#Jonathan Hudson
#Student Number 12347890
#Date: 2020-08-26
#Lecture Practice
#Draw stars at locations given by user

#Import turtle
import turtle 

#CONSTANTS
WIDTH = 800
HEIGHT = 600

#Main function (Loops taking two integer inputs from user for (x,y) cooridinate in (800,600) window
#Draws star at that location indicated colour
#Loop stops once one of coordinate inputs is the empty line "" (i.e. pressing Enter for input)
def main():
        pointer = setup()
        #Get (x, y)
        sXLocation = input("Enter new x coordinate in (800,600) window: ")
        sYLocation = input("Enter new y coordinate in (800,600) window: ")
        #Loop as long as not empty string
        while sXLocation != "" and sYLocation != "":
                #Change to integer (we assume they are valid numbers)
                x = int(sXLocation)
                y = int(sYLocation)
                #Set color (prompts for it's own input)
                setColor(pointer)
                #Go to x,y and draw a star
                gotoAndDrawStar(pointer,x,y)
                #Get next location
                sXLocation = input("Enter new x coordinate in (800,600) window: ")
                sYLocation = input("Enter new y coordinate in (800,600) window: ")
        #Done main loop
        print("Done")

#Sets up window and gets turtle pointer (uses WIDTH AND HEIGHT constants)
#Pointer is hidden and delay set to 0 to speed up drawing
#Pen is set to up
#Parameters:
#       None
#Returns:
#       Turtle drawing pointer
def setup():
        pointer = turtle.Turtle()
        screen = turtle.getscreen()
        screen.setup(WIDTH, HEIGHT, 0, 0)
        screen.setworldcoordinates(0, 0, WIDTH, HEIGHT)
        pointer.hideturtle()
        screen.delay(delay=0)
        pointer.up()
        return pointer

#Sets pen color (for star color), takes its own input as a string (doesn't do cast so no crash possible)
#Parameters:
#       Turtle drawing pointer
#Returns:
#       None (however, state of turtle pen color is changed
def setColor(pointer):
        sColor = input("Enter color [1:red 2:green 3:blue otherwise:black]: ")
        if sColor == "1":
                pointer.color("red")
        elif sColor == "2":
                pointer.color("green")
        elif sColor == "3":
                pointer.color("blue")
        else:
                pointer.color("black")	


#Moves pen to indicated (x,y) location and draws a star with edges of parameter length
#Parameters:
#       Turtle drawing pointer
#       (x,y) coordinate to draw star at, (400,300) centre of screen is default
#       length of edge (point to point), 100 is default
#Returns:
#       None (however window will have star drawn in it)
def gotoAndDrawStar(pointer,x=400,y=300,length=100):
        pointer.goto(x,y)
        pointer.setheading(0)
        pointer.down()
        drawStar(pointer, length)
        pointer.up()
      

#Draws a star with pen at current position with edges of parameter length
#Parameters:
#       Turtle drawing pointer
#       length of edge (point to point), 100 is default
#Returns:
#       None (however window will have star drawn in it)  
def drawStar(pointer, length=100):
	for i in range(5):
		pointer.forward(length)
		pointer.right(144)


main()