Coomer Image Download Button

Adds a small download icon to images on Coomer post pages.

您需要先安装一个扩展,例如 篡改猴Greasemonkey暴力猴,之后才能安装此脚本。

您需要先安装一个扩展,例如 篡改猴暴力猴,之后才能安装此脚本。

您需要先安装一个扩展,例如 篡改猴暴力猴,之后才能安装此脚本。

您需要先安装一个扩展,例如 篡改猴Userscripts ,之后才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey,才能安装此脚本。

您需要先安装用户脚本管理器扩展后才能安装此脚本。

(我已经安装了用户脚本管理器,让我安装!)

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

(我已经安装了用户样式管理器,让我安装!)

// ==UserScript==
// @name         Coomer Image Download Button
// @namespace    http://tampermonkey.net/
// @version      1.5
// @description  Adds a small download icon to images on Coomer post pages.
// @match        https://coomer.st/*
// @grant        GM_xmlhttpRequest
// @grant        GM_addStyle
// @grant        GM_download
// @connect      *
// @run-at       document-end
// @author       nereids
// @icon         https://icons.duckduckgo.com/ip3/coomer.st.ico
// @license      MIT
// ==/UserScript==

(function () {
  'use strict';

  let imageCounter = 0;
  let lastUrl = location.href;

  // --- Styles ---
  GM_addStyle(`
    .coomer-dl-btn {
      position: absolute;
      bottom: 6px;
      left: 6px;
      width: 30px;
      height: 30px;
      border-radius: 50%;
      background: rgba(0,0,0,0.5);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      z-index: 2147483647;
      border: none;
      padding: 0;
    }
    .coomer-dl-btn svg { width:20px; height:20px; fill: white; pointer-events: none; }
    .coomer-dl-btn.downloading { opacity: 0.7; transform: scale(0.98); }
  `);

  // SVG download icon
  const ICON_SVG = `<svg xmlns="http://www.w3.org/2000/svg" height="48px" viewBox="0 -960 960 960" width="48px" fill="#e3e3e3"><path d="M434.5-396.5v-329q0-19 13.25-32.25T480.5-771q19 0 32.25 13.25T526-725.5V-395l119-119q13.5-13.5 32-13.5t32 14q13.5 13.5 13.5 32t-13.5 32L512.5-253q-14 14-33.5 14t-33-14L249.5-449.5Q236-463 235.75-481.25t13.75-32.25q14-13.5 32.75-14t32.75 13l119.5 118Z"/></svg>`;

  function getUserAndPost() {
    const userMatch = location.pathname.match(/\/user\/([^/]+)/);
    const postMatch = location.pathname.match(/\/post\/(\d+)/);
    return {
      username: userMatch ? userMatch[1] : "",
      postId: postMatch ? postMatch[1] : ""
    };
  }

  function findOriginal(img) {
    const anc = img.closest('a');
    if (anc && anc.href && /\/data\//.test(anc.href)) {
      return anc.href.split('?')[0];
    }
    if (img.srcset) {
      const candidates = img.srcset.split(',').map(s => s.trim().split(/\s+/)[0]);
      for (const c of candidates) {
        if (/\/data\//.test(c)) return c.split('?')[0];
      }
    }
    const attrs = ['data-src', 'data-full', 'data-original', 'data-img', 'data-lazy-src'];
    for (const a of attrs) {
      const v = img.getAttribute(a);
      if (v && /\/data\//.test(v)) return v.split('?')[0];
    }
    if (!img.src) return null;
    try {
      const u = new URL(img.src, location.href);
      u.pathname = u.pathname.replace('/thumbnail', '');
      if (u.hostname === 'img.coomer.st') u.hostname = 'n4.coomer.st';
      u.search = '';
      return u.toString();
    } catch (e) {
      return img.src.split('?')[0];
    }
  }

  function getExtension(url) {
    const m = url.match(/\.([a-zA-Z0-9]+)(?:\?|$)/);
    return m ? "." + m[1] : ".jpg";
  }

  function buildFilename(url, username, postId) {
    imageCounter += 1;
    return `${username}-${postId}_${imageCounter}${getExtension(url)}`;
  }

  function downloadBinary(url, filename, btn) {
    if (btn) btn.classList.add('downloading');
    GM_xmlhttpRequest({
      method: 'GET',
      url,
      responseType: 'arraybuffer',
      onload(res) {
        if (btn) btn.classList.remove('downloading');
        if (res.status >= 200 && res.status < 300 && res.response) {
          let ct = 'application/octet-stream';
          if (res.responseHeaders) {
            const m = res.responseHeaders.match(/content-type:\s*([^\r\n;]+)/i);
            if (m) ct = m[1].trim();
          }
          const blob = new Blob([res.response], { type: ct });
          const blobUrl = URL.createObjectURL(blob);
          const a = document.createElement('a');
          a.href = blobUrl;
          a.download = filename;
          document.body.appendChild(a);
          a.click();
          a.remove();
          setTimeout(() => URL.revokeObjectURL(blobUrl), 5000);
        } else {
          console.error('Binary download failed, status:', res.status);
          fallbackDownload(url, filename);
        }
      },
      onerror(err) {
        if (btn) btn.classList.remove('downloading');
        console.error('GM_xmlhttpRequest error', err);
        fallbackDownload(url, filename);
      },
      ontimeout() {
        if (btn) btn.classList.remove('downloading');
        console.error('GM_xmlhttpRequest timeout');
        fallbackDownload(url, filename);
      }
    });
  }

  function fallbackDownload(url, filename) {
    try {
      if (typeof GM_download === 'function') {
        try {
          GM_download({ url, name: filename });
          return;
        } catch (e) {
          GM_download(url, filename);
          return;
        }
      }
    } catch (e) {
      console.warn('GM_download fallback failed', e);
    }
    window.open(url, '_blank');
  }

  function addButtonsOnce() {
    const { username, postId } = getUserAndPost();
    if (!username || !postId) return; // only on post pages

    const images = Array.from(document.querySelectorAll('img'));
    images.forEach(img => {
      if (img.dataset.cdlAdded) return;
      if (!img.src || (!img.src.includes('/thumbnail/') && !img.src.includes('/data/'))) {
        img.dataset.cdlAdded = '1';
        return;
      }

      const orig = findOriginal(img);
      if (!orig) {
        img.dataset.cdlAdded = '1';
        return;
      }

      const parent = img.parentElement || img;
      const cs = getComputedStyle(parent);
      if (cs.position === 'static') {
        parent.style.position = 'relative';
        parent.dataset._cdl_posset = '1';
      }

      const btn = document.createElement('button');
      btn.className = 'coomer-dl-btn';
      btn.type = 'button';
      btn.title = 'Download full-size image';
      btn.innerHTML = ICON_SVG;
      btn.addEventListener('click', function (e) {
        e.stopPropagation();
        e.preventDefault();
        const filename = buildFilename(orig, username, postId);
        downloadBinary(orig, filename, btn);
      }, { capture: true });

      parent.appendChild(btn);
      img.dataset.cdlAdded = '1';
    });
  }

  function runForPost() {
    const { username, postId } = getUserAndPost();
    if (username && postId) {
      imageCounter = 0; // reset per post
      addButtonsOnce();
    }
  }

  // Watch for DOM changes
  const mo = new MutationObserver(addButtonsOnce);
  mo.observe(document.body, { childList: true, subtree: true });

  // Watch for URL changes (SPA navigation)
  function checkUrlChange() {
    if (location.href !== lastUrl) {
      lastUrl = location.href;
      runForPost();
    }
  }
  setInterval(checkUrlChange, 500);

  // Initial run
  runForPost();

})();