#!/usr/bin/env python3

# The MIT License (MIT)
#
# Copyright (c) 2015 Stany MARCEL <stanypub@gmail.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.


import ast
import os
import shlex
from collections import OrderedDict
import operator as op

OPERATORS = {
	ast.Add	: op.add,
	ast.Sub	: op.sub,
	ast.Mult   : op.mul,
	ast.Div	: op.floordiv,
	ast.Mod	: op.mod,
	ast.LShift : op.lshift,
	ast.RShift : op.rshift,
	ast.BitOr  : op.or_,
	ast.BitXor : op.xor,
	ast.BitAnd : op.and_,
	ast.Invert : op.invert,
	ast.Not	: op.not_,
	ast.UAdd   : op.pos,
	ast.USub   : op.neg,
	ast.And	: op.and_,
	ast.Or	 : op.or_,
	ast.Eq	 : op.eq,
	ast.NotEq  : op.ne,
	ast.Lt	 : op.lt,
	ast.LtE	: op.le,
	ast.Gt	 : op.gt,
	ast.GtE	: op.ge,
}

def eval_expr(expr):

	""" Eval and expression inside a #define using a suppart of python grammar """

	def _eval(node):
		if isinstance(node, ast.Constant):
			return node.value
		elif isinstance(node, ast.BinOp):
			return OPERATORS[type(node.op)](_eval(node.left), _eval(node.right))
		elif isinstance(node, ast.UnaryOp):
			return OPERATORS[type(node.op)](_eval(node.operand))
		elif isinstance(node, ast.BoolOp):
			values = [_eval(x) for x in node.values]
			return OPERATORS[type(node.op)](**values)
		else:
			raise TypeError(node)

	return _eval(ast.parse(expr, mode='eval').body)


def defines(base, include):

	""" Extract #define from base/include following #includes """

	parsed = set()
	fname = os.path.normpath(os.path.abspath(os.path.join(base, include)))
	parsed.add(fname)

	lexer = shlex.shlex(open(fname), posix=True)

	lexer.whitespace = ' \t\r'
	lexer.commenters = ''
	lexer.quotes = '"'

	out = OrderedDict()

	def parse_c_comments(lexer, tok, ntok):
		if tok != '/' or ntok != '*':
			return False
		quotes = lexer.quotes
		lexer.quotes = ''
		while True:
			tok = lexer.get_token()
			ntok = lexer.get_token()
			if tok == '*' and ntok == '/':
				lexer.quotes = quotes
				break
			else:
				lexer.push_token(ntok)
		return True

	def parse_cpp_comments(lexer, tok, ntok):
		if tok != '/' or ntok != '/':
			return False
		quotes = lexer.quotes
		lexer.quotes = ''
		while True:
			tok = lexer.get_token()
			if tok == '\n':
				lexer.quotes = quotes
				lexer.push_token(tok)
				break
		return True

	while True:
		tok = lexer.get_token()
		if not tok or tok == '':
			break
		ntok = lexer.get_token()

		if parse_c_comments(lexer, tok, ntok):
			continue
		if parse_cpp_comments(lexer, tok, ntok):
			continue

		if tok != '\n' or ntok != '#':
			lexer.push_token(ntok)
			continue

		tok = lexer.get_token()
		if tok == 'define':
			name = lexer.get_token()
			expr = ''
			while True:

				tok = lexer.get_token()
				ntok = lexer.get_token()

				if parse_c_comments(lexer, tok, ntok):
					continue
				if parse_cpp_comments(lexer, tok, ntok):
					continue
				lexer.push_token(ntok)

				if not tok or tok == '':
					break
				if tok == '\n':
					lexer.push_token(tok)
					break

				if tok in out:
					tok = str(out[tok])
				expr = expr + tok

			try:
				val = eval_expr(expr)
				out[name] = val
			except (SyntaxError, TypeError):
				pass
		elif tok == 'include':

			tok = lexer.get_token()
			if tok == '<':
				name = ''
				while True:
					tok = lexer.get_token()
					if tok == '>':
						break
					name = name + tok
			else:
				name = tok
			fname = os.path.normpath(os.path.abspath(os.path.join(base, name)))
			if os.path.isfile(fname) and not fname in parsed:
				parsed.add(fname)
				lexer.push_source(open(fname))
		else:
			lexer.push_token(tok)


	return out


if __name__ == '__main__':
	import sys
	definesDict = defines(sys.argv[1], sys.argv[2])
	for k, v in definesDict.items():
		print("{}:\t{}".format(k, v))
