// ==UserScript==
// @name         学习通文档下载助手
// @namespace    https://github.com/user/chaoxing-doc-downloader
// @version      7.0
// @description  通过 /ananas/status API 获取真实下载链接，自动捕获文档信息
// @author       You
// @match        *://mooc1.chaoxing.com/*
// @match        *://mooc2.chaoxing.com/*
// @match        *://mooc1-2.chaoxing.com/*
// @match        *://mooc2-1.chaoxing.com/*
// @match        *://*.*.chaoxing.com/*
// @match        *://*.*.mooc.chaoxing.com/*
// @match        *://*.*.zxx.chaoxing.com/*
// @match        *://*.*.superstar.com/*
// @grant        GM_xmlhttpRequest
// @grant        GM_setValue
// @grant        GM_getValue
// @connect      chaoxing.com
// @connect      mooc.chaoxing.com
// @connect      cldisk.com
// @connect      s3.cldisk.com
// @connect      d0.cldisk.com
// @connect      cs.cldisk.com
// @connect      *
// @run-at       document-idle
// @license MIT
// ==/UserScript==

(function () {
    'use strict';

    // ==================== 全局数据存储 ====================
    let capturedDocs = []; // 已捕获的文档信息列表
    let capturedFileIds = new Set();

    /**
     * 拦截所有 XHR 请求，捕获 /ananas/status/{fileId} 响应
     */
    function interceptXHR() {
        if (window._chaoxing_xhr_intercepted) return;
        window._chaoxing_xhr_intercepted = true;

        const origXHROpen = XMLHttpRequest.prototype.open;
        const origXHRSend = XMLHttpRequest.prototype.send;

        XMLHttpRequest.prototype.open = function (method, url, ...rest) {
            this._chaoxing_url = url ? String(url) : '';
            this._chaoxing_method = method || 'GET';
            return origXHROpen.apply(this, [method, url, ...rest]);
        };

        XMLHttpRequest.prototype.send = function (...args) {
            const url = this._chaoxing_url || '';

            // 监控 /ananas/status/ 请求
            if (url.includes('/ananas/status/')) {
                this.addEventListener('load', () => {
                    try {
                        const resp = JSON.parse(this.responseText);
                        if (resp && resp.status === 'success' && resp.objectid) {
                            const fileId = resp.objectid;
                            if (!capturedFileIds.has(fileId)) {
                                capturedFileIds.add(fileId);
                                capturedDocs.push({
                                    fileId: fileId,
                                    filename: resp.filename || 'unknown.pdf',
                                    downloadUrl: resp.download || '',
                                    pdfUrl: resp.pdf || '',
                                    httpUrl: resp.http || '',
                                    length: resp.length || 0,
                                    pagenum: resp.pagenum || 0,
                                });
                                console.log('[学习通下载v7] 捕获文档:', resp.filename);
                            }
                        }
                    } catch (e) { /* ignore */ }
                });
            }

            return origXHRSend.apply(this, args);
        };
    }

    /**
     * 扫描 body 中的 file_ 模式来发现更多文件
     */
    function scanForFileIds() {
        const bodyHtml = document.body ? document.body.innerHTML || '' : '';
        const fileMatches = bodyHtml.match(/file_([a-f0-9]{32})/gi);
        if (fileMatches) {
            fileMatches.forEach((m) => {
                const id = m.replace('file_', '');
                if (!capturedFileIds.has(id)) {
                    capturedFileIds.add(id);
                    // 延迟调用 API 获取详细信息
                    getFileInfo(id);
                }
            });
        }

        // 也扫描所有 script 标签
        document.querySelectorAll('script').forEach((script) => {
            const text = script.textContent || '';
            const matches = text.match(/file_([a-f0-9]{32})/gi);
            if (matches) {
                matches.forEach((m) => {
                    const id = m.replace('file_', '');
                    if (!capturedFileIds.has(id)) {
                        capturedFileIds.add(id);
                        getFileInfo(id);
                    }
                });
            }
        });
    }

    /**
     * 通过 API 获取文件信息
     */
    function getFileInfo(fileId) {
        if (!fileId || capturedFileIds.has(fileId)) {
            return Promise.resolve(null);
        }

        return new Promise((resolve) => {
            capturedFileIds.add(fileId);

            GM_xmlhttpRequest({
                method: 'GET',
                url: `https://mooc1.chaoxing.com/ananas/status/${fileId}?flag=normal`,
                headers: {
                    'Referer': window.location.href,
                    'Accept': 'application/json',
                },
                onload: function (response) {
                    try {
                        const data = JSON.parse(response.responseText);
                        if (data && data.status === 'success') {
                            capturedDocs.push({
                                fileId: data.objectid || fileId,
                                filename: data.filename || `document_${fileId}.pdf`,
                                downloadUrl: data.download || '',
                                pdfUrl: data.pdf || '',
                                httpUrl: data.http || '',
                                length: data.length || 0,
                                pagenum: data.pagenum || 0,
                            });
                            console.log('[学习通下载v7] API 获取到:', data.filename);
                        }
                        resolve(data);
                    } catch (e) {
                        resolve(null);
                    }
                },
                onerror: function () {
                    resolve(null);
                },
            });
        });
    }

