#!/usr/bin/python

# Elizalike --- Ling/CSE 472 Assignment I

# Simple automated conversation agent, in the style of
# Weizenbaum's Eliza.  Invoke by typing:

#        python elizalike.py

# from a command prompt or unix shell.

# The basic script provided as part of the assignment takes care
# of input and output, gives one example regular expression, and
# provides a series of comments (preceded by #) indicating what
# you should add.


import re
import sys

print "Welcome to Elizalike.  Talk to me! (Or type \"bye\" to quit.)\n"

# Start an infinite loop

while True:

    # Read in the user's input
    string = raw_input("Patient: ")

    # Allow user to quit
    if re.search(string,r'bye|Bye|BYE'):
        
        print "Elizalike: Well, it was nice talking to you!\n"
        sys.exit()

    # Insert a tag at the beginning of the line to identify
    # it as Eliza's reponse, and to make finding word boundaries
    # easier.
   
    string = re.sub('^','Elizalike: ',string) 

    # Replace all instances of "you are" with "---Eliza-is---":
    # Note how (\W) and \1, etc are used to mark word boundaries
    # and keep whatever non-word character was in the input in the
    # output.

    string = re.sub(r'(\W)[Yy]ou are(\W)','\g<1>---Eliza-is---\g<2>',string)

    # A brief note about syntax:  The function re.sub takes three
    # arguments: a regular expression to search for in the string,
    # a replacement string to replace it with, and the string to
    # operate on.  It returns a new string, which the above expression
    # is storing in the variable 'string'.

    # Remaining statements for changing second person reference
    # in the input to third person reference (temporarily):






    # Other transformations on the input that don't have to do with
    # person reference:




    # Statements for changing first person reference to second
    # person reference:






    # Statements for changing third person Eliza reference to
    # first person reference:







    # Print the reply

    print string