# Starter file for drawing a star chart from a series of data files
# Uses Turtle Graphics for plotting
from turtle import *

# Size of overall star chart
SIZE = 400

# Given original x and y coordinates in range [-1, 1], return coordinates
# scaled to new size as a tuple
def trans_coords_pixel(orig_x, orig_y, size):
    new_x = orig_x * size
    new_y = orig_y * size
    
    return (new_x, new_y)

# Draw a star of a particular size at a given position, passed in as a tuple
def draw_star(position, size):
    up()
    goto(position[0] - 1, position[1] - 1)
    down()
    fill(True)
    for i in range(4):
        right(90)
        forward(size)
    fill(False)

# Reads a data file and returns a dictionary of star names such that
# the key is a star name and the value is its Draper number 
def read_star_info(stars_file):
    star_names = {}
    for line in stars_file:
        line = line.strip().split()
        draper_no = line[3]

        if len(line) >= 7:
            names = ""
            for i in range(6, len(line)):
                names += line[i] + " "
            names = names.split(";")
            for name in names:
                star_names[name.strip()] = draper_no
    return star_names

# Very simple example of a function that returns multiple values
def person_data():
    name = "Daffy"
    age = 10
    salary = 50000
    return name, age, salary

bgcolor("black")
color("white")

# Draw some sample stars
draw_star(trans_coords_pixel(.5, .5, SIZE), 2)
draw_star(trans_coords_pixel(1, 1, SIZE), 2)
draw_star(trans_coords_pixel(-1, -1, SIZE), 2)

# Print out all star names found in file mapped to their Draper numbers
stars_file = open("stars.txt")
star_names = read_star_info(stars_file)
print star_names

# Example call on a function that returns multiple values
p_name, p_age, salary = person_data()
print p_age