import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:go_router/go_router.dart';
import 'package:social_app/core/constants/app_constants.dart';
import 'package:social_app/core/di/injection.dart';
import 'package:social_app/core/router/app_routes.dart';
import 'package:social_app/core/theme/design_tokens.dart';
import 'package:social_app/shared/widgets/app_button.dart';
import 'package:social_app/shared/widgets/app_loading_indicator.dart';
import 'package:social_app/shared/widgets/app_pressable.dart';
import 'package:social_app/shared/widgets/destructive_action_sheet.dart';
import 'package:social_app/shared/widgets/toast/toast.dart';
import 'package:social_app/shared/widgets/toast/toast_type.dart';
import 'package:social_app/shared/utils/phone_display_formatter.dart';
import 'package:social_app/features/auth/presentation/bloc/auth_bloc.dart';
import 'package:social_app/features/auth/presentation/bloc/auth_event.dart';
import 'package:social_app/features/auth/presentation/bloc/auth_state.dart';
import 'package:social_app/features/friends/data/friends_api.dart';
import 'package:social_app/features/settings/data/settings_api.dart';
import 'package:social_app/features/settings/data/services/settings_user_cache.dart';
import 'package:social_app/features/users/data/models/user_response.dart';
import 'package:social_app/features/users/data/users_api.dart';
import 'package:social_app/features/home/ui/navigation/home_return_policy.dart';
import '../widgets/settings_page_scaffold.dart';

const settingsProfileEditButtonKey = ValueKey('settings_profile_edit_button');
const settingsLogoutButtonKey = ValueKey('settings_logout_button');

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

  @override
  State<SettingsScreen> createState() => _SettingsScreenState();
}

class _SettingsScreenState extends State<SettingsScreen> {
  final UsersApi _usersApi = sl<UsersApi>();
  final FriendsApi _friendsApi = sl<FriendsApi>();
  final SettingsUserCache _userCache = sl<SettingsUserCache>();

  UserResponse? _user;
  bool _isLoading = true;
  int _friendsCount = 0;
  String? _firstFriendName;

  @override
  void initState() {
    super.initState();
    final cachedUser = _userCache.cachedUser;
    if (cachedUser != null) {
      _user = cachedUser;
      _isLoading = false;
    }
    _loadData();
  }

  Future<void> _loadData() async {
    try {
      final user = await _userCache.getOrLoad(_usersApi.getMe);
      if (mounted) {
        setState(() {
          _user = user;
          _isLoading = false;
        });
      }
    } catch (e) {
      if (mounted && _user == null) {
        setState(() {
          _isLoading = false;
        });
      }
    }

    try {
      final friends = await _friendsApi.getFriends();

      if (mounted) {
        setState(() {
          _friendsCount = friends.length;
          _firstFriendName = friends.isNotEmpty
              ? friends.first.friend.username
              : null;
        });
      }
    } catch (e) {
      // Keep profile available even when contacts fail.
    }
  }

  @override
  Widget build(BuildContext context) {
    return SettingsPageScaffold(
      title: '设置',
      onBack: () => returnToHomePreserveState(context, forceGoHome: true),
      body: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          _buildProfileHero(),
          const SizedBox(height: AppSpacing.lg),
          _buildQuickActions(context),
          const SizedBox(height: AppSpacing.lg),
          _buildSubscriptionCard(),
          const SizedBox(height: AppSpacing.lg),
          _buildMenuCard(context),
          const SizedBox(height: AppSpacing.xl),
          _buildLogoutAction(),
        ],
      ),
    );
  }

  Widget _buildSectionLabel(String label) {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: AppSpacing.xs),
      child: Text(
        label,
        style: const TextStyle(
          fontSize: 13,
          fontWeight: FontWeight.w600,
          color: AppColors.slate500,
        ),
      ),
    );
  }

  Widget _buildProfileHero() {
    if (_isLoading) {
      return Container(
        width: double.infinity,
        height: 120,
        padding: const EdgeInsets.all(AppSpacing.xl),
        decoration: BoxDecoration(
          color: AppColors.white,
          borderRadius: BorderRadius.circular(AppRadius.xxl),
        ),
        child: const Center(child: AppLoadingIndicator(size: 22)),
      );
    }

    final username = _user?.username ?? '未设置';
    final phone = _user?.phone == null
        ? '未设置'
        : formatPhoneForDisplay(_user?.phone);

