"""
Example "Arcade" library code.

If Python and Arcade are installed, this example can be run from the command line with:
python -m arcade.examples.decorator_drawing_example
"""

# Library imports
import arcade
import random

SCREEN_WIDTH = 800
SCREEN_HEIGHT = 600
SCREEN_TITLE = "Drawing With Decorators Example"

window = arcade.open_window(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)

bird_list = []


def setup():
    create_birds()
    arcade.schedule(update, 1 / 60)
    arcade.run()


def create_birds():
    for bird_count in range(10):
        x = random.randrange(SCREEN_WIDTH)
        y = random.randrange(SCREEN_HEIGHT/2, SCREEN_HEIGHT)
        bird_list.append([x, y])


def update(delta_time):
    """
    This is run every 1/60 of a second or so. Do not draw anything
    in this function.
    """
    change_y = 0.3

    for bird in bird_list:
        bird[0] += change_y
        if bird[0] > SCREEN_WIDTH + 20:
            bird[0] = -20


@window.event
def on_draw():
    """
    This is called every time we need to update our screen. About 60
    times per second.

    Just draw things in this function, don't update where they are.
    """
    # Call our drawing functions.
    draw_background()
    draw_birds()
    draw_trees()


def draw_background():
    """
    This function draws the background. Specifically, the sky and ground.
    """
    # Draw the sky in the top two-thirds
    arcade.draw_rectangle_filled(SCREEN_WIDTH / 2, SCREEN_HEIGHT * 2 / 3,
                                 SCREEN_WIDTH - 1, SCREEN_HEIGHT * 2 / 3,
                                 arcade.color.SKY_BLUE)

    # Draw the ground in the bottom third
    arcade.draw_rectangle_filled(SCREEN_WIDTH / 2, SCREEN_HEIGHT / 6,
                                 SCREEN_WIDTH - 1, SCREEN_HEIGHT / 3,
                                 arcade.color.DARK_SPRING_GREEN)


def draw_birds():
    for bird in bird_list:
        # Draw the bird.
        draw_bird(bird[0], bird[1])


def draw_bird(x, y):
    """
    Draw a bird using a couple arcs.
    """
    arcade.draw_arc_outline(x, y, 20, 20, arcade.color.BLACK, 0, 90)
    arcade.draw_arc_outline(x + 40, y, 20, 20, arcade.color.BLACK, 90, 180)


def draw_trees():

    # Draw the top row of trees
    for x in range(45, SCREEN_WIDTH, 90):
        draw_pine_tree(x, SCREEN_HEIGHT / 3)

    # Draw the bottom row of trees
    for x in range(65, SCREEN_WIDTH, 90):
        draw_pine_tree(x, (SCREEN_HEIGHT / 3) - 120)


def draw_pine_tree(center_x, center_y):
    """
    This function draws a pine tree at the specified location.

    Args:
      :center_x: x position of the tree center.
      :center_y: y position of the tree trunk center.
    """
    # Draw the trunk center_x
    arcade.draw_rectangle_filled(center_x, center_y, 20, 40, arcade.color.DARK_BROWN)

    tree_bottom_y = center_y + 20

    # Draw the triangle on top of the trunk
    point_list = ((center_x - 40, tree_bottom_y),
                  (center_x, tree_bottom_y + 100),
                  (center_x + 40, tree_bottom_y))

    arcade.draw_polygon_filled(point_list, arcade.color.DARK_GREEN)


if __name__ == "__main__":
    setup()