#!/bin/env python2

import array
import fcntl

import argh

LIRC_MODE_PULSE = 2

def ioc(dir, type, nr, size):
	return (dir << 30) | (type << 8) | nr | (size << 16)

IOC_WRITE = 1
IOC_READ = 2
LIRC_SET_SEND_MODE = ioc(IOC_WRITE, ord('i'), 0x11, 4)
LIRC_SET_SEND_CARRIER = ioc(IOC_WRITE, ord('i'), 0x13, 4)

def ioctl(file, op, arg):
	if isinstance(arg, int):
		arg = array.array('i', [arg])
	ret = fcntl.ioctl(file.fileno(), op, arg)
	if ret < 0:
		raise OSError(-ret)

def make_payload(temp, mode, fan, vane, time=0):
	temp = temp - 16
	assert 0 <= temp <= 15
	weird_mode = {
		'heat': 0,
		'dry': 1,
		'cool': 3, # sic
		'auto': 3,
	}[mode]
	mode = {
		'heat': 1,
		'dry': 2,
		'cool': 3,
		'auto': 4,
	}[mode]
	fan = {
		'auto': 0,
		'low': 1,
		'med': 2,
		'high': 3,
	}[fan]
	vane = 7 if vane == 'auto' else int(vane)
	payload = [
		0x23,
		0xcb,
		0x26,
		0x01,
		0x00,
		0x20,
		mode << 2,
		temp,
		0x30 | (weird_mode << 1),
		0x40 | (vane << 3) | fan,
		time,
	] + 6 * [0]
	payload.append(sum(payload) % 256)
	return payload

def encode_payload(payload):
	assert len(payload) == 18, len(payload)
	for byte in payload:
		for i in range(8):
			bit = 1 & (byte >> i)
			yield 20
			yield 60 if bit else 20
	yield 20

def make_pulses(temp, mode, fan, vane):
	payload = make_payload(temp, mode, fan, vane)
	payload = list(encode_payload(payload))
	assert len(payload) == 144 + 145, len(payload)
	packet = [160, 77] + payload
	full = packet + [800] + packet
	full = [x * 21 for x in full]
	return full

@argh.arg('temp', type=int)
@argh.arg('--mode', choices=['heat', 'cool', 'dry', 'auto'])
@argh.arg('--fan', choices=['high', 'med', 'low', 'auto'])
@argh.arg('--vane', choices=['auto', '0', '1', '2', '3', '4', '5', '6'])
def main(temp, mode='heat', fan='high', vane='auto', devpath='/dev/lirc0'):
	data = make_pulses(temp, mode, fan, vane)
	dev = open(devpath, 'w')
	ioctl(dev, LIRC_SET_SEND_MODE, LIRC_MODE_PULSE)
	ioctl(dev, LIRC_SET_SEND_CARRIER, 38000)
	dev.write(array.array('i', data).tostring())
	dev.close()

argh.dispatch_command(main)