// ==UserScript==
// @name         WELearn - Auto Answer
// @version      91.78
// @description  点击试题页面即答题
// @match        https://welearn.sflep.com/*
// @match        https://centercourseware.sflep.com/*
// @author       Rito
// ==/UserScript==

(function () {
    'use strict';

    const SCRIPT_STATE_KEY = 'weleran_auto_answer_enabled';

    // --- UI创建函数 (仅在顶层窗口运行) ---
    function createToggleUI() {
        const isEnabled = () => localStorage.getItem(SCRIPT_STATE_KEY) !== 'false';

        const button = document.createElement('div');
        button.style.position = 'fixed';
        button.style.bottom = '20px';
        button.style.right = '20px';
        button.style.width = '60px';
        button.style.height = '60px';
        button.style.borderRadius = '50%';
        button.style.color = 'white';
        button.style.display = 'flex';
        button.style.justifyContent = 'center';
        button.style.alignItems = 'center';
        button.style.cursor = 'pointer';
        button.style.zIndex = '9999';
        button.style.fontSize = '14px';
        button.style.boxShadow = '0 2px 10px rgba(0,0,0,0.2)';
        button.title = '点击切换自动答题';

        const updateButtonState = () => {
            if (isEnabled()) {
                // button.style.backgroundColor = '#4CAF50'; // Green
                button.textContent = '答题:开';
            } else {
                // button.style.backgroundColor = '#f44336'; // Red
                button.textContent = '答题:关';
            }
        };
        
        // --- 彩色循环样式 ---
        let hue = 0;
        setInterval(() => {
            hue = (hue + 1) % 360;
            if (!isEnabled()) {
                button.style.backgroundColor = `hsl(${hue}, 80%, 60%)`;
            } else {
                button.style.backgroundColor = `hsl(${hue}, 80%, 30%)`; // Darker when on
            }
        }, 20);

        // --- 拖动功能 ---
        let isDragging = false;
        let hasDragged = false;
        let offsetX, offsetY;

        button.addEventListener('mousedown', (e) => {
            isDragging = true;
            hasDragged = false;
            const rect = button.getBoundingClientRect();
            offsetX = e.clientX - rect.left;
            offsetY = e.clientY - rect.top;
            button.style.cursor = 'grabbing';
            e.preventDefault();
        });

        document.addEventListener('mousemove', (e) => {
            if (!isDragging) return;
            hasDragged = true;
            let newX = e.clientX - offsetX;
            let newY = e.clientY - offsetY;

            // 限制在视窗内
            newX = Math.max(0, Math.min(newX, window.innerWidth - button.offsetWidth));
            newY = Math.max(0, Math.min(newY, window.innerHeight - button.offsetHeight));

            button.style.left = `${newX}px`;
            button.style.top = `${newY}px`;
            button.style.bottom = 'auto';
            button.style.right = 'auto';
        });

        document.addEventListener('mouseup', () => {
            if (isDragging) {
                isDragging = false;
                button.style.cursor = 'pointer';
            }
        });


        button.addEventListener('click', (e) => {
            // 如果发生了拖动，则阻止点击事件
            if (hasDragged) {
                e.stopPropagation();
                return;
            }
            const current = isEnabled();
            localStorage.setItem(SCRIPT_STATE_KEY, !current);
            updateButtonState();
            // 刷新iframe以立即应用更改
            const iframe = document.querySelector('iframe');
            if (iframe) {
                iframe.contentWindow.location.reload();
            }
        });

        updateButtonState();
        document.body.appendChild(button);
    }

    // --- 核心逻辑 (仅在iframe内运行) ---
    function runAutoAnswer() {
        // 检查开关状态
        if (localStorage.getItem(SCRIPT_STATE_KEY) === 'false') {
            console.log('[WELearn Auto Answer] 功能已关闭，跳过执行。');
            return;
        }

        console.log('[WELearn Auto Answer] Running in iframe:', location.href);

        // 0) 先展开，避免未渲染导致找不到
        document.querySelectorAll('.white_frame').forEach(frame => {
            const toggleBtn = frame.querySelector('[data-itemtype="toggle"], .toggle, .expand');
            if (toggleBtn) toggleBtn.click();
            frame.style.display = 'block';
            frame.style.visibility = 'visible';
        });

        // 已填标记，避免重复填同一控件
        const filledInputs = new Set();
        const filledChoices = new Set();

        // 1) 按页面顺序遍历每一个 data-solution（每个小问一个）
        const nodes = document.querySelectorAll('[data-solution]');

        nodes.forEach((node, idx) => {
            // 提取答案文本（优先属性）
            const ans = node.getAttribute('data-solution')?.trim() || node.textContent.trim();
            if (!ans) {
                console.log(`第${idx + 1}小问：答案为空，跳过`);
                return;
            }

            // 2) 选择题：data-solution 在 <li> 上，直接标记该 <li>
            if (node.tagName.toLowerCase() === 'li') {
                if (!filledChoices.has(node)) {
                    node.setAttribute('data-choiced', '');
                    // 可选：触发点击以激活平台事件
                    try { node.click(); } catch { }
                    filledChoices.add(node);
                }
                console.log(`第${idx + 1}小问（选择题）已选中：${node.textContent.trim()}`);
                return;
            }

            // 3) 填空题：data-solution 不在 <li> 上，需要只填入当前小问的控件
            // 3.1 找到当前小问的最近容器（避免作用到整题）
            const subContainer =
                node.closest('[data-itemtype="blank"], [data-itemtype="options"], [data-controltype]') ||
                node.parentElement;

            // 3.2 在该小问容器内寻找尚未填过的输入控件（input/textarea/contenteditable）
            const target =
                subContainer.querySelector('input:not([data-filled]), textarea:not([data-filled]), [contenteditable]:not([data-filled])')
                // 如果上面没找到，退一步：先找跟 node 最近的一个输入控件
                || node.closest('.white_frame')?.querySelector('input:not([data-filled]), textarea:not([data-filled]), [contenteditable]:not([data-filled])');

            if (!target) {
                console.log(`第${idx + 1}小问：未找到可填入的控件，答案=${ans}`);
                return;
            }

            // 3.3 精准填入当前控件，并标记避免重复
            if ('value' in target) target.value = ans;
            else target.textContent = ans;
            target.setAttribute('data-filled', '');
            filledInputs.add(target);

            // 可选：触发事件让平台感知输入变化
            try {
                target.dispatchEvent(new Event('input', { bubbles: true }));
                target.dispatchEvent(new Event('change', { bubbles: true }));
                target.dispatchEvent(new Event('blur', { bubbles: true }));
            } catch { }

            console.log(`第${idx + 1}小问（填空题）已填入：${ans}`);
        });

        console.log('完成：按小问粒度填入，已避免整题串填。');
    }

    // --- 脚本入口 ---
    if (window.top !== window) {
        // 在 iframe 中，执行核心逻辑
        runAutoAnswer();
    } else {
        // 在顶层窗口中，创建UI并输出提示
        console.log('[WELearn Auto Answer] Running in top frame (UI created):', location.href);
        // 等待DOM加载完毕再创建UI
        if (document.readyState === 'loading') {
            document.addEventListener('DOMContentLoaded', createToggleUI);
        } else {
            createToggleUI();
        }
    }
})();