#!/usr/bin/python

"""
<OWNER> = Siteshwar Vashisht 
<YEAR> = 2012 

Copyright (c) 2012, Siteshwar Vashisht 
All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""

import os, sys, re

config_file = None
prompt_buff = ""
i = 0
quote_started = False
bash_builtins = ["export"]

#Remove leading and trailing single quotes from a string
def remove_single_quotes(input):
	start = 0
	end = len(input)
	if input[0] == "'":
		start = 1
	if input[end-1] == "'":
		end = end - 1 
	return input[start:end]

#Find outside quotes
def contains_outside_quotes(input, ch):
	in_quotes = False

	i = 0
	
	while i < len(input):
		if input[i] == ch and in_quotes == False:
			return True
		elif input[i] == '\\' and in_quotes == True:
			i = i+1	
		elif input[i] == '"':
			in_quotes = not in_quotes
		elif input[i] == "'" and not in_quotes:
			i = i + 1
			while input[i] != "'":
				i = i + 1	

		i = i + 1

	return False 


#Replace characters outside double quotes
def replace_outside_quotes(input, oldchar, newchar, change_all = True):
	in_quotes = False
	newstr = [] 

	i = 0
	
	while i < len(input):
		if input[i] == oldchar and in_quotes == False:
			newstr.append(newchar)
			i = i+1

			if change_all == True:
				continue	
			else:
				while i < len(input):
					newstr.append(input[i])
					i = i + 1
				#Break loop and return all the characters in list by joining them
				break	
		elif input[i] == '\\' and in_quotes == True:
			newstr.append(input[i])
			i = i+1	
		elif input[i] == '"':
			in_quotes=not in_quotes
		elif input[i] == "'" and not in_quotes:
			newstr.append(input[i])
			i = i + 1
			while input[i] != "'":
				newstr.append(input[i])
				i = i + 1	

		newstr.append(input[i])
		i = i + 1

	return ''.join(newstr)	


#Parse input passed to the script
def parse_input(input):
	env_regex = re.compile("(.*?)=(.*)")	
	env_regex_matched = re.search(env_regex, input)

	while env_regex_matched != None:
		env_name = env_regex_matched.group(1)
		env_value = env_regex_matched.group(2)
		env_var = env_regex_matched.group(0)	

		if env_name[:5] == "alias":
			add_alias(env_name[6:], env_value)
		elif env_name == "PS1":
			parse_bash_prompt(env_value)	
		else:
			config_file.write("set_default " + env_name + ' "' + env_value + '"') 
		#Move to next line
		config_file.write("\n")
		input = input[env_regex_matched.end():]
		env_regex_matched = re.search(env_regex, input)

#Add an alias as a function in fish
def add_alias(alias_name, alias_value):
		alias_value = remove_single_quotes(alias_value)

		while contains_outside_quotes(alias_value,"`"):
			alias_value = replace_outside_quotes(alias_value, '`', '(', False)
			alias_value = replace_outside_quotes(alias_value, '`', ')', False)

		config_file.write("function " + alias_name)
		for line in alias_value.split(";"):
			line = line.strip()
			tokens = line.split(' ')
			first_token = tokens[0].strip()
			if first_token in bash_builtins:
				print first_token, " is a bash builtin"			
				if first_token == "export":
					var_regex = re.compile("(.*?)=(.*)")	
					var_regex_matched = re.search(var_regex, line[7:])
			
					if var_regex_matched != None:
						stripped_name = var_regex_matched.group(1).strip()	
						config_file.write("\n\tset -gx " + var_regex_matched.group(1).strip() + " " + var_regex_matched.group(2).strip())
					else:
						export_name = line[6:].strip()
						config_file.write("\n\tset -gx " + export_name + " $" + export_name ) 

			elif "=" in first_token:
					var_regex = re.compile("(.*?)=(.*)")	
					var_regex_matched = re.search(var_regex, line)
			
					if var_regex_matched != None:
						stripped_name = var_regex_matched.group(1).strip()	
						config_file.write("\n\tset " + var_regex_matched.group(1).strip() + " " + var_regex_matched.group(2).strip() )
			else:
					if len(line.strip()) > 0:
						config_file.write( "\n\t" + line.strip() + " $argv" )
		config_file.write("\nend;\n")

