import { projectRef } from "@/lib/projects";
import { rangeResponse } from "@/lib/report/serve.mjs";
import { isTakeId, listTakes, previewFile } from "@/lib/report/takes.mjs";

export const dynamic = "force-dynamic";

// One take's preview mp4, to a <video> element. ?project&take&v.
//
// Names, never paths: the take must be one the listing returns -- so a take
// whose take.json was skipped is not served either -- and its file is the one
// its take.json names, confined to its own directory by previewFile.
//
// `v` is the video route's contract: the mtime the listing reported, and only
// a matching one may be cached, because a re-render writes the same path.
export async function GET(request: Request) {
  const url = new URL(request.url);
  const takeId = url.searchParams.get("take") ?? "";
  if (!isTakeId(takeId)) return new Response("take must be a take id", { status: 400 });
  const project = await projectRef(url.searchParams.get("project") ?? "");
  if (!project) return new Response("no such project", { status: 404 });
  const take = (await listTakes(project.dir)).takes.find((t) => t.id === takeId);
  if (!take) return new Response("no such take", { status: 404 });
  const file = await previewFile(project.dir, take);
  if (!file) return new Response("this take has no preview yet", { status: 404 });

  const fresh = url.searchParams.get("v") === String(file.mtimeMs);
  return rangeResponse(request, {
    abs: file.abs,
    size: file.size,
    headers: {
      "content-type": "video/mp4",
      "accept-ranges": "bytes",
      "cache-control": fresh ? "private, max-age=3600, immutable" : "private, no-store",
      "x-video-mtime": String(file.mtimeMs),
    },
  });
}