// ==UserScript==
// @name         超星学习通自动答题
// @namespace    http://tampermonkey.net/
// @version      2.0.0
// @description  调用 DeepSeek API 自动作答，支持单选、多选、判断、填空、简答，带自动翻页、模型选择、智能暂停
// @author       dmhnb6
// @match        *://mooc1.chaoxing.com/mooc-ans/mooc2/work/dowork*
// @grant        GM_xmlhttpRequest
// @grant        GM_setValue
// @grant        GM_getValue
// @connect      api.deepseek.com
// ==/UserScript==

(function() {
    'use strict';

    // ===========================
    // 用户默认配置（可在面板中动态修改）
    // ===========================
    let API_KEY = GM_getValue('deepseek_api_key', ''); // 从存储读取，无则留空
    let MODEL = 'deepseek-v4-flash';            // 模型：deepseek-v4-flash / deepseek-v4-pro
    let ENABLE_THINKING = false;                // 思考模式（仅Pro有效）
    const DELAY = 100;                          // 每题完成后等待（毫秒）
    const JUMP_DELAY = 100;                     // 点击题号后等待题目出现的最大时间（毫秒）
    // ===========================

    // 全局状态
    let isPaused = false;
    let isRunning = false;
    let solvingController = null;
    let currentSheetItems = [];
    let currentIdx = 0;                         // 即将处理的题目索引

    // UI 元素
    let progressBar, progressText, statusLabel;
    let startBtn, pauseBtn, resumeCurrentBtn;
    let modelSelect, thinkingCheckbox;

    const sleep = (ms) => new Promise(resolve => setTimeout(resolve, ms));

    // 获取可用模型列表
    async function fetchModels(apiKey = API_KEY) {
        return new Promise((resolve) => {
            if (!apiKey || apiKey.trim() === '') {
                resolve(['deepseek-v4-flash', 'deepseek-v4-pro']);
                return;
            }
            GM_xmlhttpRequest({
                method: 'GET',
                url: 'https://api.deepseek.com/models',
                headers: {
                    'Accept': 'application/json',
                    'Authorization': `Bearer ${apiKey}`
                },
                timeout: 8000,
                onload: function(res) {
                    try {
                        const data = JSON.parse(res.responseText);
                        const models = data.data.map(m => m.id).filter(id => id);
                        resolve(models.length ? models : ['deepseek-v4-flash', 'deepseek-v4-pro']);
                    } catch { resolve(['deepseek-v4-flash', 'deepseek-v4-pro']); }
                },
                onerror: () => resolve(['deepseek-v4-flash', 'deepseek-v4-pro']),
                ontimeout: () => resolve(['deepseek-v4-flash', 'deepseek-v4-pro'])
            });
        });
    }

