// 家长中心页面 — 只读查看孩子日记 + 心情统计 + 数据导出/删除
//
// 通过 ParentBloc 驱动家长中心状态：
// - 进入页面 → ParentLoadChildren 加载孩子列表
// - 无孩子 → 显示绑定入口
// - 有孩子 → 显示孩子卡片 + 4 个功能按钮
// - 日记查看 → ParentViewJournals → 日记列表
// - 数据导出 → ParentExportData → 展示导出结果
// - 数据删除 → 确认对话框 → ParentDeleteData
// 保留 PIPL 合规提示。

import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:go_router/go_router.dart';
import 'package:intl/intl.dart';

import '../../../core/theme/app_colors.dart';
import '../../../core/theme/app_radius.dart';
import '../../../core/utils/file_download.dart';
import '../bloc/parent_bloc.dart';

/// 家长中心页面 — 家长查看孩子日记和统计数据
class ParentPage extends StatefulWidget {
  const ParentPage({super.key});

  @override
  State<ParentPage> createState() => _ParentPageState();
}

class _ParentPageState extends State<ParentPage> {
  final _childIdController = TextEditingController();

  @override
  void initState() {
    super.initState();
    // 进入页面自动加载孩子列表
    context.read<ParentBloc>().add(const ParentLoadChildren());
  }

  @override
  void dispose() {
    _childIdController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;

    return Scaffold(
      appBar: AppBar(title: const Text('家长中心')),
      body: BlocConsumer<ParentBloc, ParentState>(
        listener: (context, state) {
          if (state is ParentError) {
            ScaffoldMessenger.of(context).showSnackBar(
              SnackBar(
                content: Text(state.message),
                backgroundColor: AppColors.error,
              ),
            );
          }
          if (state is ParentDataDeleted) {
            ScaffoldMessenger.of(context).showSnackBar(
              const SnackBar(
                content: Text('孩子数据已删除'),
                backgroundColor: AppColors.success,
              ),
            );
            // 删除后重新加载列表
            context.read<ParentBloc>().add(const ParentLoadChildren());
          }
        },
        builder: (context, state) {
          if (state is ParentLoading) {
            return const Center(child: CircularProgressIndicator());
          }

          // 日记列表视图
          if (state is ParentJournalsLoaded) {
            return _JournalListView(
              childId: state.childId,
              journals: state.journals,
              onBack: () =>
                  context.read<ParentBloc>().add(const ParentLoadChildren()),
            );
          }

          // 导出数据视图
          if (state is ParentDataExported) {
            return _ExportDataView(
              childId: state.childId,
              data: state.data,
              onBack: () =>
                  context.read<ParentBloc>().add(const ParentLoadChildren()),
            );
          }

          // 孩子列表或绑定入口
          final children = state is ParentChildrenLoaded ? state.children : <ChildBinding>[];

          return SingleChildScrollView(
            padding: const EdgeInsets.all(16),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                // 页面标题区
                _HeaderCard(theme: theme, colorScheme: colorScheme),
                const SizedBox(height: 20),

                // 孩子列表或绑定入口
                if (children.isEmpty) ...[
                  _BindChildSection(
                    controller: _childIdController,
                    onBind: () {
                      final childId = _childIdController.text.trim();
                      if (childId.isEmpty) return;
                      context.read<ParentBloc>().add(ParentBindChild(childId));
                      _childIdController.clear();
                    },
                  ),
                ] else ...[
                  _ChildListSection(
                    children: children,
                    theme: theme,
                    colorScheme: colorScheme,
                  ),
                  const SizedBox(height: 20),
                  _ActionGrid(
                    children: children,
                    onViewJournals: (childId) => context
                        .read<ParentBloc>()
                        .add(ParentViewJournals(childId)),
                    onExport: (childId) => context
                        .read<ParentBloc>()
                        .add(ParentExportData(childId)),
                    onDelete: (childId) => _showDeleteConfirmDialog(
                      context,
                      childId,
                    ),
                    onMoodStats: (childId) {
                      // 复用已有心情统计页面 — 带孩子 ID 参数
                      context.push('/mood?child_id=$childId');
                    },
                  ),
                ],

                const SizedBox(height: 24),

                // PIPL 提示
                _PiplNotice(theme: theme, colorScheme: colorScheme),
              ],
            ),
          );
        },
      ),
    );
  }

