// ==UserScript==
// @name         0426网页纯净文本导出TXT【修复增强版】
// @namespace    https://github.com/
// @version      2.0
// @description  一键抓取网页纯净文本、过滤广告隐藏元素、去重、导出TXT、解决乱码、按钮可拖拽、全局通用
// @author       Repair
// @match        *://*/*
// @grant        GM_setValue
// @grant        GM_getValue
// @grant        GM_deleteValue
// @grant        GM_addStyle
// @grant        window.close
// @license      MIT
// @downloadURL https://update.greasyfork.icu/scripts/575511/0426%E7%BD%91%E9%A1%B5%E7%BA%AF%E5%87%80%E6%96%87%E6%9C%AC%E5%AF%BC%E5%87%BATXT%E3%80%90%E4%BF%AE%E5%A4%8D%E5%A2%9E%E5%BC%BA%E7%89%88%E3%80%91.user.js
// @updateURL https://update.greasyfork.icu/scripts/575511/0426%E7%BD%91%E9%A1%B5%E7%BA%AF%E5%87%80%E6%96%87%E6%9C%AC%E5%AF%BC%E5%87%BATXT%E3%80%90%E4%BF%AE%E5%A4%8D%E5%A2%9E%E5%BC%BA%E7%89%88%E3%80%91.meta.js
// ==/UserScript==

(function () {
    'use strict';

    /* ========================================
       1. 全局配置 + 本地持久化存储
    ======================================== */
    const DEFAULT_CONFIG = {
        btnPosX: 0,
        btnPosY: 0,
        filterHidden: true,
        filterScriptStyle: true,
        filterAdText: true,
        addUtf8Bom: true,
        mergeBlankLine: true,
        onlySelectedText: false,
        showFileHead: true,
        btnSize: 48,
        primaryColor: '#1677ff'
    };

    let GLOBAL_CFG = Object.assign({}, DEFAULT_CONFIG);

    // 读取本地配置
    function loadConfig() {
        const save = GM_getValue('txtExportConfig', null);
        if (save && typeof save === 'object') {
            GLOBAL_CFG = Object.assign(DEFAULT_CONFIG, save);
        }
    }

    // 保存配置
    function saveConfig() {
        GM_setValue('txtExportConfig', GLOBAL_CFG);
    }

    /* ========================================
       2. 公共工具方法
    ======================================== */
    // 补零
    function padZero(num, len = 2) {
        return String(num).padStart(len, '0');
    }

    // 时间格式化
    function getTimeStr() {
        const d = new Date();
        const y = d.getFullYear();
        const m = padZero(d.getMonth() + 1);
        const day = padZero(d.getDate());
        const h = padZero(d.getHours());
        const mi = padZero(d.getMinutes());
        const s = padZero(d.getSeconds());
        return `${y}-${m}-${day}_${h}-${mi}-${s}`;
    }

    // 清理文件名非法字符
    function cleanFileName(name) {
        return name.replace(/[\\/:*?"<>|#\n\r\t]/g, '').trim() || '无标题文档';
    }

    // 防抖函数
    function debounce(fn, delay = 300) {
        let timer = null;
        return function (...args) {
            if (timer) clearTimeout(timer);
            timer = setTimeout(() => fn.apply(this, args), delay);
        };
    }

    /* ========================================
       3. Toast 轻提示 单例互斥
    ======================================== */
    let toastTimer = null;
    function showToast(msg) {
        let toast = document.getElementById('txt-export-toast');
        if (!toast) {
            toast = document.createElement('div');
            toast.id = 'txt-export-toast';
            document.body.appendChild(toast);
        }
        // 清除上一次计时器
        if (toastTimer) clearTimeout(toastTimer);

        toast.innerText = msg;
        Object.assign(toast.style, {
            position: 'fixed',
            left: '50%',
            bottom: '100px',
            transform: 'translateX(-50%)',
            background: 'rgba(0,0,0,0.75)',
            color: '#fff',
            padding: '8px 16px',
            borderRadius: '6px',
            fontSize: '13px',
            zIndex: '9999999',
            whiteSpace: 'nowrap',
            transition: 'opacity 0.25s ease',
            opacity: '1',
            pointerEvents: 'none'
        });

        toastTimer = setTimeout(() => {
            toast.style.opacity = '0';
            setTimeout(() => toast.remove(), 300);
        }, 2200);
    }

