rawAnswer}'),
                    ],
                    const SizedBox(height: 4),
                    Text(
                      _relativeTime(evidence.createdAt),
                      style: Theme.of(context).textTheme.bodyMedium,
                    ),
                  ],
                ),
              ),
          ],
          const Text(
            'A0 四技能评估',
            style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600),
          ),
          Text(
            '评估不会提供翻译或句框；第二套题组须在第一套通过至少 24 小时后完成。',
            style: Theme.of(context).textTheme.bodyMedium,
          ),
          for (final pack in a0AssessmentPacks)
            SecondaryButton(
              label: state.canStartAssessmentPack(pack.id)
                  ? '开始 ${pack.id}'
                  : '${pack.id} 需等待第一套评估通过 24 小时',
              onPressed: state.canStartAssessmentPack(pack.id)
                  ? () => onOpenAssessment(pack)
                  : null,
            ),
          SecondaryButton(label: '调整学习与 AI 设置', onPressed: onSettings),
        ],
      ),
    );
  }

  static String _evidenceLabel(EvidenceKind outcome) => switch (outcome) {
    EvidenceKind.independentSuccess => '独立完成',
    EvidenceKind.assisted => '带提示完成',
    EvidenceKind.languageError => '需要复核',
    EvidenceKind.pending => '稍后完成',
    EvidenceKind.exposure => '已查看',
  };

  static String _relativeTime(DateTime time) {
    final difference = DateTime.now().difference(time);
    if (difference.inMinutes < 1) return '刚刚';
    if (difference.inHours < 1) return '${difference.inMinutes} 分钟前';
    if (difference.inDays < 1) return '${difference.inHours} 小时前';
    return '${difference.inDays} 天前';
  }
}

class _AbilityRow extends StatelessWidget {
  const _AbilityRow({
    required this.icon,
    required this.title,
    required this.note,
    required this.completed,
  });
  final IconData icon;
  final String title;
  final String note;
  final bool completed;
  @override
  Widget build(BuildContext context) => Padding(
    padding: const EdgeInsets.symmetric(vertical: 8),
    child: Row(
      children: [
        Icon(icon, color: completed ? AppColors.green : AppColors.muted),
        const SizedBox(width: 12),
        Expanded(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text(title, style: const TextStyle(fontWeight: FontWeight.w600)),
              Text(note, style: Theme.of(context).textTheme.bodyMedium),
            ],
          ),
        ),
      ],
    ),
  );
}

class SettingsPage extends StatefulWidget {
  const SettingsPage({super.key, required this.state, this.onBack});
  final AppState state;
  final VoidCallback? onBack;

  @override
  State<SettingsPage> createState() => _SettingsPageState();
}

class _SettingsPageState extends State<SettingsPage> {
  late final TextEditingController endpoint;
  late final TextEditingController model;
  final apiKey = TextEditingController();
  bool _testingConnection = false;

  @override
  void initState() {
    super.initState();
    endpoint = TextEditingController(text: widget.state.aiEndpoint);
    model = TextEditingController(text: widget.state.aiModel);
  }

