# @name    Facebook
# @desc    Follower count of a Facebook Page
# @author  elalquimistadebits
# @version 1.2
# @config  page   text   "Facebook Page ID" default="" maxlen=32
# @config  token  text   "Page Access Token" default="" maxlen=256
# @config  every  number "Refresh interval" default=60 min=5 max=1440 unit=min
# @config  color  color  "Facebook color" default=#0866FF


class Facebook
  var url, page, token, period, color
  var count, label, full, err
  var ticks, busy
  var opts, ramp

  def init()
    self.page = store.get("page")
    self.token = store.get("token")
    self.period = store.get("every") * 60
    self.color = store.get("color")

    self.url = "https://graph.facebook.com/" +
               self.page +
               "?fields=followers_count"

    self.count = store.get("who") == self.page ? store.get("n") : nil
    self.label = self.count == nil ? nil : self.human(self.count)
    self.full = self.count == nil ? nil : str(self.count)

    self.err = false
    self.ticks = 9
    self.busy = false

    self.opts = {
      'headers': {
        'Authorization': "Bearer " + self.token,
        'User-Agent': 'AWTRIX-NG'
      },
      'find': "\"followers_count\"",
      'keep': 64
    }

    # Facebook blue gradient for follower count
    self.ramp = [0x0866FF, 0x5FA8FF]
  end


  def human(n)
    if n < 1000
      return str(n)
    end

    var d = 1000
    var suf = "K"

    if n >= 1000000000
      d = 1000000000
      suf = "B"
    elif n >= 1000000
      d = 1000000
      suf = "M"
    end

    var v = n / (d + 0.0)

    if v >= 10
      return str(round(v)) + suf
    end

    var t = round(v * 10)
    return str(int(t / 10)) + "." + str(t % 10) + suf
  end


  def on_body(body, status)
    self.busy = false
    shared.set("f", 0)

    if status != 200 || body == nil
      self.err = true
      return
    end

    var m = re.search(
      "\"followers_count\"\\s*:\\s*(\\d+)",
      body
    )

    if m == nil
      self.err = true
      return
    end

    var n = num(m[1])

    if n == nil
      self.err = true
      return
    end

    self.err = false

    if n == self.count
      return
    end

    self.count = n
    self.full = str(n)
    self.label = self.human(n)

    store.set("n", n)
    store.set("who", self.page)
  end


  def tls_busy()
    for k : shared.keys()
      if size(k) > 2 &&
         k[size(k) - 2 .. size(k) - 1] == ".f" &&
         shared.get(k) == 1

        var a = shared.age(k)

        if a != nil && a < 20000
          return true
        end
      end
    end

    return false
  end


  def loop()
    if self.ticks <= 0
      if !self.busy && !self.tls_busy()
        self.ticks = self.period
        self.busy = true

        shared.set("f", 1)

        http.get(
          self.url,
          / b, st -> self.on_body(b, st),
          self.opts
        )
      end
    end

    self.ticks -= 1
  end


  def draw()
    clear()

    # Facebook 8x8 icon
    rect_fill(0, 0, 8, 8, self.color)

    # Slim Facebook "f"
    pixel(4, 1, 0xFFFFFF)
    pixel(5, 1, 0xFFFFFF)

    pixel(4, 2, 0xFFFFFF)

    pixel(3, 3, 0xFFFFFF)
    pixel(4, 3, 0xFFFFFF)
    pixel(5, 3, 0xFFFFFF)

    pixel(4, 4, 0xFFFFFF)
    pixel(4, 5, 0xFFFFFF)
    pixel(4, 6, 0xFFFFFF)


    if self.label != nil
      var avail = width() - 9

      var s = self.full
      var w = text_ink_width(s)

      if w > avail
        s = self.label
        w = text_ink_width(s)
      end

      # Gradient follower count
      ramp_text(
        9 + (avail - w) / 2,
        6,
        s,
        self.ramp
      )

      return
    end


    var s = self.err ? "?" : "..."
    var w = text_ink_width(s)

    text(
      9 + (width() - 9 - w) / 2,
      6,
      s,
      self.err ? 0xCC7722 : 0x555555
    )
  end

end

return Facebook()