import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:qr_flutter/qr_flutter.dart';
import 'package:sales_chat/providers/invite_provider.dart';
import 'package:sales_chat/providers/chat_provider.dart';
import 'package:sales_chat/models/invite.dart';
import 'package:sales_chat/theme/app_theme.dart';
import 'package:sales_chat/services/api_service.dart';
import 'package:intl/intl.dart';

/// 邀请页面 —— Twitter 风格
class InvitePage extends StatefulWidget {
  const InvitePage({super.key});

  @override
  State<InvitePage> createState() => _InvitePageState();
}

class _InvitePageState extends State<InvitePage> {
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) => _loadData());
  }

  Future<void> _loadData() async {
    final inviteProvider = context.read<InviteProvider>();
    final chatProvider = context.read<ChatProvider>();

    // 先确保群组数据已加载
    await chatProvider.loadGroups();

    await Future.wait([
      inviteProvider.loadInvites(),
      inviteProvider.loadAvailableGroups(chatProvider.groups),
    ]);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('邀请'),
        actions: [
          IconButton(
            icon: const Icon(Icons.refresh),
            onPressed: _loadData,
          ),
        ],
      ),
      body: Consumer<InviteProvider>(
        builder: (context, inviteProvider, _) {
          if (inviteProvider.isLoading && inviteProvider.invites.isEmpty) {
            return const Center(child: CircularProgressIndicator());
          }

          return SingleChildScrollView(
            physics: const AlwaysScrollableScrollPhysics(),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                // 创建邀请按钮 —— 顶部醒目主色按钮
                _buildCreateInviteButton(),
                const SizedBox(height: 8),

                // 我的邀请列表
                _buildInviteListSection(inviteProvider),
              ],
            ),
          );
        },
      ),
    );
  }

  /// 创建邀请按钮 —— 醒目的主色按钮，非卡片样式
  Widget _buildCreateInviteButton() {
    return Container(
      width: double.infinity,
      color: AppTheme.cardBackground,
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 16),
      child: ElevatedButton.icon(
        onPressed: () => _showCreateInviteDialog(),
        icon: const Icon(Icons.add, size: 20),
        label: const Text('创建新邀请'),
        style: ElevatedButton.styleFrom(
          backgroundColor: AppTheme.primaryColor,
          foregroundColor: Colors.white,
          padding: const EdgeInsets.symmetric(vertical: 12),
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(8),
          ),
          elevation: 0,
        ),
      ),
    );
  }

  /// 邀请列表区块
  Widget _buildInviteListSection(InviteProvider inviteProvider) {
    return Container(
      color: AppTheme.cardBackground,
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          // 区块标题
          const Padding(
            padding: EdgeInsets.fromLTRB(16, 16, 16, 0),
            child: Text(
              '我的邀请',
              style: TextStyle(
                fontSize: 15,
                fontWeight: FontWeight.w600,
                color: AppTheme.textPrimary,
              ),
            ),
          ),

          if (inviteProvider.invites.isEmpty)
            _buildEmptyState()
          else
            ..._buildInviteListItems(inviteProvider.invites),
        ],
      ),
    );
  }

  /// 构建邀请列表项（带分隔线）
  List<Widget> _buildInviteListItems(List invites) {
    final items = <Widget>[];
    for (int i = 0; i < invites.length; i++) {
      final invite = invites[i];
      items.add(_InviteListTile(
        invite: invite,
        onTap: () => _showInviteDetail(invite),
        onDeactivate: () => _deactivateInvite(invite.code),
      ));
      if (i < invites.length - 1) {
        items.add(const Padding(
          padding: EdgeInsets.only(left: 16),
          child: Divider(height: 0.5, thickness: 0.5),
        ));
      }
    }
    return items;
  }

  /// 空状态
  Widget _buildEmptyState() {
    return Padding(
      padding: const EdgeInsets.all(32),
      child: Center(
        child: Column(
          children: [
            Icon(
              Icons.card_giftcard_outlined,
              size: 48,
              color: AppTheme.textHint,
            ),
            const SizedBox(height: 16),
            Text(
              '暂无邀请',
              style: TextStyle(color: AppTheme.textSecondary, fontSize: 14),
            ),
            const SizedBox(height: 8),
            Text(
              '点击上方按钮创建您的第一个邀请',
              style: TextStyle(color: AppTheme.textHint, fontSize: 12),
            ),
          ],
        ),
      ),
    );
  }

