import 'package:flutter/material.dart';
import 'package:flutter/services.dart'; // /* 숫자만 입력 위해 */
import 'package:http/http.dart' as http;
import 'dart:convert';

// Server API (서버 API)
import '../plugins/api.dart';

// Main Page (메인 페이지)
import '../views/room/main_page.dart';

// Alert modal dialog (알람 모달창)
import '../dialogs/response_dialog.dart';

class SurveyPage extends StatefulWidget {
  final String nickname;

  const SurveyPage({
    Key? key,
    required this.nickname,
  }) : super(key: key);

  @override
  State<SurveyPage> createState() => _SurveyPageState();
}

class _SurveyPageState extends State<SurveyPage> {
  int _currentIndex = 0; 
  /* 현재 페이지 인덱스 (0~4) */

  List<String> _questions = [];
  /* 전체 질문 목록 (5개 예시) */
  List<String> _questionsOriginal = [];
  /* 질문의 한글 원본 목록 */

  final List<String?> _answers = List.filled(5, null, growable: false);
  /* 사용자가 입력한 답변(5개) */

  final Map<int, String> _selectedRadioValue = {};
  /* 각 페이지별 라디오 선택 값 */
  final Map<int, TextEditingController> _textControllers = {};
  /* 각 페이지별 텍스트필드 컨트롤러 */

  @override
  void initState() {
    super.initState();

    // Set questions (질문 설정)
    _questions = [
      "Q1. How old are you, ${widget.nickname}?",
      /* "Q1. ${widget.nickname}님의 나이는 어떻게 되나요?" */

      "Q2. What is your occupation, ${widget.nickname}?",
      /* "Q2. ${widget.nickname}님의 직업이 무엇인가요?" */

      "Q3. How did you hear about ALLSCORE, ${widget.nickname}?",
      /* "Q3. ${widget.nickname}님은 올스코어 앱을 어떻게 알게 됐나요?" */

      "Q4. Where have you experienced ALLSCORE, ${widget.nickname}?",
      /* "Q4. ${widget.nickname}님은 올스코어 앱을 어디서 경험하셨나요?" */

      "Q5. Do you plan to keep using ALLSCORE?",
      /* "Q5. 올스코어를 계속 사용할 의사가 있나요?" */
    ];

    // Original Korean questions (원래 한글 질문 목록)
    _questionsOriginal = [
      "나이는 어떻게 되나요?",
      "직업이 무엇인가요?",
      "올스코어 앱을 어떻게 알게 됐나요?",
      "올스코어 앱을 어디서 경험하셨나요?",
      "올스코어를 계속 사용할 의사가 있나요?",
    ];

    // Initialize TextEditingController for each page
    // (페이지마다 TextEditingController 초기화)
    for (int i = 0; i < _questions.length; i++) {
      _textControllers[i] = TextEditingController();
    }
  }

  @override
  void dispose() {
    // Dispose text controllers (텍스트 컨트롤러 정리)
    for (var ctrl in _textControllers.values) {
      ctrl.dispose();
    }
    super.dispose();
  }

  /// Exit the survey (설문 그만하기)
  Future<void> _onExitSurvey() async {
    Navigator.pushAndRemoveUntil(
      context,
      MaterialPageRoute(builder: (_) => const MainPage()),
      (route) => false,
    );
  }

  /// Next button (다음 버튼)
  void _onNext() {
    if (!_validateCurrentPage()) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Please fill in all required fields.' 
          /* '값을 모두 입력해 주세요.' */)),
      );
      return;
    }

    if (_currentIndex < _questions.length - 1) {
      setState(() {
        _currentIndex++;
      });
    }
  }

  /// Previous button (이전 버튼)
  void _onPrev() {
    if (_currentIndex > 0) {
      setState(() {
        _currentIndex--;
      });
    }
  }

  /// Submit (제출하기)
  Future<void> _onSubmit() async {
    if (!_validateCurrentPage()) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Please fill in all required fields.'
          /* '값을 모두 입력해 주세요.' */)),
      );
      return;
    }

    // body: {"QNA": ["질문1","답변1","질문2","답변2", ... ]}
    final List<String> qnaList = [];
    for (int i = 0; i < _questionsOriginal.length; i++) {
      qnaList.add(_questionsOriginal[i]);
      /* 한글 질문 넣기 */
      qnaList.add(_answers[i] ?? '');
      /* 사용자 답변 */
    }

    final requestBody = {
      "QNA": qnaList,
    };

    try {
      final response = await Api.serverRequest(uri: '/survey/collect', body: requestBody);
      if (response['result'] == 'OK') {
        final resp = response['response'] ?? {};
        if (resp['result'] == 'OK') {
          // Survey submitted (설문 제출 성공)
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(content: Text('Your survey has been submitted. Thank you!'
              /* '설문이 제출되었습니다. 감사합니다!' */)),
          );
          Navigator.pushAndRemoveUntil(
            context, 
            MaterialPageRoute(builder: (_) => const MainPage()),
            (route) => false,
          );
        } else {
          showResponseDialog(context, 'Error' /* 오류 */, 'Failed to submit the survey.'
            /* '설문 제출 실패' */);
        }
      } else {
        showResponseDialog(context, 'Error' /* 오류 */, 'Failed to submit the survey.'
          /* '설문 제출 실패' */);
      }
    } catch (e) {
      showResponseDialog(context, 'Error' /* 오류 */, 'Failed to submit the survey.'
        /* '설문 제출 실패' */);
    }
  }