    function createUI() {
        const panel = document.createElement('div');
        panel.style = `
            position: fixed; top: 10px; left: 50%; transform: translateX(-50%);
            z-index: 10000; width: 500px; background: #fff; padding: 15px;
            border-radius: 10px; box-shadow: 0 4px 15px rgba(0,0,0,0.3);
            font-family: sans-serif; border: 1px solid #ddd;
            font-size: 13px;
        `;
        panel.innerHTML = `
            <!-- API Key 行 -->
            <div style="margin-bottom:10px;display:flex;align-items:center;gap:5px;">
                <span style="font-size:12px;font-weight:bold;color:#333;">🔑 Key:</span>
                <input type="password" id="auto-api-key-input" style="flex:1;padding:4px;border:1px solid #ccc;border-radius:4px;font-size:12px;" placeholder="请输入 DeepSeek API Key">
                <button id="auto-save-key-btn" style="padding:4px 8px;background:#27ae60;color:#fff;border:none;border-radius:4px;cursor:pointer;font-size:12px;">💾保存</button>
                <span id="auto-key-status" style="font-size:11px;color:#999;"></span>
            </div>
            <div style="margin-bottom:10px;font-weight:bold;color:#333;display:flex;justify-content:space-between;">
                <span>✍️ 答题助手 (DeepSeek)</span>
                <span id="auto-status-label" style="color:#f39c12;font-size:12px;">待命中</span>
            </div>
            <div style="font-size:11px;color:#888;margin-bottom:8px;display:flex;align-items:center;gap:10px;">
                <span>模型：</span>
                <select id="auto-model-select" style="font-size:11px;padding:2px;"></select>
                <label style="display:flex;align-items:center;gap:3px;cursor:pointer;margin-left:8px;">
                    <input type="checkbox" id="auto-thinking-checkbox" style="margin:0;">
                    <span>思考模式</span>
                </label>
            </div>
            <div style="width:100%;background:#eee;border-radius:5px;height:10px;overflow:hidden;margin-bottom:10px;">
                <div id="auto-progress-bar" style="width:0%;height:100%;background:#4CAF50;transition:width 0.3s;"></div>
            </div>
            <div style="display:flex;justify-content:space-between;align-items:center;">
                <span id="auto-progress-text" style="font-size:12px;color:#666;">准备就绪</span>
                <div>
                    <button id="auto-resume-current-btn" style="padding:5px 10px;background:#3498db;color:#fff;border:none;border-radius:4px;cursor:pointer;margin-right:5px;display:none;">📍 从当前开始</button>
                    <button id="auto-start-btn" style="padding:5px 15px;background:#2ecc71;color:#fff;border:none;border-radius:4px;cursor:pointer;font-weight:bold;">▶ 开始答题</button>
                    <button id="auto-pause-btn" style="padding:5px 10px;background:#e74c3c;color:#fff;border:none;border-radius:4px;cursor:pointer;margin-left:5px;display:none;">⏸ 暂停</button>
                </div>
            </div>
        `;
        document.body.appendChild(panel);

        progressBar = document.getElementById('auto-progress-bar');
        progressText = document.getElementById('auto-progress-text');
        statusLabel = document.getElementById('auto-status-label');
        startBtn = document.getElementById('auto-start-btn');
        pauseBtn = document.getElementById('auto-pause-btn');
        resumeCurrentBtn = document.getElementById('auto-resume-current-btn');
        modelSelect = document.getElementById('auto-model-select');
        thinkingCheckbox = document.getElementById('auto-thinking-checkbox');

        // 加载模型列表
        fetchModels().then(models => {
            modelSelect.innerHTML = models.map(m => `<option value="${m}" ${m === MODEL ? 'selected' : ''}>${m}</option>`).join('');
        });
        modelSelect.addEventListener('change', () => { MODEL = modelSelect.value; });
        thinkingCheckbox.checked = ENABLE_THINKING;
        thinkingCheckbox.addEventListener('change', () => { ENABLE_THINKING = thinkingCheckbox.checked; });

        // ---- 核心按钮逻辑 ----
        startBtn.onclick = () => {
            const isRestart = (startBtn.innerText === '重新开始');
            if (isRestart) {
                currentIdx = 0;
                isPaused = false;
                statusLabel.innerText = "正在重新开始...";
            }
            if (!isRunning || isRestart) {
                if (solvingController) solvingController.abort();
                isRunning = true;
                startBtn.style.display = 'none';
                pauseBtn.style.display = 'inline-block';
                pauseBtn.innerText = '暂停';
                pauseBtn.style.background = '#e74c3c';
                resumeCurrentBtn.style.display = 'none';
                startSolve();
            }
        };

        pauseBtn.onclick = () => {
            isPaused = !isPaused;
            if (isPaused) {
                pauseBtn.innerText = '恢复';
                pauseBtn.style.background = '#f1c40f';
                statusLabel.innerText = '已暂停';
                startBtn.innerText = '重新开始';
                startBtn.style.background = '#3498db';
                startBtn.style.display = 'inline-block';
                // 暂停时显示“从当前开始”
                resumeCurrentBtn.style.display = 'inline-block';
            } else {
                // 恢复：回溯到前一道题（最小为0）
                currentIdx = Math.max(0, currentIdx - 1);
                pauseBtn.innerText = '暂停';
                pauseBtn.style.background = '#e74c3c';
                statusLabel.innerText = '运行中';
                startBtn.style.display = 'none';
                resumeCurrentBtn.style.display = 'none';
            }
        };

