// lib/pages/study_take_exam_page.dart
import 'dart:async';
import 'package:flutter/material.dart';
import 'package:intl/intl.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/http/modules/edu_api.dart';
import 'package:qhd_prevention/pages/my_appbar.dart';
import 'package:qhd_prevention/http/ApiService.dart';
import 'package:qhd_prevention/services/SessionService.dart';
import 'dart:convert';

import 'package:qhd_prevention/tools/tools.dart';

class Question {
  final String questionDry;
  final String questionType;
  final String questionId;
  final String answer; // 正确答案（如果接口返回）
  final double score;
  final Map<String, String> options;

  // 用户选择的答案（UI 中变化）
  String choiceAnswer;

  Question({
    required this.questionDry,
    required this.questionType,
    required this.questionId,
    required this.answer,
    required this.score,
    required this.options,
    this.choiceAnswer = '',
  });

  factory Question.fromJson(Map<String, dynamic> json) {
    final type = '${json['questionType'] ?? ''}';
    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? ?? '';
      }
    }
    // 保留原接口回传的参考答案（若有）
    final answer = json['answer'] as String? ?? '';
    final qDry = json['questionDry'] as String? ?? '';
    final qId = json['questionId'] as String? ?? '';
    double score = json['score'];

    return Question(
      questionDry: qDry,
      questionType: type,
      questionId: qId,
      answer: answer,
      score: score,
      options: opts,
    );
  }

  /// 构造提交给后端的最小字段对象
  Map<String, dynamic> toSubmitJson() {
    return {
      'questionId': questionId,
      'answer': answer,
      'choiceAnswer': choiceAnswer,
      'score': score,
    };
  }
}

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

  final Map<String, dynamic> examInfo;
  final Map signInfo;

  @override
  State<StudyTakeExamPage> createState() => _StudyTakeExamPageState();
}

class _StudyTakeExamPageState extends State<StudyTakeExamPage> {
  late final List<Question> questions;
  late final Map<String, dynamic> info;
  int current = 0;
  late int remainingSeconds;
  Timer? _timer;
  final String _startExamTime = DateFormat('yyyy-MM-dd HH:mm:ss').format(DateTime.now());

  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 as Map<String, dynamic>? ?? {};
    final rawList = widget.examInfo['questionList'] as List<dynamic>? ?? [];
    questions = rawList.map((e) => Question.fromJson(e as Map<String, dynamic>)).toList();
    final minutes = info['examTime'] as int? ?? 0;
    remainingSeconds = minutes * 60;
    _startTimer();
  }

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

  Future<void> _showTip(String content) {
    return CustomAlertDialog.showAlert(
      context,
      title: '温馨提示',
      content: content,
      confirmText: '确认',
    );
  }

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

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

  /// 重置页面以便“继续考试”
  void _resetForRetry() {
    // 清空每题的选择
    for (var q in questions) {
      q.choiceAnswer = '';
    }
    // 重置当前题索引、计时等
    setState(() {
      current = 0;
      final minutes = info['examTime'] as int? ?? 0;
      remainingSeconds = minutes * 60;
    });
    // 重新启动计时器
    _startTimer();
  }

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

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

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

  void _confirmSubmit() async {
    if (!_validateCurrentAnswer()) return;
    final ok = await CustomAlertDialog.showConfirm(
      context,
      title: '温馨提示',
      content: '请确认是否交卷！',
      cancelText: '取消',
    );
    if (ok) {
      _submit();
    }
  }

  Future<void> _submit() async {

    // 按原逻辑：若多选题需要去掉逗号（保留你的业务要求）
    for (var q in questions) {
      if (q.questionType == '2') {
        // 如果后端期待无逗号格式的话保留这一步，否则可删
        q.choiceAnswer = q.choiceAnswer.replaceAll(',', '');
      }
    }

    // 构造真正的 JSON 数组（而不是 JSON 字符串）
    final questionList = questions.map((q) => q.toSubmitJson()).toList();

    final data = {
      'studentId': widget.signInfo['studentId'] ?? '',
      'classId': widget.examInfo['classId'] ?? '',
      'corpinfoId': SessionService.instance.tenantId ?? '',
      'classExamPaperId': widget.examInfo['classExamPaperId'] ?? '',
      'examPaperId': widget.examInfo['examPaperId'] ?? '',
      'studentSignId': widget.signInfo['studentSignId'],
      'examTimeBegin': _startExamTime,
      // 当前时间就是结束时间
      'examTimeEnd': DateFormat('yyyy-MM-dd HH:mm:ss').format(DateTime.now()),
      'questionList': questionList, // 这里放真正的 List<Map<String,dynamic>>
    };
   // final r = await CustomAlertDialog.showConfirm(context, title: '参数', content: jsonEncode(data));
   // if (!r) return;
    LoadingDialogHelper.show(message: '正在提交');

    final res = await EduApi.submitExam(data);
    LoadingDialogHelper.hide();

    if (res['success']) {
      final data = res['data'] as Map<String, dynamic>? ?? {};
      final score = data['examScore'] ?? 0;
      final passed = data['result'] == 1;

      // 弹窗告诉用户结果：通过直接返回上一页；未通过给“继续考试 / 确定”两个按钮
      final result = await CustomAlertDialog.showConfirm(
        context,
        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: passed ? '' : '继续考试',
        confirmText: '确定',
      );

      // 如果考试通过或用户点击了“确定”，则返回上一页
      if (passed || result) {
        Navigator.of(context).pop();
        return;
      }

      // 到这里说明：未通过且用户点击了“继续考试” -> 重置页面状态并继续考试
      _resetForRetry();
    } else {
      // 可选：处理失败情况并提示错误信息
      final msg = res['message'] ?? '提交失败，请重试';
      ToastUtil.showError(context, msg);
    }
  }

  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.choiceAnswer),
        onChanged: (val) => q.choiceAnswer = 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.choiceAnswer.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: 15),
                  ),
                ),
              ],
            ),
          ),
        );
      }).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: true, // 禁用返回
      child: Scaffold(
        backgroundColor: Colors.white,
        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(
                            '试卷名称：${widget.examInfo['examName'] ?? ''}',
                            style: const TextStyle(
                              color: Colors.white,
                              fontSize: 16,
                              fontWeight: FontWeight.bold,
                            ),
                          ),
                          const SizedBox(height: 8),
                          Text(
                            '当前试题 ${current + 1}/${questions.length}',
                            style: const TextStyle(
                              color: Colors.white,
                              fontSize: 15,
                            ),
                          ),
                          const SizedBox(height: 8),
                          Text(
                            '考试剩余时间：$_formattedTime',
                            style: const TextStyle(
                              color: Colors.white,
                              fontSize: 15,
                            ),
                          ),
                        ],
                      ),
                    ),
                  ),
                ],
              ),
              const SizedBox(height: 16),
              if (q != null)
                Expanded(
                  child: SingleChildScrollView(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          '${current + 1}. ${q.questionDry} （${questionTypeMap[q.questionType] ?? ''}）',
                          style: const TextStyle(
                            fontWeight: FontWeight.w500,
                            fontSize: 15,
                          ),
                        ),
                        const SizedBox(height: 16),
                        _buildOptions(q),
                        const SizedBox(height: 24),
                      ],
                    ),
                  ),
                )
              else
                const Expanded(child: SizedBox()),
              const SizedBox(height: 8),
              Row(
                children: [
                  if (current > 0)
                    Expanded(
                      child: CustomButton(
                        text: '上一题',
                        backgroundColor: const Color(0xFFD7D7D7),
                        textColor: 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,
                      ),
                    ),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}