#!/usr/bin/env python
# Parses linux/input.h scanning for #define KEY_FOO 134
# Prints C header files or Python files that can be used as
# mapping and lookup tables.
#

from __future__ import print_function
import re
import sys

class Bits(object):
	pass

prefixes = [
		"EV_",
		"REL_",
		"ABS_",
		"KEY_",
		"BTN_",
		"LED_",
		"SND_",
		"MSC_",
		"SW_",
		"FF_",
		"SYN_",
		"REP_",
		"INPUT_PROP_",
]

blacklist = [
		"EV_VERSION",
		"BTN_MISC",
		"BTN_MOUSE",
		"BTN_JOYSTICK",
		"BTN_GAMEPAD",
		"BTN_DIGI",
		"BTN_WHEEL",
		"BTN_TRIGGER_HAPPY"
]

btn_additional = [
		[0, "BTN_A"],
		[0, "BTN_B"],
		[0, "BTN_X"],
		[0, "BTN_Y"],
]

names = [
		"REL_",
		"ABS_",
		"KEY_",
		"BTN_",
		"LED_",
		"SND_",
		"MSC_",
		"SW_",
		"FF_",
		"SYN_",
		"REP_",
]

def print_bits(bits, prefix):
	if  not hasattr(bits, prefix):
		return
	print("static const char * const %s_map[%s_MAX + 1] = {" % (prefix, prefix.upper()))
	for val, name in list(getattr(bits, prefix).items()):
		print("	[%s] = \"%s\"," % (name, name))
	if prefix == "key":
		for val, name in list(getattr(bits, "btn").items()):
			print("	[%s] = \"%s\"," % (name, name))
	print("};")
	print("")

def print_map(bits):
	print("static const char * const * const event_type_map[EV_MAX + 1] = {")

	for prefix in prefixes:
		if prefix == "BTN_" or prefix == "EV_" or prefix == "INPUT_PROP_":
			continue
		print("	[EV_%s] = %s_map," % (prefix[:-1], prefix[:-1].lower()))

	print("};")
	print("")

	print("#pragma GCC diagnostic push")
	print("#pragma GCC diagnostic ignored \"-Woverride-init\"")
	print("static const int ev_max[EV_MAX + 1] = {")
	print("	[0 ... EV_MAX] = -1,")
	for prefix in prefixes:
		if prefix == "BTN_" or prefix == "EV_" or prefix == "INPUT_PROP_":
			continue
		print("	[EV_%s] = %s_MAX," % (prefix[:-1], prefix[:-1]))
	print("};")
	print("#pragma GCC diagnostic pop /* \"-Woverride-init\" */")
	print("")

def print_python_map(bits):
	print("map = {")

	for val, name in list(getattr(bits, "ev").items()):
		name = name[3:]
		if name == "REP" or name == "PWR"  or name == "FF_STATUS"  or name == "MAX":
			continue
		print("	%d : %s_map," % (val, name.lower()))

	print("}")
	print("")

def print_lookup(bits, prefix):
	if not hasattr(bits, prefix):
		return

	names = list(getattr(bits, prefix).items())
	if prefix == "btn":
		names = names + btn_additional;

	for val, name in sorted(names, key=lambda e: e[1]):
		print("	{ .name = \"%s\", .value = %s }," % (name, name))

def print_lookup_table(bits):
	print("struct name_entry {")
	print("	const char *name;")
	print("	unsigned int value;")
	print("};")
	print("")
	print("static const struct name_entry ev_names[] = {")
	print_lookup(bits, "ev")
	print("};")
	print("")

	print("static const struct name_entry code_names[] = {")
	for prefix in sorted(names, key=lambda e: e):
		print_lookup(bits, prefix[:-1].lower())
	print("};")
	print("")


def print_mapping_table(bits):
	print("/* THIS FILE IS GENERATED, DO NOT EDIT */")
	print("")
	print("#ifndef EVENT_NAMES_H")
	print("#define EVENT_NAMES_H")
	print("")

	for prefix in prefixes:
		if prefix == "BTN_":
			continue
		print_bits(bits, prefix[:-1].lower())

	print_map(bits)
	print_lookup_table(bits)

	print("#endif /* EVENT_NAMES_H */")

def parse_define(bits, line):
	m = re.match(r"^#define\s+(\w+)\s+(\w+)", line)
	if m == None:
		return

	name = m.group(1)

	if name in blacklist:
		return

	try:
		value = int(m.group(2), 0)
	except ValueError:
		return

	for prefix in prefixes:
		if not name.startswith(prefix):
			continue

		attrname = prefix[:-1].lower()

		if not hasattr(bits, attrname):
			setattr(bits, attrname, {})
		b = getattr(bits, attrname)
		b[value] = name

def parse(fp):
	bits = Bits()

	lines = fp.readlines()
	for line in lines:
		if not line.startswith("#define"):
			continue
		parse_define(bits, line)

	return bits

def usage(prog):
	print("Usage: %s /path/to/linux/input.h" % prog)

if __name__ == "__main__":
	if len(sys.argv) != 2:
		usage(sys.argv[0])
		sys.exit(2)

	with open(sys.argv[1]) as f:
		bits = parse(f)
		print_mapping_table(bits)
