import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:provider/provider.dart';
import 'package:intl/intl.dart';
import 'dart:math';

import '../../models/event_model.dart';
import '../../services/auth_service.dart';
import '../../services/event_service.dart';
import '../../widgets/loading_indicator.dart';

class EventFormScreen extends StatefulWidget {
  final Event? event; // null이면 새 이벤트 생성, 아니면 이벤트 수정

  const EventFormScreen({
    Key? key,
    this.event,
  }) : super(key: key);

  @override
  State<EventFormScreen> createState() => _EventFormScreenState();
}

class _EventFormScreenState extends State<EventFormScreen> {
  final _formKey = GlobalKey<FormState>();
  bool _isLoading = false;
  bool _isInit = false;
  final _currencyFormat = NumberFormat.currency(locale: 'ko_KR', symbol: '₩', decimalDigits: 0);

  // 폼 필드 컨트롤러
  final _titleController = TextEditingController();
  final _descriptionController = TextEditingController();
  final _locationController = TextEditingController();
  final _maxParticipantsController = TextEditingController();
  final _gameCountController = TextEditingController();
  final _participantFeeController = TextEditingController();
  final _publicHashController = TextEditingController();
  final _accessPasswordController = TextEditingController();

  // 이벤트 데이터
  String? _type;
  String? _status;
  DateTime _startDate = DateTime.now();
  DateTime? _endDate;
  DateTime? _registrationDeadline;

  // 이벤트 유형 및 상태 옵션
  final List<String> _typeOptions = ['개인전', '팀전', '리그', '토너먼트', '연습', '기타'];
  final List<String> _statusOptions = ['활성', '대기', '취소', '완료'];
  
  // 이벤트 유형 및 상태별 색상
  final Map<String, Color> _typeColors = {
    '개인전': Colors.blue,
    '팀전': Colors.green,
    '리그': Colors.purple,
    '토너먼트': Colors.orange,
    '연습': Colors.teal,
    '기타': Colors.grey,
  };
  
  final Map<String, Color> _statusColors = {
    '활성': Colors.green,
    '대기': Colors.amber,
    '취소': Colors.red,
    '완료': Colors.blue,
  };

  @override
  void initState() {
    super.initState();
    
    // 수정 모드인 경우 기존 데이터 로드
    if (widget.event != null) {
      _titleController.text = widget.event!.title;
      _descriptionController.text = widget.event!.description ?? '';
      _locationController.text = widget.event!.location ?? '';
      _maxParticipantsController.text = widget.event!.maxParticipants?.toString() ?? '';
      _gameCountController.text = widget.event!.gameCount?.toString() ?? '';
      _participantFeeController.text = widget.event!.participantFee?.toString() ?? '';
      _publicHashController.text = widget.event!.publicHash ?? '';
      _accessPasswordController.text = widget.event!.accessPassword ?? '';
      
      _type = widget.event!.type;
      _status = widget.event!.status;
      _startDate = widget.event!.startDate;
      _endDate = widget.event!.endDate;
      _registrationDeadline = widget.event!.registrationDeadline;
    } else {
      // 새 이벤트 생성 시 기본값 설정
      _type = _typeOptions[0];
      _status = _statusOptions[0];
      _generatePublicHash(); // 새 이벤트는 공개 해시 자동 생성
    }
  }

  @override
  void dispose() {
    _titleController.dispose();
    _descriptionController.dispose();
    _locationController.dispose();
    _maxParticipantsController.dispose();
    _gameCountController.dispose();
    _participantFeeController.dispose();
    _publicHashController.dispose();
    _accessPasswordController.dispose();
    super.dispose();
  }

  // 공개 URL 해시 생성
  void _generatePublicHash() {
    const chars = 'abcdefghijklmnopqrstuvwxyz0123456789';
    final random = Random();
    final hash = String.fromCharCodes(
      Iterable.generate(
        8,
        (_) => chars.codeUnitAt(random.nextInt(chars.length)),
      ),
    );
    
    _publicHashController.text = hash;
  }

  // 이벤트 저장
  Future<void> _saveEvent() async {
    if (!_formKey.currentState!.validate()) {
      return;
    }
    
    setState(() {
      _isLoading = true;
    });
    
    try {
      final eventService = Provider.of<EventService>(context, listen: false);
      final authService = Provider.of<AuthService>(context, listen: false);
      
