import 'dart:async';

import 'package:flutter/material.dart';

import '../api/oa_client.dart';
import '../im/chat_prefs.dart';
import '../pages/chat_page.dart';
import '../pages/notices_page.dart';
import '../pages/pick_people_page.dart';
import '../pages/scan_login_page.dart';
import '../pages/system_notice_page.dart';
import '../session/session.dart';
import '../theme.dart';
import '../widgets/common.dart';
import '../widgets/desktop_ui.dart';
import '../widgets/wecom.dart';

class MessagesPage extends StatefulWidget {
  const MessagesPage({
    super.key,
    required this.session,
    required this.api,
    this.desktopPane = false,
    this.desktopStyle = false,
    this.selectedId,
    this.onSelectConv,
  });
  final SessionStore session;
  final OaClient api;
  final bool desktopPane;
  final bool desktopStyle;
  final String? selectedId;
  final void Function(Map<String, dynamic> row)? onSelectConv;

  @override
  State<MessagesPage> createState() => _MessagesPageState();
}

class _MessagesPageState extends State<MessagesPage> {
  List<Map<String, dynamic>> _items = [];
  bool _loading = true;
  String _err = '';
  String _filter = 'all';
  String _q = '';
  bool _showSearch = false;
  Timer? _imDebounce;

  @override
  void initState() {
    super.initState();
    widget.session.im.addListener(_onIm);
    ChatPrefs.ensure().then((_) {
      if (mounted) setState(() {});
    });
    _load();
  }

  @override
  void dispose() {
    _imDebounce?.cancel();
    widget.session.im.removeListener(_onIm);
    super.dispose();
  }

  void _onIm() {
    _imDebounce?.cancel();
    _imDebounce = Timer(const Duration(milliseconds: 250), () {
      if (mounted) _load();
    });
  }

  Future<void> _load() async {
    try {
      final data = await widget.api.get('/im/conversations');
      if (!mounted) return;
      setState(() {
        _items = asMaps(data);
        _loading = false;
        _err = '';
      });
    } catch (e) {
      if (!mounted) return;
      setState(() {
        _loading = false;
        if (_items.isEmpty) _err = '$e';
      });
    }
  }

  int get _unread {
    var n = 0;
    for (final r in _items) {
      if (ChatPrefs.muted('${r['id'] ?? ''}')) continue;
      final id = '${r['id'] ?? ''}';
      final fake = ChatPrefs.fakeUnread(id);
      if (fake > 0) {
        n += fake;
        continue;
      }
      n += (r['unread'] as num?)?.toInt() ?? 0;
    }
    return n;
  }

  Future<void> _showDesktopConvMenu(Map<String, dynamic> r, Offset pos) async {
    final id = '${r['id'] ?? ''}';
    if (id.isEmpty) return;
    final muted = ChatPrefs.muted(id);
    final pinned = ChatPrefs.pinned(id);
    final unread = (r['unread'] as num?)?.toInt() ?? 0;
    final fake = ChatPrefs.fakeUnread(id);
    final selected = await showMenu<String>(
      context: context,
      position: RelativeRect.fromLTRB(pos.dx, pos.dy, pos.dx + 1, pos.dy + 1),
      items: [
        if (unread == 0 && fake == 0)
          const PopupMenuItem(value: 'unread', child: Text('标为未读')),
        PopupMenuItem(value: 'mute', child: Text(muted ? '取消免打扰' : '消息免打扰')),
        PopupMenuItem(value: 'pin', child: Text(pinned ? '取消置顶' : '置顶')),
        const PopupMenuItem(value: 'hide', child: Text('不显示')),
        const PopupMenuDivider(),
        const PopupMenuItem(value: 'clear', child: Text('清空聊天记录')),
        const PopupMenuItem(value: 'delete', child: Text('删除')),
      ],
    );
    if (!mounted || selected == null) return;
    switch (selected) {
      case 'unread':
        await ChatPrefs.setFakeUnread(id, 1);
      case 'mute':
        await ChatPrefs.setMuted(id, !muted);
      case 'pin':
        await ChatPrefs.setPinned(id, !pinned);
      case 'hide':
        await ChatPrefs.setHidden(id, true);
      case 'clear':
        await ChatPrefs.clearHistory(id);
      case 'delete':
        await ChatPrefs.setHidden(id, true);
    }
    if (mounted) {
      setState(() {});
      await _load();
    }
  }

