import 'dart:convert';
import 'school_identity.dart';
import 'school_term.dart';

class ExamRecord {
  const ExamRecord({
    required this.code,
    required this.name,
    this.assessment = '',
    this.candidate = '',
    this.sequence = '',
    this.room = '',
    this.seat = '',
    this.time = '',
    this.date = '', this.status = '', this.notes = '', this.examTypeId,
  });
  final String code, name, assessment, candidate, sequence, room, seat, time;
  final String date, status, notes;
  final int? examTypeId;
  String get undergraduateKey => jsonEncode([examTypeId,code,date,time,room,seat]);
  Map<String, dynamic> toJson() => {
    'code': code,
    'name': name,
    'assessment': assessment,
    'candidate': candidate,
    'sequence': sequence,
    'room': room,
    'seat': seat,
    'time': time,
    'date':date, 'status':status, 'notes':notes, 'examTypeId':examTypeId,
  };
  factory ExamRecord.fromJson(Map<String, dynamic> json) {
    String field(String key, {bool optional=false}) {
      final value = optional && !json.containsKey(key) ? '' : json[key];
      if (value is! String || value.length > 1000) {
        throw const FormatException('考试信息无效');
      }
      return value;
    }

    final record = ExamRecord(
      code: field('code'),
      name: field('name'),
      assessment: field('assessment'),
      candidate: field('candidate'),
      sequence: field('sequence'),
      room: field('room'),
      seat: field('seat'),
      time: field('time'),
      date:field('date',optional:true), status:field('status',optional:true), notes:field('notes',optional:true),
      examTypeId:json['examTypeId'] as int?,
    );
    if (record.code.isEmpty || record.name.isEmpty) {
      throw const FormatException('考试课程无效');
    }
    return record;
  }
}

class ExamSchedule {
  ExamSchedule({
    required this.semesterLabel,
    required this.termId,
    required List<ExamRecord> records,
    this.school = SupportedSchool.uestcGraduate,
    Set<int> requestedExamTypes = const {},
  }) : records = List.unmodifiable(records), requestedExamTypes=Set.unmodifiable(requestedExamTypes);
  final String semesterLabel, termId;
  final List<ExamRecord> records;
  final SupportedSchool school;
  final Set<int> requestedExamTypes;
  Map<String, dynamic> toJson() => {
    'semesterLabel': semesterLabel,
    'termId': termId,
    'records': records.map((r) => r.toJson()).toList(),
    'schoolId':school.id, 'requestedExamTypes':requestedExamTypes.toList()..sort(),
  };
  factory ExamSchedule.fromJson(Map<String, dynamic> json) {
    try {
    final label = json['semesterLabel'],
        id = json['termId'],
        rows = json['records'];
    if (label is! String ||
        label.trim().isEmpty ||
        id is! String ||
        !RegExp(r'^\d+$').hasMatch(id) ||
        rows is! List ||
        rows.length > 500) {
      throw const FormatException('考试列表无效');
    }
    final records = rows
        .map((r) => ExamRecord.fromJson(Map<String, dynamic>.from(r as Map)))
        .toList();
    final school=json['schoolId']==null ? SupportedSchool.uestcGraduate : SupportedSchool.fromId(json['schoolId'] as String);
    final rawTypes=json['requestedExamTypes'] ?? <int>[];
    if(rawTypes is! List || rawTypes.any((t)=>t is! int || t<1 || t>3)) throw const FormatException('考试类型无效');
    final types=rawTypes.cast<int>().toSet();
    SchoolTerm(int.parse(id),school:school);
    if(school==SupportedSchool.uestcUndergraduate && (types.isEmpty || records.any((r)=>!types.contains(r.examTypeId)))) {
      throw const FormatException('本科考试类型无效');
    }
    if (records.map((r) => school==SupportedSchool.uestcGraduate ? r.code : r.undergraduateKey).toSet().length != records.length) {
      throw const FormatException('考试课程重复');
    }
    return ExamSchedule(semesterLabel: label, termId: id, records: records,school:school,requestedExamTypes:types);
    } catch (_) { throw const FormatException('考试列表无效'); }
  }
}