add core api

src/common/services/file-storage/abstract.file-storage.ts

@@ -0,0 +1,14 @@
+export type FileResult = {
+	name: string;
+	mimeType: string;
+	extension: string;
+	buffer: Buffer;
+};
+
+export abstract class AbstractFileStorage {
+	public abstract storeFile(buffer: Buffer, name?: string): Promise<FileResult>;
+
+	public abstract retrieveFile(name: string): Promise<FileResult>;
+
+	public abstract removeFile(name: string): Promise<void>;
+}

src/common/services/file-storage/local.file-storage.ts

@@ -0,0 +1,59 @@
+import { InvalidFileBufferError } from "@/common/errors/invalid-file-buffer.error";
+import {
+	AbstractFileStorage,
+	type FileResult,
+} from "@/common/services/file-storage/abstract.file-storage";
+import { fileTypeFromBuffer } from "file-type";
+import { join } from "node:path";
+
+const STORAGE_DIRECTORY = join(process.cwd(), "storage");
+
+export class LocalFileStorage extends AbstractFileStorage {
+	public constructor() {
+		super();
+	}
+
+	public async storeFile(buffer: Buffer, name?: string): Promise<FileResult> {
+		const fileType = await fileTypeFromBuffer(buffer);
+		if (!fileType) {
+			throw new InvalidFileBufferError(
+				buffer,
+				"Unable to determine file type from buffer.",
+			);
+		}
+
+		const fileName = name ?? `${Date.now()}.${fileType.ext}`;
+
+		const filePath = join(STORAGE_DIRECTORY, fileName);
+
+		await Bun.write(filePath, buffer, { createPath: true });
+
+		return {
+			name: fileName,
+			buffer,
+			mimeType: fileType.mime,
+			extension: fileType.ext,
+		};
+	}
+
+	public async retrieveFile(name: string): Promise<FileResult> {
+		const filePath = join(STORAGE_DIRECTORY, name);
+
+		const file = Bun.file(filePath);
+
+		const fileName = file.name ?? name;
+
+		return {
+			name: fileName,
+			buffer: Buffer.from(await file.arrayBuffer()),
+			mimeType: file.type,
+			extension: fileName.split(".").pop() ?? "",
+		};
+	}
+
+	public async removeFile(name: string): Promise<void> {
+		const filePath = join(STORAGE_DIRECTORY, name);
+
+		await Bun.file(filePath).delete();
+	}
+}