  /// 删除确认对话框
  void _showDeleteConfirmDialog(BuildContext context, String childId) {
    final theme = Theme.of(context);

    showDialog(
      context: context,
      builder: (dialogContext) => AlertDialog(
        shape: RoundedRectangleBorder(borderRadius: AppRadius.lgBorder),
        title: Row(
          children: [
            Icon(Icons.warning_amber_rounded, color: AppColors.warning, size: 28),
            const SizedBox(width: 12),
            const Text('确认删除'),
          ],
        ),
        content: Text(
          '此操作将永久删除该孩子的所有日记数据，包括文字、图片和贴纸。'
          '\n\n根据《个人信息保护法》，此操作不可撤销。',
          style: theme.textTheme.bodyMedium,
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(dialogContext).pop(),
            child: const Text('取消'),
          ),
          FilledButton(
            style: FilledButton.styleFrom(
              backgroundColor: AppColors.error,
              shape: RoundedRectangleBorder(
                borderRadius: AppRadius.smBorder,
              ),
            ),
            onPressed: () {
              Navigator.of(dialogContext).pop();
              context.read<ParentBloc>().add(ParentDeleteData(childId));
            },
            child: const Text('确认删除'),
          ),
        ],
      ),
    );
  }
}

// ===== 子组件 =====

/// 标题卡片 — 孩子信息概览
class _HeaderCard extends StatelessWidget {
  const _HeaderCard({
    required this.theme,
    required this.colorScheme,
  });

  final ThemeData theme;
  final ColorScheme colorScheme;

  @override
  Widget build(BuildContext context) {
    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(borderRadius: AppRadius.lgBorder),
      color: colorScheme.primaryContainer,
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Row(
          children: [
            CircleAvatar(
              radius: 28,
              backgroundColor: AppColors.rose.withValues(alpha: 0.2),
              child: const Text('👶', style: TextStyle(fontSize: 24)),
            ),
            const SizedBox(width: 16),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    '孩子的日记',
                    style: theme.textTheme.titleMedium?.copyWith(
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                  const SizedBox(height: 4),
                  Text(
                    '查看和管理孩子的日记数据',
                    style: theme.textTheme.bodySmall?.copyWith(
                      color: colorScheme.onSurface.withValues(alpha: 0.6),
                    ),
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}

/// 绑定孩子入口 — 输入框 + 绑定按钮
class _BindChildSection extends StatelessWidget {
  const _BindChildSection({
    required this.controller,
    required this.onBind,
  });

  final TextEditingController controller;
  final VoidCallback onBind;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;

