const MASTODON_INSTANCE_URL = Deno.env.get("MASTODON_INSTANCE_URL"); // e.g. https://botsin.space
const MASTODON_ACCESS_TOKEN = Deno.env.get("MASTODON_ACCESS_TOKEN"); // you can get this at $INSTANCE_URL/settings/applications

// first we need to find out which files we can post, and which ones we already
// have posted

console.log("Picking file to post…");
const alreadyPostedFiles = new Set();
for await (const dirEntry of Deno.readDir("./posts/.posted")) {
  if (dirEntry.isSymlink) {
    alreadyPostedFiles.add(dirEntry.name);
  }
}

const availableFiles = [];
for await (const dirEntry of Deno.readDir("./posts/")) {
  if (dirEntry.name === ".gitignore") continue;

  if (dirEntry.isFile && !alreadyPostedFiles.has(dirEntry.name)) {
    availableFiles.push(dirEntry.name);
  }
}

console.log(`Found ${availableFiles.length} files which are not yet posted`);

if (availableFiles.length === 0) {
  console.log("Nothing left to post at the moment. Bye!");
  Deno.exit();
}

const fileToPost =
  availableFiles[Math.floor(Math.random() * availableFiles.length)];
const bytes = await Deno.readFile(`./posts/${fileToPost}`);

// we need two requests
// 1. upload media
// 2. create status with media id

// see https://docs.joinmastodon.org/methods/media/#v2
const mediaData = new FormData();
mediaData.append("file", new Blob([bytes]));

type MediaResponse = {
  "id": string;
  "type": string;
  "url": string;
  "preview_url": string;
  "remote_url": null;
  "text_url": string;
  "meta": {
    "focus": {
      "x": number;
      "y": number;
    };
    "original": {
      "width": number;
      "height": number;
      "size": string;
      "aspect": number;
    };
    "small": {
      "width": number;
      "height": number;
      "size": string;
      "aspect": number;
    };
  };
  "description": string;
  "blurhash": string;
};

console.log("Sending post request to", `${MASTODON_INSTANCE_URL}/api/v2/media`);
const mediaRequest = await fetch(`${MASTODON_INSTANCE_URL}/api/v2/media`, {
  method: "POST",
  headers: {
    Authorization: `Bearer ${MASTODON_ACCESS_TOKEN}`,
  },
  body: mediaData,
}).then((res) => res.json()) as unknown as MediaResponse;
console.log("mediaRequest", mediaRequest);

// see https://docs.joinmastodon.org/methods/statuses/#create
const statusData = new FormData();
statusData.append("media_ids[]", mediaRequest.id);

console.log(
  "Sending post request to",
  `${MASTODON_INSTANCE_URL}/api/v1/statuses`,
);
const statusRequest = await fetch(`${MASTODON_INSTANCE_URL}/api/v1/statuses`, {
  method: "POST",
  headers: {
    Authorization: `Bearer ${MASTODON_ACCESS_TOKEN}`,
  },
  body: statusData,
}).then((res) => res.json());
console.log("statusRequest", statusRequest);

console.log("Linking posted file so we can skip it in the future…");
// FIXME: This requires unrestricted `--allow-read` and `--allow-write` at the;
// deno should provide a finer-grained permission prompt here
await Deno.symlink(`./posts/${fileToPost}`, `./posts/.posted/${fileToPost}`);
console.log("Done!");