#!/usr/local/bin/python

""" Convert C programs to Python programs automatically """

import sys, os, string

def main():
	for file in sys.argv[1:]:
		convert_to_python(file)

def convert_to_python(filename):
	if filename[-2:] == ".c":
		convert_c_to_python(filename)

def convert_c_to_python(filename):
	new_filename = filename[:-2] + ".py"
	try:
		f = open(filename, "r")
		lines = f.readlines()
		f.close()
	except IOError:
		print "File", filename, "is unreadable. Skipping."
		return
	try:
		f = open(new_filename, "r")
		f.close()
		print "File", new_filename, "already exists. Skipping."
		return
	except IOError:
		pass
	f = open(new_filename, "w")
	f.write("#!/usr/local/bin/python\n")
	for line in lines:
		converted_line = c_line_to_python(line)
		f.write(converted_line)
	f.write("\nmain()\n\n")
	f.close()
	os.system("chmod +x " + new_filename)
	print new_filename

line_starts = [
		["/*",				"##"	],
		[" */",				"##"	],
		["*/",				"##"	],
		[" *",				"# "	],
		["*",				"#"	],
		["//",				"##"	],
		["#include <stdlib.h>",		"import os"	],
		["#include <stdio.h>",		"import sys"	],
		["#include <ctype.h>",		"import string"	],
		["#include <string.h>",		"import string"	],
		["#include <math.h>",		"import math"	],
		["#include <time.h>",		"import time"	],
		["#include <graphapp.h>",	"from graphapp import *"],
		["#include <",			"import "	],
		['#include "',			"import "	],
		["main()",			"def main():"	],
		["void main()",			"def main():"	],
		["main(void)",			"def main():"	],
		["void main(void)",		"def main():"	],
		["int main()",			"def main():"	],
		["main(int argc, char **argv)",		"def main():"	],
		["main(int argc, char *argv[])",	"def main():"	],
		["void main(int argc, char **argv)",	"def main():"	],
		["void main(int argc, char *argv[])",	"def main():"	],
		["int main(int argc, char **argv)",	"def main():"	],
		["int main(int argc, char *argv[])",	"def main():"	],
		["void ",			"def ",		":"],
		["int ",			"def ",		":"],
		["char *",			"def ",		":"],
		["else",			"else",		":"],
	]

line_ends = [
		["{",		""	],
		["}",		""	],
		[";",		""	],
	]

whole_lines = [
		["{",		""	],
		["}",		""	],
	]

def c_line_to_python(line):
	if (line == "") or (line == "\n"):
		return line
	words = string.join(string.split(line))
	for pattern in whole_lines:
		if words == pattern[0]:
			line = pattern[1]
	has_newline = (line[-1:] == '\n')
	if has_newline:
		line = line[:-1]
	for pattern in line_ends:
		length = len(pattern[0])
		if line[-length:] == pattern[0]:
			line = line[:-length] + pattern[1]
	for pattern in line_starts:
		length = len(pattern[0])
		if line[:length] == pattern[0]:
			line = pattern[1] + line[length:]
			if len(pattern) == 3:
				line = line + pattern[2]
	if has_newline:
		line = line + "\n"
	return line

if __name__ == "__main__":
	main()