  @override
  void dispose() {
    endpoint.dispose();
    model.dispose();
    apiKey.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => AppPage(
    appBar: AppBar(
      leading: IconButton(
        icon: const Icon(Icons.arrow_back),
        tooltip: "返回",
        onPressed: () {
          if (widget.onBack != null) {
            widget.onBack!();
          } else if (Navigator.canPop(context)) {
            Navigator.pop(context);
          }
        },
      ),
      title: const Text('学习设置'),
    ),
    child: SpacedColumn(
      spacing: 4,
      children: [
        _SettingTile(
          title: '每日学习时间',
          subtitle: '${widget.state.dailyMinutes} 分钟',
          onTap: () => _chooseDuration(context),
        ),
        SwitchListTile(
          contentPadding: const EdgeInsets.symmetric(horizontal: 4),
          title: const Text('默认显示中文提示'),
          subtitle: const Text('A0 阶段开启'),
          value: widget.state.showChineseHints,
          activeThumbColor: AppColors.green,
          onChanged: widget.state.toggleChineseHints,
        ),
        SwitchListTile(
          contentPadding: const EdgeInsets.symmetric(horizontal: 4),
          title: const Text('保存原始录音'),
          subtitle: const Text('录音功能启用后仅保存在本机'),
          value: widget.state.keepRecordings,
          activeThumbColor: AppColors.green,
          onChanged: widget.state.toggleKeepRecordings,
        ),
        _SettingTile(
          title: '已保存的录音',
          subtitle: '回听或删除本机英语练习录音',
          onTap: () => _showRecordings(context),
        ),
        _SettingTile(
          title: '清除已保存的录音',
          subtitle: '只删除本机原始音频，不影响学习进度或 AI 密钥',
          onTap: () => _confirmDeleteRecordings(context),
        ),
        const Divider(height: 28),
        const Text(
          '云同步与多端备份',
          style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600),
        ),
        const Text(
          '支持通过自建服务器在 Android / iOS / macOS 之间同步学习进度与复习掌握度。离线自动缓存，联网自动双向合并。',
          style: TextStyle(fontSize: 12, color: AppColors.muted),
        ),
        AnimatedBuilder(
          animation: SyncCoordinator.instance,
          builder: (context, _) => _SettingTile(
            title: SyncCoordinator.instance.isLoggedIn
                ? '同步账号：${SyncCoordinator.instance.username}'
                : '配置云端同步账号',
            subtitle: SyncCoordinator.instance.isLoggedIn
                ? '已连接自建服务器 · 点击管理同步'
                : '未登录 · 点击配置自建服务器并登录',
            onTap: () => SyncSettingsSheet.show(context, widget.state),
          ),
        ),
        const Divider(height: 28),
        const Text(
          'AI 对话服务',
          style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600),
        ),
        const Text(
          '订阅版 ChatGPT / Gemini 不能直接作为 App API 使用。请使用自己的 API Key，或填写兼容 OpenAI 接口的 CLIProxyAPI 地址。密钥不在此页面保存。',
          style: TextStyle(fontSize: 12, color: AppColors.muted),
        ),
        DropdownButtonFormField<AiProviderType>(
          value: widget.state.aiProvider,
          decoration: const InputDecoration(
            labelText: '服务类型',
            border: OutlineInputBorder(),
          ),
          items: const [
            DropdownMenuItem(
              value: AiProviderType.mock,
              child: Text('内置练习模式（无需网络）'),
            ),
            DropdownMenuItem(
              value: AiProviderType.openAi,
              child: Text('OpenAI API'),
            ),
            DropdownMenuItem(
              value: AiProviderType.gemini,
              child: Text('Gemini API'),
            ),
            DropdownMenuItem(
              value: AiProviderType.compatible,
              child: Text('OpenAI 兼容 / CLIProxyAPI'),
            ),
          ],
          onChanged: (value) {
            if (value == null) return;
            setState(() {
              widget.state.setAiProvider(value);
