// 🧑‍🤝‍🧑 백품타 친구 화면 (UI 전용). "실시간 출석 현황"과 같은 패밀리룩을 따른다.
// 서버 통신/상태는 lib/function/friend_controller.dart가 담당한다.
import 'package:flutter/material.dart';
import '../function/friend_controller.dart';
import '../theme/app_palette.dart';
import 'app_notice.dart';
import 'title_pill.dart';

class FriendsScreen extends StatefulWidget {
  final String studentId;
  final String studentName;

  const FriendsScreen({
    super.key,
    required this.studentId,
    required this.studentName,
  });

  @override
  State<FriendsScreen> createState() => _FriendsScreenState();
}

class _FriendsScreenState extends State<FriendsScreen> {
  late final FriendController _controller;

  @override
  void initState() {
    super.initState();
    _controller = FriendController(
      studentId: widget.studentId,
      studentName: widget.studentName,
    );
    _controller.init();
  }

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

  Future<void> _showAddFriendDialog() async {
    final idController = TextEditingController();
    final result = await showDialog<bool>(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: const Text('친구 추가'),
        content: TextField(
          controller: idController,
          keyboardType: TextInputType.number,
          decoration: const InputDecoration(
            labelText: '친구 학번',
            border: OutlineInputBorder(),
          ),
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(dialogContext, false),
            child: const Text('취소', style: TextStyle(color: Colors.grey)),
          ),
          ElevatedButton(
            style: ElevatedButton.styleFrom(
              backgroundColor: AppPalette.ink,
              foregroundColor: AppPalette.paper,
            ),
            onPressed: () => Navigator.pop(dialogContext, true),
            child: const Text('신청하기'),
          ),
        ],
      ),
    );
    if (result != true || idController.text.trim().isEmpty) return;
    final (success, message) = await _controller.sendRequest(
      idController.text.trim(),
    );
    if (!mounted) return;
    AppNotice.show(
      context,
      message,
      icon: success ? Icons.check_circle_rounded : Icons.error_outline_rounded,
    );
  }

  Future<void> _respond(int requestId, bool accept) async {
    final (_, message) = await _controller.respondRequest(requestId, accept);
    if (!mounted) return;
    AppNotice.show(context, message);
  }

  Future<void> _remove(String friendId) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: const Text('친구 삭제'),
        content: const Text('이 친구를 삭제하시겠습니까?'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(dialogContext, false),
            child: const Text('취소', style: TextStyle(color: Colors.grey)),
          ),
          TextButton(
            onPressed: () => Navigator.pop(dialogContext, true),
            child: const Text('삭제', style: TextStyle(color: Colors.red)),
          ),
        ],
      ),
    );
    if (confirmed != true) return;
    final (_, message) = await _controller.removeFriend(friendId);
    if (!mounted) return;
    AppNotice.show(context, message);
  }

