v3: performance pass, bundle size pass, i18n pass, docker pass

api/routes/thumbnails.ts

@@ -0,0 +1,110 @@
+import { Router } from "@oak/oak";
+import { APIErrorCode, APIException } from "../model/interfaces.ts";
+import { getDump } from "../services/dump-service.ts";
+import { DUMPS_DIR, THUMBNAILS_DIR } from "../config.ts";
+
+const router = new Router({ prefix: "/api/thumbnails" });
+
+async function ffmpegAvailable(): Promise<boolean> {
+  try {
+    const cmd = new Deno.Command("ffmpeg", {
+      args: ["-version"],
+      stderr: "null",
+      stdout: "null",
+    });
+    const { success } = await cmd.output();
+    return success;
+  } catch {
+    return false;
+  }
+}
+
+async function generateThumbnail(
+  srcPath: string,
+  outPath: string,
+): Promise<void> {
+  await Deno.mkdir(THUMBNAILS_DIR, { recursive: true });
+  const cmd = new Deno.Command("ffmpeg", {
+    args: [
+      "-ss",
+      "00:00:01",
+      "-i",
+      srcPath,
+      "-frames:v",
+      "1",
+      "-vf",
+      "scale=320:-1",
+      "-f",
+      "image2",
+      "-y",
+      outPath,
+    ],
+    stdout: "null",
+    stderr: "null",
+  });
+  const { success } = await cmd.output();
+  if (!success) throw new Error("ffmpeg failed");
+}
+
+router.get("/:dumpId", async (ctx) => {
+  const { dumpId } = ctx.params;
+
+  if (!/^[0-9a-f-]{36}$/.test(dumpId)) {
+    throw new APIException(APIErrorCode.BAD_REQUEST, 400, "Invalid dump ID");
+  }
+
+  const dump = getDump(dumpId);
+
+  if (dump.kind !== "file" || !dump.fileMime?.startsWith("video/")) {
+    throw new APIException(
+      APIErrorCode.NOT_FOUND,
+      404,
+      "No video for this dump",
+    );
+  }
+
+  const thumbPath = `${THUMBNAILS_DIR}/${dumpId}.jpg`;
+
+  // Serve cached thumbnail if it exists
+  try {
+    const data = await Deno.readFile(thumbPath);
+    ctx.response.headers.set("Content-Type", "image/jpeg");
+    ctx.response.headers.set(
+      "Cache-Control",
+      "public, max-age=31536000, immutable",
+    );
+    ctx.response.body = data;
+    return;
+  } catch {
+    // Not cached yet — generate it
+  }
+
+  if (!await ffmpegAvailable()) {
+    throw new APIException(
+      APIErrorCode.NOT_FOUND,
+      404,
+      "Thumbnail generation unavailable",
+    );
+  }
+
+  const srcPath = `${DUMPS_DIR}/${dumpId}`;
+  try {
+    await generateThumbnail(srcPath, thumbPath);
+  } catch {
+    throw new APIException(
+      APIErrorCode.NOT_FOUND,
+      404,
+      "Could not generate thumbnail",
+    );
+  }
+
+  const data = await Deno.readFile(thumbPath);
+  ctx.response.headers.set("Content-Type", "image/jpeg");
+  ctx.response.headers.set(
+    "Cache-Control",
+    "public, max-age=31536000, immutable",
+  );
+  ctx.response.body = data;
+});
+
+export default router;