              if (value == AiProviderType.gemini &&
                  endpoint.text.trim().isEmpty) {
                endpoint.text =
                    'https://generativelanguage.googleapis.com/v1beta';
                model.text = model.text.trim().isEmpty
                    ? 'gemini-2.5-flash'
                    : model.text;
              }
            });
          },
        ),
        TextField(
          controller: endpoint,
          keyboardType: TextInputType.url,
          decoration: const InputDecoration(
            labelText: 'Base URL（可选）',
            hintText:
                'OpenAI / 兼容： https://…/v1；Gemini： https://generativelanguage.googleapis.com/v1beta',
            border: OutlineInputBorder(),
          ),
        ),
        TextField(
          controller: model,
          decoration: const InputDecoration(
            labelText: '模型名称（可选）',
            hintText: '例如 gpt-4.1-mini',
            border: OutlineInputBorder(),
          ),
        ),
        TextField(
          controller: apiKey,
          obscureText: true,
          decoration: const InputDecoration(
            labelText: 'API Key（仅保存到设备安全存储）',
            border: OutlineInputBorder(),
          ),
        ),
        PrimaryButton(
          label: '保存服务设置',
          onPressed: () async {
            widget.state.saveAiConfiguration(
              endpoint: endpoint.text,
              model: model.text,
            );
            if (apiKey.text.trim().isNotEmpty) {
              await AiService.instance.saveApiKey(apiKey.text);
            }
            if (!context.mounted) return;
            ScaffoldMessenger.of(
              context,
            ).showSnackBar(const SnackBar(content: Text('服务设置已保存。')));
          },
        ),
        SecondaryButton(
          label: _testingConnection ? '正在测试连接...' : '测试连接',
          onPressed: _testingConnection
              ? null
              : () async {
                  setState(() => _testingConnection = true);
                  final result = await AiService.instance.testConnection(
                    provider: widget.state.aiProvider,
                    endpoint: endpoint.text,
                    model: model.text,
                    explicitApiKey: apiKey.text,
                  );
                  if (!mounted) return;
                  setState(() => _testingConnection = false);
                  ScaffoldMessenger.of(context).showSnackBar(
                    SnackBar(
                      content: Text(result.message),
                      backgroundColor:
                          result.ok ? AppColors.green : Colors.redAccent,
                      duration: const Duration(seconds: 4),
                    ),
                  );
                },
        ),
        SecondaryButton(
          label: '从配置文件重载 (ai_config.json)',
          onPressed: () async {
            final ok = await widget.state.reloadAiConfigFromAsset();
            if (!mounted) return;
            if (ok) {
              setState(() {
                endpoint.text = widget.state.aiEndpoint;
                model.text = widget.state.aiModel;
              });
              ScaffoldMessenger.of(context).showSnackBar(
                const SnackBar(
                  content: Text('已从 assets/config/ai_config.json 载入配置。'),
                ),
              );
            } else {
              ScaffoldMessenger.of(context).showSnackBar(
                const SnackBar(content: Text('未找到配置文件或解析失败。')),
              );
            }
          },
        ),
        const Divider(height: 28),
        _DangerAction(
          label: '清除学习进度',
          message:
              '这会清除本机的课程/分段进度、草稿、复习队列、学习作答证据、掌握记录、对话草稿、AI 补练缓存和阶段评估结果，且不可恢复。不会删除 API 密钥、AI 服务设置或已保存的原始录音；录音请使用下方独立操作删除。',
          onConfirm: widget.state.clearProgress,
        ),
      ],
    ),
  );

