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…')
await Deno.symlink(`./posts/${fileToPost}`, `./posts/.posted/${fileToPost}`)
console.log('Done!')