        resumeCurrentBtn.onclick = () => {
            if (solvingController) solvingController.abort();
            isPaused = false;
            const currentLi = getCurrentLi();
            if (currentLi) {
                const items = document.querySelectorAll('.topicNumber_list li');
                currentIdx = Array.from(items).indexOf(currentLi);
                if (currentIdx < 0) currentIdx = 0;
            } else {
                currentIdx = 0;
            }
            isRunning = true;
            startBtn.style.display = 'none';
            pauseBtn.style.display = 'inline-block';
            pauseBtn.innerText = '暂停';
            pauseBtn.style.background = '#e74c3c';
            resumeCurrentBtn.style.display = 'none';
            statusLabel.innerText = `从第 ${currentIdx+1} 题开始...`;
            startSolve();
        };

        // 监听答题卡变化，动态更新“从当前开始”按钮可见性
        updateResumeCurrentVisibility();
        const observer = new MutationObserver(() => updateResumeCurrentVisibility());
        const topicLists = document.querySelectorAll('.topicNumber_list');
        topicLists.forEach(list => observer.observe(list, { childList: true, subtree: true, attributes: true, attributeFilter: ['class'] }));


        const keyInput = document.getElementById('auto-api-key-input');
        const saveKeyBtn = document.getElementById('auto-save-key-btn');
        const keyStatus = document.getElementById('auto-key-status');

        // 初始化输入框的值
        keyInput.value = API_KEY;

        // 保存 Key 按钮事件
        saveKeyBtn.addEventListener('click', async () => {
            const newKey = keyInput.value.trim();
            if (!newKey) {
                keyStatus.textContent = 'Key 不能为空';
                keyStatus.style.color = 'red';
                return;
            }
            // 持久化存储
            GM_setValue('deepseek_api_key', newKey);
            API_KEY = newKey;   // 更新全局变量

            keyStatus.textContent = '已保存，正在刷新模型列表...';
            keyStatus.style.color = '#27ae60';

            // 重新获取模型列表并更新下拉框
            const models = await fetchModels(newKey);
            modelSelect.innerHTML = models.map(m => `<option value="${m}" ${m === MODEL ? 'selected' : ''}>${m}</option>`).join('');

            keyStatus.textContent = '✅ 已保存';
            setTimeout(() => { if (keyStatus.textContent === '✅ 已保存') keyStatus.textContent = ''; }, 2000);
        });
    }

    // 获取当前题目的 <li> 元素（兼容 current active 或仅 current）
    function getCurrentLi() {
        return document.querySelector('.topicNumber_list li.current.active') ||
               document.querySelector('.topicNumber_list li.current');
    }

    // 根据运行状态和答题卡高亮控制“从当前开始”按钮显示
    function updateResumeCurrentVisibility() {
        const currentLi = getCurrentLi();
        // 仅在未运行时显示（运行时由各事件控制隐藏）
        if (!isRunning && !isPaused) {
            resumeCurrentBtn.style.display = currentLi ? 'inline-block' : 'none';
        }
        // 其他情况（运行中/暂停中）由事件明确控制，不在此处修改
    }

    function startSolve() {
        if (!API_KEY || API_KEY.trim() === '') {
            alert('请先输入并保存 DeepSeek API Key！');
            return;
        }
        const sheetItems = document.querySelectorAll('.topicNumber_list li');
        if (!sheetItems.length) {
            alert('未找到答题卡题目');
            return;
        }
        currentSheetItems = Array.from(sheetItems);
        solvingController = new AbortController();
        solveAllQuestions(solvingController.signal);
    }

    function waitForQuestionElement(qId, timeout = JUMP_DELAY) {
        const startTime = Date.now();
        return new Promise((resolve) => {
            const check = () => {
                const el = document.querySelector(`.questionLi[data="${qId}"]`);
                if (el) resolve(el);
                else if (Date.now() - startTime > timeout) resolve(null);
                else requestAnimationFrame(check);
            };
            check();
        });
    }

