Add production-ready media library

lib/media-storage.ts

@@ -0,0 +1,90 @@
+import { randomUUID } from "crypto";
+import { mkdir, rm, writeFile } from "fs/promises";
+import path from "path";
+
+export const MEDIA_UPLOAD_ROOT = path.join(process.cwd(), "public", "uploads", "media");
+export const MAX_MEDIA_FILE_SIZE = 5 * 1024 * 1024;
+
+const MIME_EXTENSIONS: Record<string, string> = {
+  "image/jpeg": ".jpg",
+  "image/png": ".png",
+  "image/webp": ".webp",
+  "image/svg+xml": ".svg",
+  "application/pdf": ".pdf",
+};
+
+export function sanitizeBaseName(value: string) {
+  return value
+    .toLowerCase()
+    .replace(/[^a-z0-9]+/g, "-")
+    .replace(/^-+|-+$/g, "")
+    .slice(0, 60);
+}
+
+export function getExtensionForMimeType(mimeType: string) {
+  return MIME_EXTENSIONS[mimeType] ?? null;
+}
+
+export function isManagedMediaFilePath(filePath: string | null | undefined) {
+  return typeof filePath === "string" && filePath.startsWith("/uploads/media/");
+}
+
+export function resolveMediaUploadPath(filePath: string) {
+  if (!isManagedMediaFilePath(filePath)) {
+    throw new Error("Only managed media uploads can be resolved.");
+  }
+
+  const relativePath = filePath.replace("/uploads/media/", "");
+  const absolutePath = path.resolve(MEDIA_UPLOAD_ROOT, relativePath);
+
+  if (!absolutePath.startsWith(MEDIA_UPLOAD_ROOT)) {
+    throw new Error("Resolved media upload path escapes the upload root.");
+  }
+
+  return absolutePath;
+}
+
+export async function removeManagedMediaFile(filePath: string | null | undefined) {
+  if (!isManagedMediaFilePath(filePath)) {
+    return false;
+  }
+
+  const managedFilePath = filePath as string;
+
+  await rm(resolveMediaUploadPath(managedFilePath), {
+    force: true,
+  });
+
+  return true;
+}
+
+export async function saveMediaUpload(file: File, folder: string) {
+  if (!file || file.size === 0) {
+    return null;
+  }
+
+  const extension = getExtensionForMimeType(file.type);
+
+  if (!extension) {
+    throw new Error("Unsupported file type.");
+  }
+
+  if (file.size > MAX_MEDIA_FILE_SIZE) {
+    throw new Error("File is too large.");
+  }
+
+  const safeBaseName = sanitizeBaseName(file.name.replace(/\.[^.]+$/, "")) || "asset";
+  const finalName = `${Date.now()}-${safeBaseName}-${randomUUID().slice(0, 8)}${extension}`;
+  const targetDir = path.join(MEDIA_UPLOAD_ROOT, folder);
+  const targetPath = path.join(targetDir, finalName);
+
+  await mkdir(targetDir, { recursive: true });
+  await writeFile(targetPath, Buffer.from(await file.arrayBuffer()));
+
+  return {
+    url: `/uploads/media/${folder}/${finalName}`,
+    fileName: finalName,
+    mimeType: file.type,
+    size: file.size,
+  };
+}