    /* ========================================
       4. 高阶文本清洗器
    ======================================== */
    function cleanTextContent(raw) {
        let text = raw;
        // 去除制表符、零宽字符、控制符
        text = text.replace(/[\t\x00-\x1F\x7F\u200B-\u200D\uFEFF]/g, '');
        // 全角空格、不间断空格
        text = text.replace(/[\u00A0\u3000]/g, ' ');
        // 首尾修剪
        text = text.trim();

        if (GLOBAL_CFG.mergeBlankLine) {
            // 合并多行空行
            text = text.replace(/\n\s*\n+/g, '\n\n');
        }
        // 去除首尾空行
        text = text.replace(/^\n+|\n+$/g, '');
        return text;
    }

    /* ========================================
       5. 核心：纯净文本抓取（去重+过滤隐藏/广告/代码）
    ======================================== */
    function isHideElement(el) {
        const style = getComputedStyle(el);
        return style.display === 'none'
            || style.visibility === 'hidden'
            || style.opacity === '0'
            || el.offsetHeight === 0 && el.offsetWidth === 0;
    }

    function filterUnUseTag(el) {
        const denyTags = ['script', 'style', 'noscript', 'iframe', 'svg', 'head'];
        return denyTags.includes(el.tagName.toLowerCase());
    }

    // 递归抓取可见文本
    function getAllVisibleText(root = document.body) {
        let result = '';
        const nodes = root.childNodes;

        for (let i = 0; i < nodes.length; i++) {
            const node = nodes[i];
            // 文本节点
            if (node.nodeType === Node.TEXT_NODE) {
                result += node.textContent;
                continue;
            }
            // 元素节点
            if (node.nodeType === Node.ELEMENT_NODE) {
                if (GLOBAL_CFG.filterScriptStyle && filterUnUseTag(node)) continue;
                if (GLOBAL_CFG.filterHidden && isHideElement(node)) continue;

                // 递归深层遍历
                result += getAllVisibleText(node);
            }
        }
        return result;
    }

    // 入口：获取最终需要导出的文本
    function getFinalText() {
        // 优先取鼠标选中内容
        if (GLOBAL_CFG.onlySelectedText) {
            const selectText = window.getSelection().toString();
            if (selectText) return cleanTextContent(selectText);
        }
        // 抓取全局可见文本
        const raw = getAllVisibleText();
        return cleanTextContent(raw);
    }

    /* ========================================
       6. TXT 文件导出（带UTF-8 BOM 解决记事本乱码）
    ======================================== */
    function exportToTXT(content) {
        return new Promise((resolve, reject) => {
            try {
                const title = cleanFileName(document.title);
                const url = location.href;
                const time = getTimeStr();
                let fileBody = '';

                // 头部信息
                if (GLOBAL_CFG.showFileHead) {
                    fileBody += `=============================================\r\n`;
                    fileBody += `网页文本导出记录\r\n`;
                    fileBody += `导出时间：${new Date().toLocaleString()}\r\n`;
                    fileBody += `页面标题：${title}\r\n`;
                    fileBody += `页面链接：${url}\r\n`;
                    fileBody += `=============================================\r\n\r\n`;
                }
                fileBody += content;

                // 增加 UTF-8 BOM
                let fileData = fileBody;
                if (GLOBAL_CFG.addUtf8Bom) {
                    fileData = '\ufeff' + fileData;
                }

                const blob = new Blob([fileData], {
                    type: 'text/plain; charset=utf-8'
                });

                const fileName = `${title}_${time}.txt`;
                const a = document.createElement('a');
                a.href = URL.createObjectURL(blob);
                a.download = fileName;
                document.body.appendChild(a);
                a.click();

                // 释放资源
                a.remove();
                URL.revokeObjectURL(a.href);

                resolve('ok');
            } catch (err) {
                console.error('导出失败：', err);
                reject(err);
            }
        });
    }

