import { Client } from "@atcute/client";
import { fetchHandler, getPds, MAX_SITE_SIZE } from "../utils.ts";

export default async function (
  did: `did:${"plc" | "web"}:${string}`,
  cid: string
): Promise<Blob> {
  // if the user has been manually taken down (cache dir deleted and replaced with empty file)
  // this errors out for quick exit
  // saving the round trip to resolve the pds and blob.
  await Deno.mkdir(`./blobs/${did}`, { recursive: true });

  const pds = await getPds(did);
  if (!pds) throw "PDS not found";

  const { data, ok } = await new Client({
    handler: fetchHandler({ service: pds }),
  }).get("com.atproto.sync.getBlob", {
    params: {
      did,
      cid,
    },
    as: "blob",
  });

  if (!ok) throw `${data.error}`;

  // if the file size cant be calculated or the file cant be written, still return the blob
  try {
    let size = 0;
    for await (const file of Deno.readDir(`./blobs/${did}`)) {
      size += (await Deno.stat(`./blobs/${did}/${file.name}`)).size;
    }
    // only write if total stays below max site size
    if (size + data.size <= MAX_SITE_SIZE)
      await Deno.writeFile(`./blobs/${did}/${cid}`, await data.bytes(), {
        createNew: true,
      });
  } catch (e) {
    console.warn(e);
  }

  return data;
}