  Future<void> _confirmDeleteRecordings(BuildContext context) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('清除已保存的录音？'),
        content: const Text('这些原始音频只保存在本机。删除后无法恢复，学习进度不会改变。'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context, false),
            child: const Text('取消'),
          ),
          FilledButton(
            style: FilledButton.styleFrom(backgroundColor: Colors.redAccent),
            onPressed: () => Navigator.pop(context, true),
            child: const Text('清除'),
          ),
        ],
      ),
    );
    if (confirmed != true || !context.mounted) return;
    final count = await VoiceService.instance.deleteAllRecordings();
    if (!context.mounted) return;
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text(count == 0 ? '没有已保存的录音。' : '已清除 $count 段本机录音。')),
    );
  }

  Future<void> _showRecordings(
    BuildContext context,
  ) => showModalBottomSheet<void>(
    context: context,
    showDragHandle: true,
    builder: (context) => SafeArea(
      child: FutureBuilder<List<String>>(
        future: VoiceService.instance.listRecordingPaths(),
        builder: (context, snapshot) {
          if (!snapshot.hasData) {
            return const Padding(
              padding: EdgeInsets.all(24),
              child: Center(child: CircularProgressIndicator()),
            );
          }
          final paths = snapshot.data!;
          if (paths.isEmpty) {
            return const Padding(
              padding: EdgeInsets.all(24),
              child: Text('还没有保存的录音。开启“保存原始录音”后，在跟读步骤完成录音即可在这里回听。'),
            );
          }
          return Padding(
            padding: const EdgeInsets.fromLTRB(16, 0, 16, 24),
            child: SpacedColumn(
              children: [
                const Text(
                  '已保存的录音',
                  style: TextStyle(fontSize: 18, fontWeight: FontWeight.w600),
                ),
                for (final path in paths)
                  SectionCard(
                    child: Row(
                      children: [
                        const Icon(Icons.mic_none, color: AppColors.green),
                        const SizedBox(width: 10),
                        Expanded(
                          child: Text(
                            path.split('/').last.replaceAll('.m4a', ''),
                          ),
                        ),
                        IconButton(
                          tooltip: '回听',
                          onPressed: () =>
                              VoiceService.instance.playRecording(path),
                          icon: const Icon(Icons.play_arrow),
                        ),
                        IconButton(
                          tooltip: '删除',
                          onPressed: () async {
                            await VoiceService.instance.deleteRecording(path);
                            if (context.mounted) Navigator.pop(context);
                          },
                          icon: const Icon(Icons.delete_outline),
                        ),
                      ],
                    ),
                  ),
              ],
            ),
          );
        },
      ),
    ),
  );

  Future<void> _chooseDuration(BuildContext context) async {
    final value = await showModalBottomSheet<int>(
      context: context,
      builder: (context) => SafeArea(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            for (final minute in [10, 20, 30])
              ListTile(
                title: Text('$minute 分钟'),
                trailing: widget.state.dailyMinutes == minute
                    ? const Icon(Icons.check)
                    : null,
                onTap: () => Navigator.pop(context, minute),
              ),
          ],
        ),
      ),
    );
    if (value != null) widget.state.setDailyMinutes(value);
  }
}

class _SettingTile extends StatelessWidget {
  const _SettingTile({
    required this.title,
    required this.subtitle,
    required this.onTap,
  });
  final String title;
  final String subtitle;
  final VoidCallback? onTap;
  @override
  Widget build(BuildContext context) => ListTile(
    contentPadding: const EdgeInsets.symmetric(horizontal: 4),
    title: Text(title),
    subtitle: Text(subtitle),
    trailing: const Icon(Icons.chevron_right),
    onTap: onTap,
  );
}

class _DangerAction extends StatelessWidget {
  const _DangerAction({
    required this.label,
    required this.message,
    required this.onConfirm,
  });
  final String label;
  final String message;
  final VoidCallback? onConfirm;
  @override
  Widget build(BuildContext context) => ListTile(
    contentPadding: const EdgeInsets.symmetric(horizontal: 4),
    title: Text(label, style: const TextStyle(color: Colors.redAccent)),
    trailing: const Icon(Icons.chevron_right, color: Colors.redAccent),
    onTap: () => showDialog<void>(
      context: context,
      builder: (context) {
        var acknowledged = false;
        return StatefulBuilder(
          builder: (context, setDialogState) => AlertDialog(
            title: Text(label),
            content: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                Text(message),
                const SizedBox(height: 12),
                const Text(
                  '会清除：课程步骤、复习、掌握记录、学习证据、评估草稿和课程对话草稿。\n不会清除：已保存录音、AI API Key 与应用设置。',
                ),
                CheckboxListTile(
                  contentPadding: EdgeInsets.zero,
                  value: acknowledged,
                  onChanged: (value) =>
                      setDialogState(() => acknowledged = value ?? false),
                  title: const Text('我了解这些本机学习数据无法恢复'),
                ),
              ],
            ),
            actions: [
              TextButton(
                onPressed: () => Navigator.pop(context),
                child: const Text('取消'),
              ),
              FilledButton(
                style: FilledButton.styleFrom(
                  backgroundColor: Colors.redAccent,
                ),
                onPressed: acknowledged
                    ? () {
                        onConfirm?.call();
                        Navigator.pop(context);
                      }
                    : null,
                child: const Text('确认清除'),
              ),
            ],
          ),
        );
      },
    ),
  );
}