  Widget _sectionHeader(String title, {int? count}) {
    return Row(
      children: [
        Container(
          width: 4,
          height: 16,
          decoration: BoxDecoration(
            color: AppPalette.ink,
            borderRadius: BorderRadius.circular(2),
          ),
        ),
        const SizedBox(width: 8),
        Text(
          title,
          style: const TextStyle(
            fontSize: 16,
            fontWeight: FontWeight.bold,
            color: AppPalette.ink,
          ),
        ),
        if (count != null) ...[
          const SizedBox(width: 6),
          Text(
            '$count명',
            style: TextStyle(fontSize: 13, color: Colors.grey[500]),
          ),
        ],
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    return ListenableBuilder(
      listenable: _controller,
      builder: (context, _) {
        return Scaffold(
          backgroundColor: AppPalette.mist,
          appBar: AppBar(
            backgroundColor: Colors.transparent,
            foregroundColor: AppPalette.ink,
            elevation: 0,
          ),
          floatingActionButton: FloatingActionButton.extended(
            backgroundColor: AppPalette.ink,
            foregroundColor: AppPalette.paper,
            onPressed: _showAddFriendDialog,
            icon: const Icon(Icons.person_add_rounded),
            label: const Text('친구 추가'),
          ),
          body: _controller.isLoading
              ? const Center(child: CircularProgressIndicator())
              : RefreshIndicator(
                  onRefresh: _controller.refresh,
                  child: ListView(
                    padding: const EdgeInsets.fromLTRB(16, 0, 16, 90),
                    children: [
                      const Center(child: TitlePill('친구')),
                      const SizedBox(height: 20),
                      if (_controller.requests.isNotEmpty) ...[
                        _sectionHeader(
                          '받은 친구 신청',
                          count: _controller.requests.length,
                        ),
                        const SizedBox(height: 10),
                        for (final r in _controller.requests)
                          Container(
                            margin: const EdgeInsets.only(bottom: 8),
                            padding: const EdgeInsets.symmetric(
                              horizontal: 16,
                              vertical: 12,
                            ),
                            decoration: BoxDecoration(
                              color: AppPalette.paper,
                              borderRadius: BorderRadius.circular(16),
                              border: Border.all(color: AppPalette.sage),
                            ),
                            child: Row(
                              children: [
                                Expanded(
                                  child: Text(
                                    '${r['name']} (${r['studentId']})',
                                    style: const TextStyle(
                                      fontWeight: FontWeight.bold,
                                    ),
                                  ),
                                ),
                                TextButton(
                                  onPressed: () =>
                                      _respond(r['requestId'] as int, false),
                                  child: const Text(
                                    '거절',
                                    style: TextStyle(color: Colors.grey),
                                  ),
                                ),
                                ElevatedButton(
                                  style: ElevatedButton.styleFrom(
                                    backgroundColor: AppPalette.ink,
                                    foregroundColor: AppPalette.paper,
                                  ),
                                  onPressed: () =>
                                      _respond(r['requestId'] as int, true),
                                  child: const Text('수락'),
                                ),
                              ],
                            ),
                          ),
                        const SizedBox(height: 20),
                      ],
                      _sectionHeader('내 친구', count: _controller.friends.length),
                      const SizedBox(height: 10),
                      if (_controller.friends.isEmpty)
                        const Padding(
                          padding: EdgeInsets.symmetric(vertical: 12),
                          child: Text(
                            '아직 친구가 없어요. 학번으로 친구를 추가해보세요.',
                            style: TextStyle(color: Colors.grey),
                          ),
                        )
                      else
                        for (final f in _controller.friends)
                          Container(
                            margin: const EdgeInsets.only(bottom: 8),
                            padding: const EdgeInsets.symmetric(
                              horizontal: 16,
                              vertical: 12,
                            ),
                            decoration: BoxDecoration(
                              color: AppPalette.paper,
                              borderRadius: BorderRadius.circular(16),
                              border: Border.all(color: AppPalette.sage),
                            ),
                            child: Row(
                              children: [
                                Container(
                                  padding: const EdgeInsets.all(6),
                                  decoration: BoxDecoration(
                                    color: AppPalette.ink.withValues(
                                      alpha: 0.06,
                                    ),
                                    shape: BoxShape.circle,
                                  ),
                                  child: const Icon(
                                    Icons.person_rounded,
                                    size: 16,
                                    color: AppPalette.ink,
                                  ),
                                ),
                                const SizedBox(width: 10),
                                Expanded(
                                  child: Text(
                                    '${f['name']} (${f['studentId']})',
                                    style: const TextStyle(
                                      fontWeight: FontWeight.bold,
                                    ),
                                  ),
                                ),
                                IconButton(
                                  icon: const Icon(
                                    Icons.person_remove_outlined,
                                    color: Colors.grey,
                                  ),
                                  onPressed: () =>
                                      _remove(f['studentId'] as String),
                                ),
                              ],
                            ),
                          ),
                    ],
                  ),
                ),
        );
      },
    );
  }
}