  Widget _wrapConv(Map<String, dynamic> r, Widget child) {
    if (!widget.desktopStyle) return child;
    return GestureDetector(
      onSecondaryTapDown: (d) => _showDesktopConvMenu(r, d.globalPosition),
      child: child,
    );
  }

  Future<void> _newChat({required bool group}) async {
    final picked = await Navigator.of(context).push<List<Map<String, dynamic>>>(
      MaterialPageRoute(
        builder: (_) => PickPeoplePage(
          api: widget.api,
          title: group ? '选择联系人' : '发起单聊',
          multiple: group,
          exclude: {widget.session.userId},
        ),
      ),
    );
    if (picked == null || picked.isEmpty) return;
    if (!group) {
      final p = picked.first;
      if (!mounted) return;
      await Navigator.of(context).push(MaterialPageRoute(
        builder: (_) => ChatPage(
          session: widget.session,
          api: widget.api,
          peerId: '${p['id']}',
          peerName: '${p['name'] ?? '同事'}',
          peerAvatarFileId: '${p['avatarFileId'] ?? ''}',
        ),
      ));
      _load();
      return;
    }
    final name = TextEditingController();
    if (!mounted) return;
    final ok = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('群名称'),
        content: TextField(
            controller: name,
            decoration: const InputDecoration(hintText: '例如：三维项目组')),
        actions: [
          TextButton(
              onPressed: () => Navigator.pop(ctx, false),
              child: const Text('取消')),
          FilledButton(
              onPressed: () => Navigator.pop(ctx, true),
              child: const Text('创建')),
        ],
      ),
    );
    if (ok == true) {
      await widget.api.post('/im/groups', {
        'name': name.text.trim().isEmpty ? '群聊' : name.text.trim(),
        'memberIds': picked.map((e) => '${e['id']}').toList(),
      });
      await _load();
    }
  }

  List<Map<String, dynamic>> get _shown {
    var list = _items;
    // 只有用户明确执行“不显示/删除”后才隐藏；阅读状态不会改变会话是否存在。
    list = list.where((e) {
      final id = '${e['id'] ?? ''}';
      return !ChatPrefs.hidden(id);
    }).toList();
    if (_filter == 'unread')
      list =
          list.where((e) => ((e['unread'] as num?)?.toInt() ?? 0) > 0).toList();
    if (_filter == 'dm')
      list = list.where((e) => e['type'] != 'group').toList();
    if (_filter == 'group')
      list = list.where((e) => e['type'] == 'group').toList();
    if (_q.isNotEmpty) {
      list = list
          .where((e) =>
              '${e['name']}${e['peerName']}${e['lastText']}'.contains(_q))
          .toList();
    }
    list = [...list]..sort((a, b) {
        final ap = ChatPrefs.pinned('${a['id'] ?? ''}');
        final bp = ChatPrefs.pinned('${b['id'] ?? ''}');
        if (ap == bp) return 0;
        return ap ? -1 : 1;
      });
    return list;
  }