    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: AppRadius.lgBorder,
        side: BorderSide(color: colorScheme.outlineVariant),
      ),
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                Container(
                  width: 44,
                  height: 44,
                  decoration: BoxDecoration(
                    color: AppColors.accent.withValues(alpha: 0.12),
                    borderRadius: BorderRadius.circular(12),
                  ),
                  child: Icon(
                    Icons.link,
                    color: AppColors.accent,
                    size: 22,
                  ),
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        '绑定孩子账号',
                        style: theme.textTheme.titleSmall?.copyWith(
                          fontWeight: FontWeight.w600,
                        ),
                      ),
                      const SizedBox(height: 2),
                      Text(
                        '输入孩子的账号 ID 建立绑定关系',
                        style: theme.textTheme.bodySmall?.copyWith(
                          color: colorScheme.onSurface.withValues(alpha: 0.5),
                        ),
                      ),
                    ],
                  ),
                ),
              ],
            ),
            const SizedBox(height: 16),
            Row(
              children: [
                Expanded(
                  child: TextField(
                    controller: controller,
                    decoration: InputDecoration(
                      hintText: '输入孩子 ID',
                      prefixIcon: const Icon(Icons.person_outline, size: 20),
                      border: OutlineInputBorder(
                        borderRadius: AppRadius.smBorder,
                        borderSide: BorderSide(color: colorScheme.outlineVariant),
                      ),
                      enabledBorder: OutlineInputBorder(
                        borderRadius: AppRadius.smBorder,
                        borderSide: BorderSide(color: colorScheme.outlineVariant),
                      ),
                      focusedBorder: OutlineInputBorder(
                        borderRadius: AppRadius.smBorder,
                        borderSide: BorderSide(color: AppColors.accent, width: 2),
                      ),
                      contentPadding: const EdgeInsets.symmetric(
                        horizontal: 12,
                        vertical: 12,
                      ),
                    ),
                    onSubmitted: (_) => onBind(),
                  ),
                ),
                const SizedBox(width: 12),
                FilledButton(
                  onPressed: onBind,
                  style: FilledButton.styleFrom(
                    backgroundColor: AppColors.accent,
                    shape: RoundedRectangleBorder(
                      borderRadius: AppRadius.smBorder,
                    ),
                    padding: const EdgeInsets.symmetric(
                      horizontal: 20,
                      vertical: 14,
                    ),
                  ),
                  child: const Text('绑定'),
                ),
              ],
            ),
            const SizedBox(height: 12),
            Container(
              padding: const EdgeInsets.all(10),
              decoration: BoxDecoration(
                color: AppColors.tertiarySoftLight,
                borderRadius: AppRadius.smBorder,
              ),
              child: Row(
                children: [
                  Icon(
                    Icons.info_outline,
                    size: 16,
                    color: AppColors.tertiary,
                  ),
                  const SizedBox(width: 8),
                  Expanded(
                    child: Text(
                      '孩子的 ID 可在孩子的"我的"页面中查看',
                      style: theme.textTheme.bodySmall?.copyWith(
                        color: AppColors.fg2Light,
                      ),
                    ),
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}

/// 孩子列表 — 显示已绑定的孩子
class _ChildListSection extends StatelessWidget {
  const _ChildListSection({
    required this.children,
    required this.theme,
    required this.colorScheme,
  });

  final List<ChildBinding> children;
  final ThemeData theme;
  final ColorScheme colorScheme;

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          '已绑定的孩子 (${children.length})',
          style: theme.textTheme.titleSmall?.copyWith(
            fontWeight: FontWeight.w600,
          ),
        ),
        const SizedBox(height: 12),
        ...children.map((child) => _ChildCard(
              binding: child,
              theme: theme,
              colorScheme: colorScheme,
              onUnbind: () {
                _showUnbindConfirmDialog(context, child.childId);
              },
            )),
      ],
    );
  }

  void _showUnbindConfirmDialog(BuildContext context, String childId) {
    showDialog(
      context: context,
      builder: (dialogContext) => AlertDialog(
        shape: RoundedRectangleBorder(borderRadius: AppRadius.lgBorder),
        title: const Text('确认解绑'),
        content: Text(
          '解绑后将无法查看该孩子的日记数据。',
          style: theme.textTheme.bodyMedium,
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(dialogContext).pop(),
            child: const Text('取消'),
          ),
          FilledButton(
            onPressed: () {
              Navigator.of(dialogContext).pop();
              context.read<ParentBloc>().add(ParentUnbindChild(childId));
            },
            child: const Text('确认解绑'),
          ),
        ],
      ),
    );
  }
}

/// 单个孩子卡片
class _ChildCard extends StatelessWidget {
  const _ChildCard({
    required this.binding,
    required this.theme,
    required this.colorScheme,
    required this.onUnbind,
  });

  final ChildBinding binding;
  final ThemeData theme;
  final ColorScheme colorScheme;
  final VoidCallback onUnbind;