      // 이벤트 데이터 준비
      final eventData = {
        'title': _titleController.text.trim(),
        'description': _descriptionController.text.trim().isEmpty ? null : _descriptionController.text.trim(),
        'location': _locationController.text.trim().isEmpty ? null : _locationController.text.trim(),
        'type': _type,
        'status': _status,
        'startDate': _startDate.toIso8601String(),
        'endDate': _endDate?.toIso8601String(),
        'maxParticipants': _maxParticipantsController.text.isEmpty ? null : int.parse(_maxParticipantsController.text),
        'gameCount': _gameCountController.text.isEmpty ? null : int.parse(_gameCountController.text),
        'participantFee': _participantFeeController.text.isEmpty ? null : double.parse(_participantFeeController.text),
        'registrationDeadline': _registrationDeadline?.toIso8601String(),
        'publicHash': _publicHashController.text.trim().isEmpty ? null : _publicHashController.text.trim(),
        'accessPassword': _accessPasswordController.text.trim().isEmpty ? null : _accessPasswordController.text.trim(),
      };
      
      if (widget.event == null) {
        // 새 이벤트 생성
        await eventService.createEvent(eventData);
        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(content: Text('이벤트가 생성되었습니다')),
          );
        }
      } else {
        // 기존 이벤트 수정
        await eventService.updateEvent(widget.event!.id, eventData);
        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(content: Text('이벤트가 수정되었습니다')),
          );
        }
      }
      
      if (mounted) {
        Navigator.of(context).pop(true); // 성공 결과와 함께 이전 화면으로 돌아가기
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _isLoading = false;
        });
        
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('이벤트 저장에 실패했습니다: $e')),
        );
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.event == null ? '새 이벤트 생성' : '이벤트 수정'),
        actions: [
          IconButton(
            icon: const Icon(Icons.save),
            onPressed: _saveEvent,
          ),
        ],
      ),
      body: _isLoading
          ? const LoadingIndicator()
          : SingleChildScrollView(
              padding: const EdgeInsets.all(16.0),
              child: Form(
                key: _formKey,
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    // 기본 정보 섹션
                    _buildSectionTitle('기본 정보'),
                    
                    // 제목
                    TextFormField(
                      controller: _titleController,
                      decoration: const InputDecoration(
                        labelText: '이벤트 제목 *',
                        hintText: '이벤트 제목을 입력하세요',
                      ),
                      validator: (value) {
                        if (value == null || value.trim().isEmpty) {
                          return '이벤트 제목을 입력해주세요';
                        }
                        return null;
                      },
                    ),
                    const SizedBox(height: 16),
                    
                    // 설명
                    TextFormField(
                      controller: _descriptionController,
                      decoration: const InputDecoration(
                        labelText: '이벤트 설명',
                        hintText: '이벤트 설명을 입력하세요',
                      ),
                      maxLines: 3,
                    ),
                    const SizedBox(height: 16),
                    
                    // 이벤트 유형
                    DropdownButtonFormField<String>(
                      value: _type,
                      decoration: const InputDecoration(
                        labelText: '이벤트 유형',
                      ),
                      items: _typeOptions
                          .map((type) => DropdownMenuItem<String>(
                                value: type,
                                child: Row(
                                  children: [
                                    Container(
                                      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
                                      decoration: BoxDecoration(
                                        color: _typeColors[type]?.withOpacity(0.2),
                                        borderRadius: BorderRadius.circular(12),
                                        border: Border.all(color: _typeColors[type] ?? Colors.grey),
                                      ),
                                      child: Text(
                                        type,
                                        style: TextStyle(color: _typeColors[type]),
                                      ),
                                    ),
                                  ],
                                ),
                              ))
                          .toList(),
                      onChanged: (value) {
                        setState(() {
                          _type = value;
                        });
                      },
                      validator: (value) {
                        if (value == null || value.isEmpty) {
                          return '이벤트 유형을 선택해주세요';
                        }
                        return null;
                      },
                    ),
                    const SizedBox(height: 8),
                    if (_type != null)
                      Align(
                        alignment: Alignment.centerLeft,
                        child: Container(
                          margin: const EdgeInsets.only(left: 12),
                          padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
                          decoration: BoxDecoration(
                            color: _typeColors[_type]?.withOpacity(0.2),
                            borderRadius: BorderRadius.circular(12),
                            border: Border.all(color: _typeColors[_type] ?? Colors.grey),
                          ),
                          child: Text(
                            _type!,
                            style: TextStyle(color: _typeColors[_type], fontSize: 12),
                          ),
                        ),
                      ),
                    const SizedBox(height: 16),
                    