  @override
  Widget build(BuildContext context) {
    final header = widget.desktopStyle
        ? DesktopPaneHeader(
            title: _unread > 0 ? '消息（$_unread）' : '消息',
            actions: [
              IconButton(
                onPressed: () => setState(() => _showSearch = !_showSearch),
                icon: const Icon(Icons.search, color: kInk, size: 20),
              ),
              Builder(
                builder: (ctx) => IconButton(
                  onPressed: () => showPlusMenu(ctx, [
                    (Icons.qr_code_scanner_outlined, '扫一扫登录电脑', () => Navigator.of(context).push(MaterialPageRoute(builder: (_) => ScanLoginPage(api: widget.api)))),
                    (Icons.chat_bubble_outline, '发起单聊', () => _newChat(group: false)),
                    (Icons.group_outlined, '发起群聊', () => _newChat(group: true)),
                  ]),
                  icon: const Icon(Icons.add, color: kInk, size: 22),
                ),
              ),
            ],
            bottom: Padding(
              padding: const EdgeInsets.fromLTRB(12, 0, 12, 10),
              child: Column(
                children: [
                  if (_showSearch) ...[
                    DesktopSearchBar(hint: '搜索', onChanged: (v) => setState(() => _q = v.trim())),
                    const SizedBox(height: 8),
                  ],
                  Row(
                    children: [
                      _filterChip('all', '全部'),
                      const SizedBox(width: 8),
                      _filterChip('unread', '未读'),
                      const SizedBox(width: 8),
                      _filterChip('dm', '单聊'),
                      const SizedBox(width: 8),
                      _filterChip('group', '群聊'),
                    ],
                  ),
                ],
              ),
            ),
          )
        : Column(
            children: [
              WxHeader(
                title: _unread > 0 ? '消息($_unread)' : '消息',
                actions: [
                  IconButton(
                    onPressed: () => setState(() => _showSearch = !_showSearch),
                    icon: const Icon(Icons.search, color: kInk),
                  ),
                  Builder(
                    builder: (ctx) => IconButton(
                      onPressed: () => showPlusMenu(ctx, [
                        (Icons.qr_code_scanner_outlined, '扫一扫登录电脑', () => Navigator.of(context).push(MaterialPageRoute(builder: (_) => ScanLoginPage(api: widget.api)))),
                        (Icons.chat_bubble_outline, '发起单聊', () => _newChat(group: false)),
                        (Icons.group_outlined, '发起群聊', () => _newChat(group: true)),
                      ]),
                      icon: const Icon(Icons.add_circle_outline, color: kInk),
                    ),
                  ),
                ],
              ),
              if (_showSearch) WxSearchBar(hint: '搜索', onChanged: (v) => setState(() => _q = v.trim())),
              Padding(
                padding: const EdgeInsets.fromLTRB(12, 0, 12, 4),
                child: Row(
                  children: [
                    _filterChip('all', '全部'),
                    const SizedBox(width: 8),
                    _filterChip('unread', '未读'),
                    const SizedBox(width: 8),
                    _filterChip('dm', '单聊'),
                    const SizedBox(width: 8),
                    _filterChip('group', '群聊'),
                  ],
                ),
              ),
            ],
          );

