# program to play rock, paper scissors
# ECS 10, May 8, 2009
import random

# function to translate number into rock, paper, scissors, ???
def what(pick):
    if pick == 0:
        return "rock"
    elif pick == 1:
        return "paper"
    elif pick == 2:
        return "scissors"
    # should never get here, so warn if you do
    return "??? (%d)" % pick

# function to read and vet user selection
# returns: 0 if rock
#          1 if paper
#          2 if scissors
#          3 to end game
#          NOTE: caller depends on these values
def getuser():
    # loop until we get good input
    while True:
        try:
            # get the input and check the type here
            v = input("Enter 0 (rock), 1 (paper), 2 (scissors), 3 (quit): ")
            v += 0;
        except EOFError:        # user wants to quit, so help her
            v = 3
                                # oops! let error check below do the work
                                # so set v to something illegal (not 0-3)
        except (SyntaxError, NameError, TypeError):
            v = -1
        # now check the value we read/were given
        if 0 <= v and v <= 3:
            break
        # this is bad, so say so
        print "You have to enter a 0, 1, 2, or 3 only"

    # tell the user what she chose and return it
    if v != 3:
        print "You pick", what(v)
    return v

# function to generate computer selection pseudo-randomly
# returns: 0 if rock
#          1 if paper
#          2 if scissors
#          NOTE: caller depends on these values
def getcomp():
    pick = random.randrange(0, 3)
    print "Computer picks", what(pick)
    return pick
    
# function to determine who wins
# parameters: user: user's selection
#             computer's selection
#             NOTE: 0 = rock, 1 = paper, 2 = scissors
# returns: 0 if user won
#          1 if computer won
#          2 if tie
#          NOTE: caller depends on these values
def whowins(user, comp):
	if user == comp:
		win = 2
	elif (user, comp) == (1, 0) or (user, comp) == (2, 1) or (user, comp) == (0, 2):
		win = 0
	else:
		win = 1
	return win

# pulling it all together
# calls: getuser(), getcomp(), whowins()
def main():
    # initialize scores
    score = [ 0, 0, 0 ]

    # now we play
    while True:
        # get the user's choice
        userchoice = getuser();
        if (userchoice == 3):
            break
        # get the computer's choice
        compchoice = getcomp();
        # figure out who won
        winner = whowins(userchoice, compchoice)
        # announce it to the world!
        if winner == 0:
            print "You win"
        elif winner == 1:
            print "Computer wins"
        elif winner == 2:
            print "Tie"
        else:
            print "*** INTERNAL ERROR *** winner is", winner
            break
        # track the new score
        score[winner] += 1;

    print "You won", score[0], "games, the computer won", score[1],
    print "games, and", score[2], "games were tied"

main()