    async function solveAllQuestions(signal) {
        const total = currentSheetItems.length;
        let completed = 0;
        let errors = 0;

        for (let i = currentIdx; i < total; i++) {
            if (signal.aborted) return;
            while (isPaused && !signal.aborted) await sleep(300);
            if (signal.aborted) return;

            const item = currentSheetItems[i];
            const qId = item.getAttribute('data');
            if (!qId) { errors++; continue; }

            statusLabel.innerText = `跳转至第 ${i+1} 题...`;
            item.click();
            const questionEl = await waitForQuestionElement(qId);
            if (signal.aborted) return;
            if (!questionEl) { errors++; continue; }

            const type = questionEl.getAttribute('typeName') || '单选题';
            const percent = Math.floor(((i + 1) / total) * 100);
            progressBar.style.width = `${percent}%`;
            progressText.innerText = `${i + 1} / ${total} (${percent}%)`;
            statusLabel.innerText = `处理第 ${i+1} 题 (${type})`;

            const titleEl = questionEl.querySelector('h3.mark_name');
            if (!titleEl) { errors++; continue; }
            const titleClone = titleEl.cloneNode(true);
            const typeSpan = titleClone.querySelector('.colorShallow');
            if (typeSpan) typeSpan.remove();
            const questionText = titleClone.textContent.replace(/\s+/g, ' ').trim();

            try {
                if (type === '单选题' || type === '多选题' || type === '判断题') {
                    const optionsStr = type !== '判断题' ? extractOptions(questionEl) : '';
                    const aiAnswer = await askAI(type, questionText, optionsStr, signal);

                    // 🔍 调试输出
                    console.log(`[题目 ${i+1}] 类型: ${type}`);
                    console.log(`[题目 ${i+1}] 题干: ${questionText.substring(0, 80)}${questionText.length > 80 ? '...' : ''}`);
                    if (optionsStr) console.log(`[题目 ${i+1}] 选项: ${optionsStr}`);
                    console.log(`[题目 ${i+1}] DeepSeek 返回:`, aiAnswer);

                    if (aiAnswer) {
                        selectOption(questionEl, aiAnswer, type) ? completed++ : errors++;
                    } else errors++;
                } else if (type === '填空题' || type === '简答题') {
                    const aiAnswer = await askAI(type, questionText, '', signal);

                    // 🔍 调试输出
                    console.log(`[题目 ${i+1}] 类型: ${type}`);
                    console.log(`[题目 ${i+1}] 题干: ${questionText.substring(0, 80)}${questionText.length > 80 ? '...' : ''}`);
                    console.log(`[题目 ${i+1}] DeepSeek 返回:`, aiAnswer);

                    if (aiAnswer) {
                        fillTextAnswer(questionEl, aiAnswer, type) ? completed++ : errors++;
                    } else errors++;
                }
                currentIdx = i + 1;
                await sleep(DELAY);
            } catch (e) {
                if (e.name === 'AbortError') return;
                errors++;
                currentIdx = i + 1;
            }
        }

        // 答题结束
        isRunning = false;
        progressBar.style.width = '100%';
        progressText.innerText = `完成 ${completed}/${total}，失败 ${errors} 题`;
        statusLabel.innerText = "全部作答完成";
        pauseBtn.style.display = 'none';
        startBtn.style.display = 'inline-block';
        startBtn.innerText = '重新开始';
        startBtn.style.background = '#2ecc71';
        // 完成后依据高亮题目决定“从当前开始”是否显示
        updateResumeCurrentVisibility();
        alert(`✅ 自动答题完成！\n成功：${completed} 题\n失败/跳过：${errors} 题\n(多次运行或使用高级模型可提高正确率)`);
    }