  /// Validate current page input (현재 페이지 입력값이 유효한지 체크)
  bool _validateCurrentPage() {
    final index = _currentIndex;
    String? answer;

    switch (index) {
      case 0:
        // Age (나이)
        final txt = _textControllers[index]?.text.trim() ?? '';
        if (txt.isEmpty) {
          return false;
        }
        answer = '$txt yrs old' 
          /* '$txt 세' */;
        break;

      case 1:
        // Occupation (직업)
        final selected = _selectedRadioValue[index];
        if (selected == null || selected.isEmpty) {
          return false;
        }
        answer = selected;
        break;

      case 2:
        // How did you hear about ALLSCORE? (앱 알게된 경로)
        final selected2 = _selectedRadioValue[index];
        if (selected2 == null || selected2.isEmpty) {
          return false;
        }
        if (selected2 == 'Others' /* '기타' */) {
          final etc = _textControllers[index]?.text.trim() ?? '';
          if (etc.isEmpty) {
            return false;
          }
          answer = "Others($etc)" 
            /* "기타($etc)" */;
        } else {
          answer = selected2;
        }
        break;

      case 3:
        // Where have you experienced? (어디서 경험?)
        final sel3 = _selectedRadioValue[index];
        if (sel3 == null || sel3.isEmpty) {
          return false;
        }
        answer = sel3;
        break;

      case 4:
        // Will you continue using ALLSCORE? (계속 사용할 의사?)
        final sel4 = _selectedRadioValue[index];
        if (sel4 == null || sel4.isEmpty) {
          return false;
        }
        final comment = _textControllers[index]?.text.trim() ?? '';
        answer = sel4 + (comment.isNotEmpty ? " / comment: $comment" 
          /* "/ 의견: $comment" */ : "");
        break;

      default:
        return false;
    }

    _answers[index] = answer;
    return true;
  }

  @override
  Widget build(BuildContext context) {
    final questionText = _questions[_currentIndex];
    /* 현재 페이지 질문 */
    final pageNumber = _currentIndex + 1;
    final totalPage = _questions.length;

    return WillPopScope(
      onWillPop: () async {
        _onExitSurvey();
        return false;
      },
      child: Scaffold(
        appBar: AppBar(
          leadingWidth: 120,
          leading: TextButton(
            onPressed: _onExitSurvey,
            child: const Text(
              'Stop Survey'
              /* '설문 그만하기' */,
              style: TextStyle(color: Colors.white),
            ),
          ),
          title: Text('Survey ($pageNumber/$totalPage)'
            /* '설문조사 ($pageNumber/$totalPage)' */),
          backgroundColor: Colors.black,
        ),
        body: SingleChildScrollView(
          child: Container(
            alignment: Alignment.center,
            padding: const EdgeInsets.all(16),
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              crossAxisAlignment: CrossAxisAlignment.center,
              children: [
                // Question text (질문)
                Text(
                  questionText,
                  style: const TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
                  textAlign: TextAlign.center,
                ),
                const SizedBox(height: 24),
                // Page-specific UI (페이지별 UI)
                _buildSurveyPage(_currentIndex),
              ],
            ),
          ),
        ),
        bottomNavigationBar: Container(
          color: Colors.white,
          padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
          child: Row(
            children: [
              if (_currentIndex > 0)
                Expanded(
                  child: ElevatedButton(
                    style: ElevatedButton.styleFrom(backgroundColor: Colors.grey),
                    onPressed: _onPrev,
                    child: const Text('Previous'
                      /* '이전' */),
                  ),
                ),
              if (_currentIndex > 0) const SizedBox(width: 8),
              Expanded(
                child: ElevatedButton(
                  style: ElevatedButton.styleFrom(backgroundColor: Colors.black),
                  onPressed: (_currentIndex < totalPage - 1) ? _onNext : _onSubmit,
                  child: Text(
                    (_currentIndex < totalPage - 1) ? 'Next' /* 다음 */ : 'Submit' /* 제출하기 */,
                    style: const TextStyle(color: Colors.white),
                  ),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  /// Build UI for each page (페이지별 UI)
  Widget _buildSurveyPage(int index) {
    switch (index) {
      case 0:
        // Age input (나이 입력)
        return Column(
          children: [
            const Text(
              '(e.g. Please enter your age in digits.)' 
              /* '(예: 나이를 숫자로 입력해 주세요.)' */,
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 16),
            TextField(
              controller: _textControllers[index],
              keyboardType: TextInputType.number,
              inputFormatters: [FilteringTextInputFormatter.digitsOnly], 
              textAlign: TextAlign.center,
              decoration: const InputDecoration(
                labelText: 'Age' 
                /* '나이' */,
                border: OutlineInputBorder(),
              ),
            ),
          ],
        );