    return Container(
      width: double.infinity,
      padding: const EdgeInsets.all(AppSpacing.xl),
      decoration: BoxDecoration(
        gradient: const LinearGradient(
          begin: Alignment.topLeft,
          end: Alignment.bottomRight,
          colors: [AppColors.white, AppColors.surfaceInfoLight],
        ),
        borderRadius: BorderRadius.circular(AppRadius.xxl),
        border: Border.all(color: AppColors.borderTertiary),
        boxShadow: [
          BoxShadow(
            color: AppColors.blue100.withValues(alpha: 0.35),
            blurRadius: 14,
            offset: const Offset(0, 4),
          ),
        ],
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Row(
            crossAxisAlignment: CrossAxisAlignment.center,
            children: [
              Container(
                width: 64,
                height: 64,
                decoration: BoxDecoration(
                  gradient: LinearGradient(
                    begin: Alignment.topLeft,
                    end: Alignment.bottomRight,
                    colors: [AppColors.blue100, AppColors.blue50],
                  ),
                  borderRadius: BorderRadius.circular(32),
                  boxShadow: [
                    BoxShadow(
                      color: Color.fromRGBO(
                        AppColors.blue400.r.toInt(),
                        AppColors.blue400.g.toInt(),
                        AppColors.blue400.b.toInt(),
                        0.2,
                      ),
                      blurRadius: 12,
                      offset: const Offset(0, 4),
                    ),
                  ],
                ),
                child: const Icon(
                  Icons.person,
                  size: 28,
                  color: AppColors.blue600,
                ),
              ),
              const SizedBox(width: AppSpacing.lg),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    Text(
                      username,
                      style: const TextStyle(
                        fontSize: 20,
                        fontWeight: FontWeight.w700,
                        color: AppColors.slate900,
                      ),
                      overflow: TextOverflow.ellipsis,
                    ),
                    const SizedBox(height: 6),
                    Text(
                      phone,
                      style: TextStyle(
                        fontSize: 13,
                        fontWeight: FontWeight.w500,
                        color: AppColors.slate500,
                      ),
                    ),
                  ],
                ),
              ),
              const SizedBox(width: AppSpacing.md),
              Column(
                crossAxisAlignment: CrossAxisAlignment.end,
                children: [
                  AppPressable(
                    key: settingsProfileEditButtonKey,
                    onTap: _onTapEditProfile,
                    borderRadius: BorderRadius.circular(AppRadius.lg),
                    child: SizedBox(
                      width: AppSpacing.xl * 2,
                      height: AppSpacing.xl * 2,
                      child: Column(
                        mainAxisAlignment: MainAxisAlignment.center,
                        crossAxisAlignment: CrossAxisAlignment.center,
                        children: [
                          const Icon(
                            Icons.edit,
                            size: 14,
                            color: AppColors.slate500,
                          ),
                          const SizedBox(height: 3),
                          Container(
                            width: 12,
                            height: 1.5,
                            decoration: BoxDecoration(
                              color: AppColors.slate400,
                              borderRadius: BorderRadius.circular(
                                AppRadius.full,
                              ),
                            ),
                          ),
                        ],
                      ),
                    ),
                  ),
                  const SizedBox(height: AppSpacing.sm),
                  _buildFreeBadge(),
                ],
              ),
            ],
          ),
        ],
      ),
    );
  }

  Widget _buildFreeBadge() {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 5),
      decoration: BoxDecoration(
        gradient: LinearGradient(
          colors: [AppColors.blue50, AppColors.surfaceInfoLight],
        ),
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: AppColors.borderQuaternary),
      ),
      child: const Text(
        'Free',
        style: TextStyle(
          fontSize: 11,
          fontWeight: FontWeight.w600,
          color: AppColors.blue600,
        ),
      ),
    );
  }

  String _buildFriendsSubtitle() {
    if (_friendsCount == 0) {
      return '暂无联系人';
    }
    if (_friendsCount == 1) {
      return '已添加 1 位：$_firstFriendName';
    }
    return '已添加 $_friendsCount 位联系人';
  }

  Widget _buildQuickActions(BuildContext context) {
    return Row(
      children: [
        Expanded(
          child: _buildActionCard(
            icon: Icons.people,
            iconColor: AppColors.blue500,
            title: '联系人',
            subtitle: _buildFriendsSubtitle(),
            onTap: () => context.push(AppRoutes.contactsList),
          ),
        ),
        const SizedBox(width: AppSpacing.md),
        Expanded(
          child: _buildActionCard(
            icon: Icons.auto_awesome,
            iconColor: AppColors.violet500,
            title: '周期计划',
            subtitle: '已启用：会议提醒',
            onTap: () => context.push(AppRoutes.settingsFeatures),
          ),
        ),
      ],
    );
  }

