// ==UserScript==
// @name         CNKI 论文下载（参考文献智能提取 + 摘要格式化保存）
// @namespace    https://www.0x99.top
// @version      0.9.5
// @description  在CNKI论文页面顶部中央添加三个按钮：保存正文、保存参考文献、保存摘要（作者.标题，来源，日期 + 摘要内容）
// @author       zmrbak
// @match        https://kns.cnki.net/reader/xml*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // ---------- 定义 XPath ----------
    const CONTENT_XPATH = '/html/body/div[3]/div/div[2]/div[2]/div/div/div[3]/div';
    const REF_XPATH    = '/html/body/div[3]/div/div[2]/div[3]/section/div[2]/div[1]/ul';
    const TITLE_XPATH  = '/html/body/div[3]/div/div[2]/div[2]/div/div/div[3]/div/div[2]/div[1]/div[1]/h1';
    const ABSTRACT_CONTAINER_XPATH = '/html/body/div[3]/div/div[2]/div[2]/div/div/div[3]/div/div[2]/div[1]';
    const META_DIV_XPATH = '/html/body/div[3]/div/section/div/div[1]/div';  // 元数据区域（来源、日期）

    // 获取来源与日期字符串（格式：来源名称, 年份(期号)）
    function getSourceAndDateStr() {
        try {
            const metaDiv = document.evaluate(META_DIV_XPATH, document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
            if (!metaDiv) return '';

            // 提取来源类型（如“期刊”、“博士论文”）
            let sourceType = '';
            const typeSpan = metaDiv.querySelector('span');
            if (typeSpan) {
                const match = typeSpan.innerText.match(/[（(](.+?)[）)]/);
                if (match) sourceType = match[1];
            }

            // 提取来源名称（期刊名或学校名）
            let sourceName = '';
            const nameLink = metaDiv.querySelector('a.xmlhref');
            if (nameLink) {
                sourceName = nameLink.innerText.trim();
            } else {
                // 如果没有链接（例如学位论文），尝试从 div 文本中提取学校名称（常见格式：在来源类型后的文本）
                const divText = metaDiv.innerText;
                const h1Title = metaDiv.querySelector('h1.xmltitle');
                if (h1Title) {
                    let rest = divText.replace(h1Title.innerText, '');
                    if (sourceType) {
                        const regex = new RegExp(`[（(]${sourceType}[）)]\\s*([^\\d]+)`);
                        const match = rest.match(regex);
                        if (match && match[1]) sourceName = match[1].trim();
                    }
                }
            }

            // 提取年份和期号
            const emList = metaDiv.querySelectorAll('em.xmlem');
            let year = '', issue = '';
            if (emList.length > 0) year = emList[0].innerText.trim();
            if (emList.length > 1) issue = emList[1].innerText.trim();

            // 构建最终来源+日期字符串
            let result = '';
            if (sourceName) {
                result = sourceName;
            } else if (sourceType) {
                result = sourceType; // 降级使用来源类型（如“博士论文”）
            } else {
                return '';  // 无可用信息
            }

            if (year) {
                result += `，${year}`;
                if (issue) result += issue;  // issue 已含括号，如“(05)”
            }
            return result;
        } catch (e) {
            console.warn('提取来源/日期失败:', e);
            return '';
        }
    }

    // 解析单条参考文献
    function parseReferenceItem(raw) {
        let text = raw.replace(/^\[\d+\]\s*/, '');
        text = text.replace(/\s*\([A-Za-z\s,.;:()]+\)\s*$/, '');
        const regex = /^(.+?)\.\s+(.+?)\[([A-Z]+)\]([^0-9]*)(\d{4})/;
        const match = text.match(regex);
        if (match) {
            let author = match[1].trim();
            let title = match[2].trim();
            let sourceType = match[3];
            let sourceDetail = match[4].trim();
            let year = match[5];
            const sourcePart = sourceDetail ? `${sourceDetail}` : '';
            return `${author}. ${title}. [${sourceType}]. ${sourcePart} ${year}.`.replace(/\s+/g, ' ').trim();
        }
        return text.trim();
    }

    function getReferenceText() {
        const result = document.evaluate(REF_XPATH, document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null);
        const ul = result.singleNodeValue;
        if (!ul) return '';
        const liList = ul.querySelectorAll('li');
        if (!liList.length) return '';
        const refs = [];
        for (const li of liList) {
            const raw = li.innerText || li.textContent || '';
            if (raw.trim()) refs.push(parseReferenceItem(raw));
        }
        return refs.join('\n');
    }

    function getTextFromXPath(xpath) {
        const result = document.evaluate(xpath, document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null);
        const node = result.singleNodeValue;
        return node ? (node.innerText || node.textContent || '').trim() : '';
    }

    // 获取格式化后的摘要（作者.标题 + 来源/日期 + 摘要单行）
    function getFormattedAbstract() {
        const container = document.evaluate(ABSTRACT_CONTAINER_XPATH, document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
        if (!container) return '';

        // 1. 提取标题
        let title = '';
        const titleElem = container.querySelector('h1.Chapter');
        if (titleElem) title = titleElem.innerText.trim();
        if (!title) title = getTextFromXPath(TITLE_XPATH);
        if (!title) title = '未知标题';

