Slack status scheduler

// Slack status schedule from https://slack.green/en/tools/slack-status-scheduler
// Paste into the console of your Slack tab (app.slack.com). It fills Slack's
// 5 scheduled-status slots with the next times from this plan, as you, using
// the same call as Set a status > Duration > Choose a start and end time.
// Times are in this computer's time zone. Paste it again any week.
(async () => {
  const SLOTS = 5
  const PLAN = [
    {"kind":"weekly","emoji":"sandwich","text":"Lunch, back at 1","days":[1,2,3,4,5],"start":"12:00","end":"13:00","pause":false},
    {"kind":"weekly","emoji":"headphones","text":"Focus time, replies after 11","days":[2,4],"start":"09:00","end":"11:00","pause":true},
    {"kind":"weekly","emoji":"children_crossing","text":"School run, back at 3:30","days":[1,2,3,4,5],"start":"15:00","end":"15:30","pause":false}
  ]
  const ERRORS = {
    "too_many_scheduled_statuses": "Slack already holds 5 scheduled statuses",
    "date_scheduled_in_past": "the start has passed",
    "date_expire_before_scheduled": "the end is before the start",
    "text_too_long": "the text is over 100 characters",
    "invalid_emoji": "this workspace has no emoji with that name"
  }
  const teamId = (location.pathname.match(/\/client\/([TE][A-Z0-9]+)/) || [])[1]
  const teams = JSON.parse(localStorage.getItem('localConfig_v2') || '{}').teams || {}
  const team = teams[teamId] || Object.values(teams)[0]
  if (!team || !team.token) return alert('Open your workspace at app.slack.com in this tab first.')

  async function api(method, fields) {
    const body = new FormData()
    body.append('token', team.token)
    for (const [key, value] of Object.entries(fields)) body.append(key, value)
    const res = await fetch('/api/' + method, { method: 'POST', body, credentials: 'include' })
    return res.json()
  }

  function nextOccurrences(plan, nowMs, count) {
    const mins = (t) => Number(t.slice(0, 2)) * 60 + Number(t.slice(3, 5))
    const out = []
    for (const s of plan) {
      if (s.kind === 'once') {
        const start = new Date(s.start).getTime()
        const end = new Date(s.end).getTime()
        if (start > nowMs && end > start) out.push({ ...s, start: start / 1000, end: end / 1000 })
        continue
      }
      const from = mins(s.start)
      let to = mins(s.end)
      if (to <= from) to += 24 * 60
      const today = new Date(nowMs)
      for (let offset = 0; offset < 56; offset++) {
        const day = new Date(today.getFullYear(), today.getMonth(), today.getDate() + offset)
        if (!s.days.includes(day.getDay())) continue
        const start = new Date(day.getFullYear(), day.getMonth(), day.getDate(), 0, from).getTime()
        const end = new Date(day.getFullYear(), day.getMonth(), day.getDate(), 0, to).getTime()
        if (start > nowMs) out.push({ ...s, start: start / 1000, end: end / 1000 })
      }
    }
    out.sort((a, b) => a.start - b.start || a.end - b.end)
    return out.slice(0, count)
  }

  const when = (s) => new Date(s * 1000).toLocaleString([], { weekday: 'short', month: 'short', day: 'numeric', hour: 'numeric', minute: '2-digit' })
  const list = await api('users.customStatus.list', {})
  if (!list.ok) return alert('Could not read your scheduled statuses: ' + list.error)
  const queued = list.scheduled_statuses || []
  const key = (emoji, text, start) => emoji + '|' + text + '|' + start
  const have = new Set(queued.map((s) => key(s.emoji, s.text, s.date_scheduled)))
  const next = nextOccurrences(PLAN, Date.now() + 60000, SLOTS)
  const todo = next.filter((o) => !have.has(key(o.emoji ? ':' + o.emoji + ':' : '', o.text, o.start)))
  const lines = []
  let free = SLOTS - queued.length
  for (const o of todo) {
    const label = when(o.start) + ' ' + (o.emoji ? ':' + o.emoji + ': ' : '') + o.text
    if (free <= 0) { lines.push('not added, no free slot: ' + label); continue }
    const res = await api('users.customStatus.schedule', {
      emoji: o.emoji ? ':' + o.emoji + ':' : '',
      text: o.text,
      date_scheduled: String(o.start),
      date_expire: String(o.end),
      is_dnd: String(o.pause),
      duration: 'custom',
    })
    if (res.ok) { free--; lines.push('added: ' + label) }
    else lines.push('failed, ' + (ERRORS[res.error] || res.error) + ': ' + label)
  }
  const after = await api('users.customStatus.list', {})
  const now = (after.scheduled_statuses || []).sort((a, b) => a.date_scheduled - b.date_scheduled)
  lines.push('Slack now holds ' + now.length + ' of ' + SLOTS + ' scheduled statuses:')
  for (const s of now) lines.push('  ' + when(s.date_scheduled) + ' to ' + when(s.date_expire) + ' ' + s.emoji + ' ' + s.text)
  if (now.length) lines.push('Paste this again after ' + when(now[0].date_scheduled) + ' to queue the next one.')
  console.log(lines.join('\n'))
  alert(lines.join('\n'))
})()