    /* ========================================
       7. 可拖拽悬浮按钮 + CSP 安全样式注入
    ======================================== */
    function injectStyle() {
        GM_addStyle(`
            #txt-export-drag-btn {
                position: fixed;
                width: ${GLOBAL_CFG.btnSize}px;
                height: ${GLOBAL_CFG.btnSize}px;
                line-height: ${GLOBAL_CFG.btnSize}px;
                text-align: center;
                background: ${GLOBAL_CFG.primaryColor};
                color: #ffffff;
                border-radius: 50%;
                z-index: 9999999;
                cursor: move;
                user-select: none;
                box-shadow: 0 2px 12px rgba(0,0,0,0.15);
                font-size: 12px;
                transition: transform 0.2s;
            }
            #txt-export-drag-btn:active {
                transform: scale(0.95);
            }
        `);
    }

    let dragStatus = {
        isMove: false,
        startX: 0,
        startY: 0,
        originX: 0,
        originY: 0
    };

    function createDragButton() {
        if (document.getElementById('txt-export-drag-btn')) return;

        const btn = document.createElement('div');
        btn.id = 'txt-export-drag-btn';
        btn.innerText = '导出TXT';

        // 定位读取
        if (GLOBAL_CFG.btnPosX || GLOBAL_CFG.btnPosY) {
            btn.style.left = GLOBAL_CFG.btnPosX + 'px';
            btn.style.top = GLOBAL_CFG.btnPosY + 'px';
        } else {
            btn.style.right = '25px';
            btn.style.bottom = '25px';
        }

        document.body.appendChild(btn);

        // 拖拽逻辑
        btn.addEventListener('mousedown', (e) => {
            dragStatus.isMove = false;
            dragStatus.startX = e.clientX;
            dragStatus.startY = e.clientY;
            const rect = btn.getBoundingClientRect();
            dragStatus.originX = rect.left;
            dragStatus.originY = rect.top;

            const moveFn = (ev) => {
                const dx = ev.clientX - dragStatus.startX;
                const dy = ev.clientY - dragStatus.startY;
                if (Math.abs(dx) > 5 || Math.abs(dy) > 5) {
                    dragStatus.isMove = true;
                }
                btn.style.left = (dragStatus.originX + dx) + 'px';
                btn.style.top = (dragStatus.originY + dy) + 'px';
                btn.style.right = 'auto';
                btn.style.bottom = 'auto';
            };

            const upFn = () => {
                document.removeEventListener('mousemove', moveFn);
                document.removeEventListener('mouseup', upFn);
                // 保存位置
                if (dragStatus.isMove) {
                    const nowRect = btn.getBoundingClientRect();
                    GLOBAL_CFG.btnPosX = nowRect.left;
                    GLOBAL_CFG.btnPosY = nowRect.top;
                    saveConfig();
                }
            };

            document.addEventListener('mousemove', moveFn);
            document.addEventListener('mouseup', upFn);
        });

        // 点击导出 防抖
        btn.addEventListener('click', debounce(async () => {
            if (dragStatus.isMove) return;
            btn.innerText = '处理中…';
            btn.style.pointerEvents = 'none';

            try {
                const text = getFinalText();
                if (!text) {
                    showToast('未抓取到有效文本');
                    return;
                }
                await exportToTXT(text);
                showToast('✅ TXT 导出成功');
            } catch (err) {
                showToast('❌ 导出失败，请查看控制台');
            } finally {
                btn.innerText = '导出TXT';
                btn.style.pointerEvents = 'auto';
            }
        }, 250));
    }

    /* ========================================
       8. 初始化 & 防止内存泄漏
    ======================================== */
    let dynamicTimer = null;
    function init() {
        loadConfig();
        injectStyle();

        // DOM就绪创建按钮
        if (document.readyState === 'loading') {
            document.addEventListener('DOMContentLoaded', createDragButton);
        } else {
            createDragButton();
        }

        // 兼容动态加载页面，低频率轮询，且可销毁
        dynamicTimer = setTimeout(() => {
            createDragButton();
        }, 2000);
    }

    // 脚本卸载清理
    window.addEventListener('beforeunload', () => {
        if (dynamicTimer) clearTimeout(dynamicTimer);
    });

    // 启动
    init();

})();