feat(meme-generator): add template listing and static serving endpoints

2026-08-03 07:46:42 +02:00 · 2026-05-08 16:05:17 +08:00
parent 3d103d5092
commit b0cb17ff55
2 changed files with 125 additions and 0 deletions
@@ -0,0 +1,121 @@
+import { createReadStream, existsSync, readFileSync } from "node:fs";
+import { join } from "node:path";
+import type { FastifyInstance, FastifyReply, FastifyRequest } from "fastify";
+
+const STATIC_DIR = join(import.meta.dirname, "../../static");
+const TEMPLATES_DIR = join(STATIC_DIR, "meme-templates");
+const FONTS_DIR = join(STATIC_DIR, "fonts");
+
+const CONTENT_TYPES: Record<string, string> = {
+  ".jpg": "image/jpeg",
+  ".jpeg": "image/jpeg",
+  ".png": "image/png",
+  ".webp": "image/webp",
+  ".ttf": "font/ttf",
+};
+
+/** Cached manifest (read once at first request, served from memory). */
+let manifestCache: string | null = null;
+
+function getManifest(): string {
+  if (manifestCache === null) {
+    manifestCache = readFileSync(join(TEMPLATES_DIR, "meme-templates.json"), "utf-8");
+  }
+  return manifestCache;
+}
+
+function hasPathTraversal(filename: string): boolean {
+  return (
+    filename.includes("..") ||
+    filename.includes("/") ||
+    filename.includes("\\") ||
+    filename.includes("\0")
+  );
+}
+
+function getContentType(filename: string): string | undefined {
+  const dot = filename.lastIndexOf(".");
+  if (dot === -1) return undefined;
+  return CONTENT_TYPES[filename.slice(dot).toLowerCase()];
+}
+
+function serveStaticFile(
+  dir: string,
+  filename: string,
+  reply: FastifyReply,
+  cacheControl: string,
+): FastifyReply | void {
+  if (hasPathTraversal(filename)) {
+    return reply.status(400).send({ error: "Invalid filename" });
+  }
+
+  const contentType = getContentType(filename);
+  if (!contentType) {
+    return reply.status(400).send({ error: "Unsupported file type" });
+  }
+
+  const filePath = join(dir, filename);
+  if (!existsSync(filePath)) {
+    return reply.status(404).send({ error: "File not found" });
+  }
+
+  const stream = createReadStream(filePath);
+  stream.on("error", () => {
+    if (!reply.raw.headersSent) {
+      reply.status(404).send({ error: "File not found" });
+    }
+  });
+
+  return reply
+    .header("Content-Type", contentType)
+    .header("Cache-Control", cacheControl)
+    .send(stream);
+}
+
+export async function registerMemeTemplates(app: FastifyInstance): Promise<void> {
+  // GET /api/v1/meme-templates -- Return the full manifest JSON
+  app.get("/api/v1/meme-templates", async (_request: FastifyRequest, reply: FastifyReply) => {
+    const manifest = getManifest();
+    return reply
+      .header("Content-Type", "application/json")
+      .header("Cache-Control", "public, max-age=3600")
+      .send(manifest);
+  });
+
+  // GET /api/v1/meme-templates/full/:filename -- Serve full-size template images
+  app.get(
+    "/api/v1/meme-templates/full/:filename",
+    async (request: FastifyRequest<{ Params: { filename: string } }>, reply: FastifyReply) => {
+      const { filename } = request.params;
+      return serveStaticFile(
+        join(TEMPLATES_DIR, "full"),
+        filename,
+        reply,
+        "public, max-age=31536000, immutable",
+      );
+    },
+  );
+
+  // GET /api/v1/meme-templates/thumbs/:filename -- Serve thumbnail images
+  app.get(
+    "/api/v1/meme-templates/thumbs/:filename",
+    async (request: FastifyRequest<{ Params: { filename: string } }>, reply: FastifyReply) => {
+      const { filename } = request.params;
+      return serveStaticFile(
+        join(TEMPLATES_DIR, "thumbs"),
+        filename,
+        reply,
+        "public, max-age=31536000, immutable",
+      );
+    },
+  );
+
+  // GET /api/v1/meme-templates/fonts/:filename -- Serve font files
+  app.get(
+    "/api/v1/meme-templates/fonts/:filename",
+    async (request: FastifyRequest<{ Params: { filename: string } }>, reply: FastifyReply) => {
+      const { filename } = request.params;
+      return serveStaticFile(FONTS_DIR, filename, reply, "public, max-age=31536000, immutable");
+    },
+  );
+}