  @override
  Widget build(BuildContext context) {
    final verifiedStr = binding.verifiedAt != null
        ? DateFormat('yyyy-MM-dd').format(binding.verifiedAt!)
        : '未验证';

    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: AppRadius.mdBorder,
        side: BorderSide(color: colorScheme.outlineVariant),
      ),
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Row(
          children: [
            CircleAvatar(
              radius: 24,
              backgroundColor: AppColors.secondary.withValues(alpha: 0.15),
              child: const Text('👧', style: TextStyle(fontSize: 20)),
            ),
            const SizedBox(width: 12),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    '孩子 ${binding.childId.substring(0, binding.childId.length > 8 ? 8 : binding.childId.length)}',
                    style: theme.textTheme.titleSmall?.copyWith(
                      fontWeight: FontWeight.w600,
                    ),
                  ),
                  const SizedBox(height: 2),
                  Text(
                    '绑定时间: $verifiedStr',
                    style: theme.textTheme.bodySmall?.copyWith(
                      color: colorScheme.onSurface.withValues(alpha: 0.5),
                    ),
                  ),
                ],
              ),
            ),
            IconButton(
              icon: Icon(
                Icons.link_off,
                size: 20,
                color: colorScheme.onSurface.withValues(alpha: 0.4),
              ),
              onPressed: onUnbind,
              tooltip: '解绑',
            ),
          ],
        ),
      ),
    );
  }
}

/// 功能操作网格 — 4 个功能按钮
class _ActionGrid extends StatefulWidget {
  const _ActionGrid({
    required this.children,
    required this.onViewJournals,
    required this.onExport,
    required this.onDelete,
    required this.onMoodStats,
  });

  final List<ChildBinding> children;
  final void Function(String childId) onViewJournals;
  final void Function(String childId) onExport;
  final void Function(String childId) onDelete;
  final void Function(String childId) onMoodStats;

  @override
  State<_ActionGrid> createState() => _ActionGridState();
}

class _ActionGridState extends State<_ActionGrid> {
  late String _selectedChildId;

  @override
  void initState() {
    super.initState();
    _selectedChildId = widget.children.isNotEmpty ? widget.children.first.childId : '';
  }

  @override
  void didUpdateWidget(covariant _ActionGrid oldWidget) {
    super.didUpdateWidget(oldWidget);
    // 当孩子列表变化时更新选中 ID
    if (oldWidget.children != widget.children) {
      if (!widget.children.any((c) => c.childId == _selectedChildId)) {
        _selectedChildId = widget.children.isNotEmpty ? widget.children.first.childId : '';
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        // 孩子选择器（多孩子时显示）
        if (widget.children.length > 1) ...[
          Text(
            '选择孩子',
            style: theme.textTheme.titleSmall?.copyWith(
              fontWeight: FontWeight.w600,
            ),
          ),
          const SizedBox(height: 8),
          Container(
            padding: const EdgeInsets.symmetric(horizontal: 12),
            decoration: BoxDecoration(
              color: colorScheme.surface,
              borderRadius: AppRadius.mdBorder,
              border: Border.all(color: colorScheme.outlineVariant),
            ),
            child: DropdownButtonHideUnderline(
              child: DropdownButton<String>(
                value: _selectedChildId.isEmpty ? null : _selectedChildId,
                isExpanded: true,
                icon: const Icon(Icons.expand_more, size: 20),
                items: widget.children.map((child) {
                  final shortId = child.childId.length > 8
                      ? child.childId.substring(0, 8)
                      : child.childId;
                  return DropdownMenuItem(
                    value: child.childId,
                    child: Row(
                      children: [
                        const Text('👧', style: TextStyle(fontSize: 18)),
                        const SizedBox(width: 8),
                        Text('孩子 $shortId'),
                      ],
                    ),
                  );
                }).toList(),
                onChanged: (v) {
                  if (v != null) setState(() => _selectedChildId = v);
                },
              ),
            ),
          ),
          const SizedBox(height: 16),
        ],