      case 1:
        // Occupation (직업)
        final jobs = [
          'Student' /* '학생' */, 
          'Office Worker' /* '회사원' */,
          'Professional' /* '전문직' */,
          'Professor/Teacher' /* '교수/교사' */,
          'Technical' /* '기술직' */,
          'Government Official' /* '공무원' */,
          'Art/Sports' /* '예술/스포츠' */,
          'Others' /* '기타' */,
        ];
        return Column(
          mainAxisSize: MainAxisSize.min,
          children: jobs.map((job) {
            return RadioListTile<String>(
              title: Text(job, textAlign: TextAlign.center),
              value: job,
              groupValue: _selectedRadioValue[index],
              onChanged: (val) {
                setState(() {
                  _selectedRadioValue[index] = val!;
                });
              },
            );
          }).toList(),
        );

      case 2:
        // How did you hear about ALLSCORE? (앱 알게된 경로)
        final paths = [
          'Friend/Acquaintance' /* '친구/지인 추천' */,
          'Social Media' /* '소셜 미디어' */,
          'Blog/Online Review' /* '블로그/온라인 리뷰' */,
          'School/Workplace' /* '학교나 직장' */,
          'Others' /* '기타' */,
        ];
        return Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            ...paths.map((p) {
              return RadioListTile<String>(
                title: Text(p, textAlign: TextAlign.center),
                value: p,
                groupValue: _selectedRadioValue[index],
                onChanged: (val) {
                  setState(() {
                    _selectedRadioValue[index] = val!;
                  });
                },
              );
            }).toList(),
            if (_selectedRadioValue[index] == 'Others' 
                /* '기타' */)
              Padding(
                padding: const EdgeInsets.only(top: 8.0),
                child: TextField(
                  controller: _textControllers[index],
                  textAlign: TextAlign.center,
                  decoration: const InputDecoration(
                    labelText: 'Please specify.'
                    /* '기타 내용을 입력해 주세요.' */,
                    border: OutlineInputBorder(),
                  ),
                ),
              ),
          ],
        );

      case 3:
        // Where have you experienced ALLSCORE? (어디서 경험?)
        final places = [
          'With Family' /* '가족과 함께' */,
          'With Friends' /* '친구들과 모임' */,
          'School (for education)' /* '학교 교육 목적' */,
          'Work Club' /* '직장 동호회' */,
          'Cafe or Public Space' /* '카페나 공공장소' */,
          'Travel' /* '여행 중' */,
          'Others' /* '기타' */,
        ];
        return Column(
          mainAxisSize: MainAxisSize.min,
          children: places.map((pl) {
            return RadioListTile<String>(
              title: Text(pl, textAlign: TextAlign.center),
              value: pl,
              groupValue: _selectedRadioValue[index],
              onChanged: (val) {
                setState(() {
                  _selectedRadioValue[index] = val!;
                });
              },
            );
          }).toList(),
        );

      case 4:
        // Will you continue using ALLSCORE? (계속 사용할 의사?)
        return Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            RadioListTile<String>(
              title: const Text('Yes' /* '네' */, textAlign: TextAlign.center),
              value: 'Yes' /* '네' */,
              groupValue: _selectedRadioValue[index],
              onChanged: (val) {
                setState(() {
                  _selectedRadioValue[index] = val!;
                });
              },
            ),
            RadioListTile<String>(
              title: const Text('No' /* '아니오' */, textAlign: TextAlign.center),
              value: 'No' /* '아니오' */,
              groupValue: _selectedRadioValue[index],
              onChanged: (val) {
                setState(() {
                  _selectedRadioValue[index] = val!;
                });
              },
            ),
            const SizedBox(height: 16),
            const Text(
              'If you have any additional comments, feel free to write them here.'
              /* '추가 의견이 있다면 자유롭게 작성해 주세요.' */,
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 8),
            TextField(
              controller: _textControllers[index],
              maxLines: 3,
              textAlign: TextAlign.center,
              decoration: const InputDecoration(
                hintText: 'e.g. inconveniences, improvement ideas, etc.'
                /* 'ex) 불편사항, 개선 아이디어 등' */,
                border: OutlineInputBorder(),
              ),
            ),
          ],
        );

      default:
        return const Text(
          'Survey question error' 
          /* '설문 문항 오류' */, 
          textAlign: TextAlign.center
        );
    }
  }
}