# 6.S189: Hangman solution
# Import statements: DO NOT delete these! DO NOT write code above this!
from random import randrange
from string import *

# -----------------------------------
# Helper code
# (you don't need to understand this helper code)
# Import hangman words

WORDLIST_FILENAME = "words.txt"

def load_words():
    """
    Returns a list of valid words. Words are strings of lowercase letters.
    
    Depending on the size of the word list, this function may
    take a while to finish.
    """
    print "Loading word list from file..."
    # inFile: file
    inFile = open(WORDLIST_FILENAME, 'r', 0)
    # line: string
    line = inFile.readline()
    # wordlist: list of strings
    wordlist = split(line)
    print "  ", len(wordlist), "words loaded."
    print 'Enter play_hangman() to play a game of hangman!'
    return wordlist

# actually load the dictionary of words and point to it with 
# the words_dict variable so that it can be accessed from anywhere
# in the program
words_dict = load_words()


# Run get_word() within your program to generate a random secret word
# by using a line like this within your program:
# secret_word = get_word()

def get_word():
    """
    Returns a random word from the word list
    """
    word=words_dict[randrange(0,len(words_dict))]
    return word

# end of helper code
# -----------------------------------


# CONSTANTS
MAX_GUESSES = 6

# GLOBAL VARIABLES
secret_word = 'claptrap' 
letters_guessed = []

# From part 3b:
def word_guessed():
    '''
    Returns True if the player has successfully guessed the word,
    and False otherwise.
    '''
    global secret_word
    global letters_guessed
    
    # Go through the secret_word and see if we've guessed all the letters
    for letter in secret_word:
        # If at least one letter isn't guessed yet, we know to return False
        if letter not in letters_guessed:
            return False

    # If we're here, we've gone through all the letters and we haven't returned
    #  False, so we must have guessed all the letters
    return True


def print_guessed():
    '''
    Prints a string that contains the word with a dash "-" in
    place of letters not guessed yet. 
    '''
    global secret_word
    global letters_guessed
    
    # Initalize a list to hold our characters
    character_list = []

    # Go through each letter in secret word to check if we've guessed it
    for letter in secret_word:
        if letter in letters_guessed:
            # If we've guessed it, we want to display it
            character_list.append(letter)
        else:
            # If we haven't guessed it, we want to display a dash
            character_list.append('-')
    # Turn it into a string and return that string
    print join(character_list, '')

def reset_env():
    '''
    A function that resets the game, if we want to play again.
    '''
    global secret_word
    global letters_guessed

    secret_word = get_word()
    letters_guessed = []


def play_hangman():
    # Actually play the hangman game

    # Update secret_word. Uncomment these two lines when you're
    # sure that EVERYTHING else works!
    global secret_word
    global letters_guessed

    secret_word  = get_word()

    mistakes_made = 0

    playing = True
   
    while playing:
        # Print guesses & word blanks out to the user
        print "You have", (MAX_GUESSES-mistakes_made), "guesses left"
        print print_guessed()

        # Get user's guess; force it to be lower case
        guess = lower(raw_input("Enter a letter to guess: "))
        # In case they enter more than one letter: force them to enter only 1
        while len(guess) > 1:
                guess = lower(raw_input("Enter a SINGLE letter to guess: "))

        # If we've already guessed this, try again
        if guess in letters_guessed:
            print "You've already guessed the letter", guess

        # Else if not guessed, see if in word
        elif guess in secret_word:
            # Add the guess to the letters_guessed list
            letters_guessed.append(guess)

            # Print a message to the user
            print "Yes, the letter", guess, "is correct."
            # See if we've guessed the word yet
            if word_guessed():
                print "Congrats! You've guessed correctly; the word was", secret_word
                # Ask the user if they want to play again
                play_again = lower(raw_input("Play again? Type yes or no: "))
                if play_again == 'yes':
                    # If we want to play again, we need to reset the environment
                    reset_env()
                    mistakes_made = 0
                else:
                    # Otherwise we want to exit the loop
                    playing = False
        
        # Otherwise, it was a miss
        else:
            # Add the guess to the letters_guessed list
            letters_guessed.append(guess)
            # Increment the mistakes-made counter
            mistakes_made += 1
            # Print a message to the user
            print "Sorry, that is not in the word."

            # Check if we're out of guesses
            if (MAX_GUESSES - mistakes_made) == 0:
                print "Sorry, you're out of guesses. The word was", secret_word
                print "See? That wasn't so hard."
                # Ask the user if they want to play again
                play_again = lower(raw_input("Play again? Type yes or no: "))
                if play_again == 'yes':
                    # If we want to play again, we need to reset the environment
                    reset_env()
                    mistakes_made = 0
                else:
                    # Otherwise we want to exit the loop
                    playing = False