    /**
     * 下载文件
     */
    function downloadFile(url, filename) {
        if (!url) {
            alert('没有可用的下载链接！');
            return;
        }

        console.log('[学习通下载v7] 开始下载:', filename);

        GM_xmlhttpRequest({
            method: 'GET',
            url: url,
            responseType: 'blob',
            headers: {
                'Referer': 'https://mooc1.chaoxing.com/',
            },
            onload: function (response) {
                if (response.status === 200 && response.response) {
                    const blob = response.response;
                    const a = document.createElement('a');
                    a.href = URL.createObjectURL(blob);
                    a.download = filename;
                    document.body.appendChild(a);
                    a.click();
                    document.body.removeChild(a);
                    URL.revokeObjectURL(a.href);
                    console.log('[学习通下载v7] 下载成功!');
                    alert(`✅ "${filename}" 已开始下载`);
                } else if (response.status === 302 || response.status === 301) {
                    const location = response.getResponseHeader('Location');
                    if (location) {
                        window.open(location, '_blank');
                        alert('文件已在新窗口打开，请手动保存 (Ctrl+S)');
                    } else {
                        window.open(url, '_blank');
                        alert('已在新的标签页中打开，请手动保存文件。');
                    }
                } else {
                    console.log('[学习通下载v7] 下载失败 (status:', response.status, ')');
                    window.open(url, '_blank');
                    alert('下载失败，已在新的标签页中打开。请手动保存。');
                }
            },
            onerror: function () {
                window.open(url, '_blank');
                alert('下载请求失败，已在新的标签页中打开。请手动保存。');
            },
        });
    }

    // ==================== UI ====================

    function createBtn() {
        const btn = document.createElement('button');
        btn.id = 'chaoxing-dl-btn';
        btn.textContent = '📥 下载文档';
        btn.style.cssText = `
            position: fixed;
            top: 20px;
            left: 20px;
            z-index: 999999;
            padding: 10px 16px;
            background: #4a90d9;
            color: white;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            font-size: 14px;
            font-weight: bold;
            box-shadow: 0 2px 8px rgba(0,0,0,0.3);
            font-family: Microsoft YaHei, sans-serif;
            transition: all 0.3s ease;
        `;

        btn.addEventListener('mouseenter', () => {
            btn.style.background = '#357abd';
            btn.style.transform = 'scale(1.05)';
        });
        btn.addEventListener('mouseleave', () => {
            btn.style.background = '#4a90d9';
            btn.style.transform = 'scale(1)';
        });

        document.body.appendChild(btn);
        return btn;
    }

    function createPanel() {
        // 移除旧面板
        const old = document.getElementById('chaoxing-dl-panel');
        if (old) old.remove();

        const panel = document.createElement('div');
        panel.id = 'chaoxing-dl-panel';
        panel.style.cssText = `
            position: fixed;
            top: 65px;
            left: 20px;
            width: 480px;
            max-height: 65vh;
            z-index: 999998;
            background: #fff;
            border-radius: 10px;
            box-shadow: 0 4px 20px rgba(0,0,0,0.3);
            display: flex;
            flex-direction: column;
            overflow: hidden;
            font-family: Microsoft YaHei, sans-serif;
        `;

        // 头部
        const header = document.createElement('div');
        header.style.cssText = `padding: 12px 16px; background: #4a90d9; color: white; display: flex; justify-content: space-between; align-items: center; flex-shrink: 0;`;
        header.innerHTML = `
            <span>📄 找到 <strong id="chaoxing-doc-count">${capturedDocs.length}</strong> 个文档</span>
            <button id="chaoxing-panel-close" style="background:none;border:none;color:white;font-size:18px;cursor:pointer;">✕</button>
        `;

        // 工具栏
        const toolbar = document.createElement('div');
        toolbar.style.cssText = `padding: 8px 12px; background: #f5f5f5; border-bottom: 1px solid #ddd; display: flex; gap: 8px; align-items: center; flex-shrink: 0;`;

        const selectAllCb = document.createElement('input');
        selectAllCb.type = 'checkbox';
        selectAllCb.id = 'chaoxing-select-all';

        const selectAllLabel = document.createElement('label');
        selectAllLabel.setAttribute('for', 'chaoxing-select-all');
        selectAllLabel.style.cssText = 'font-size: 13px; color: #666; cursor: pointer;';
        selectAllLabel.textContent = '全选';

        const downloadAllBtn = document.createElement('button');
        downloadAllBtn.textContent = '⬇ 下载全部';
        downloadAllBtn.style.cssText = `margin-left: auto; padding: 4px 12px; background: #28a745; color: white; border: none; border-radius: 4px; cursor: pointer; font-size: 12px; font-weight: bold;`;

        toolbar.appendChild(selectAllCb);
        toolbar.appendChild(selectAllLabel);
        toolbar.appendChild(downloadAllBtn);