def parse_control_sequence():
	ch = next_prompt_char()
	ch2 = None
	
	while (ch != ""):
		if ch == "\\":
			ch2 = next_prompt_char()
			if (ch2 == "]"):
				return
		ch = next_prompt_char()

def is_digit(ch):
	if ch>='0' and ch<='9': 
		return True
	return False

def set_prompt_buff(value):
	global i, buff
	i = 0
	buff = value 

def next_prompt_char():
	global i, buff
	if (i < len(buff)):
		next = buff[i] 
		i = i+1
	else:
		next = ""
	return next

def unget_prompt_char():
	global i
	i = i - 1

def add_to_echo(str, is_special=True):
	global quote_started
	
	if (is_special == True):
		if (quote_started == True):
#			print "Ending Quote for", str
			config_file.write('"')
			quote_started = False
	else:
		if (quote_started == False):
#			print "Starting Quote for", str
			config_file.write('"')
			quote_started = True

	config_file.write(str)

def check_end_quote():
	global quote_started

	if quote_started == True:
#		print "Ending quote",
		config_file.write('"')

def parse_bash_prompt(bash_prompt):
	set_prompt_buff(bash_prompt)
	config_file.write("function fish_prompt\n")

	if ("\\$" in bash_prompt):
		config_file.write("\tif test (id -u) -eq \"0\"\n") 
		config_file.write("\t\tset uid_prompt \"#\"\n") 
		config_file.write("\telse\n") 
		config_file.write("\t\tset uid_prompt \"\\$\"\n") 
		config_file.write("\tend;\n")

	config_file.write('\techo -n ')

	ch = next_prompt_char()
	ch2 = None
	while (ch != ""):
		if ( ch == "\\"):
			ch2 = next_prompt_char()	
			if (ch2 == ""):
				continue
			elif (ch2 == "a"):
				add_to_echo('\\a')
			elif (ch2 == "d"):
				add_to_echo('(date +"%a %b %d")')
			elif (ch2 == "e"):
				sys.std.out.write('\e')
			elif (ch2 == "h"):
				add_to_echo("(hostname | cut -d\".\" -f1)")
			elif (ch2 == "H"):
				add_to_echo("(hostname)")
			elif (ch2 == "j"):
				add_to_echo("(jobs | wc -l)")
			elif (ch2 == "l"):
				add_to_echo("basename (tty)")
			elif (ch2 == "n"):
				add_to_echo(' \\n ')
			elif (ch2 == "r"):
				add_to_echo(' \\r ')
			elif (ch2 == "s"):
				add_to_echo("fish", False)
			elif (ch2 == "t"):
				add_to_echo('(date +"%H:%M:%S")')
			elif (ch2 == "T"):
				add_to_echo('(date +"%I:%M:%S")')
			elif (ch2 == "@"):
				add_to_echo('(date +"%I:%M %p")')
			elif (ch2 == "u"):
				add_to_echo("$USER")
			elif (ch2 == "w"):
				add_to_echo("(pwd)")
			elif (ch2 == "W"):
				add_to_echo("(basename ( pwd ) )")
			elif (ch2 == "$"):
				add_to_echo(" $uid_prompt ")	
			elif (is_digit(ch2)):
				temp = int(ch2)
				ch = next_prompt_char()
				if (is_digit(ch)):
					temp = (temp*8) + int(ch)
				else:
					add_to_echo(chr(temp), False)
					unget_prompt_char()	
				ch = next_prompt_char()
				if (is_digit(ch)):
					temp = ((temp/10)*64) + ((temp%10)*8) + int(ch)
					add_to_echo(chr(temp), False)
				else:
					add_to_echo(chr(temp), False)
					unget_prompt_char()	
			elif (ch2 == "\\"):
				add_to_echo("\\")
			elif (ch2 == "["):
				parse_control_sequence()
			elif (ch2 ==  "]"):
				print "Unexpected ]"
			elif (ch2 == "v" or ch2 == "V"):
				add_to_echo("(fish -v 2>| cut -d\" \" -f3)")
			else:
				print "Unknown escape character"
		else:
			add_to_echo(ch,False)
		ch = next_prompt_char()
	check_end_quote()
	config_file.write("\nend\n")

if __name__  == "__main__":
	input = sys.stdin.read()
	config_file = open( os.environ["HOME"] + "/.config/fish/bash_config.fish","a")
	parse_input(input)