  /// 创建邀请对话框
  Future<void> _showCreateInviteDialog() async {
    final chatProvider = context.read<ChatProvider>();
    var groups = chatProvider.groups;

    // 如果没有群组，先创建一个
    if (groups.isEmpty) {
      final created = await _showCreateGroupDialog();
      if (!created) return;
      groups = chatProvider.groups;
      if (groups.isEmpty) return;
    }

    String? selectedGroupId = groups.first.id;
    int expiryDays = 7;

    await showDialog(
      context: context,
      builder: (context) => StatefulBuilder(
        builder: (context, setState) {
          return AlertDialog(
            title: const Text('创建邀请'),
            content: Column(
              mainAxisSize: MainAxisSize.min,
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                // 群组选择
                DropdownButtonFormField<String>(
                  value: selectedGroupId,
                  decoration: const InputDecoration(
                    labelText: '选择群组',
                    border: OutlineInputBorder(),
                  ),
                  items: groups.map((g) {
                    return DropdownMenuItem(
                      value: g.id,
                      child: Text(g.name),
                    );
                  }).toList(),
                  onChanged: (value) {
                    setState(() {
                      selectedGroupId = value;
                    });
                  },
                ),
                const SizedBox(height: 16),

                // 有效期
                Text('有效期（天）', style: Theme.of(context).textTheme.bodySmall),
                Slider(
                  value: expiryDays.toDouble(),
                  min: 1,
                  max: 30,
                  divisions: 29,
                  label: '$expiryDays 天',
                  onChanged: (value) {
                    setState(() {
                      expiryDays = value.round();
                    });
                  },
                ),
                Text(
                  '$expiryDays 天',
                  style: TextStyle(color: AppTheme.textSecondary),
                ),
              ],
            ),
            actions: [
              TextButton(
                onPressed: () => Navigator.pop(context),
                child: const Text('取消'),
              ),
              ElevatedButton(
                onPressed: () async {
                  final inviteProvider = context.read<InviteProvider>();
                  Navigator.pop(context);

                  final invite = await inviteProvider.createInvite(
                    groupId: selectedGroupId!,
                    expiresInDays: expiryDays,
                  );

                  if (invite != null && mounted) {
                    _showInviteDetail(invite);
                  }
                },
                child: const Text('创建'),
              ),
            ],
          );
        },
      ),
    );
  }

  /// 显示邀请详情底部弹窗
  void _showInviteDetail(Invite invite) {
    showModalBottomSheet(
      context: context,
      isScrollControlled: true,
      backgroundColor: AppTheme.cardBackground,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(12)),
      ),
      builder: (context) => _InviteDetailSheet(invite: invite),
    );
  }

  /// 停用邀请确认
  Future<void> _deactivateInvite(String code) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('停用邀请'),
        content: const Text('确定吗？此邀请将不再可用。'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context, false),
            child: const Text('取消'),
          ),
          TextButton(
            onPressed: () => Navigator.pop(context, true),
            style: TextButton.styleFrom(foregroundColor: AppTheme.errorColor),
            child: const Text('停用'),
          ),
        ],
      ),
    );

    if (confirmed == true && mounted) {
      final inviteProvider = context.read<InviteProvider>();
      await inviteProvider.deactivateInvite(code);
    }
  }

