require 'serialport'
require 'sphero/request'
require 'sphero/response'
require 'thread'

class Sphero
  VERSION = '1.1.0'

  class << self
    def start(dev, &block)
      sphero = self.new dev
      sphero.instance_eval(&block) if block_given?
      sphero
    rescue Errno::EBUSY
      retry
    end
  end

  def initialize dev
    initialize_serialport
    @dev  = 0x00
    @seq  = 0x00
    @lock = Mutex.new
  end

  def ping
    write Request::Ping.new(@seq)
  end

  def version
    write Request::GetVersioning.new(@seq)
  end

  def bluetooth_info
    write Request::GetBluetoothInfo.new(@seq)
  end

  def auto_reconnect= time_s
    write Request::SetAutoReconnect.new(@seq, time_s)
  end

  def auto_reconnect
    write(Request::GetAutoReconnect.new(@seq)).time
  end

  def disable_auto_reconnect
    write Request::SetAutoReconnect.new(@seq, 0, 0x00)
  end

  def power_state
    write Request::GetPowerState.new(@seq)
  end

  def sleep wakeup = 0, macro = 0
    write Request::Sleep.new(@seq, wakeup, macro)
  end

  def roll speed, heading, state = true
    write Request::Roll.new(@seq, speed, heading, state ? 0x01 : 0x00)
  end

  def stop
    roll 0, 0
  end

  def heading= h
    write Request::Heading.new(@seq, h)
  end

  def rgb r, g, b, persistant = false
    write Request::SetRGB.new(@seq, r, g, b, persistant ? 0x01 : 0x00)
  end

  # This retrieves the "user LED color" which is stored in the config block
  # (which may or may not be actively driven to the RGB LED).
  def user_led
    write Request::GetRGB.new(@seq)
  end

  # Brightness 0x00 - 0xFF
  def back_led_output= h
    write Request::SetBackLEDOutput.new(@seq, h)
  end

  # Rotation Rate 0x00 - 0xFF
  def rotation_rate= h
    write Request::SetRotationRate.new(@seq, h)
  end

  # just a nicer alias for Ruby's own sleep
  def keep_going(duration)
    sleep duration
  end

  private
  
  def initialize_serialport
    @sp = SerialPort.new dev, 115200, 8, 1, SerialPort::NONE
  end

  def write packet
    header = nil
    body   = nil

    @lock.synchronize do
      @sp.write packet.to_str
      @seq += 1

      header   = @sp.read(5).unpack 'C5'
      body     = @sp.read header.last
    end

    response = packet.response header, body

    if response.success?
      response
    else
      raise response
    end
  end
end