# @name    Puls
# @desc    Heart rate from a Bluetooth chest strap or watch, with a heart beating in time
# @author  awtrix-ng
# @version 1.3
# @config  match text  "Device name" default="" help="Start of the sensor's Bluetooth name; empty takes the first heart-rate sensor seen"
# @config  skip  text  "Ignore"      default="" help="A heart-rate sensor to pass over, by the start of its name"
# @config  low   number "Rest below" default=60 min=30 max=120 unit=bpm
# @config  high  number "Hard above" default=150 min=100 max=220 unit=bpm

import ble
import string

class Puls
  var state, since, bpm, seen, conn, scan, trend, label, hue, big, small, match, skip, low, high

  def init()
    self.state = ble.available() ? "scan" : "none"
    self.since = 0
    self.bpm = 0
    self.seen = 0
    self.trend = []
    self.label = ""
    self.hue = 0
    self.match = store.get("match", "")
    self.skip = store.get("skip", "")
    self.low = store.get("low", 60)
    self.high = store.get("high", 150)
    # Two hearts as row bitmasks, 11 and 9 columns wide: the big one on the beat.
    self.big = [0x18C, 0x3DE, 0x7FF, 0x7FF, 0x7FF, 0x3FE, 0x1FC, 0x0F8, 0x070, 0x020]
    self.small = [0x0D8, 0x1FC, 0x1FC, 0x1FC, 0x0F8, 0x070, 0x020]
  end

  def setup()
    if self.state == "scan" self.find() end
  end

  # Scan for the Heart Rate service, take the first sensor whose name fits, subscribe to its
  # measurement. Every way of losing it - a scan that cannot start, a failed connect, a dropped link,
  # a sensor gone quiet - leads back here.
  def find()
    if self.scan != nil ble.stop(self.scan) end
    if self.conn != nil ble.disconnect(self.conn) end
    self.state = "scan"
    self.since = now_ms()
    self.conn = nil
    self.scan = ble.scan(def (dev, err)
      if self.state != "scan" return end
      if dev == nil
        if err != nil
          log("Puls: " + str(err))
          self.scan = nil
          timer.after(3000, / -> self.find())
        end
        return
      end
      var name = dev.find("name", "")
      if self.skip != "" && string.find(name, self.skip) == 0 return end
      if self.match != "" && string.find(name, self.match) != 0 return end
      self.state = "link"
      self.since = now_ms()
      ble.stop(self.scan)
      self.scan = nil
      self.conn = ble.connect(dev["addr"], def (conn, e)
        if conn == nil
          log("Puls: " + str(e))
          self.conn = nil
          timer.after(3000, / -> self.find())
          return
        end
        ble.on_disconnect(conn, def (why)
          self.conn = nil
          timer.after(2000, / -> self.find())
        end)
        ble.subscribe(conn, "180d", "2a37", def (data, e2)
          if data == nil
            log("Puls: " + str(e2))
            ble.disconnect(conn)
            return
          end
          var v = (data[0] & 1) != 0 ? data.get(1, 2) : data[1]
          if v <= 0 return end
          self.bpm = v
          self.seen = now_ms()
          self.state = "live"
        end)
      end, {"random": dev["random"]})
    end, {"uuid": "180d", "active": true, "dedupe": 0})
    if self.scan == nil self.state = "none" end
  end

  def loop()
    var t = now_ms()
    var fresh = self.state == "live" && t - self.seen < 5000
    if fresh
      self.label = str(self.bpm)
      self.hue = self.bpm < self.low ? 200 : self.bpm < 100 ? 120 : self.bpm < self.high ? 45 : 0
      self.trend.push(self.bpm)
      if size(self.trend) > 36 self.trend.remove(0) end
    elif self.state == "live" && t - self.seen > 15000 && self.conn != nil
      ble.disconnect(self.conn)
      self.conn = nil
    elif self.state == "link" && t - self.since > 20000
      self.find()
    end
    if !fresh
      self.label = self.state == "none" ? "KEIN BT" : self.state == "scan" ? "SUCHE" : self.state == "link" ? "VERBINDE" : "WARTE"
    end
  end

  def draw()
    clear()
    var t = now_ms()
    var live = self.state == "live" && t - self.seen < 5000
    var period = live ? 60000 / self.bpm : 1600
    var phase = t % period
    var beat = phase < 110 || (phase > 220 && phase < 300)
    var rows = beat ? self.big : self.small
    var w = beat ? 11 : 9
    var x0 = beat ? 1 : 2
    var y0 = beat ? 3 : 5
    var core = live ? hsv(355, 90, beat ? 90 : 55) : hsv(220, 40, beat ? 35 : 20)
    for r : 0 .. size(rows) - 1
      var bits = rows[r]
      for c : 0 .. w - 1
        if ((bits >> (w - 1 - c)) & 1) != 0 pixel(x0 + c, y0 + r, core) end
      end
    end
    if beat && live
      pixel(x0 + 2, y0 + 1, 0xFFB0B0)
      pixel(x0 + 3, y0 + 1, 0xFF8080)
    end
    if live
      var color = hsv(self.hue, 85, 90)
      font("large")
      var right = text(15, 9, self.label, color)
      font("small")
      text(17 + right, 9, "BPM", 0x606060)
    else
      text(15, 9, self.label, 0x707090)
    end
    var n = size(self.trend)
    if n > 1
      var lo = self.trend[0]
      var hi = lo
      for v : self.trend
        if v < lo lo = v end
        if v > hi hi = v end
      end
      var span = hi - lo < 10 ? 10 : hi - lo
      var shade = live ? hsv(self.hue, 80, 45) : 0x282828
      for i : 0 .. n - 1
        var y = 15 - (self.trend[i] - lo) * 4 / span
        pixel(width() - n + i, y, i == n - 1 && live ? hsv(self.hue, 85, 90) : shade)
      end
    end
  end
end

return Puls()