// ==UserScript==
// @name         物理实验助手
// @namespace    http://tampermonkey.net/
// @version      1.2.0
// @description  完美解决乱序、空选项导致判断题错位的问题。自动提取隐藏域答案并勾选，支持自动答题记忆、禁用网页弹窗、面板自由拖动。
// @author       毫厘
// @match        http://59.69.101.153/lab/Reports/*
// @match        http://59.69.103.147/Reports/*
// @grant        none
// @license      MIT
// ==/UserScript==

(function() {
    'use strict';

    // 1. 创建美化的 UI 面板
    function createPanel() {
        if (document.getElementById('auto-helper-panel')) return; // 防止重复注入

        const panel = document.createElement('div');
        panel.id = 'auto-helper-panel';
        panel.innerHTML = `
            <div id="helper-header" title="按住此处可拖动面板">
                <span>实验助手 v1.2</span>
                <button id="toggle-btn">-</button>
            </div>
            <div id="helper-body">
                <div id="answer-list">正在获取答案...</div>
                <label class="auto-run-wrapper" title="勾选后，下次进入页面会自动填写答案">
                    <input type="checkbox" id="auto-run-chk">
                    <span>开启一键自动答题</span>
                </label>
                <button id="auto-fill-btn">点击自动一键勾选</button>

            </div>
        `;
        document.body.appendChild(panel);

        const style = document.createElement('style');
        style.textContent = `
            #auto-helper-panel {
                position: fixed; top: 20px; right: 20px; width: 230px;
                background: #ffffff; border-radius: 8px; z-index: 10000;
                box-shadow: 0 4px 20px rgba(0,0,0,0.15); font-family: sans-serif;
                overflow: hidden; border: 1px solid #e0e0e0; transition: height 0.3s ease;
            }
            #helper-header {
                background: #4CAF50; color: white; padding: 10px 15px;
                display: flex; justify-content: space-between; align-items: center;
                font-weight: bold; cursor: move; user-select: none;
            }
            #toggle-btn {
                background: rgba(255,255,255,0.2); border: none; color: white;
                cursor: pointer; border-radius: 4px; padding: 2px 8px; font-weight: bold;
            }
            #helper-body { padding: 15px; }
            #answer-list { margin-bottom: 12px; font-size: 13px; color: #333; line-height: 1.6; max-height: 250px; overflow-y: auto;}
            .answer-item { border-bottom: 1px dashed #eee; padding: 4px 0; }
            .answer-val { color: #e91e63; font-weight: bold; margin-left: 5px; }
            .auto-run-wrapper {
                display: flex; align-items: center; margin-bottom: 12px; font-size: 13px;
                color: #2c3e50; cursor: pointer; user-select: none;
            }
            .auto-run-wrapper input { margin-right: 6px; cursor: pointer; }
            #auto-fill-btn {
                width: 100%; background: #4CAF50; color: white; border: none;
                padding: 10px; border-radius: 5px; cursor: pointer; font-size: 14px;
                transition: background 0.2s; font-weight: bold;
            }
            #auto-fill-btn:hover { background: #45a049; }
            #helper-footer { font-size: 11px; color: #999; margin-top: 10px; text-align: center; }
            .collapsed #helper-body { display: none; }
        `;
        document.head.appendChild(style);

        // 面板折叠逻辑
        document.getElementById('toggle-btn').onclick = (e) => {
            e.stopPropagation(); // 防止触发拖拽
            panel.classList.toggle('collapsed');
            document.getElementById('toggle-btn').textContent = panel.classList.contains('collapsed') ? '+' : '-';
        };

        // 面板拖动逻辑
        makeDraggable(panel, document.getElementById('helper-header'));
    }

    // 实现拖拽功能的通用函数
    function makeDraggable(panel, handle) {
        let isDragging = false, offsetX, offsetY;

        handle.addEventListener('mousedown', (e) => {
            if (e.target.id === 'toggle-btn') return;
            isDragging = true;
            const rect = panel.getBoundingClientRect();
            // 将right定位转换为left定位，防止拖拽时跳动
            panel.style.right = 'auto';
            panel.style.left = rect.left + 'px';
            panel.style.top = rect.top + 'px';

            offsetX = e.clientX - rect.left;
            offsetY = e.clientY - rect.top;
            panel.style.transition = 'none'; // 拖动时取消动画避免迟钝
        });

        document.addEventListener('mousemove', (e) => {
            if (!isDragging) return;
            let x = e.clientX - offsetX;
            let y = e.clientY - offsetY;

            // 防止拖出屏幕可视区域
            x = Math.max(0, Math.min(x, window.innerWidth - panel.offsetWidth));
            y = Math.max(0, Math.min(y, window.innerHeight - panel.offsetHeight));

            panel.style.left = `${x}px`;
            panel.style.top = `${y}px`;
        });

        document.addEventListener('mouseup', () => {
            if (isDragging) {
                isDragging = false;
                panel.style.transition = 'height 0.3s ease'; // 恢复动画
            }
        });
    }

