// ==UserScript==
// @name         国自然结题报告下载助手
// @namespace    nsfc-report-pdf
// @version      2.0.3
// @description  在国家自然科学基金官网查看结题报告时，本人完成滑块验证后，一键自动翻页，把整份报告保存为一个 PDF。仅供个人学习查阅。
// @license      MIT
// @tag          国自然
// @tag          结题报告
// @tag          PDF
// @tag          科研工具
// @author       researchsheep
// @copyright    2026, researchsheep
// @match        https://kd.nsfc.cn/finalDetails*
// @require      https://cdn.jsdelivr.net/npm/jspdf@2.5.2/dist/jspdf.umd.min.js#sha256=85ba2cc3ff858a20fa49fe6e457bec863ea40b55a9f3725e58a940e62f6f61a4
// @grant        GM_xmlhttpRequest
// @connect      kd.nsfc.cn
// @run-at       document-start
// ==/UserScript==

(function () {
  'use strict';
  const API = location.origin + '/api';
  const MAX_PAGES = 500;
  const DELAY_MS = 1000;
  const BUSY_WAITS = [5, 15, 30];
  const CAP_ATTR = 'data-nsfc-report-req';

  const hook = `(${function (ATTR) {
    const XP = XMLHttpRequest.prototype;
    const oOpen = XP.open, oSet = XP.setRequestHeader, oSend = XP.send;
    XP.open = function (m, u) { this.__nsfc = { url: String(u), headers: {} }; return oOpen.apply(this, arguments); };
    XP.setRequestHeader = function (k, v) { if (this.__nsfc) this.__nsfc.headers[k] = v; return oSet.apply(this, arguments); };
    XP.send = function (body) {
      const info = this.__nsfc;
      if (info && info.url.indexOf('completeProjectReport') !== -1) {
        info.body = typeof body === 'string' ? body : '';
        this.addEventListener('load', () => {
          const root = document.documentElement;
          const p = new URLSearchParams(info.body);
          let j = null;
          try { j = JSON.parse(this.responseText); } catch (e) { }
          const ok = !!(j && j.code === 200 && j.data && j.data.url);
          const log = JSON.parse(root.getAttribute(ATTR + '-log') || '[]');
          log.push({ t: new Date().toTimeString().slice(0, 8), index: p.get('index'), tryCode: p.has('tryCode'), code: j ? j.code : this.status, msg: j && !ok ? j.message : '' });
          root.setAttribute(ATTR + '-log', JSON.stringify(log.slice(-15)));
          if (!ok) return;
          root.setAttribute(ATTR, JSON.stringify(info));
          const pages = JSON.parse(root.getAttribute(ATTR + '-pages') || '{}');
          if (p.get('id')) { pages[p.get('id') + ':' + p.get('index')] = j.data.url; }
          root.setAttribute(ATTR + '-pages', JSON.stringify(pages));
        });
      }
      return oSend.apply(this, arguments);
    };
    document.addEventListener('nsfc-pdf-req', e => {
      const { seq, url, headers, body } = JSON.parse(e.detail);
      const x = new XMLHttpRequest();
      const reply = (status, text) => document.dispatchEvent(new CustomEvent('nsfc-pdf-res', { detail: JSON.stringify({ seq, status, text }) }));
      oOpen.call(x, 'POST', url);
      for (const k in headers) oSet.call(x, k, headers[k]);
      x.onload = () => reply(x.status, x.responseText);
      x.onerror = () => reply(0, '');
      oSend.call(x, body);
    });
  }})(${JSON.stringify(CAP_ATTR)});`;
  const s = document.createElement('script');
  s.textContent = hook;
  (document.head || document.documentElement).appendChild(s);
  s.remove();

  const captured = () => JSON.parse(document.documentElement.getAttribute(CAP_ATTR) || 'null');

  let reqSeq = 0;
  function pageXhr(url, headers, body) {
    const seq = ++reqSeq;
    return new Promise((resolve, reject) => {
      const timer = setTimeout(() => { document.removeEventListener('nsfc-pdf-res', on); reject(new Error('官网请求超时')); }, 60000);
      function on(e) {
        const r = JSON.parse(e.detail);
        if (r.seq !== seq) return;
        clearTimeout(timer);
        document.removeEventListener('nsfc-pdf-res', on);
        try { resolve(JSON.parse(r.text)); } catch (err) { const e2 = new Error('官网返回异常 HTTP ' + r.status); e2.status = r.status; reject(e2); }
      }
      document.addEventListener('nsfc-pdf-res', on);
      document.dispatchEvent(new CustomEvent('nsfc-pdf-req', { detail: JSON.stringify({ seq, url, headers, body }) }));
    });
  }