        Text(
          '功能',
          style: theme.textTheme.titleSmall?.copyWith(
            fontWeight: FontWeight.w600,
          ),
        ),
        const SizedBox(height: 12),
        _ActionCard(
          icon: Icons.auto_stories_outlined,
          iconColor: AppColors.accent,
          iconBgColor: AppColors.accent.withValues(alpha: 0.12),
          title: '日记查看',
          subtitle: '只读查看孩子的日记和评语',
          onTap: () => widget.onViewJournals(_selectedChildId),
        ),
        const SizedBox(height: 12),
        _ActionCard(
          icon: Icons.bar_chart_outlined,
          iconColor: AppColors.secondary,
          iconBgColor: AppColors.secondary.withValues(alpha: 0.12),
          title: '心情统计',
          subtitle: '查看孩子的写作频率和心情趋势',
          onTap: () => widget.onMoodStats(_selectedChildId),
        ),
        const SizedBox(height: 12),
        _ActionCard(
          icon: Icons.download_outlined,
          iconColor: AppColors.tertiary,
          iconBgColor: AppColors.tertiary.withValues(alpha: 0.12),
          title: '数据导出',
          subtitle: '导出孩子的所有日记数据',
          onTap: () => widget.onExport(_selectedChildId),
        ),
        const SizedBox(height: 12),
        _ActionCard(
          icon: Icons.delete_outline,
          iconColor: AppColors.error,
          iconBgColor: AppColors.error.withValues(alpha: 0.12),
          title: '数据删除',
          subtitle: '永久删除孩子的日记数据',
          onTap: () => widget.onDelete(_selectedChildId),
        ),
      ],
    );
  }
}

/// 功能操作卡片
class _ActionCard extends StatelessWidget {
  const _ActionCard({
    required this.icon,
    required this.iconColor,
    required this.iconBgColor,
    required this.title,
    required this.subtitle,
    required this.onTap,
  });

  final IconData icon;
  final Color iconColor;
  final Color iconBgColor;
  final String title;
  final String subtitle;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;

    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: AppRadius.mdBorder,
        side: BorderSide(color: colorScheme.outlineVariant),
      ),
      child: InkWell(
        onTap: onTap,
        borderRadius: AppRadius.mdBorder,
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Row(
            children: [
              Container(
                width: 44,
                height: 44,
                decoration: BoxDecoration(
                  color: iconBgColor,
                  borderRadius: BorderRadius.circular(12),
                ),
                child: Icon(icon, color: iconColor, size: 22),
              ),
              const SizedBox(width: 16),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      title,
                      style: theme.textTheme.titleSmall?.copyWith(
                        fontWeight: FontWeight.w600,
                      ),
                    ),
                    const SizedBox(height: 2),
                    Text(
                      subtitle,
                      style: theme.textTheme.bodySmall?.copyWith(
                        color: colorScheme.onSurface.withValues(alpha: 0.5),
                      ),
                    ),
                  ],
                ),
              ),
              Icon(
                Icons.chevron_right,
                color: colorScheme.onSurface.withValues(alpha: 0.3),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

/// 日记列表视图 — 只读查看孩子日记
class _JournalListView extends StatelessWidget {
  const _JournalListView({
    required this.childId,
    required this.journals,
    required this.onBack,
  });

  final String childId;
  final List<Map<String, dynamic>> journals;
  final VoidCallback onBack;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;