                    // 상태
                    DropdownButtonFormField<String>(
                      value: _status,
                      decoration: const InputDecoration(
                        labelText: '상태',
                      ),
                      items: _statusOptions
                          .map((status) => DropdownMenuItem<String>(
                                value: status,
                                child: Row(
                                  children: [
                                    Container(
                                      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
                                      decoration: BoxDecoration(
                                        color: _statusColors[status]?.withOpacity(0.2),
                                        borderRadius: BorderRadius.circular(12),
                                        border: Border.all(color: _statusColors[status] ?? Colors.grey),
                                      ),
                                      child: Text(
                                        status,
                                        style: TextStyle(color: _statusColors[status]),
                                      ),
                                    ),
                                  ],
                                ),
                              ))
                          .toList(),
                      onChanged: (value) {
                        setState(() {
                          _status = value;
                        });
                      },
                      validator: (value) {
                        if (value == null || value.isEmpty) {
                          return '상태를 선택해주세요';
                        }
                        return null;
                      },
                    ),
                    const SizedBox(height: 8),
                    if (_status != null)
                      Align(
                        alignment: Alignment.centerLeft,
                        child: Container(
                          margin: const EdgeInsets.only(left: 12),
                          padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
                          decoration: BoxDecoration(
                            color: _statusColors[_status]?.withOpacity(0.2),
                            borderRadius: BorderRadius.circular(12),
                            border: Border.all(color: _statusColors[_status] ?? Colors.grey),
                          ),
                          child: Text(
                            _status!,
                            style: TextStyle(color: _statusColors[_status], fontSize: 12),
                          ),
                        ),
                      ),
                    const SizedBox(height: 24),
                    
                    // 날짜 및 시간 섹션
                    _buildSectionTitle('날짜 및 시간'),
                    
                    // 시작 날짜
                    ListTile(
                      title: const Text('시작 날짜 및 시간 *'),
                      subtitle: Text(
                        DateFormat('yyyy년 MM월 dd일 HH:mm').format(_startDate),
                      ),
                      trailing: const Icon(Icons.calendar_today),
                      onTap: () async {
                        final date = await showDatePicker(
                          context: context,
                          initialDate: _startDate,
                          firstDate: DateTime(2020),
                          lastDate: DateTime(2030),
                        );
                        
                        if (date != null) {
                          final time = await showTimePicker(
                            context: context,
                            initialTime: TimeOfDay.fromDateTime(_startDate),
                          );
                          
                          if (time != null && mounted) {
                            setState(() {
                              _startDate = DateTime(
                                date.year,
                                date.month,
                                date.day,
                                time.hour,
                                time.minute,
                              );
                            });
                          }
                        }
                      },
                    ),
                    const SizedBox(height: 8),
                    
                    // 종료 날짜
                    ListTile(
                      title: const Text('종료 날짜 및 시간 (선택)'),
                      subtitle: _endDate != null
                          ? Text(
                              DateFormat('yyyy년 MM월 dd일 HH:mm').format(_endDate!),
                            )
                          : const Text('설정되지 않음'),
                      trailing: Row(
                        mainAxisSize: MainAxisSize.min,
                        children: [
                          if (_endDate != null)
                            IconButton(
                              icon: const Icon(Icons.clear),
                              onPressed: () {
                                setState(() {
                                  _endDate = null;
                                });
                              },
                            ),
                          const Icon(Icons.calendar_today),
                        ],
                      ),
                      onTap: () async {
                        final date = await showDatePicker(
                          context: context,
                          initialDate: _endDate ?? _startDate.add(const Duration(hours: 2)),
                          firstDate: DateTime(2020),
                          lastDate: DateTime(2030),
                        );
                        
