Fix: migrate Imgur images to BlitzKit hosting

packages/website/src/core/blitzkit/docImages.ts

@@ -0,0 +1,32 @@
+import { alias } from "@blitzkit/core";
+
+const EXTERNAL_IMAGE = /^https?:\/\//;
+const MARKDOWN_IMAGES = [
+  /!\[[^\]]*\]\((\S+?)(?:\s+"[^"]*")?\)/g,
+  /<img[^>]*\ssrc=["']([^"']+)["']/g,
+];
+
+export function isExternalImage(src: string) {
+  return EXTERNAL_IMAGE.test(src);
+}
+
+export function docImageId(url: string) {
+  let hash = 0x811c9dc5;
+
+  for (let index = 0; index < url.length; index++) {
+    hash ^= url.charCodeAt(index);
+    hash = Math.imul(hash, 0x01000193) >>> 0;
+  }
+
+  return hash.toString(16).padStart(8, "0");
+}
+
+export function docImageUrl(url: string) {
+  return alias("api", `/docs/images/${docImageId(url)}.webp`);
+}
+
+export function externalDocImages(markdown: string) {
+  return MARKDOWN_IMAGES.flatMap((pattern) =>
+    Array.from(markdown.matchAll(pattern), (match) => match[1]),
+  ).filter(isExternalImage);
+}