initial commit

lib/images.ts

@@ -0,0 +1,107 @@
+import { mkdir, readdir, rename, rm, stat, writeFile } from "node:fs/promises";
+import path from "node:path";
+import { HttpError } from "./errors";
+import { IMG_ROOT, safeJoin } from "./paths";
+import { SLUG_RE } from "./validate";
+import type { BlogPost, ImageFile } from "./types";
+
+/* Uploaded media lives in portfolio/public/img/blog/<slug>/ and is referenced
+ * from posts as "img/blog/<slug>/<file>" (no leading slash, as the site's
+ * card and gallery components prepend "/"). */
+
+export const ALLOWED_EXT = [".png", ".jpg", ".jpeg", ".gif", ".webp", ".svg", ".mp4"];
+export const MAX_UPLOAD_BYTES = 20 * 1024 * 1024;
+
+export function postImageDir(slug: string): string {
+  if (!SLUG_RE.test(slug)) throw new HttpError(400, "invalid slug");
+  return safeJoin(IMG_ROOT, slug);
+}
+
+export function imageRelSrc(slug: string, name: string): string {
+  return `img/blog/${slug}/${name}`;
+}
+
+async function exists(p: string): Promise<boolean> {
+  return stat(p).then(() => true, () => false);
+}
+
+export async function listImages(slug: string): Promise<ImageFile[]> {
+  const dir = postImageDir(slug);
+  let names: string[];
+  try {
+    names = await readdir(dir);
+  } catch {
+    return [];
+  }
+  const files: ImageFile[] = [];
+  for (const name of names.sort()) {
+    if (!ALLOWED_EXT.includes(path.extname(name).toLowerCase())) continue;
+    const info = await stat(path.join(dir, name));
+    if (info.isFile()) files.push({ name, src: imageRelSrc(slug, name), size: info.size });
+  }
+  return files;
+}
+
+/** "My Screenshot (2).PNG" -> "my-screenshot-2.png" */
+function sanitizeName(original: string): string {
+  const ext = path.extname(original).toLowerCase();
+  const base = path
+    .basename(original, path.extname(original))
+    .toLowerCase()
+    .replace(/[^a-z0-9._-]+/g, "-")
+    .replace(/^[-.]+|-+$/g, "");
+  return (base || "image") + ext;
+}
+
+export async function saveUpload(slug: string, file: File): Promise<ImageFile> {
+  const name = sanitizeName(file.name);
+  const ext = path.extname(name);
+  if (!ALLOWED_EXT.includes(ext)) {
+    throw new HttpError(400, `${file.name}: only ${ALLOWED_EXT.join(", ")} files are allowed`);
+  }
+  if (file.size > MAX_UPLOAD_BYTES) {
+    throw new HttpError(413, `${file.name}: larger than ${MAX_UPLOAD_BYTES / 1024 / 1024} MB`);
+  }
+
+  const dir = postImageDir(slug);
+  await mkdir(dir, { recursive: true });
+
+  // Never overwrite: name.png, name-1.png, name-2.png, ...
+  const stem = path.basename(name, ext);
+  let finalName = name;
+  for (let i = 1; await exists(path.join(dir, finalName)); i++) finalName = `${stem}-${i}${ext}`;
+
+  await writeFile(safeJoin(dir, finalName), Buffer.from(await file.arrayBuffer()));
+  return { name: finalName, src: imageRelSrc(slug, finalName), size: file.size };
+}
+
+export async function deleteImage(slug: string, name: string): Promise<void> {
+  const target = safeJoin(postImageDir(slug), name);
+  if (path.dirname(target) !== postImageDir(slug)) throw new HttpError(400, "invalid file name");
+  await rm(target, { force: true });
+}
+
+export async function deleteImageDir(slug: string): Promise<void> {
+  await rm(postImageDir(slug), { recursive: true, force: true });
+}
+
+/**
+ * Moves a post's media folder on slug rename and rewrites every reference to
+ * it in the post (gallery entries and inline body links).
+ */
+export async function renameImageDir(post: BlogPost, from: string, to: string): Promise<void> {
+  const src = postImageDir(from);
+  const dest = postImageDir(to);
+  if (await exists(src)) {
+    if (await exists(dest)) throw new HttpError(409, `image folder for "${to}" already exists`);
+    await rename(src, dest);
+  }
+  const oldPrefix = `img/blog/${from}/`;
+  const newPrefix = `img/blog/${to}/`;
+  post.details = post.details.split(oldPrefix).join(newPrefix);
+  post.images = post.images?.map((img) =>
+    typeof img === "string"
+      ? img.replace(oldPrefix, newPrefix)
+      : { ...img, src: img.src.replace(oldPrefix, newPrefix) }
+  );
+}