    return ColoredBox(
      color: Colors.white,
      child: Column(
        children: [
          header,
          if (_loading)
            const LinearProgressIndicator(minHeight: 2, color: kBind),
          if (_err.isNotEmpty)
            Padding(
                padding: const EdgeInsets.all(16),
                child: Text(_err, style: const TextStyle(color: kDanger))),
          Expanded(
            child: RefreshIndicator(
              onRefresh: _load,
              child: ListView(
                padding: EdgeInsets.zero,
                children: [
                  ConvTile(
                    title: '公告',
                    preview: '公司通知与制度',
                    avatarIcon: Icons.campaign,
                    avatarColor: const Color(0xFFE75D5D),
                    avatarLabel: '告',
                    onTap: () => Navigator.of(context).push(MaterialPageRoute(
                      builder: (_) => NoticesPage(api: widget.api),
                    )),
                  ),
                  if (_shown.isEmpty && !_loading)
                    const Padding(
                      padding: EdgeInsets.only(top: 48),
                      child: EmptyHint('还没有会话。点右上角 + 或到通讯录找同事。'),
                    ),
                  for (final r in _shown)
                    _wrapConv(
                      r,
                      widget.desktopStyle
                          ? ConvTile(
                              title: '${r['name'] ?? r['peerName'] ?? '同事'}',
                              preview: '${r['lastText'] ?? ''}',
                              time: shortTime(r['lastAt']),
                              muted: ChatPrefs.muted('${r['id'] ?? ''}'),
                              unread: ChatPrefs.muted('${r['id'] ?? ''}')
                                  ? 0
                                  : (ChatPrefs.fakeUnread('${r['id'] ?? ''}') > 0
                                      ? ChatPrefs.fakeUnread('${r['id'] ?? ''}')
                                      : ((r['unread'] as num?)?.toInt() ?? 0)),
                              avatarLabel: '${r['peerId']}' == '0' ? '?' : '${r['name'] ?? r['peerName'] ?? '同'}',
                              avatarIcon: '${r['peerId']}' == '0' ? Icons.notifications : (r['type'] == 'group' ? Icons.groups : null),
                              avatarColor: '${r['peerId']}' == '0' ? const Color(0xFF07C160) : (r['type'] == 'group' ? const Color(0xFF07C160) : null),
                              avatarFileId: r['type'] == 'group' ? null : '${r['avatarFileId'] ?? ''}',
                              api: widget.api,
                              selected: widget.desktopPane && widget.selectedId == '${r['id'] ?? ''}',
                              onTap: () async {
                                final id = '${r['id'] ?? ''}';
                                if (id.isNotEmpty) await ChatPrefs.setFakeUnread(id, 0);
                                if (widget.desktopPane && widget.onSelectConv != null) {
                                  widget.onSelectConv!(r);
                                  return;
                                }
                                await Navigator.of(context).push(MaterialPageRoute(
                                  builder: (_) => '${r['peerId']}' == '0'
                                      ? SystemNoticePage(session: widget.session, api: widget.api, conversationId: id)
                                      : ChatPage(
                                          session: widget.session,
                                          api: widget.api,
                                          peerId: '${r['peerId'] ?? ''}',
                                          conversationId: id,
                                          peerName: '${r['name'] ?? r['peerName'] ?? '同事'}',
                                          isGroup: r['type'] == 'group',
                                          peerAvatarFileId: '${r['avatarFileId'] ?? ''}',
                                        ),
                                ));
                                _load();
                              },
                            )
                          : _SwipeConversation(
                              id: '${r['id'] ?? ''}',
                              api: widget.api,
                              onChanged: _load,
                              child: ConvTile(
                                title: '${r['name'] ?? r['peerName'] ?? '同事'}',
                                preview: '${r['lastText'] ?? ''}',
                                time: shortTime(r['lastAt']),
                                muted: ChatPrefs.muted('${r['id'] ?? ''}'),
                                unread: ChatPrefs.muted('${r['id'] ?? ''}')
                                    ? 0
                                    : ((r['unread'] as num?)?.toInt() ?? 0),
                                avatarLabel: '${r['peerId']}' == '0'
                                    ? '?'
                                    : '${r['name'] ?? r['peerName'] ?? '同'}',
                                avatarIcon: '${r['peerId']}' == '0'
                                    ? Icons.notifications
                                    : (r['type'] == 'group' ? Icons.groups : null),
                                avatarColor: '${r['peerId']}' == '0'
                                    ? const Color(0xFF07C160)
                                    : (r['type'] == 'group'
                                        ? const Color(0xFF07C160)
                                        : null),
                                avatarFileId: r['type'] == 'group'
                                    ? null
                                    : '${r['avatarFileId'] ?? ''}',
                                api: widget.api,
                                selected: widget.desktopPane && widget.selectedId == '${r['id'] ?? ''}',
                                onTap: () async {
                                  if (widget.desktopPane && widget.onSelectConv != null) {
                                    widget.onSelectConv!(r);
                                    return;
                                  }
                                  await Navigator.of(context).push(MaterialPageRoute(
                                    builder: (_) => '${r['peerId']}' == '0'
                                        ? SystemNoticePage(session: widget.session, api: widget.api, conversationId: '${r['id'] ?? ''}')
                                        : ChatPage(
                                      session: widget.session,
                                      api: widget.api,
                                      peerId: '${r['peerId'] ?? ''}',
                                      conversationId: '${r['id'] ?? ''}',
                                      peerName: '${r['name'] ?? r['peerName'] ?? '同事'}',
                                      isGroup: r['type'] == 'group',
                                      peerAvatarFileId: '${r['avatarFileId'] ?? ''}',
                                    ),
                                  ));
                                  _load();
                                },
                              ),
                            ),
                    ),
                  const SizedBox(height: 24),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _filterChip(String id, String label) {
    final on = _filter == id;
    return GestureDetector(
      onTap: () => setState(() => _filter = id),
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
        decoration: BoxDecoration(
          color: on ? const Color(0xFFE8F3FF) : Colors.transparent,
          borderRadius: BorderRadius.circular(12),
        ),
        child: Text(label,
            style: TextStyle(
                fontSize: 13,
                color: on ? kBind : kMute,
                fontWeight: on ? FontWeight.w600 : FontWeight.w400)),
      ),
    );
  }
}