    return Column(
      children: [
        // 返回按钮 + 标题
        SafeArea(
          child: Padding(
            padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
            child: Row(
              children: [
                IconButton(
                  icon: const Icon(Icons.arrow_back),
                  onPressed: onBack,
                ),
                Expanded(
                  child: Text(
                    '孩子的日记',
                    style: theme.textTheme.titleMedium?.copyWith(
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                ),
                Icon(
                  Icons.visibility_outlined,
                  size: 20,
                  color: colorScheme.onSurface.withValues(alpha: 0.4),
                ),
                const SizedBox(width: 4),
                Text(
                  '只读',
                  style: theme.textTheme.bodySmall?.copyWith(
                    color: colorScheme.onSurface.withValues(alpha: 0.4),
                  ),
                ),
              ],
            ),
          ),
        ),
        // 日记列表
        Expanded(
          child: journals.isEmpty
              ? Center(
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      const Text('📝', style: TextStyle(fontSize: 48)),
                      const SizedBox(height: 16),
                      Text(
                        '暂无日记',
                        style: theme.textTheme.titleMedium?.copyWith(
                          color: colorScheme.onSurface.withValues(alpha: 0.5),
                        ),
                      ),
                    ],
                  ),
                )
              : ListView.separated(
                  padding: const EdgeInsets.symmetric(horizontal: 16),
                  itemCount: journals.length,
                  separatorBuilder: (_, _) => const SizedBox(height: 12),
                  itemBuilder: (context, index) {
                    final journal = journals[index];
                    return _JournalCard(
                      journal: journal,
                      theme: theme,
                      colorScheme: colorScheme,
                    );
                  },
                ),
        ),
      ],
    );
  }
}

/// 单条日记卡片（只读）
class _JournalCard extends StatelessWidget {
  const _JournalCard({
    required this.journal,
    required this.theme,
    required this.colorScheme,
  });

  final Map<String, dynamic> journal;
  final ThemeData theme;
  final ColorScheme colorScheme;

  @override
  Widget build(BuildContext context) {
    final title = journal['title'] as String? ?? '无标题';
    final createdAt = journal['created_at'] as String? ?? '';
    final preview = journal['preview'] as String? ??
        journal['content'] as String? ??
        '';
    final moodEmoji = journal['mood_emoji'] as String? ?? '';

    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: AppRadius.mdBorder,
        side: BorderSide(color: colorScheme.outlineVariant),
      ),
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                if (moodEmoji.isNotEmpty) ...[
                  Text(moodEmoji, style: const TextStyle(fontSize: 18)),
                  const SizedBox(width: 8),
                ],
                Expanded(
                  child: Text(
                    title,
                    style: theme.textTheme.titleSmall?.copyWith(
                      fontWeight: FontWeight.w600,
                    ),
                    maxLines: 1,
                    overflow: TextOverflow.ellipsis,
                  ),
                ),
                if (createdAt.isNotEmpty)
                  Text(
                    _formatDate(createdAt),
                    style: theme.textTheme.bodySmall?.copyWith(
                      color: colorScheme.onSurface.withValues(alpha: 0.4),
                      fontSize: 12,
                    ),
                  ),
              ],
            ),
            if (preview.isNotEmpty) ...[
              const SizedBox(height: 8),
              Text(
                preview,
                style: theme.textTheme.bodyMedium?.copyWith(
                  color: colorScheme.onSurface.withValues(alpha: 0.7),
                  height: 1.5,
                ),
                maxLines: 3,
                overflow: TextOverflow.ellipsis,
              ),
            ],
          ],
        ),
      ),
    );
  }

  String _formatDate(String isoStr) {
    try {
      final dt = DateTime.parse(isoStr);
      return DateFormat('MM-dd').format(dt);
    } catch (e) {
      debugPrint('ParentPage._formatDate 失败: $e');
      return '';
    }
  }
}