        // 列表
        const listContainer = document.createElement('div');
        listContainer.style.cssText = `flex: 1; overflow-y: auto; padding: 8px 0;`;

        panel.appendChild(header);
        panel.appendChild(toolbar);
        panel.appendChild(listContainer);
        document.body.appendChild(panel);

        // 事件
        document.getElementById('chaoxing-panel-close').onclick = () => panel.remove();

        selectAllCb.addEventListener('change', () => {
            listContainer.querySelectorAll('input[type="checkbox"]').forEach((cb) => {
                cb.checked = selectAllCb.checked;
            });
        });

        downloadAllBtn.onclick = () => {
            const checked = listContainer.querySelectorAll('input[type="checkbox"]:checked');
            if (checked.length === 0) { alert('请至少勾选一个文档'); return; }

            checked.forEach((cb, i) => {
                const idx = parseInt(cb.dataset.index);
                const doc = capturedDocs[idx];
                if (doc) {
                    const url = doc.downloadUrl || doc.pdfUrl;
                    setTimeout(() => {
                        if (url) downloadFile(url, doc.filename);
                    }, i * 800);
                }
            });
        };

        // 渲染
        if (capturedDocs.length === 0) {
            listContainer.innerHTML = `
                <div style="padding: 20px; text-align: center; color: #999;">
                    <div style="font-size: 30px; margin-bottom: 8px;">😔</div>
                    <div>页面上没有发现文档</div>
                </div>
            `;
        } else {
            capturedDocs.forEach((doc, index) => {
                const item = document.createElement('div');
                item.style.cssText = `padding: 10px 16px; border-bottom: 1px solid #f0f0f0; transition: background 0.2s;`;
                item.onmouseover = () => (item.style.background = '#f8f9fa');
                item.onmouseout = () => (item.style.background = 'transparent');

                const fileSize = doc.length ? (doc.length / 1024 / 1024).toFixed(1) + ' MB' : '';
                const pages = doc.pagenum ? doc.pagenum + ' 页' : '';

                const url = doc.downloadUrl || doc.pdfUrl || doc.httpUrl;

                item.innerHTML = `
                    <div style="display: flex; align-items: flex-start; gap: 8px;">
                        <input type="checkbox" checked data-index="${index}" style="margin-top: 4px;">
                        <div style="flex: 1; min-width: 0;">
                            <div style="font-size: 13px; color: #333; word-break: break-all; line-height: 1.4;">${doc.filename}</div>
                            <div style="font-size: 11px; color: #999; margin-top: 2px;">${fileSize} ${pages}</div>
                        </div>
                    </div>
                    <div style="display: flex; gap: 6px; margin-top: 8px; margin-left: 22px;">
                        ${doc.pdfUrl ? `<button class="dl-open" data-url="${doc.pdfUrl}" style="padding: 2px 8px; background: #e9ecef; border: none; border-radius: 3px; cursor: pointer; font-size: 11px;">👁 预览</button>` : ''}
                        ${url ? `<button class="dl-download" data-url="${url}" data-filename="${doc.filename}" style="padding: 2px 8px; background: #28a745; color: white; border: none; border-radius: 3px; cursor: pointer; font-size: 11px;">⬇ 下载</button>` : ''}
                    </div>
                `;

                // 预览
                const openBtn = item.querySelector('.dl-open');
                if (openBtn) {
                    openBtn.onclick = () => window.open(openBtn.dataset.url, '_blank');
                }

                // 下载
                const dlBtn = item.querySelector('.dl-download');
                if (dlBtn) {
                    dlBtn.onclick = () => downloadFile(dlBtn.dataset.url, dlBtn.dataset.filename);
                }

                listContainer.appendChild(item);
            });
        }
    }

    // ==================== 启动 ====================

    let toggleBtn;

    function init() {
        interceptXHR();
        scanForFileIds();
        toggleBtn = createBtn();

        // 按钮点击事件 — 直接用 onclick 绑定
        toggleBtn.onclick = function () {
            toggleBtn.textContent = '⏳ 扫描中...';
            toggleBtn.disabled = true;

            // 再扫描一次，捕获新加载的内容
            setTimeout(() => {
                scanForFileIds();
                createPanel();
                toggleBtn.textContent = '📥 下载文档';
                toggleBtn.disabled = false;
            }, 500);
        };

        // 初始面板
        setTimeout(() => {
            console.log('[学习通下载v7] 初始状态 - 捕获到', capturedDocs.length, '个文档');
            if (capturedDocs.length > 0) {
                console.log('[学习通下载v7] 文档列表:', capturedDocs.map((d) => d.filename).join(', '));
            }
            // 如果已经有文档，自动弹出面板
            if (capturedDocs.length > 0) {
                createPanel();
            }
        }, 1000);
    }

    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', init);
    } else {
        init();
    }
})();