  /// 创建群组对话框（没有群组时自动弹出）
  Future<bool> _showCreateGroupDialog() async {
    final name = await showDialog<String>(
      context: context,
      builder: (context) {
        final controller = TextEditingController();
        return AlertDialog(
          title: const Text('创建群组'),
          content: Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              const Text('您还没有群组，需要先创建一个群组才能生成邀请。'),
              const SizedBox(height: 16),
              TextField(
                controller: controller,
                autofocus: true,
                decoration: const InputDecoration(
                  labelText: '群组名称',
                  hintText: '例如：客户交流群',
                ),
              ),
            ],
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.pop(context),
              child: const Text('取消'),
            ),
            ElevatedButton(
              onPressed: () => Navigator.pop(context, controller.text.trim()),
              child: const Text('创建'),
            ),
          ],
        );
      },
    );

    if (name == null || name.isEmpty) return false;

    try {
      final apiService = context.read<ApiService>();
      await apiService.createGroup(name);
      await context.read<ChatProvider>().loadGroups();
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('群组已创建')),
        );
      }
      return true;
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('创建失败：$e')),
        );
      }
      return false;
    }
  }
}

/// 邀请列表行 —— 卡片背景行，邀请码 + 状态徽章 + 统计
class _InviteListTile extends StatelessWidget {
  final Invite invite;
  final VoidCallback onTap;
  final VoidCallback onDeactivate;

  const _InviteListTile({
    required this.invite,
    required this.onTap,
    required this.onDeactivate,
  });

  @override
  Widget build(BuildContext context) {
    final dateFormat = DateFormat('yyyy-MM-dd HH:mm');

    return InkWell(
      onTap: onTap,
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 14),
        child: Row(
          children: [
            // 左侧：邀请码 + 统计
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  // 第一行：邀请码 + 状态
                  Row(
                    children: [
                      // 邀请码（等宽字体）
                      Text(
                        invite.code,
                        style: const TextStyle(
                          fontFamily: 'monospace',
                          fontSize: 15,
                          fontWeight: FontWeight.w500,
                          color: AppTheme.textPrimary,
                        ),
                      ),
                      const SizedBox(width: 8),
                      // 状态徽章
                      Container(
                        padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
                        decoration: BoxDecoration(
                          color: invite.isValid
                              ? AppTheme.successColor.withValues(alpha: 0.1)
                              : AppTheme.errorColor.withValues(alpha: 0.1),
                          borderRadius: BorderRadius.circular(4),
                        ),
                        child: Text(
                          invite.isValid ? '有效' : '已失效',
                          style: TextStyle(
                            fontSize: 11,
                            color: invite.isValid ? AppTheme.successColor : AppTheme.errorColor,
                            fontWeight: FontWeight.w500,
                          ),
                        ),
                      ),
                    ],
                  ),
                  const SizedBox(height: 6),
                  // 第二行：点击数 + 加入数
                  Row(
                    children: [
                      Icon(Icons.touch_app_outlined, size: 14, color: AppTheme.textHint),
                      const SizedBox(width: 3),
                      Text(
                        '${invite.clickCount} 点击',
                        style: const TextStyle(color: AppTheme.textHint, fontSize: 12),
                      ),
                      const SizedBox(width: 12),
                      Icon(Icons.person_add_outlined, size: 14, color: AppTheme.textHint),
                      const SizedBox(width: 3),
                      Text(
                        '${invite.joinCount} 加入',
                        style: const TextStyle(color: AppTheme.textHint, fontSize: 12),
                      ),
                      if (invite.expiresAt != null) ...[
                        const SizedBox(width: 12),
                        Icon(Icons.schedule, size: 14, color: AppTheme.textHint),
                        const SizedBox(width: 3),
                        Text(
                          dateFormat.format(invite.expiresAt!),
                          style: const TextStyle(color: AppTheme.textHint, fontSize: 12),
                        ),
                      ],
                    ],
                  ),
                ],
              ),
            ),
            // 右侧：删除按钮或箭头
            if (!invite.isValid)
              GestureDetector(
                onTap: onDeactivate,
                child: const Padding(
                  padding: EdgeInsets.all(4),
                  child: Icon(Icons.delete_outline, size: 20, color: AppTheme.textHint),
                ),
              )
            else
              const Icon(Icons.chevron_right, color: AppTheme.textHint, size: 20),
          ],
        ),
      ),
    );
  }
}

/// 邀请详情底部弹窗 —— Twitter 风格
class _InviteDetailSheet extends StatelessWidget {
  final Invite invite;

  const _InviteDetailSheet({required this.invite});

