# tree.py - recursive tree drawings
# original from Miller/Ranum
# updated by cmc, 3/3/2015

# try len = 100

import random
import sys
import turtle

# original Listing 9.3
def draw1(len, t):
    if len < 5:
        return
    t.forward(len)
    t.right(30)
    draw1(len - 15, t)
    t.left(60)
    draw1(len - 15, t)
    t.right(30)
    t.backward(len)

# second version (used by main) adds randomness
# and color based on Exercises 9.11-9.13
def draw2(len, t):
    if len < 5:
        return
    if len < 15:
        t.color("green")
    else:
        t.color("brown")
    t.down()
    t.forward(len)
    angle = random.randint(15, 45)
    shrink = random.randint(5, 25)
    t.right(angle)
    draw2(len - shrink, t)
    t.left(2 * angle)
    draw2(len - shrink, t)
    t.right(angle)
    t.up()
    t.backward(len)

# added a main method to get user requests from command line
def main():
    '''
      starts the application, and processes first command
      line argument if present - integer trunk len assumed
    '''
    defaultLen = 80

    if len(sys.argv) < 2:
        trunkLen = defaultLen
    else:
        try:
            trunkLen = int(sys.argv[1])
        except:
            print("\nError:", sys.exc_info()[0])
            print("Setting trunk length to ", defaultLen)
            trunkLen = defaultLen

    t = turtle.Turtle()
    t.speed(10)
    t.hideturtle()
    t.right(90)
    t.up()
    t.forward(250)
    t.right(180)
    t.down()

    draw2(trunkLen, t)
    t.up()
    t.right(90)
    t.forward(5)
    t.down()
    t.color("black")
    t.write("Done. Click to exit.", font=('Arial', 12, 'bold'))
    t.getscreen().exitonclick()

main()