                        if (date != null) {
                          final time = await showTimePicker(
                            context: context,
                            initialTime: _endDate != null
                                ? TimeOfDay.fromDateTime(_endDate!)
                                : TimeOfDay.fromDateTime(_startDate.add(const Duration(hours: 2))),
                          );
                          
                          if (time != null && mounted) {
                            setState(() {
                              _endDate = DateTime(
                                date.year,
                                date.month,
                                date.day,
                                time.hour,
                                time.minute,
                              );
                            });
                          }
                        }
                      },
                    ),
                    const SizedBox(height: 8),
                    
                    // 등록 마감일
                    ListTile(
                      title: const Text('등록 마감일 (선택)'),
                      subtitle: _registrationDeadline != null
                          ? Text(
                              DateFormat('yyyy년 MM월 dd일 HH:mm').format(_registrationDeadline!),
                            )
                          : const Text('설정되지 않음'),
                      trailing: Row(
                        mainAxisSize: MainAxisSize.min,
                        children: [
                          if (_registrationDeadline != null)
                            IconButton(
                              icon: const Icon(Icons.clear),
                              onPressed: () {
                                setState(() {
                                  _registrationDeadline = null;
                                });
                              },
                            ),
                          const Icon(Icons.calendar_today),
                        ],
                      ),
                      onTap: () async {
                        final date = await showDatePicker(
                          context: context,
                          initialDate: _registrationDeadline ?? _startDate.subtract(const Duration(days: 1)),
                          firstDate: DateTime(2020),
                          lastDate: DateTime(2030),
                        );
                        
                        if (date != null) {
                          final time = await showTimePicker(
                            context: context,
                            initialTime: _registrationDeadline != null
                                ? TimeOfDay.fromDateTime(_registrationDeadline!)
                                : TimeOfDay.fromDateTime(_startDate.subtract(const Duration(days: 1))),
                          );
                          
                          if (time != null && mounted) {
                            setState(() {
                              _registrationDeadline = DateTime(
                                date.year,
                                date.month,
                                date.day,
                                time.hour,
                                time.minute,
                              );
                            });
                          }
                        }
                      },
                    ),
                    const SizedBox(height: 24),
                    
                    // 장소 및 참가자 섹션
                    _buildSectionTitle('장소 및 참가자'),
                    
                    // 장소
                    TextFormField(
                      controller: _locationController,
                      decoration: const InputDecoration(
                        labelText: '장소',
                        hintText: '이벤트 장소를 입력하세요',
                      ),
                    ),
                    const SizedBox(height: 16),
                    
                    // 최대 참가자 수
                    TextFormField(
                      controller: _maxParticipantsController,
                      decoration: const InputDecoration(
                        labelText: '최대 참가자 수',
                        hintText: '최대 참가자 수를 입력하세요',
                        suffixText: '명',
                      ),
                      keyboardType: TextInputType.number,
                      validator: (value) {
                        if (value != null && value.isNotEmpty) {
                          if (int.tryParse(value) == null) {
                            return '숫자를 입력해주세요';
                          }
                        }
                        return null;
                      },
                    ),
                    const SizedBox(height: 16),
                    
                    // 게임 수
                    TextFormField(
                      controller: _gameCountController,
                      decoration: const InputDecoration(
                        labelText: '게임 수',
                        hintText: '게임 수를 입력하세요',
                        suffixText: '게임',
                      ),
                      keyboardType: TextInputType.number,
                      validator: (value) {
                        if (value != null && value.isNotEmpty) {
                          final numValue = int.tryParse(value);
                          if (numValue == null) {
                            return '숫자를 입력해주세요';
                          }
                          if (numValue <= 0) {
                            return '1 이상의 숫자를 입력해주세요';
                          }
                        }
                        return null;
                      },
                    ),
                    const SizedBox(height: 16),
                    
