// ==UserScript==
// @name         CNKI 文献详情页 - 保存摘要（含来源日期）
// @namespace    https://www.0x99.top
// @version      1.2
// @description  在CNKI文献详情页顶部中央添加按钮，保存格式化摘要：作者. 标题, 来源信息\n摘要: 内容
// @author       zmrbak
// @match        https://kns.cnki.net/kcms2/article/abstract?*
// @match        https://kns.cnki.net/kcms/detail/*
// @match        https://kns.cnki.net/kcms2/detail/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // 获取标题（从 .wx-tit h1）
    function getTitle() {
        const titleElem = document.querySelector('.wx-tit h1');
        if (titleElem) {
            let title = titleElem.innerText.trim();
            // 移除可能附带的视频标记等
            title = title.replace(/\s*<span.*<\/span>/, '').trim();
            return title;
        }
        return '未知标题';
    }

    // 获取作者列表（从 #authorpart 下的 a 链接，去除上标数字）
    function getAuthors() {
        const authorContainer = document.getElementById('authorpart');
        if (!authorContainer) return [];
        const authorLinks = authorContainer.querySelectorAll('a');
        const authors = [];
        for (let link of authorLinks) {
            let name = link.innerText.trim();
            // 去除上标数字（如 "陈国青1" -> "陈国青"）
            name = name.replace(/\d+$/, '').trim();
            if (name) authors.push(name);
        }
        // 去重（保留顺序）
        return [...new Map(authors.map(a => [a, a])).values()];
    }

    // 获取来源信息（期刊名、年份、卷期、页码）
    function getSourceInfo() {
        const topTip = document.querySelector('.top-tip span');
        if (!topTip) return '';

        // 获取所有文本内容（包含链接内的文本）
        let rawText = topTip.innerText || topTip.textContent || '';
        // 去除“查看该刊数据库收录来源”和“使用帮助”等额外文字
        rawText = rawText.replace(/查看该刊数据库收录来源.*$/, '')
                         .replace(/使用帮助.*$/, '')
                         .trim();
        // 合并多余空白
        rawText = rawText.replace(/\s+/g, ' ').trim();
        // 去掉末尾可能的标点
        return rawText;
    }

    // 获取摘要文本
    function getAbstractText() {
        let abstract = '';
        const summarySpan = document.getElementById('ChDivSummary');
        if (summarySpan) {
            abstract = summarySpan.innerText.trim();
        }
        if (!abstract) {
            const abstractInput = document.getElementById('abstract_text');
            if (abstractInput && abstractInput.value) {
                abstract = abstractInput.value.trim();
            }
        }
        if (!abstract) {
            const rowDiv = Array.from(document.querySelectorAll('.row')).find(row => {
                const span = row.querySelector('.rowtit');
                return span && span.innerText.includes('摘要');
            });
            if (rowDiv) {
                const abstractSpan = rowDiv.querySelector('.abstract-text');
                if (abstractSpan) abstract = abstractSpan.innerText.trim();
            }
        }
        return abstract.replace(/\s+/g, ' ').trim();
    }

    // 获取文件名基础（用标题，清理非法字符）
    function getBaseFileName() {
        let title = getTitle();
        title = title.replace(/[\\/:*?"<>|]/g, '');
        if (title.length > 100) title = title.slice(0, 100);
        return title;
    }

    // 保存文本文件
    function saveAsTextFile(content, filename) {
        if (!content) {
            alert('未找到摘要内容，可能页面结构已变化。');
            return false;
        }
        const blob = new Blob([content], { type: 'text/plain;charset=utf-8' });
        const link = document.createElement('a');
        const url = URL.createObjectURL(blob);
        link.href = url;
        link.download = filename;
        document.body.appendChild(link);
        link.click();
        document.body.removeChild(link);
        URL.revokeObjectURL(url);
        return true;
    }

    // 创建按钮（顶部居中）
    function createButton() {
        const btn = document.createElement('button');
        btn.textContent = '📝 保存摘要';
        btn.id = 'cnki-detail-save-abstract-btn';
        btn.style.cssText = `
            position: fixed;
            left: 50%;
            transform: translateX(-50%);
            top: 12px;
            z-index: 9999;
            padding: 8px 20px;
            font-size: 14px;
            font-weight: bold;
            color: #fff;
            background-color: #2c7da0;
            border: none;
            border-radius: 30px;
            cursor: pointer;
            box-shadow: 0 2px 8px rgba(0,0,0,0.2);
            transition: background-color 0.2s;
            display: block;
            width: auto;
            min-width: 120px;
            text-align: center;
            font-family: system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
        `;
        btn.onmouseover = () => btn.style.backgroundColor = '#1f5e7a';
        btn.onmouseout = () => btn.style.backgroundColor = '#2c7da0';
        btn.addEventListener('click', () => {
            const title = getTitle();
            const authors = getAuthors();
            const authorStr = authors.length ? authors.join(',') : '未知作者';
            const sourceInfo = getSourceInfo();
            const abstract = getAbstractText();

            if (!abstract) {
                alert('未找到摘要内容，请确认页面已完全加载。');
                return;
            }

            // 格式：作者. 标题, 来源信息\n摘要: 内容
            let firstLine = `${authorStr}. ${title}`;
            if (sourceInfo) {
                firstLine += `, ${sourceInfo}`;
            }
            const content = `${firstLine}\n摘要: ${abstract}`;
            const filename = `${getBaseFileName()}_摘要.txt`;
            const success = saveAsTextFile(content, filename);
            if (success) {
                const notice = document.createElement('div');
                notice.textContent = `✅ 摘要已保存: ${filename}`;
                notice.style.cssText = `
                    position: fixed;
                    bottom: 20px;
                    right: 20px;
                    background: #4caf50;
                    color: white;
                    padding: 6px 12px;
                    border-radius: 4px;
                    font-size: 12px;
                    z-index: 10000;
                    opacity: 0.9;
                `;
                document.body.appendChild(notice);
                setTimeout(() => notice.remove(), 3000);
            }
        });
        return btn;
    }

    function addButton() {
        if (document.getElementById('cnki-detail-save-abstract-btn')) return;
        const btn = createButton();
        document.body.appendChild(btn);
    }

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