from microbit import *
import random
import time
 
# CONSTANT
N_X = 5 # nr pixels in x direction
N_Y = 5 # nr pixels in x direction
ASTEROID_DELAY_MAX = 500
ASTEROID_DELAY_MIN = 100
ASTEROID_DELAY_DELTA = 50
TIME_LEVEL_UPDATE = 2000
GAME_OVER_SLEEP = 2000
IMAGE_GAME_OVER = Image.ANGRY
 
ASTEROID_BRIGHTNESS = 5
PLAYER_BRIGHTNESS = 9
SLEEP_TIME_MS = 20
 
def game():
    # VARIABLES
    player_x = N_X // 2
    asteroid_x = random.randint(0,N_X-1)
    asteroid_y = 0
    asteroid_delay = ASTEROID_DELAY_MAX
    t0 = time.ticks_ms()
    time_last_asteroid_update = t0
    time_last_level_update = t0
    level = 1
    
    # GAME LOOP
    while True:
        # get current time
        t1 = time.ticks_ms()

        # update level
        if t1 - time_last_level_update > TIME_LEVEL_UPDATE:
            if asteroid_delay > ASTEROID_DELAY_MIN:
                asteroid_delay -= ASTEROID_DELAY_DELTA
            else:
                asteroid_delay = ASTEROID_DELAY_MIN
            level += 1
            time_last_level_update = t1

        # update asteroid position
        if t1 - time_last_asteroid_update > asteroid_delay:
            if asteroid_y < N_Y-1:
                asteroid_y += 1
            else:
                asteroid_x = random.randint(0,N_X-1)
                asteroid_y = 0
            time_last_asteroid_update = t1

        # update player (button presses)
        if button_a.get_presses() and player_x > 0:
            player_x -= 1
        elif button_b.get_presses() and player_x < N_X-1:
            player_x += 1

        # collision check
        if asteroid_y == N_Y-1 and asteroid_x == player_x:
            return level

        # update display
        display.clear()
        display.set_pixel(player_x,N_Y-1,PLAYER_BRIGHTNESS)
        display.set_pixel(asteroid_x,asteroid_y,ASTEROID_BRIGHTNESS)
        # short sleep
        sleep(SLEEP_TIME_MS)
 
def game_over(level):
    display.show(IMAGE_GAME_OVER)
    sleep(GAME_OVER_SLEEP)
    display.scroll("Level: " + str(level))
    display.show(IMAGE_GAME_OVER)
    while True: # restart
        if button_a.get_presses() or button_b.get_presses():
            return
 
while True:
    level = game()
    game_over(level)