let currentQuestionnaire = null;

function formatDate(timestamp) {
    if (!timestamp) return '-';
    const date = new Date(timestamp);
    return `${date.getFullYear()}-${String(date.getMonth() + 1).padStart(2, '0')}-${String(date.getDate()).padStart(2, '0')}`;
}

function renderQuestion(question, index) {
    const questionHtml = `
        <div class="question-item">
            <div class="question-item-title">
                ${index + 1}. ${question.title}
                ${question.required ? '<span style="color: red; margin-left: 5px;">*</span>' : ''}
            </div>
            ${
                question.type === 'text' ? 
                `<div class="question-content">
                    <textarea class="text-answer" name="question_${question.id}"
                        style="width: 100%; min-height: 100px; padding: 8px; margin-top: 10px; resize: vertical;"
                        placeholder="请在此输入您的答案"></textarea>
                </div>` :
                `<div class="options">
                    ${question.options.map(option => `
                        <div class="option-item">
                            <input type="${question.type}" 
                                   id="option_${question.id}_${option.id}"
                                   name="question_${question.id}"
                                   value="${option.id}">
                            <label for="option_${question.id}_${option.id}">${option.content}</label>
                        </div>
                    `).join('')}
                </div>`
            }
            <div class="error-message" id="error_${question.id}">此题为必答题</div>
        </div>
    `;
    return questionHtml;
}

function loadQuestionnaire() {
    const urlParams = new URLSearchParams(window.location.search);
    const questionnaireId = urlParams.get('id');
    
    if (!questionnaireId) {
        alert('问卷ID不存在！');
        window.location.href = 'myQuestion.html';
        return;
    }

    const questionnaireList = JSON.parse(localStorage.getItem('questionnaireList') || '[]');
    const questionnaire = questionnaireList.find(q => q.id === questionnaireId);

    if (!questionnaire) {
        alert('问卷不存在！');
        window.location.href = 'myQuestion.html';
        return;
    }

    if (questionnaire.status !== '已发布') {
        alert('该问卷尚未发布！');
        window.location.href = 'myQuestion.html';
        return;
    }

    currentQuestionnaire = questionnaire;

    // 填充问卷信息
    document.querySelector('.question-title').textContent = questionnaire.title;
    document.querySelector('.end-time').textContent = formatDate(questionnaire.data.endTime);
    document.querySelector('.status').textContent = questionnaire.status;

    // 渲染问题列表
    const questionListHtml = questionnaire.data.questions
        .map((question, index) => renderQuestion(question, index))
        .join('');
    document.querySelector('.question-list').innerHTML = questionListHtml;
}

function validateAnswers() {
    let isValid = true;
    currentQuestionnaire.data.questions.forEach(question => {
        if (!question.required) return;

        const errorElement = document.getElementById(`error_${question.id}`);
        if (question.type === 'text') {
            const answer = document.querySelector(`textarea[name="question_${question.id}"]`).value.trim();
            if (!answer) {
                errorElement.style.display = 'block';
                isValid = false;
            } else {
                errorElement.style.display = 'none';
            }
        } else {
            const checked = document.querySelector(`input[name="question_${question.id}"]:checked`);
            if (!checked) {
                errorElement.style.display = 'block';
                isValid = false;
            } else {
                errorElement.style.display = 'none';
            }
        }
    });
    return isValid;
}

function submitQuestionnaire() {
    if (!validateAnswers()) {
        alert('请回答所有问题！');
        return;
    }

    const answers = {
        questionnaireId: currentQuestionnaire.id,
        submitTime: new Date().getTime(),
        answers: currentQuestionnaire.data.questions.map(question => {
            if (question.type === 'text') {
                return {
                    questionId: question.id,
                    type: question.type,
                    answer: document.querySelector(`textarea[name="question_${question.id}"]`).value.trim()
                };
            } else {
                const selectedOptions = Array.from(
                    document.querySelectorAll(`input[name="question_${question.id}"]:checked`)
                ).map(input => parseInt(input.value));
                return {
                    questionId: question.id,
                    type: question.type,
                    answer: selectedOptions
                };
            }
        })
    };

    // 保存答案到 localStorage
    let answersList = JSON.parse(localStorage.getItem('questionnaireAnswers') || '[]');
    answersList.push(answers);
    localStorage.setItem('questionnaireAnswers', JSON.stringify(answersList));

    alert('问卷提交成功！');
    window.location.href = 'myQuestion.html';
}

window.onload = loadQuestionnaire;