    // API 调用
    function askAI(type, question, optionsStr, signal) {
        let sys = "你是一个助手。";
        if (type === "单选题" || type === "判断题") sys = "只回答案字母或'正确'/'错误'，不解释。";
        else if (type === "多选题") sys = "只回答正确字母组合，如ABC，不解释。";
        else if (type === "填空题") sys = "多空答案用###分隔，不解释。";
        else if (type === "简答题") sys = "提供精炼答案内容。";

        const userMessage = `题型: ${type}\n题目: ${question}${optionsStr ? '\n选项: ' + optionsStr : ''}`;

        const body = {
            model: MODEL,
            messages: [
                { role: 'system', content: sys },
                { role: 'user', content: userMessage }
            ],
            temperature: 0.1,
            max_tokens: 256,
            top_p: 1,
            frequency_penalty: 0,
            presence_penalty: 0,
            stream: false,
            response_format: { type: 'text' }
        };
        if (ENABLE_THINKING && MODEL.includes('pro')) {
            body.thinking = { type: 'enabled' };
            body.reasoning_effort = 'high';
        }

        return new Promise((resolve) => {
            const xhr = GM_xmlhttpRequest({
                method: 'POST',
                url: 'https://api.deepseek.com/chat/completions',
                headers: {
                    'Content-Type': 'application/json',
                    'Accept': 'application/json',
                    'Authorization': `Bearer ${API_KEY}`
                },
                data: JSON.stringify(body),
                timeout: 20000,
                onload: function(res) {
                    try {
                        const data = JSON.parse(res.responseText);
                        resolve(data.choices?.[0]?.message?.content?.trim() ?? null);
                    } catch { resolve(null); }
                },
                onerror: () => resolve(null),
                ontimeout: () => resolve(null)
            });
            if (signal) {
                signal.addEventListener('abort', () => {
                    if (xhr?.abort) xhr.abort();
                    resolve(null);
                });
            }
        });
    }

    function extractOptions(questionEl) {
        return Array.from(questionEl.querySelectorAll('.answerBg')).map(div => {
            const letterSpan = div.querySelector('.num_option, .num_option_dx');
            const letter = letterSpan ? letterSpan.textContent.trim() : '';
            const textDiv = div.querySelector('.answer_p p');
            const text = textDiv ? textDiv.textContent.trim() : div.textContent.replace(letter, '').trim();
            return letter ? `${letter}. ${text}` : '';
        }).filter(Boolean).join(' | ');
    }

    function selectOption(questionEl, aiAnswer, type) {
        let selected = false;
        questionEl.querySelectorAll('.answerBg').forEach(div => {
            const letterSpan = div.querySelector('.num_option, .num_option_dx');
            const letter = letterSpan ? letterSpan.textContent.trim().toUpperCase() : '';
            const isChecked = div.getAttribute('aria-checked') === 'true';
            if ((type === '单选题' || type === '多选题') && aiAnswer.includes(letter) && !isChecked) {
                div.click();
                selected = true;
            } else if (type === '判断题') {
                const text = div.textContent.trim();
                if ((aiAnswer.includes('正确') && text.includes('对')) || (aiAnswer.includes('错误') && text.includes('错'))) {
                    if (!isChecked) { div.click(); selected = true; }
                }
            }
        });
        return selected;
    }

    function fillTextAnswer(questionEl, aiAnswer, type) {
        if (!aiAnswer) return false;
        const textareas = questionEl.querySelectorAll('textarea[id^="answer"]');
        if (!textareas.length) return false;
        const answers = type === '填空题' ? aiAnswer.split('###') : [aiAnswer];
        textareas.forEach((ta, idx) => {
            const id = ta.id;
            if (typeof UE !== 'undefined' && UE.getEditor) {
                try {
                    const editor = UE.getEditor(id);
                    if (editor?.ready) editor.ready(() => editor.setContent(answers[idx] || answers[0]));
                } catch { ta.value = answers[idx] || answers[0]; }
            } else ta.value = answers[idx] || answers[0];
            ta.dispatchEvent(new Event('input', { bubbles: true }));
        });
        const qId = questionEl.getAttribute('data');
        if (window.loadEditorAnswerd) window.loadEditorAnswerd(qId, type === '填空题' ? 2 : 4);
        return true;
    }

    window.addEventListener('load', () => setTimeout(createUI, 2000));
})();