  const sleep = ms => new Promise(r => setTimeout(r, ms));
  const projectId = () => new URLSearchParams(location.search).get('id');

  async function nsfcPost(path, params, headers) {
    const r = await fetch(API + path, {
      method: 'POST',
      credentials: 'include',
      headers: { 'Content-Type': 'application/x-www-form-urlencoded;charset=UTF-8', ...(headers || {}) },
      body: new URLSearchParams(params).toString(),
    });
    return r.json();
  }

  function reportPage(index) {
    const cap = captured();
    const params = new URLSearchParams(cap.body);
    params.delete('tryCode');
    params.set('index', String(index));
    return pageXhr(cap.url, cap.headers, params.toString());
  }

  function gmRequest(opts) {
    return new Promise((resolve, reject) => {
      GM_xmlhttpRequest({ ...opts, onload: resolve, onerror: reject, ontimeout: () => reject(new Error('超时')) });
    });
  }

  async function fetchImage(url) {
    const res = await gmRequest({ method: 'GET', url: new URL(url, location.origin).href, responseType: 'arraybuffer', timeout: 60000 });
    if (res.status !== 200) { const e = new Error('图片下载失败 HTTP ' + res.status); e.status = res.status; throw e; }
    const buf = new Uint8Array(res.response);
    const fmt = buf[0] === 0x89 && buf[1] === 0x50 ? 'PNG' : (buf[0] === 0xff && buf[1] === 0xd8 ? 'JPEG' : null);
    const blob = new Blob([buf], { type: fmt === 'PNG' ? 'image/png' : 'image/jpeg' });
    const img = await new Promise((ok, bad) => {
      const i = new Image();
      i.onload = () => ok(i);
      i.onerror = () => bad(new Error('图片无法解析'));
      i.src = URL.createObjectURL(blob);
    });
    if (fmt) return { data: buf, fmt, w: img.naturalWidth, h: img.naturalHeight };
    const c = document.createElement('canvas');
    c.width = img.naturalWidth; c.height = img.naturalHeight;
    c.getContext('2d').drawImage(img, 0, 0);
    return { data: c.toDataURL('image/jpeg', 0.92), fmt: 'JPEG', w: c.width, h: c.height };
  }

  const box = document.createElement('div');
  box.style.cssText = 'position:fixed;right:20px;bottom:20px;z-index:99999;background:#fff;border:1px solid #d0d7de;' +
    'border-radius:10px;box-shadow:0 4px 16px rgba(0,0,0,.15);padding:12px 14px;width:270px;font:13px/1.6 system-ui,"Microsoft YaHei",sans-serif;color:#1f2328';
  box.innerHTML =
    '<div style="font-weight:600;margin-bottom:6px">结题报告 → PDF</div>' +
    '<div style="color:#6b7280">先点官网的「查看报告」并完成滑块验证，再点下面的按钮。</div>' +
    '<button data-k="go" style="width:100%;margin-top:8px;padding:8px;border:0;border-radius:6px;background:#1f5fbf;color:#fff;font-size:14px;cursor:pointer">下载全部页为 PDF</button>' +
    '<div data-k="st" style="margin-top:6px;white-space:pre-wrap;word-break:break-all"></div>';
  const mount = () => document.body.appendChild(box);
  if (document.body) mount(); else document.addEventListener('DOMContentLoaded', mount);
  const $ = k => box.querySelector(`[data-k="${k}"]`);
  const status = (t, color) => { $('st').textContent = t; $('st').style.color = color || '#1f2328'; };

  async function run() {
    const id = projectId();
    if (!id) return status('地址里没有项目 id', '#b91c1c');

    let title = id;
    try {
      const info = await nsfcPost('/baseQuery/conclusionProjectInfo/' + id, {});
      if (info.code === 200 && info.data) title = `${info.data.ratifyNo}_${info.data.projectName}`;
    } catch (e) { }
    title = title.replace(/[\\/:*?"<>|]/g, '_');

    const { jsPDF } = window.jspdf;
    let doc = null, pages = 0, lastUrl = null;

    const cap = captured();
    if (!cap) {
      return status('还没看到官网加载报告：请先点官网的「查看报告」并拖动滑块，看到报告第一页后再点我。\n' +
        '（如果刚更新过脚本，请先刷新页面再验证一次）', '#b91c1c');
    }
    if (new URLSearchParams(cap.body).get('id') !== id) {
      return status('记录到的是别的项目的报告请求，请刷新页面后重新验证。', '#b91c1c');
    }

