import 'dart:async';
import 'package:flutter/material.dart';
import 'package:qhd_prevention/customWidget/custom_alert_dialog.dart';
import 'package:qhd_prevention/customWidget/custom_button.dart';
import 'package:qhd_prevention/customWidget/toast_util.dart';
import 'package:qhd_prevention/pages/home/study/study_detail_page.dart';
import 'package:qhd_prevention/pages/my_appbar.dart';
import 'package:qhd_prevention/http/ApiService.dart';
import 'dart:convert';

class Question {
  final Map<String, dynamic> rawData;
  final String questionDry;
  final String questionType;
  final Map<String, String> options;
  String checked;

  Question({
    required this.rawData,
    required this.questionDry,
    required this.questionType,
    required this.options,
    this.checked = '',
  });

  factory Question.fromJson(Map<String, dynamic> json) {
    final type = json['QUESTIONTYPE'] as String? ?? '1';
    final opts = <String, String>{};
    if (type == '1' || type == '2' || type == '3') {
      opts['A'] = json['OPTIONA'] as String? ?? '';
      opts['B'] = json['OPTIONB'] as String? ?? '';
      if (type != '3') {
        opts['C'] = json['OPTIONC'] as String? ?? '';
        opts['D'] = json['OPTIOND'] as String? ?? '';
      }
    }
    final raw = Map<String, dynamic>.from(json);
    return Question(
      rawData: raw,
      questionDry: json['QUESTIONDRY'] as String? ?? '',
      questionType: type,
      options: opts,
    );
  }
}

class TakeExamPage extends StatefulWidget {
  const TakeExamPage({
    required this.examInfo,
    required this.examType,
    super.key,
  });

  final Map<String, dynamic> examInfo;
  final TakeExamType examType;

  @override
  State<TakeExamPage> createState() => _TakeExamPageState();
}

class _TakeExamPageState extends State<TakeExamPage> {
  late final List<Question> questions;
  late final Map<String, dynamic> info;
  int current = 0;
  late int remainingSeconds;
  Timer? _timer;

  final questionTypeMap = <String, String>{
    '1': '单选题',
    '2': '多选题',
    '3': '判断题',
    '4': '填空题',
  };

  @override
  void initState() {
    super.initState();
    info = widget.examInfo['pd'] as Map<String, dynamic>? ?? {};
    final rawList = widget.examInfo['inputQue'] as List<dynamic>? ?? [];
    questions =
        rawList
            .map((e) => Question.fromJson(e as Map<String, dynamic>))
            .toList();

    final numberOfExams = widget.examInfo['NUMBEROFEXAMS'] as String? ?? '0';
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (numberOfExams == '-9999') {
        _showTip('强化学习考试开始，限时${info['ANSWERSHEETTIME']}分钟，请注意答题时间！');
      } else {
        _showTip('您无考试次数！');
      }
    });

    final minutes = info['ANSWERSHEETTIME'] as int? ?? 0;
    remainingSeconds = minutes * 60;
    _startTimer();
  }

  @override
  void dispose() {
    _timer?.cancel();
    super.dispose();
  }

  Future<void> _showTip(String content) {
    return showDialog<void>(
      context: context,
      builder:
          (_) => CustomAlertDialog(
            title: '温馨提示',
            content: content,
            cancelText: '',
            confirmText: '确定',
            onConfirm: () {},
          ),
    );
  }

  bool _validateCurrentAnswer() {
    final q = questions[current];
    if (q.checked.isEmpty) {
      _showTip('请对本题进行作答。');
      return false;
    }
    if (q.questionType == '2' && q.checked.split(',').length < 2) {
      _showTip('多选题最少需要选择两个答案。');
      return false;
    }
    return true;
  }

  void _startTimer() {
    _timer = Timer.periodic(const Duration(seconds: 1), (timer) {
      if (remainingSeconds <= 0) {
        timer.cancel();
        _onTimeUp();
      } else {
        setState(() => remainingSeconds--);
      }
    });
  }

  void _chooseTopic(String type, String key) {
    final q = questions[current];
    if (type == 'radio' || type == 'judge') {
      q.checked = (q.checked == key) ? '' : key;
    } else {
      final arr = q.checked.isNotEmpty ? q.checked.split(',') : <String>[];
      if (arr.contains(key))
        arr.remove(key);
      else
        arr.add(key);
      arr.sort();
      q.checked = arr.join(',');
    }
    setState(() {});
  }

  void _nextQuestion() {
    if (!_validateCurrentAnswer()) return;
    if (current < questions.length - 1) setState(() => current++);
  }

  void _previousQuestion() {
    if (current > 0) setState(() => current--);
  }

  void _confirmSubmit() {
    if (!_validateCurrentAnswer()) return;
    showDialog<void>(
      context: context,
      builder:
          (_) => CustomAlertDialog(
            title: '温馨提示',
            content: '请确认是否交卷！',
            cancelText: '取消',
            onCancel: () {},
            onConfirm: _submit,
          ),
    );
  }