  Widget _buildActionCard({
    required IconData icon,
    required Color iconColor,
    required String title,
    required String subtitle,
    required VoidCallback onTap,
  }) {
    return AppPressable(
      onTap: onTap,
      borderRadius: BorderRadius.circular(AppRadius.xl),
      child: Container(
        constraints: const BoxConstraints(minHeight: 136),
        padding: const EdgeInsets.all(AppSpacing.lg),
        decoration: BoxDecoration(
          color: AppColors.white,
          borderRadius: BorderRadius.circular(AppRadius.xl),
          border: Border.all(color: AppColors.borderSecondary),
          boxShadow: [
            BoxShadow(
              color: AppColors.slate200.withValues(alpha: 0.45),
              blurRadius: 8,
              offset: const Offset(0, 2),
            ),
          ],
        ),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                Container(
                  width: 36,
                  height: 36,
                  decoration: BoxDecoration(
                    color: AppColors.surfaceTertiary,
                    borderRadius: BorderRadius.circular(10),
                  ),
                  child: Icon(icon, size: 18, color: iconColor),
                ),
                const Spacer(),
                Icon(Icons.chevron_right, size: 16, color: AppColors.slate300),
              ],
            ),
            const SizedBox(height: AppSpacing.md),
            Text(
              title,
              style: const TextStyle(
                fontSize: 16,
                fontWeight: FontWeight.w600,
                color: AppColors.slate900,
              ),
            ),
            const SizedBox(height: 2),
            Text(
              subtitle,
              style: TextStyle(
                fontSize: 12,
                fontWeight: FontWeight.w500,
                color: AppColors.slate500,
              ),
              maxLines: 1,
              overflow: TextOverflow.ellipsis,
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildSubscriptionCard() {
    return Container(
      padding: const EdgeInsets.all(AppSpacing.lg),
      decoration: BoxDecoration(
        gradient: LinearGradient(
          begin: Alignment.topLeft,
          end: Alignment.bottomRight,
          colors: [AppColors.white, AppColors.surfaceInfoLight],
        ),
        borderRadius: BorderRadius.circular(AppRadius.xl),
        border: Border.all(color: AppColors.borderTertiary),
        boxShadow: [
          BoxShadow(
            color: AppColors.slate200.withValues(alpha: 0.4),
            blurRadius: 8,
            offset: const Offset(0, 2),
          ),
        ],
      ),
      child: Row(
        children: [
          Container(
            width: 44,
            height: 44,
            decoration: BoxDecoration(
              gradient: LinearGradient(
                begin: Alignment.topLeft,
                end: Alignment.bottomRight,
                colors: [AppColors.blue100, AppColors.blue50],
              ),
              borderRadius: BorderRadius.circular(12),
              boxShadow: [
                BoxShadow(
                  color: AppColors.blue200.withValues(alpha: 0.45),
                  blurRadius: 6,
                  offset: const Offset(0, 1),
                ),
              ],
            ),
            child: const Icon(
              Icons.workspace_premium,
              size: 22,
              color: AppColors.blue600,
            ),
          ),
          const SizedBox(width: AppSpacing.md),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                const Text(
                  '升级到 Pro',
                  style: TextStyle(
                    fontSize: 16,
                    fontWeight: FontWeight.w600,
                    color: AppColors.slate900,
                  ),
                ),
                const SizedBox(height: 2),
                Text(
                  '解锁更多高级功能',
                  style: TextStyle(
                    fontSize: 13,
                    fontWeight: FontWeight.w500,
                    color: AppColors.slate500,
                  ),
                ),
              ],
            ),
          ),
          Container(
            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
            decoration: BoxDecoration(
              gradient: const LinearGradient(
                colors: [AppColors.blue500, AppColors.blue600],
              ),
              borderRadius: BorderRadius.circular(20),
              boxShadow: [
                BoxShadow(
                  color: const Color(0x4D60A5FA),
                  blurRadius: 8,
                  offset: const Offset(0, 2),
                ),
              ],
            ),
            child: const Text(
              '升级',
              style: TextStyle(
                fontSize: 13,
                fontWeight: FontWeight.w600,
                color: AppColors.white,
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildMenuCard(BuildContext context) {
    return Container(
      decoration: BoxDecoration(
        color: AppColors.white,
        borderRadius: BorderRadius.circular(AppRadius.xl),
        border: Border.all(color: AppColors.borderSecondary),
      ),
      child: Column(
        children: [
          _buildMenuItem(
            icon: Icons.notifications,
            title: '提醒设置',
            onTap: () {},
          ),
          _buildDivider(),
          _buildMenuItem(
            icon: Icons.bookmark,
            title: '我的记忆',
            onTap: () => context.push(AppRoutes.settingsMemory),
          ),
          _buildDivider(),
          _buildMenuItem(
            icon: Icons.system_update,
            title: '检查更新',
            trailing: 'v${AppConstants.version}',
            onTap: _checkForUpdates,
          ),
        ],
      ),
    );
  }

