#!/usr/bin/ruby -w

require "enumerable/statistics"
require "serialport"

SENSOR_BITS = 12
SENSOR_MAX = (1 << SENSOR_BITS) - 1

$stdout.sync = true
def log(msg)
  $stdout.write("#{Time.now.strftime("%H:%M:%S")} #{msg}\n")
  $stdout.flush
end

sensors = []

SerialPort.open("/dev/ttyACM1", 115200, 8, 1, SerialPort::NONE) do | port |

  log("Allowing sensors to settle...")

  sleep(3)
  begin
    port.read_nonblock(16 << 20)
  rescue IO::WaitReadable
  end
  port.readline

  log("Reading soil moisture sensors...")

  10.times do
    raw = port.readline
    raise "Cannot parse sensor results #{raw.inspect}" unless raw =~ /\[([^\]]+)\]/

    sensors << $1.split(/\s+/).filter { | x | not x.empty? }.map { | x | x.to_i }

    log("Raw sensor results: \t#{sensors[-1].join("\t")}")
  end

end

avgsensors = []
stdsensors = []

sensors.transpose.each do | sensor |
  avgsensors << sensor.mean.round
  stdsensors << sensor.stdev.round
end

log("Avg sensor results: \t#{avgsensors.join("\t")} \t(per sensor)")
log("SDv sensor results: \t#{stdsensors.join("\t")} \t(per sensor)")

avg = sensors.flatten.mean.round
std = sensors.flatten.stdev.round

log("Avg sensor results: \t#{avg} \t(#{(100.0 * avg.to_f / SENSOR_MAX.to_f).round}%) \t(overall)")
log("SDv sensor results: \t#{std} \t(overall)")