  @override
  Widget build(BuildContext context) {
    final dateFormat = DateFormat('yyyy-MM-dd HH:mm');
    final inviteUrl = invite.link ?? 'http://localhost:3000/join/${invite.code}';

    return Container(
      padding: const EdgeInsets.all(24),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          // 顶部把手
          Container(
            width: 36,
            height: 4,
            decoration: BoxDecoration(
              color: AppTheme.dragHandleColor,
              borderRadius: BorderRadius.circular(2),
            ),
          ),
          const SizedBox(height: 16),
          const Text(
            '邀请详情',
            style: TextStyle(
              fontSize: 17,
              fontWeight: FontWeight.w600,
              color: AppTheme.textPrimary,
            ),
          ),
          const SizedBox(height: 24),

          // 二维码
          Container(
            padding: const EdgeInsets.all(16),
            decoration: BoxDecoration(
              color: AppTheme.cardBackground,
              borderRadius: BorderRadius.circular(12),
              border: Border.all(color: AppTheme.dividerColor),
            ),
            child: QrImageView(
              data: inviteUrl,
              size: 200,
              backgroundColor: AppTheme.cardBackground,
            ),
          ),
          const SizedBox(height: 20),

          // 统计数据
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: [
              _SheetStatItem(label: '点击数', value: '${invite.clickCount}'),
              Container(
                width: 0.5,
                height: 30,
                color: AppTheme.dividerColor,
              ),
              _SheetStatItem(label: '加入数', value: '${invite.joinCount}'),
              Container(
                width: 0.5,
                height: 30,
                color: AppTheme.dividerColor,
              ),
              _SheetStatItem(
                label: '创建时间',
                value: invite.createdAt != null
                    ? dateFormat.format(invite.createdAt!)
                    : '无',
              ),
            ],
          ),
          const SizedBox(height: 20),

          // 邀请链接
          Container(
            padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
            decoration: BoxDecoration(
              color: AppTheme.chatInputBg,
              borderRadius: BorderRadius.circular(8),
            ),
            child: Row(
              children: [
                Expanded(
                  child: Text(
                    inviteUrl,
                    style: const TextStyle(fontSize: 13, color: AppTheme.textSecondary),
                    maxLines: 1,
                    overflow: TextOverflow.ellipsis,
                  ),
                ),
                GestureDetector(
                  onTap: () {
                    // 复制到剪贴板
                  },
                  child: Container(
                    padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
                    decoration: BoxDecoration(
                      color: AppTheme.primaryColor.withValues(alpha: 0.1),
                      borderRadius: BorderRadius.circular(4),
                    ),
                    child: const Text(
                      '复制',
                      style: TextStyle(
                        fontSize: 12,
                        color: AppTheme.primaryColor,
                        fontWeight: FontWeight.w500,
                      ),
                    ),
                  ),
                ),
              ],
            ),
          ),
          const SizedBox(height: 20),

          // 操作按钮
          Row(
            children: [
              Expanded(
                child: OutlinedButton.icon(
                  onPressed: () {
                    // 分享
                  },
                  icon: const Icon(Icons.share, size: 18),
                  label: const Text('分享'),
                  style: OutlinedButton.styleFrom(
                    padding: const EdgeInsets.symmetric(vertical: 12),
                  ),
                ),
              ),
              const SizedBox(width: 12),
              Expanded(
                child: ElevatedButton.icon(
                  onPressed: () {
                    // 保存二维码
                  },
                  icon: const Icon(Icons.download, size: 18),
                  label: const Text('保存二维码'),
                  style: ElevatedButton.styleFrom(
                    padding: const EdgeInsets.symmetric(vertical: 12),
                  ),
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }
}

/// 底部弹窗统计项
class _SheetStatItem extends StatelessWidget {
  final String label;
  final String value;

  const _SheetStatItem({required this.label, required this.value});

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Text(
          value,
          style: const TextStyle(
            fontSize: 16,
            fontWeight: FontWeight.w600,
            color: AppTheme.textPrimary,
          ),
        ),
        const SizedBox(height: 4),
        Text(
          label,
          style: const TextStyle(
            fontSize: 12,
            color: AppTheme.textHint,
          ),
        ),
      ],
    );
  }
}