/// 导出数据视图 — 展示导出结果 + 下载按钮
class _ExportDataView extends StatelessWidget {
  const _ExportDataView({
    required this.childId,
    required this.data,
    required this.onBack,
  });

  final String childId;
  final Map<String, dynamic> data;
  final VoidCallback onBack;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;
    final journalCount = (data['journal_count'] as num?)?.toInt() ?? 0;
    final exportDate = data['export_date'] as String? ??
        DateFormat('yyyy-MM-dd HH:mm').format(DateTime.now());

    return Column(
      children: [
        // 返回按钮 + 标题
        SafeArea(
          child: Padding(
            padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
            child: Row(
              children: [
                IconButton(
                  icon: const Icon(Icons.arrow_back),
                  onPressed: onBack,
                ),
                Expanded(
                  child: Text(
                    '数据导出',
                    style: theme.textTheme.titleMedium?.copyWith(
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                ),
              ],
            ),
          ),
        ),
        // 导出结果
        Expanded(
          child: SingleChildScrollView(
            padding: const EdgeInsets.all(16),
            child: Column(
              children: [
                // 成功图标
                Container(
                  width: 80,
                  height: 80,
                  decoration: BoxDecoration(
                    color: AppColors.success.withValues(alpha: 0.12),
                    shape: BoxShape.circle,
                  ),
                  child: Icon(
                    Icons.check_circle_outline,
                    color: AppColors.success,
                    size: 40,
                  ),
                ),
                const SizedBox(height: 20),
                Text(
                  '导出成功',
                  style: theme.textTheme.titleLarge?.copyWith(
                    fontWeight: FontWeight.bold,
                  ),
                ),
                const SizedBox(height: 24),
                // 数据概要卡片
                Card(
                  elevation: 0,
                  shape: RoundedRectangleBorder(
                    borderRadius: AppRadius.mdBorder,
                    side: BorderSide(color: colorScheme.outlineVariant),
                  ),
                  child: Padding(
                    padding: const EdgeInsets.all(20),
                    child: Column(
                      children: [
                        _ExportInfoRow(
                          label: '导出时间',
                          value: exportDate,
                          theme: theme,
                          colorScheme: colorScheme,
                        ),
                        const SizedBox(height: 12),
                        _ExportInfoRow(
                          label: '日记数量',
                          value: '$journalCount 篇',
                          theme: theme,
                          colorScheme: colorScheme,
                        ),
                        const SizedBox(height: 12),
                        _ExportInfoRow(
                          label: '数据格式',
                          value: 'JSON',
                          theme: theme,
                          colorScheme: colorScheme,
                        ),
                      ],
                    ),
                  ),
                ),
                const SizedBox(height: 20),
                // 下载按钮
                SizedBox(
                  width: double.infinity,
                  child: FilledButton.icon(
                    onPressed: () => _handleDownload(context),
                    icon: const Icon(Icons.download_rounded, size: 20),
                    label: const Text('下载 JSON 文件'),
                    style: FilledButton.styleFrom(
                      backgroundColor: AppColors.secondary,
                      shape: RoundedRectangleBorder(
                        borderRadius: AppRadius.smBorder,
                      ),
                      padding: const EdgeInsets.symmetric(vertical: 14),
                    ),
                  ),
                ),
                const SizedBox(height: 20),
                // JSON 预览（折叠面板）
                _JsonPreviewCard(data: data),
                const SizedBox(height: 16),
                // PIPL 提示
                Container(
                  padding: const EdgeInsets.all(12),
                  decoration: BoxDecoration(
                    color: AppColors.tertiarySoftLight,
                    borderRadius: AppRadius.smBorder,
                  ),
                  child: Row(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Icon(
                        Icons.shield_outlined,
                        size: 18,
                        color: AppColors.tertiary,
                      ),
                      const SizedBox(width: 8),
                      Expanded(
                        child: Text(
                          '根据《个人信息保护法》，您有权导出孩子的全部个人数据。'
                          '导出数据仅供个人查阅，请妥善保管。',
                          style: theme.textTheme.bodySmall?.copyWith(
                            color: AppColors.fg2Light,
                          ),
                        ),
                      ),
                    ],
                  ),
                ),
              ],
            ),
          ),
        ),
      ],
    );
  }

