##
## This file is part of the sigrok project.
##
## Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
##

#
# Nintendo Wii Nunchuk decoder
#

# TODO: Description

# FIXME: This is just some example input for testing purposes...
example_packets = [
	# START condition.
	{'type': 'S',  'range': (10, 11), 'data': None, 'ann': ''},

	# Nunchuk init: Write 0x40,0x00 to slave address 0x54.
	{'type': 'AW', 'range': (12, 13), 'data': 0x54, 'ann': ''},
	{'type': 'DW', 'range': (14, 15), 'data': 0x40, 'ann': ''},
	{'type': 'AW', 'range': (16, 17), 'data': 0x54, 'ann': ''},
	{'type': 'DW', 'range': (18, 19), 'data': 0x00, 'ann': ''},

	# Get data: Read 6 bytes of data.
	{'type': 'DR', 'range': (20, 21), 'data': 0x11, 'ann': ''},
	{'type': 'DR', 'range': (22, 23), 'data': 0x22, 'ann': ''},
	{'type': 'DR', 'range': (24, 25), 'data': 0x33, 'ann': ''},
	{'type': 'DR', 'range': (26, 27), 'data': 0x44, 'ann': ''},
	{'type': 'DR', 'range': (28, 29), 'data': 0x55, 'ann': ''},
	{'type': 'DR', 'range': (30, 31), 'data': 0x66, 'ann': ''},

	# STOP condition.
	{'type': 'P',  'range': (32, 33), 'data': None, 'ann': ''},
]

def decode(inbuf):
	"""Nintendo Wii Nunchuk decoder"""

	# FIXME: Get the data in the correct format in the first place.
	inbuf = [ord(x) for x in inbuf]
	out = []
	o = {}

	# TODO: Pass in metadata.

	# States
	IDLE, START, NUNCHUK_SLAVE, INIT, INITIALIZED = range(5)
	state = IDLE # TODO: Can we assume a certain initial state?

	sx = sy = ax = ay = az = bz = bc = 0

	databytecount = 0

	# Loop over all I2C packets.
	for p in example_packets:
		if p['type'] == 'S': # TODO: Handle 'Sr' here, too?
			state = START

		elif p['type'] == 'Sr':
			pass # FIXME

		elif p['type'] == 'AR':
			# TODO: Error/Warning, not supported, I think.
			pass

		elif p['type'] == 'AW':
			# The Wii Nunchuk always has slave address 0x54.
			# TODO: Handle this stuff more correctly.
			if p['data'] == 0x54:
				pass # TODO
			else:
				pass # TODO: What to do here? Ignore? Error?

		elif p['type'] == 'DR' and state == INITIALIZED:
			if databytecount == 0:
				sx = p['data']
			elif databytecount == 1:
				sy = p['data']
			elif databytecount == 2:
				ax = p['data'] << 2
			elif databytecount == 3:
				ay = p['data'] << 2
			elif databytecount == 4:
				az = p['data'] << 2
			elif databytecount == 5:
				bz =  (p['data'] & (1 << 0)) >> 0
				bc =  (p['data'] & (1 << 1)) >> 1
				ax |= (p['data'] & (3 << 2)) >> 2
				ay |= (p['data'] & (3 << 4)) >> 4
				az |= (p['data'] & (3 << 6)) >> 6
				# del o
				o = {'type': 'D', 'range': (0, 0), 'data': []}
			 	o['data'] = [sx, sy, ax, ay, az, bz, bc]
				# sx = sy = ax = ay = az = bz = bc = 0
			else:
				pass # TODO

			if 0 <= databytecount <= 5:
				databytecount += 1

			# TODO: If 6 bytes read -> save and reset

		# TODO
		elif p['type'] == 'DR' and state != INITIALIZED:
			pass

		elif p['type'] == 'DW':
			if p['data'] == 0x40 and state == START:
				state = INIT
			elif p['data'] == 0x00 and state == INIT:
				o = {'type': 'I', 'range': (0, 0), 'data': []}
				o['data'] = [0x40, 0x00]
				out.append(o)
				state = INITIALIZED
			else:
				pass # TODO

		elif p['type'] == 'P':
			out.append(o)
			state = INITIALIZED
			databytecount = 0

	print out

	# FIXME
	return ''

def register():
	return {
		'id': 'nunchuk',
		'name': 'Nunchuk',
		'longname': 'Nintendo Wii Nunchuk decoder',
		'desc': 'Decodes the Nintendo Wii Nunchuk I2C-based protocol.',
		'longdesc': '...',
		'author': 'Uwe Hermann',
		'email': 'uwe@hermann-uwe.de',
		'license': 'gplv2+',
		'in': ['i2c'],
		'out': ['nunchuck'],
		'probes': [
			# TODO
		],
		'options': {
			# TODO
		},
		# 'start': start,
		# 'report': report,
	}

# Use psyco (if available) as it results in huge performance improvements.
try:
	import psyco
	psyco.bind(decode)
except ImportError:
	pass