feat(media): add mvp1 upload pipeline baseline

apps/admin/src/lib/media/local-storage.ts

@@ -0,0 +1,66 @@
+import { randomUUID } from "node:crypto"
+import { mkdir, writeFile } from "node:fs/promises"
+import path from "node:path"
+
+type StoreUploadParams = {
+  file: File
+  mediaType: string
+}
+
+type StoredUpload = {
+  storageKey: string
+}
+
+const FALLBACK_EXTENSION = "bin"
+
+function resolveBaseDirectory(): string {
+  const configured = process.env.CMS_MEDIA_LOCAL_STORAGE_DIR?.trim()
+
+  if (configured) {
+    return path.resolve(configured)
+  }
+
+  return path.resolve(process.cwd(), ".data", "media")
+}
+
+function normalizeSegment(value: string): string {
+  return value
+    .toLowerCase()
+    .replace(/[^a-z0-9._-]+/g, "-")
+    .replace(/^-+|-+$/g, "")
+}
+
+function extensionFromFilename(fileName: string): string {
+  const extension = path.extname(fileName).slice(1)
+
+  if (!extension) {
+    return FALLBACK_EXTENSION
+  }
+
+  const normalized = normalizeSegment(extension)
+
+  return normalized.length > 0 ? normalized : FALLBACK_EXTENSION
+}
+
+function buildStorageKey(mediaType: string, fileName: string): string {
+  const now = new Date()
+  const year = String(now.getUTCFullYear())
+  const month = String(now.getUTCMonth() + 1).padStart(2, "0")
+  const normalizedType = normalizeSegment(mediaType) || "generic"
+  const extension = extensionFromFilename(fileName)
+
+  return [normalizedType, year, month, `${randomUUID()}.${extension}`].join("/")
+}
+
+export async function storeUploadLocally(params: StoreUploadParams): Promise<StoredUpload> {
+  const storageKey = buildStorageKey(params.mediaType, params.file.name)
+  const baseDirectory = resolveBaseDirectory()
+  const outputPath = path.join(baseDirectory, storageKey)
+
+  await mkdir(path.dirname(outputPath), { recursive: true })
+
+  const bytes = new Uint8Array(await params.file.arrayBuffer())
+  await writeFile(outputPath, bytes)
+
+  return { storageKey }
+}