                    // 게임 수
                    TextFormField(
                      controller: _gameCountController,
                      decoration: const InputDecoration(
                        labelText: '게임 수',
                        hintText: '게임 수를 입력하세요',
                      ),
                      keyboardType: TextInputType.number,
                      validator: (value) {
                        if (value != null && value.isNotEmpty) {
                          if (int.tryParse(value) == null) {
                            return '숫자를 입력해주세요';
                          }
                        }
                        return null;
                      },
                    ),
                    const SizedBox(height: 16),
                    
                    // 참가비
                    TextFormField(
                      controller: _participantFeeController,
                      decoration: const InputDecoration(
                        labelText: '참가비',
                        hintText: '참가비를 입력하세요',
                        prefixText: '₩',
                      ),
                      keyboardType: TextInputType.number,
                      validator: (value) {
                        if (value != null && value.isNotEmpty) {
                          if (double.tryParse(value) == null) {
                            return '숫자를 입력해주세요';
                          }
                        }
                        return null;
                      },
                      onChanged: (value) {
                        if (value.isNotEmpty) {
                          final numericValue = double.tryParse(value);
                          if (numericValue != null) {
                            // 입력 중에는 포맷을 적용하지 않음
                          }
                        }
                      },
                    ),
                    const SizedBox(height: 4),
                    if (_participantFeeController.text.isNotEmpty && double.tryParse(_participantFeeController.text) != null)
                      Align(
                        alignment: Alignment.centerRight,
                        child: Text(
                          '표시: ${_currencyFormat.format(double.parse(_participantFeeController.text))}',
                          style: TextStyle(color: Colors.grey[600], fontSize: 12),
                        ),
                      ),
                    
                    const SizedBox(height: 24),
                    
                    // 공개 접근 섹션
                    _buildSectionTitle('공개 접근'),
                    
                    // 공개 URL 해시
                    Row(
                      children: [
                        Expanded(
                          child: TextFormField(
                            controller: _publicHashController,
                            decoration: const InputDecoration(
                              labelText: '공개 URL 해시',
                              hintText: '공개 URL 해시를 입력하세요',
                            ),
                          ),
                        ),
                        IconButton(
                          icon: const Icon(Icons.refresh),
                          onPressed: () {
                            setState(() {
                              _generatePublicHash();
                            });
                          },
                          tooltip: '새 해시 생성',
                        ),
                        IconButton(
                          icon: const Icon(Icons.copy),
                          onPressed: () {
                            final publicUrl = 'https://bowling.example.com/events/${_publicHashController.text}';
                            Clipboard.setData(ClipboardData(text: publicUrl));
                            ScaffoldMessenger.of(context).showSnackBar(
                              const SnackBar(content: Text('공개 URL이 클립보드에 복사되었습니다')),
                            );
                          },
                          tooltip: 'URL 복사',
                        ),
                      ],
                    ),
                    const SizedBox(height: 4),
                    if (_publicHashController.text.isNotEmpty)
                      Padding(
                        padding: const EdgeInsets.only(left: 12),
                        child: Text(
                          'https://bowling.example.com/events/${_publicHashController.text}',
                          style: TextStyle(color: Colors.blue[700], fontSize: 12),
                        ),
                      ),
                    
                    const SizedBox(height: 16),
                    
                    // 접근 비밀번호
                    TextFormField(
                      controller: _accessPasswordController,
                      decoration: const InputDecoration(
                        labelText: '접근 비밀번호 (선택)',
                        hintText: '접근 비밀번호를 입력하세요',
                      ),
                      obscureText: true,
                    ),
                    const SizedBox(height: 32),
                    
                    // 저장 버튼
                    SizedBox(
                      width: double.infinity,
                      child: ElevatedButton(
                        onPressed: _saveEvent,
                        style: ElevatedButton.styleFrom(
                          padding: const EdgeInsets.symmetric(vertical: 16),
                        ),
                        child: Text(
                          widget.event == null ? '이벤트 생성' : '이벤트 수정',
                          style: const TextStyle(fontSize: 16),
                        ),
                      ),
                    ),
                  ],
                ),
              ),
            ),
    );
  }

  // 섹션 제목 위젯
  Widget _buildSectionTitle(String title) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          title,
          style: const TextStyle(
            fontSize: 18,
            fontWeight: FontWeight.bold,
          ),
        ),
        const Divider(),
        const SizedBox(height: 8),
      ],
    );
  }
}