  /// 触发文件下载
  Future<void> _handleDownload(BuildContext context) async {
    final filename = '暖记_数据导出_${DateFormat('yyyy-MM-dd').format(DateTime.now())}.json';
    final success = await downloadJsonFile(data, filename);
    if (context.mounted) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(success ? '文件已开始下载' : '下载失败，请重试'),
          backgroundColor: success ? AppColors.success : AppColors.error,
        ),
      );
    }
  }
}

/// JSON 预览折叠卡片
class _JsonPreviewCard extends StatefulWidget {
  const _JsonPreviewCard({required this.data});

  final Map<String, dynamic> data;

  @override
  State<_JsonPreviewCard> createState() => _JsonPreviewCardState();
}

class _JsonPreviewCardState extends State<_JsonPreviewCard> {
  bool _expanded = false;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;

    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: AppRadius.mdBorder,
        side: BorderSide(color: colorScheme.outlineVariant),
      ),
      child: Column(
        children: [
          InkWell(
            onTap: () => setState(() => _expanded = !_expanded),
            borderRadius: BorderRadius.vertical(
              top: const Radius.circular(12),
              bottom: _expanded ? Radius.zero : const Radius.circular(12),
            ),
            child: Padding(
              padding: const EdgeInsets.all(16),
              child: Row(
                children: [
                  Icon(
                    Icons.data_object,
                    size: 20,
                    color: colorScheme.onSurface.withValues(alpha: 0.5),
                  ),
                  const SizedBox(width: 12),
                  Text(
                    'JSON 数据预览',
                    style: theme.textTheme.titleSmall?.copyWith(
                      fontWeight: FontWeight.w600,
                    ),
                  ),
                  const Spacer(),
                  Icon(
                    _expanded ? Icons.expand_less : Icons.expand_more,
                    size: 20,
                    color: colorScheme.onSurface.withValues(alpha: 0.4),
                  ),
                ],
              ),
            ),
          ),
          if (_expanded) ...[
            const Divider(height: 1),
            Container(
              width: double.infinity,
              constraints: const BoxConstraints(maxHeight: 300),
              padding: const EdgeInsets.all(16),
              child: SingleChildScrollView(
                child: Text(
                  const JsonEncoder.withIndent('  ').convert(widget.data),
                  style: TextStyle(
                    fontFamily: 'JetBrains Mono',
                    fontSize: 12,
                    height: 1.5,
                    color: colorScheme.onSurface.withValues(alpha: 0.7),
                  ),
                ),
              ),
            ),
          ],
        ],
      ),
    );
  }
}

/// 导出信息行
class _ExportInfoRow extends StatelessWidget {
  const _ExportInfoRow({
    required this.label,
    required this.value,
    required this.theme,
    required this.colorScheme,
  });

  final String label;
  final String value;
  final ThemeData theme;
  final ColorScheme colorScheme;

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        Text(
          label,
          style: theme.textTheme.bodyMedium?.copyWith(
            color: colorScheme.onSurface.withValues(alpha: 0.6),
          ),
        ),
        Text(
          value,
          style: theme.textTheme.bodyMedium?.copyWith(
            fontWeight: FontWeight.w600,
          ),
        ),
      ],
    );
  }
}

/// PIPL 合规提示
class _PiplNotice extends StatelessWidget {
  const _PiplNotice({
    required this.theme,
    required this.colorScheme,
  });

  final ThemeData theme;
  final ColorScheme colorScheme;

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.all(12),
      decoration: BoxDecoration(
        color: colorScheme.surfaceContainerHighest,
        borderRadius: BorderRadius.circular(12),
      ),
      child: Row(
        children: [
          Icon(
            Icons.shield_outlined,
            size: 18,
            color: colorScheme.onSurface.withValues(alpha: 0.5),
          ),
          const SizedBox(width: 8),
          Expanded(
            child: Text(
              '根据《个人信息保护法》，您有权查阅、更正、删除和导出孩子的数据。',
              style: theme.textTheme.bodySmall?.copyWith(
                color: colorScheme.onSurface.withValues(alpha: 0.5),
              ),
            ),
          ),
        ],
      ),
    );
  }
}