    const known = JSON.parse(document.documentElement.getAttribute(CAP_ATTR + '-pages') || '{}');
    const officialLog = () => JSON.parse(document.documentElement.getAttribute(CAP_ATTR + '-log') || '[]')
      .map(r => `${r.t} 第${r.index}页 ${r.tryCode ? '带凭证' : '不带凭证'} → ${r.code}${r.msg ? ' ' + r.msg : ''}`).join('\n');
    let refused = null, busy = null;
    const missing = [];

    async function getUrl(index) {
      const k = id + ':' + index;
      if (known[k]) return { url: known[k] };
      let j;
      for (let attempt = 0; ; attempt++) {
        try { j = await reportPage(index); break; } catch (e) {
          if (![0, 429, 502, 503, 504].includes(e.status) || attempt >= BUSY_WAITS.length) {
            if ([0, 429, 502, 503, 504].includes(e.status)) return { busy: e.message };
            throw e;
          }
          for (let t = BUSY_WAITS[attempt]; t > 0; t--) {
            status(`官网繁忙（${e.message}），${t} 秒后重试第 ${index} 页…`);
            await sleep(1000);
          }
        }
      }
      await sleep(DELAY_MS);
      if (j.code !== 200 || !j.data || !j.data.url) {
        const msg = j.message || ('code=' + j.code);
        return /验证/.test(msg) ? { refused: msg } : { end: true };
      }
      known[k] = j.data.url;
      return { url: j.data.url };
    }
    async function loadImage(url) {
      for (let attempt = 0; ; attempt++) {
        try { return await fetchImage(url); } catch (e) {
          if (e.status === 404) {
            if (attempt === 0) { await sleep(1000); continue; }
            return null;
          }
          if (attempt >= BUSY_WAITS.length) throw e;
          for (let t = BUSY_WAITS[attempt]; t > 0; t--) {
            status(`图片服务器繁忙（${e.message}），${t} 秒后重试…`);
            await sleep(1000);
          }
        }
      }
    }

    for (let index = 1; index <= MAX_PAGES; index++) {
      status(`正在获取第 ${index} 页…`);
      const r = await getUrl(index);
      if (r.busy) { busy = { index, msg: r.busy }; break; }
      if (r.refused) { refused = { index, msg: r.refused }; break; }
      if (r.end || r.url === lastUrl) break;
      lastUrl = r.url;

      const im = await loadImage(r.url);
      if (!im) {
        status(`第 ${index} 页图片取不到，检查后面是否还有…`);
        let more = false;
        for (let k = 1; k <= 2 && !more; k++) {
          const r2 = await getUrl(index + k);
          if (r2.busy) { busy = { index: index + k, msg: r2.busy }; break; }
          if (r2.refused) { refused = { index: index + k, msg: r2.refused }; break; }
          if (r2.url && await loadImage(r2.url)) more = true;
        }
        if (busy || refused || !more) break;
        missing.push(index);
        continue;
      }
      const orient = im.w > im.h ? 'l' : 'p';
      if (!doc) doc = new jsPDF({ unit: 'px', format: [im.w, im.h], orientation: orient, compress: true, hotfixes: ['px_scaling'] });
      else doc.addPage([im.w, im.h], orient);
      doc.addImage(im.data, im.fmt, 0, 0, im.w, im.h, undefined, 'FAST');
      pages++;
    }
    const missNote = missing.length ? `\n注意：第 ${missing.join('、')} 页图片取不到，已跳过。` : '';

    if (busy) {
      return status(`官网一直繁忙（${busy.msg}），停在第 ${busy.index} 页（已取到 ${pages} 页，未生成 PDF）。
` +
        '可能是短时间内请求太多被限流了，请过几分钟再试。', '#b91c1c');
    }
    if (refused) {
      return status(`官网在第 ${refused.index} 页拒绝：${refused.msg}（已取到 ${pages} 页，未生成 PDF）\n` +
        `官网自己的报告请求记录：\n${officialLog() || '（无）'}`, '#b91c1c');
    }
    if (!pages) return status('一页也没取到。\n官网请求记录：\n' + (officialLog() || '（无）'), '#b91c1c');

    status(`共 ${pages} 页，正在生成 PDF…`);
    doc.setProperties({ title });
    doc.save(title + '.pdf');
    status(`完成：${pages} 页，已保存到浏览器的下载文件夹。${missNote}`, missing.length ? '#92400e' : '#15803d');
  }

  $('go').addEventListener('click', async () => {
    $('go').disabled = true; $('go').style.opacity = '.6';
    try { await run(); } catch (e) { status('出错：' + (e && e.message || e), '#b91c1c'); }
    $('go').disabled = false; $('go').style.opacity = '1';
  });
})();