  Widget _buildMenuItem({
    required IconData icon,
    required String title,
    String? trailing,
    required VoidCallback onTap,
  }) {
    return AppPressable(
      onTap: onTap,
      borderRadius: BorderRadius.circular(AppRadius.md),
      child: Container(
        height: 56,
        padding: const EdgeInsets.symmetric(horizontal: 14),
        child: Row(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: [
            Row(
              children: [
                Icon(icon, size: 20, color: AppColors.slate500),
                const SizedBox(width: 10),
                Text(
                  title,
                  style: const TextStyle(
                    fontSize: 16,
                    fontWeight: FontWeight.w500,
                    color: AppColors.slate900,
                  ),
                ),
              ],
            ),
            Row(
              children: [
                if (trailing != null) ...[
                  Text(
                    trailing,
                    style: const TextStyle(
                      fontSize: 14,
                      color: AppColors.slate400,
                    ),
                  ),
                  const SizedBox(width: 6),
                ],
                const Icon(
                  Icons.chevron_right,
                  size: 18,
                  color: AppColors.slate400,
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildDivider() {
    return Container(
      height: 1,
      margin: const EdgeInsets.symmetric(horizontal: 14),
      color: AppColors.slate100,
    );
  }

  Future<void> _onTapEditProfile() async {
    final changed = await context.push<bool>(AppRoutes.settingsEditProfile);
    if (changed == true && mounted) {
      final cached = _userCache.cachedUser;
      if (cached != null) {
        setState(() {
          _user = cached;
        });
      }
    }
  }

  Future<void> _onTapLogout() async {
    final confirmed = await showDestructiveActionSheet(
      context,
      title: '退出登录',
      message: '确定退出当前账户吗？',
      confirmText: '确认退出',
    );
    if (!confirmed || !mounted) {
      return;
    }

    _userCache.invalidate();
    final authBloc = context.read<AuthBloc>();
    authBloc.add(AuthLoggedOut());
    try {
      await authBloc.stream
          .firstWhere((state) => state is AuthUnauthenticated)
          .timeout(const Duration(seconds: 5));
    } catch (_) {
      if (!mounted) return;
      Toast.show(context, '退出失败，请稍后重试', type: ToastType.error);
      return;
    }
    if (!mounted) return;
    context.go(AppRoutes.authLogin);
  }

  Future<void> _checkForUpdates() async {
    try {
      final settingsApi = sl<SettingsApi>();
      final result = await settingsApi.checkUpdates(
        currentVersionCode: AppConstants.build,
        currentVersionName: AppConstants.version,
        platform: 'android',
      );

      if (!mounted) return;

      if (!result.hasUpdate) {
        Toast.show(context, '当前已是最新版本', type: ToastType.success);
        return;
      }

      final message = result.updateType == 'required'
          ? '有新版本可用 (${result.latestVersionName})，请立即更新'
          : '发现新版本 (${result.latestVersionName})，是否更新？';

      final shouldUpdate = await showDialog<bool>(
        context: context,
        builder: (context) => AlertDialog(
          title: const Text('检查更新'),
          content: Text(message),
          actions: [
            TextButton(
              onPressed: () => Navigator.pop(context, false),
              child: const Text('取消'),
            ),
            if (result.downloadUrl != null)
              TextButton(
                onPressed: () => Navigator.pop(context, true),
                child: const Text('更新'),
              ),
          ],
        ),
      );

      if (shouldUpdate == true && result.downloadUrl != null && mounted) {
        Toast.show(
          context,
          '下载链接: ${result.downloadUrl}',
          type: ToastType.info,
        );
      }
    } catch (e) {
      if (!mounted) return;
      Toast.show(context, '检查更新失败', type: ToastType.error);
    }
  }

  Widget _buildLogoutAction() {
    return SizedBox(
      width: double.infinity,
      height: 52,
      child: AppButton(
        key: settingsLogoutButtonKey,
        text: '退出登录',
        isOutlined: true,
        onPressed: () => _onTapLogout(),
      ),
    );
  }
}