        // 2. 提取作者
        let authors = [];
        const authorUl = container.querySelector('ul.Chapter-people');
        if (authorUl) {
            const items = authorUl.querySelectorAll('li');
            for (let li of items) {
                let name = '';
                const link = li.querySelector('a');
                if (link) {
                    name = link.innerText.trim();
                } else {
                    name = li.innerText.trim();
                }
                if (name && !name.includes('大学') && !name.includes('学院') && !name.includes('研究中心')) {
                    authors.push(name);
                }
            }
        }
        if (authors.length === 0) {
            const authorElems = document.querySelectorAll('.author, .authors, span.author, a.author');
            for (let elem of authorElems) {
                let name = (elem.innerText || elem.textContent).trim();
                if (name && !name.includes('大学') && !name.includes('学院')) authors.push(name);
            }
        }
        authors = [...new Set(authors)];
        let authorStr = authors.length ? authors.join(',') : '未知作者';

        // 3. 提取来源与日期（新增）
        const sourceDateStr = getSourceAndDateStr();

        // 4. 提取摘要文本
        let abstractText = '';
        const paras = container.querySelectorAll('.para');
        let abstractPara = null;
        for (let para of paras) {
            const text = para.innerText || para.textContent || '';
            if (text.includes('摘要:')) {
                abstractPara = para;
                break;
            }
        }
        if (abstractPara) {
            let fullText = abstractPara.innerText.trim();
            fullText = fullText.replace(/^摘要[：:]\s*/, '');
            abstractText = fullText.replace(/\s+/g, ' ').trim();
        }
        if (!abstractText) {
            const abstractElem = document.querySelector('.abstract, .abstract-text, [class*="abstract"]');
            if (abstractElem) abstractText = abstractElem.innerText.trim();
        }
        if (!abstractText) abstractText = '无摘要内容';

        // 格式化输出
        let firstLine = `${authorStr}. ${title}`;
        if (sourceDateStr) {
            firstLine += `，${sourceDateStr}`;
        }
        const secondLine = `摘要: ${abstractText}`;
        return `${firstLine}\n${secondLine}`;
    }

    function getBaseTitle() {
        let title = getTextFromXPath(TITLE_XPATH);
        if (!title) {
            const now = new Date();
            title = `${now.getFullYear()}-${now.getMonth()+1}-${now.getDate()}_${now.getHours()}-${now.getMinutes()}-${now.getSeconds()}`;
        }
        title = title.replace(/[\\/:*?"<>|]/g, '');
        if (title.length > 100) title = title.slice(0, 100);
        return title;
    }

    function saveAsTextFile(content, filename) {
        if (!content) {
            alert('未找到目标文本，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;
    }

    function showNotice(message, isError = false) {
        const notice = document.createElement('div');
        notice.textContent = message;
        notice.style.cssText = `
            position: fixed;
            bottom: 20px;
            right: 20px;
            background: ${isError ? '#f44336' : '#4caf50'};
            color: white;
            padding: 6px 12px;
            border-radius: 4px;
            font-size: 12px;
            z-index: 10001;
            opacity: 0.9;
            max-width: 350px;
            word-break: break-all;
        `;
        document.body.appendChild(notice);
        setTimeout(() => notice.remove(), 3000);
    }

    function createStyledButton(text, onClick) {
        const btn = document.createElement('button');
        btn.textContent = text;
        btn.style.cssText = `
            padding: 6px 16px;
            font-size: 14px;
            font-weight: bold;
            color: #fff;
            background-color: #2c7da0;
            border: none;
            border-radius: 30px;
            cursor: pointer;
            transition: background-color 0.2s, transform 0.1s;
            box-shadow: 0 1px 3px rgba(0,0,0,0.2);
            white-space: nowrap;
            font-family: inherit;
        `;
        btn.onmouseover = () => btn.style.backgroundColor = '#1f5e7a';
        btn.onmouseout = () => btn.style.backgroundColor = '#2c7da0';
        btn.addEventListener('click', onClick);
        return btn;
    }

    function addButtons() {
        const oldContainer = document.getElementById('cnki-buttons-container');
        if (oldContainer) oldContainer.remove();
        ['cnki-save-content-btn', 'cnki-save-ref-btn', 'cnki-save-abstract-btn'].forEach(id => {
            const oldBtn = document.getElementById(id);
            if (oldBtn) oldBtn.remove();
        });

        const container = document.createElement('div');
        container.id = 'cnki-buttons-container';
        container.style.cssText = `
            position: fixed;
            top: 12px;
            left: 50%;
            transform: translateX(-50%);
            display: flex;
            gap: 12px;
            z-index: 10000;
            background: transparent;
            padding: 4px 0;
            box-shadow: none;
        `;

        const contentBtn = createStyledButton('📄 保存正文', () => {
            const content = getTextFromXPath(CONTENT_XPATH);
            const filename = `${getBaseTitle()}.txt`;
            const success = saveAsTextFile(content, filename);
            showNotice(success ? `✅ 正文已保存: ${filename}` : '⚠️ 未找到正文内容');
        });
        contentBtn.id = 'cnki-save-content-btn';

        const refBtn = createStyledButton('📚 保存参考文献', () => {
            const refText = getReferenceText();
            const filename = `${getBaseTitle()}_参考文献.txt`;
            const success = saveAsTextFile(refText, filename);
            showNotice(success ? `✅ 参考文献已保存: ${filename}` : '⚠️ 未找到参考文献');
        });
        refBtn.id = 'cnki-save-ref-btn';

        const abstractBtn = createStyledButton('📝 保存摘要', () => {
            const abstractText = getFormattedAbstract();
            const filename = `${getBaseTitle()}_摘要.txt`;
            const success = saveAsTextFile(abstractText, filename);
            showNotice(success ? `✅ 摘要已保存: ${filename}` : '⚠️ 未找到摘要内容');
        });
        abstractBtn.id = 'cnki-save-abstract-btn';

        container.appendChild(contentBtn);
        container.appendChild(refBtn);
        container.appendChild(abstractBtn);
        document.body.appendChild(container);
    }

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