/// 微信式左滑操作栏：操作不会误删服务器会话，删除仅隐藏本机列表。
class _SwipeConversation extends StatefulWidget {
  const _SwipeConversation(
      {required this.id,
      required this.api,
      required this.child,
      required this.onChanged});
  final String id;
  final OaClient api;
  final Widget child;
  final Future<void> Function() onChanged;

  @override
  State<_SwipeConversation> createState() => _SwipeConversationState();
}

class _SwipeConversationState extends State<_SwipeConversation> {
  double _offset = 0;
  static const _width = 216.0;

  Future<void> _hide() async {
    if (!mounted) return;
    final ok = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('隐藏会话'),
        content: const Text('仅从消息列表隐藏，不会删除聊天记录。确定继续吗？'),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text('取消')),
          FilledButton(onPressed: () => Navigator.pop(ctx, true), child: const Text('确定')),
        ],
      ),
    );
    if (ok != true) {
      if (mounted) setState(() => _offset = 0);
      return;
    }
    await ChatPrefs.setHidden(widget.id, true);
    await widget.onChanged();
  }

  Future<void> _toggleMute() async {
    await ChatPrefs.setMuted(widget.id, !ChatPrefs.muted(widget.id));
    if (mounted) setState(() => _offset = 0);
    await widget.onChanged();
  }

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      height: 76,
      child: GestureDetector(
        behavior: HitTestBehavior.opaque,
        onHorizontalDragUpdate: (d) => setState(() => _offset = (_offset + d.delta.dx).clamp(-_width, 0)),
        onHorizontalDragEnd: (_) => setState(() => _offset = _offset < -80 ? -_width : 0),
        child: Stack(
          fit: StackFit.expand,
          children: [
            Align(
              alignment: Alignment.centerRight,
              child: Row(
                mainAxisSize: MainAxisSize.min,
                children: [
                  _action('免打扰', const Color(0xFFFFA940), _toggleMute),
                  _action('不显示', const Color(0xFF8C8C8C), _hide),
                  _action('删除', const Color(0xFFF5222D), _hide),
                ],
              ),
            ),
            AnimatedContainer(
              duration: const Duration(milliseconds: 160),
              curve: Curves.easeOut,
              transform: Matrix4.translationValues(_offset, 0, 0),
              color: Colors.white,
              child: widget.child,
            ),
          ],
        ),
      ),
    );
  }

  Widget _action(String label, Color color, Future<void> Function() onTap) {
    return SizedBox(
      width: 72,
      height: double.infinity,
      child: Material(
        color: color,
        child: InkWell(
          onTap: () async => onTap(),
          child: Center(
              child: Text(label,
                  style: const TextStyle(color: Colors.white, fontSize: 13))),
        ),
      ),
    );
  }
}