"""
CSCI 101 Iteration examples
"""
from random import *

def number_guessing_game():
    """
    Implements a simple number-guessing game: picks a secret number, prompts
    the users for guesses, each time telling them whether they've guessed too
    high, too low, or correctly.  Continues until a correct guess is given.
    """

    # generate a random number
    secret = randint(0, 100)

    # initially, the guess is invalid
    guess = -1

    # loop until the user guesses the right number
    while guess != secret:
        guess = int(input('Guess a number: '))
        if guess > secret:
            print('too high')
        elif guess < secret:
            print('too low')
        else:
            print('correct!')


def number_guessing_game2():
    """
    Implements a simple number-guessing game: picks a secret number, prompts
    the users for guesses, each time telling them whether they've guessed too
    high, too low, or correctly.  Continues until a correct guess is given.
    (Alternate version that uses a Boolean variable. Either version is fine.)
    """

    # generate a random number
    secret = randint(0, 100)

    # initially, the guess is invalid
    correct = False

    while not correct:   # same as "while correct == False"
        # ask the user for a guess
        guess = int(input("Guess a number: "))

        # tell them where their guess lies relative to the answer
        if guess > secret:
            print("too high")
        elif guess < secret:
            print("too low")
        else:
            print("correct!")
            correct = True


def investmentDoubles(rate):
    """
    Return the number of years for an investment to double at given rate.
    """
    initial = 100       # any initial value will work
    current = initial
    years = 0
    while current < 2*initial:
        current += rate * current      # short for current = current + rate*current
        years += 1                     # short for years = years + 1
    return years


def shift_letter(letter, num):
    """
    Shifts a letter up num places in the alphabet with wraparound
    """
    ALPHABET = "abcdefghijklmnopqrstuvwxyz "

    # get the index of the current letter
    index = ALPHABET.find(letter)
    # we use the mod operator (%) for wraparound
    return ALPHABET[(index + num) % len(ALPHABET)]

    
def fools_encrypt(msg):
    """
    Duplicate each letter in msg 3 times
    """
    secret = ''
    for c in msg:
        secret += c*3
    return secret


def fools_decrypt(secret):
    """
    Pull out every 3rd character from secret
    """
    msg = secret[::3]
    return msg


from turtle import *
import random

def draw_square(side_length):
    forward(side_length)
    right(90)
    forward(side_length)
    right(90)
    forward(side_length)
    right(90)
    forward(side_length)
    right(90)

def draw_square_with_loop(side_length):
    for i in range(4):       # do the following 2 indented lines 4 times
        forward(side_length)
        right(90)
                

def add_circles(number):
    """
    Add number colored circles of radius 6 randomly through the screen
    """
    x_range = int(window_width()/2)
    y_range = int(window_height()/2)
    
    for i in range(number):
        x = random.randint(-x_range, x_range)
        y = random.randint(-y_range, y_range)
        
        # set the fill color of the circles (uncomment one of the following two):
        setcolor_xy(x, y)
        #setcolor_random()
            
        pu()
        goto(x,y)
        pd()        
        begin_fill();
        circle(6)
        end_fill();

def setcolor_xy(x, y):
    """Set the fill color based on x, y coordinates"""
    if x < 0 and y < 0:
        fillcolor("blue")
    elif x < 0 and y > 0:
        fillcolor("purple")
    elif x > 0 and y < 0:
        fillcolor("red")
    else:
        fillcolor("yellow")        
        
def setcolor_random():
    """Set the fill color randomly from: blue, purple, red and yellow"""
    colornum = random.randint(1,4)
    
    if colornum == 1:
        fillcolor("blue")
    elif colornum == 2:
        fillcolor("purple")
    elif colornum == 3:
        fillcolor("red")
    else: # colornum == 4
        fillcolor("yellow")        

# To try the code above, uncomment these lines
##tracer(False)
##add_circles(200)
##update()
##done()