Image Proxy

Proxy Imgur (UK Ban) and any image that errors.

您需要先安裝使用者腳本管理器擴展,如 TampermonkeyGreasemonkeyViolentmonkey 之後才能安裝該腳本。

You will need to install an extension such as Tampermonkey to install this script.

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyViolentmonkey 後才能安裝該腳本。

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyUserscripts 後才能安裝該腳本。

你需要先安裝一款使用者腳本管理器擴展,比如 Tampermonkey,才能安裝此腳本

您需要先安裝使用者腳本管理器擴充功能後才能安裝該腳本。

(我已經安裝了使用者腳本管理器,讓我安裝!)

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

(我已經安裝了使用者樣式管理器,讓我安裝!)

// ==UserScript==
// @name         Image Proxy
// @namespace    danielytuk/IMGPROXY
// @version      1.0.1
// @description  Proxy Imgur (UK Ban) and any image that errors.
// @license      Unlicense
// @match        *://*/*
// @homepageURL  https://github.com/danielytuk/UserScripts
// @supportURL   https://github.com/danielytuk/UserScripts/Issues
// @icon         https://proxy.duckduckgo.com/iu/?u=https://imgur.com/favicon.ico
// @run-at       document-start
// ==/UserScript==

(() => {
  "use strict";

  const P1 = "https://external-content.duckduckgo.com/iu/?u=";
  const P2 = "https://searx.namejeff.xyz/image_proxy?url=";

  const LAZY = ["data-src", "data-original"]; // keep tiny; add more if you really need
  const st = new WeakMap(); // el -> { o: originalAbsUrl, a: attempts, done: decidedOnce }

  const prox = (base, u) => base + encodeURIComponent(u);
  const isProxied = (u) => u && (u.indexOf(P1) === 0 || u.indexOf(P2) === 0 || u.indexOf("data:") === 0 || u.indexOf("blob:") === 0);

  const abs = (u) => {
    if (!u) return "";
    u = ("" + u).trim();
    if (!u) return "";
    if (u.slice(0, 2) === "//") u = location.protocol + u;
    try { return new URL(u, location.href).href; } catch { return ""; }
  };

  const isImgurI = (u) => {
    try { return new URL(u).hostname === "i.imgur.com"; } catch { return false; }
  };

  const getState = (el) => {
    let x = st.get(el);
    if (!x) { x = { o: "", a: 0, done: false }; st.set(el, x); }
    return x;
  };

  const pickImgUrl = (img) => img.getAttribute("src") || (LAZY[0] && img.getAttribute(LAZY[0])) || (LAZY[1] && img.getAttribute(LAZY[1])) || "";

  const rewriteSrcsetImgurOnly = (ss) => {
    if (!ss) return ss;
    // Each entry: "url [descriptor]"
    const parts = ss.split(",");
    for (let i = 0; i < parts.length; i++) {
      const p = parts[i].trim();
      if (!p) continue;
      const sp = p.search(/\s/);
      const urlPart = sp === -1 ? p : p.slice(0, sp);
      const rest = sp === -1 ? "" : p.slice(sp);
      const u = abs(urlPart);
      if (u && !isProxied(u) && isImgurI(u)) parts[i] = prox(P1, u) + rest;
    }
    return parts.join(", ");
  };

  const ensureErrorHandler = (img) => {
    if (img.__mip_err) return;
    img.__mip_err = 1;

    img.addEventListener("error", () => {
      const x = getState(img);

      // Capture a stable original only once, from the first non-proxied URL we can see.
      if (!x.o) {
        const u = abs(pickImgUrl(img) || img.currentSrc || img.src);
        if (u && !isProxied(u)) x.o = u;
      }
      if (!x.o) return;

      // Advance fallback only a limited number of times.
      // original -> P1 -> P2 -> original, then stop.
      x.a++;
      if (x.a === 1) img.src = prox(P1, x.o);
      else if (x.a === 2) img.src = prox(P2, x.o);
      else if (x.a === 3) img.src = x.o;
    }, { passive: true });
  };

  const processImg = (img) => {
    if (!img || img.nodeType !== 1 || img.tagName !== "IMG") return;

    ensureErrorHandler(img);

    const x = getState(img);
    if (x.done) return;

    const u0 = abs(pickImgUrl(img));
    if (!u0) return; // wait until it has a URL; we'll see it again via mutations

    if (!x.o && !isProxied(u0)) x.o = u0;

    // Only pre-proxy i.imgur.com
    if (!isProxied(u0) && isImgurI(u0)) {
      const p = prox(P1, u0);
      img.setAttribute("src", p);
      for (let i = 0; i < LAZY.length; i++) if (img.hasAttribute(LAZY[i])) img.setAttribute(LAZY[i], p);
    }

    if (img.hasAttribute("srcset")) {
      const ss = img.getAttribute("srcset") || "";
      const n = rewriteSrcsetImgurOnly(ss);
      if (n !== ss) img.setAttribute("srcset", n);
    }

    x.done = true; // only decide/update once
  };

  const processSource = (el) => {
    if (!el || el.nodeType !== 1 || el.tagName !== "SOURCE" || !el.hasAttribute("srcset")) return;

    const x = getState(el);
    if (x.done) return;

    const ss = el.getAttribute("srcset") || "";
    if (!ss) return;

    const n = rewriteSrcsetImgurOnly(ss);
    if (n !== ss) el.setAttribute("srcset", n);

    x.done = true;
  };

  // --- fast batching ---
  const q = new Set();
  let raf = 0;

  const flush = () => {
    raf = 0;
    q.forEach((el) => {
      if (el.tagName === "IMG") processImg(el);
      else processSource(el);
    });
    q.clear();
  };

  const enqueue = (n) => {
    if (!n || n.nodeType !== 1) return;

    // Direct node
    if (n.tagName === "IMG" || (n.tagName === "SOURCE" && n.hasAttribute("srcset"))) q.add(n);

    // Descendants (only when needed)
    if (n.querySelectorAll) {
      const list = n.querySelectorAll("img,source[srcset]");
      for (let i = 0; i < list.length; i++) q.add(list[i]);
    }

    if (!raf) raf = requestAnimationFrame(flush);
  };

  // Observe DOM changes & attribute updates, but each element gets "decided" only once.
  new MutationObserver((ms) => {
    for (let i = 0; i < ms.length; i++) {
      const m = ms[i];
      if (m.type === "childList") {
        for (let j = 0; j < m.addedNodes.length; j++) enqueue(m.addedNodes[j]);
      } else {
        enqueue(m.target);
      }
    }
  }).observe(document.documentElement, {
    subtree: true,
    childList: true,
    attributes: true,
    attributeFilter: ["src", "srcset"].concat(LAZY),
  });

  // Initial scan (cheap enough once)
  const scan = () => {
    const list = document.querySelectorAll("img,source[srcset]");
    for (let i = 0; i < list.length; i++) enqueue(list[i]);
  };

  if (document.readyState === "loading") document.addEventListener("DOMContentLoaded", scan, { once: true });
  else scan();
})();