    // 2. 完美提取数据（彻底解决乱序和空白选项问题）
    function getQuestionsData() {
        const data = [];
        const hiddenInputs = document.querySelectorAll('input[id^="result_refer_pre"]');

        hiddenInputs.forEach((hiddenInput) => {
            const match = hiddenInput.id.match(/result_refer_pre(\d+)/);
            if (!match) return;
            const index = parseInt(match[1]);
            const value = hiddenInput.value;

            const selectedLetters = [];
            const elementsToClick =[];

            // 获取该题目下所有带有真实文本(label)的有效选项
            const validLabels = document.querySelectorAll(`label[for^="pre${index}_op"]`);
            const labelMap = {};
            validLabels.forEach((lbl, idx) => {
                let forId = lbl.getAttribute('for');
                labelMap[forId] = {
                    text: lbl.innerText.trim(),
                    visualIndex: idx // 该选项在可见选项里的实际排序 0->A, 1->B...
                };
            });

            // 遍历答案隐藏域，比如 "0010"
            for (let i = 0; i < value.length; i++) {
                if (value[i] === '1') {
                    let targetId = `pre${index}_op${i}`;
                    let targetCheckbox = document.querySelector(`#${targetId}`);

                    if (targetCheckbox) {
                        elementsToClick.push(targetCheckbox);

                        let labelInfo = labelMap[targetId];
                        if (labelInfo) {
                            // 优先尝试从 label 文本截取如 "A.正确" 中的 "A"
                            let letterMatch = labelInfo.text.match(/^[A-G]/i);
                            if (letterMatch) {
                                selectedLetters.push(letterMatch[0].toUpperCase());
                            } else {
                                // 兜底：如果文本没写A/B，按它在所有可见选项中的顺位映射 (0=A, 1=B)
                                const optionsMap = ['A', 'B', 'C', 'D', 'E', 'F', 'G'];
                                selectedLetters.push(optionsMap[labelInfo.visualIndex] || '?');
                            }
                        } else {
                            // 如果连 label 都没有，记作未知 ?
                            selectedLetters.push('?');
                        }
                    }
                }
            }

            data.push({
                index: index,
                rawLetters: [...new Set(selectedLetters)].sort(), // 去重并按字母表排序(如 AC 而不会是 CA)
                elements: elementsToClick
            });
        });

        return data.sort((a, b) => a.index - b.index); // 确保按题号排序
    }

    // 3. 更新面板显示
    function updateAnswers(data) {
        let listHtml = '';
        if (data.length === 0) {
            listHtml = '<div style="color:red; text-align:center;">未找到题目<br>请确认是否在预习页</div>';
        } else {
            data.forEach((item, i) => {
                listHtml += `<div class="answer-item">第${i + 1}题：<span class="answer-val">${item.rawLetters.join('') || '无'}</span></div>`;
            });
        }
        document.getElementById('answer-list').innerHTML = listHtml;
    }

    // 4. 执行自动勾选逻辑
    function selectAnswers(isAuto = false) {
        const data = getQuestionsData();

        data.forEach(item => {
            // 先获取当前题目的所有选项，用于覆盖和取消原本勾错的选项
            const allOptionsDom = document.querySelectorAll(`input[id^="pre${item.index}_op"]`);

            allOptionsDom.forEach(el => {
                // 如果当前复选框被禁用(例如已提交状态)，跳过点击以免报错
                if (el.disabled) return;

                let shouldBeChecked = item.elements.includes(el);

                // 如果当前状态与目标状态不一致，则触发点击
                if (el.checked !== shouldBeChecked) {
                    el.click(); // 触发页面本身的监听事件
                    if (el.checked !== shouldBeChecked) {
                        el.checked = shouldBeChecked; // 强制兜底勾选
                        el.dispatchEvent(new Event('change', { bubbles: true }));
                    }
                }
            });
        });

        // 按钮状态反馈
        const btn = document.getElementById('auto-fill-btn');
        btn.textContent = isAuto ? '已自动勾选完毕！' : '勾选完成！';
        btn.style.background = '#2196F3';
        setTimeout(() => { btn.textContent = '手动一键勾选'; btn.style.background = '#4CAF50'; }, 2000);
    }

    // 初始化脚本
    window.addEventListener('load', () => {
        createPanel();

        // 解析数据并渲染面板
        const questionsData = getQuestionsData();
        updateAnswers(questionsData);

        // 处理自动答题功能
        const autoRunChk = document.getElementById('auto-run-chk');
        const isAutoRun = localStorage.getItem('physics_helper_autorun') === 'true';
        autoRunChk.checked = isAutoRun;

        // 勾选框事件
        autoRunChk.addEventListener('change', (e) => {
            localStorage.setItem('physics_helper_autorun', e.target.checked);
            if (e.target.checked) selectAnswers(true);
        });

        // 手动点击事件
        document.getElementById('auto-fill-btn').onclick = () => selectAnswers(false);

        // 如果开启了自动答题，延迟500ms执行（等待DOM节点彻底渲染完毕）
        if (isAutoRun && questionsData.length > 0) {
            setTimeout(() => selectAnswers(true), 500);
        }
    });
})();