// Variables used by Scriptable.
// These must be at the very top of the file. Do not edit.
// icon-color: pink; icon-glyph: headphones-alt;
// Last.fm to Mastodon
// by @zicklepop@nyan.lol
//
// Set a profile field to your currently playing track
//
// Requirements:
// - API Key from Last.fm: https://www.last.fm/api
// - Token from Mastodon with permission scopes for:
//   `read:account` and `write:account`
//   - Find it on your Mastodon instance website under
//     Settings -> Development -> New Application

// Script Constants
// - Ignore, just defining before use
//   Continue down to config

const LASTFM_URL_IN_VALUE = 'LASTFM_URL_IN_VALUE'
const LASTFM_IN_NAME = 'LASTFM_IN_NAME'

// Config
// - Put in your details below
// - Find Field By:
//   - When set to LASTFM_URL_IN_VALUE the script will
//     look for a last.fm url in a field value and set
//     the title of the field to the current track
//   - When set to LASTFM_IN_NAME the script will look
//     for a field title that is `last.fm` (case-insenstive)
//     and set the value to the current track

const LASTFM_USERNAME = ''
const LASTFM_API_KEY = ''
const MASTODON_INSTANCE = '' // ie: social.lol
const MASTODON_TOKEN = ''
const FIND_FIELD_BY = LASTFM_URL_IN_VALUE // or LASTFM_IN_NAME

// More Script Constants
// - You can ignore this too

const LASTFM_API = `http://ws.audioscrobbler.com/2.0/?method=user.getrecenttracks&user=${LASTFM_USERNAME}&api_key=${LASTFM_API_KEY}&format=json&limit=1`
const MASTODON_GET_ACCOUNT_API = `https://${MASTODON_INSTANCE}/api/v1/accounts/verify_credentials`
const MASTODON_UPDATE_FIELDS_API = `https://${MASTODON_INSTANCE}/api/v1/accounts/update_credentials`
const MASTODON_HEADERS = {
  'Content-Type': 'application/json',
  Authorization: `Bearer ${MASTODON_TOKEN}`,
}

// Last FM Related Functions

function formatTrackString(track) {
  const { artist, album, name } = track
  const albumName = album['#text']
  const artistName = artist['#text']

  // If you want to change the format of the track
  // value, you would do it here.
  return `${artistName} - ${albumName} - ${name}`
}

async function getLatestTrack() {
  const res = new Request(LASTFM_API)
  const data = await res.loadJSON()
  const track = data.recenttracks.track[0]
  return formatTrackString(track)
}

// Mastodon Related Functions

function findProfileField(el, i) {
  const { name, value } = el
  if (FIND_FIELD_BY === LASTFM_URL_IN_VALUE) {
    return value.toLowerCase().indexOf('last.fm/user/') >= 0
  }
  if (FIND_FIELD_BY === LASTFM_IN_NAME) {
    return name.toLowerCase().indexOf('last.fm') >= 0
  }
  return false
}

function buildFieldParams(fields) {
  return fields.reduce((out, { name, value }, index) => {
    const prefix = index === 0 ? '?' : '&'
    return `${out}${prefix}fields_attributes[${index}][name]=${encodeURIComponent(
      name
    )}&fields_attributes[${index}][value]=${encodeURIComponent(value)}`
  }, '')
}

async function getFields() {
  const res = new Request(MASTODON_GET_ACCOUNT_API)
  res.headers = MASTODON_HEADERS
  const data = await res.loadJSON()
  const { source } = data
  const { fields } = source
  const targetField = fields.find(findProfileField)
  const index = fields.indexOf(targetField)
  return { index, fields }
}

async function updateMastodonField() {
  const latestTrack = await getLatestTrack()
  const { fields, index } = await getFields()
  let hasChange = false

  if (FIND_FIELD_BY === LASTFM_URL_IN_VALUE) {
    if (fields[index].name !== latestTrack) {
      hasChange = true
      fields[index].name = latestTrack
    }
  }
  if (FIND_FIELD_BY === LASTFM_IN_NAME) {
    if (fields[index].value !== latestTrack) {
      hasChange = true
      fields[index].value = latestTrack
    }
  }

  if (hasChange) {
    const apiUrl = `${MASTODON_UPDATE_FIELDS_API}${buildFieldParams(fields)}`
    const res = new Request(apiUrl)
    res.headers = MASTODON_HEADERS
    res.method = 'PATCH'
    const data = await res.loadJSON()

    if (data.error) {
      console.log(`Error: ${data.error}`)
    } else {
      console.log('Updated')
    }
  } else {
    console.log('No change')
  }
}

await updateMastodonField()