import pygame, random

# Define some colors
black = (0, 0, 0)
white = (255, 255, 255)
red = (255, 0, 0)
green = (0, 255, 0)
blue = (0, 0, 255)

pygame.init()

# Set the width and height of the screen
map_width = 800
map_height = 800
size = [map_width, map_height]
screen = pygame.display.set_mode(size)

# Display name
pygame.display.set_caption("Natural Selection Game")

# Loop until the user clicks the close button.
done = False

# Used to manage how fast the screen updates
clock = pygame.time.Clock()

# -------- Organism -----------
class Organism:

    def __init__(self):
        # Speed and direction
        self.change_x = random.randrange(0,6)
        self.change_y = random.randrange(0,6)

        # Dimensions
        self.width = random.randrange(5,50)
        self.height = random.randrange(5,50)

        # Diet (WIP)
        self.color = random.choice([red, green, blue])

        # Starting position
        self.x = random.randrange(0 + self.width, 800 - self.width)
        self.y = random.randrange(0 + self.height, 800 - self.height)

    # Spawn
    def spawn(self, screen):
        pygame.draw.ellipse(screen, self.color, [self.x, self.y, self.width, self.height])

    # Initiate movement
    def move(self):
        self.x += self.change_x
        self.y += self.change_y

    # Bounce
    def bounce(self, map_width, map_height):
        if self.x < 0 or self.x > map_width - self.width:
            self.change_x = self.change_x * -1
        if self.y < 0 or self.y > map_height - self.height:
            self.change_y = self.change_y * -1

# Initial spawning conditions
org_list = []
org_number = 15

for i in range(0,org_number):
    org = Organism()
    org_list.append(org)

# -------- Main Program Loop -----------
while not done:
    # ---- Event Processing ----
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True

    # ---- Logic ----
    # Movement
    for i in org_list:
        i.move()
        i.bounce(map_width, map_height)

    # Reproduction

    # ---- Drawing ----
    # Set the screen background
    screen.fill(white)

    # Spawn organisms
    for i in org_list:
        i.spawn(screen)

    # --- Wrap-up
    # Limit to 60 frames per second
    clock.tick(60)

    # Go ahead and update the screen with what we've drawn.
    pygame.display.flip()

# Close everything down
pygame.quit()