  Future<void> _submit() async {
    for (var q in questions) {
      if (q.questionType == '2') q.checked = q.checked.replaceAll(',', '');
      q.rawData['checked'] = q.checked;
    }
    final data = {
      'STAGEEXAMPAPERINPUT_ID':
          widget.examInfo['STRENGTHEN_PAPER_QUESTION_ID'],
      'STUDENT_ID': widget.examInfo['STUDENT_ID'],
      'CLASS_ID': widget.examInfo['CLASS_ID'],
      'NUMBEROFEXAMS': widget.examInfo['NUMBEROFEXAMS'],
      'entrySite': widget.examType.name,
      'PASSSCORE': info['PASSSCORE'],
      'EXAMSCORE': info['EXAMSCORE'],
      'EXAMTIMEBEGIN': info['EXAMTIMEBEGIN'],
      'options': jsonEncode(questions.map((q) => q.rawData).toList()),
    };
    final res = await ApiService.submitExam(data);
    if (res['result'] == 'success') {
      final score = res['examScore'] ?? '0';
      final passed = res['examResult'] != '0';
      showDialog<void>(
        context: context,
        builder:
            (_) => CustomAlertDialog(
              title: '温馨提示',
              content:
                  passed
                      ? '您的成绩为 $score 分，恭喜您通过本次考试，请继续保持！'
                      : '您的成绩为 $score 分，很遗憾您没有通过本次考试，请再接再厉！',
              cancelText: '',
              confirmText: '确定',
              onConfirm: () {
                Navigator.pop(context);
              },
            ),
      );
    }
  }

  void _onTimeUp() {
    ToastUtil.showError(context, '考试时间已结束');
    _submit();
  }

  Widget _buildOptions(Question q) {
    if (q.questionType == '4') {
      return TextField(
        controller: TextEditingController(text: q.checked),
        onChanged: (val) => q.checked = val,
        maxLength: 255,
        decoration: const InputDecoration(
          hintText: '请输入内容',
          border: OutlineInputBorder(),
        ),
      );
    }
    final keys = q.questionType == '3' ? ['A', 'B'] : ['A', 'B', 'C', 'D'];
    return Column(
      children:
          keys.map((key) {
            final active = q.checked.split(',').contains(key);
            return GestureDetector(
              onTap:
                  () => _chooseTopic(
                    q.questionType == '3'
                        ? 'judge'
                        : (q.questionType == '2' ? 'multiple' : 'radio'),
                    key,
                  ),
              child: Container(
                margin: const EdgeInsets.symmetric(vertical: 8),
                child: Row(
                  children: [
                    Container(
                      width: 40,
                      height: 40,
                      alignment: Alignment.center,
                      decoration: BoxDecoration(
                        color: active ? Colors.blue : Colors.grey.shade200,
                        shape: BoxShape.circle,
                      ),
                      child: Text(
                        key,
                        style: TextStyle(
                          color: active ? Colors.white : Colors.black87,
                        ),
                      ),
                    ),
                    const SizedBox(width: 16),
                    Expanded(
                      child: Text(
                        q.options[key] ?? '',
                        style: const TextStyle(fontSize: 16),
                      ),
                    ),
                  ],
                ),
              ),
            );
          }).toList(),
    );
  }

  String get _formattedTime {
    final m = remainingSeconds ~/ 60;
    final s = remainingSeconds % 60;
    return '${m.toString().padLeft(2, '0')}:${s.toString().padLeft(2, '0')}';
  }

  @override
  Widget build(BuildContext context) {
    final q = questions.isNotEmpty ? questions[current] : null;
    return PopScope(
      canPop: false, // 禁用返回

      child: Scaffold(
        appBar: const MyAppbar(title: '课程考试', isBack: false,),
        body: Padding(
          padding: const EdgeInsets.all(16),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Stack(
                children: [
                  Container(
                    width: double.infinity,
                    height: 120,
                    decoration: BoxDecoration(
                      image: const DecorationImage(
                        image: AssetImage('assets/study/bgimg1.png'),
                        fit: BoxFit.cover,
                      ),
                      borderRadius: BorderRadius.circular(8),
                    ),
                  ),
                  Positioned.fill(
                    child: Center(
                      child: Column(
                        mainAxisSize: MainAxisSize.min,
                        children: [
                          Text(
                            '考试科目：${info['EXAMNAME'] ?? ''}',
                            style: const TextStyle(
                              color: Colors.white,
                              fontSize: 18,
                              fontWeight: FontWeight.bold,
                            ),
                          ),
                          const SizedBox(height: 8),
                          Text(
                            '当前试题 ${current + 1}/${questions.length}',
                            style: const TextStyle(
                              color: Colors.white,
                              fontSize: 16,
                            ),
                          ),
                          const SizedBox(height: 8),
                          Text(
                            '考试剩余时间：$_formattedTime',
                            style: const TextStyle(
                              color: Colors.white,
                              fontSize: 16,
                            ),
                          ),
                        ],
                      ),
                    ),
                  ),
                ],
              ),
              const SizedBox(height: 16),
              if (q != null) ...[
                Text(
                  '${current + 1}. ${q.questionDry} （${questionTypeMap[q.questionType] ?? ''}）',
                  style: const TextStyle(
                    fontWeight: FontWeight.bold,
                    fontSize: 18,
                  ),
                ),
                const SizedBox(height: 16),
                _buildOptions(q),
              ],
              const Spacer(),
              Row(
                children: [
                  if (current > 0)
                    Expanded(
                      child: CustomButton(
                        text: '上一题',
                        backgroundColor: Colors.grey.shade200,
                        textStyle: const TextStyle(color: Colors.black54),
                        onPressed: _previousQuestion,
                      ),
                    ),
                  if (current > 0 && current < questions.length - 1)
                    const SizedBox(width: 16),
                  if (current < questions.length - 1)
                    Expanded(
                      child: CustomButton(
                        text: '下一题',
                        backgroundColor: Colors.blue,
                        onPressed: _nextQuestion,
                      ),
                    ),
                  if (current == questions.length - 1)
                    Expanded(
                      child: CustomButton(
                        text: '交卷',
                        backgroundColor: Colors.blue,
                        onPressed: _confirmSubmit,
                      ),
                    ),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}