import threading
import time
import random


class GameLoop():
    """Implements a loop that calls tick every 1/fps

    tick gets called with the time delta to the last call as parameter
    if fixed_dt is True the tick function gets called with 1/fps
    """

    def __init__(self, fps=1, tick=None, fixed_dt=False, args=None):
        self.fps = fps
        self.tick = tick if tick is not None else self.default_tick
        self.args = args or tuple()
        self.fixed_dt = fixed_dt
        self.running = False
        self.last_frame_time = time.time()
        self.thread = threading.Thread(target=self.loop)

    def loop(self):
        while self.running:
            current_time = time.time()
            dt = current_time - self.last_frame_time
            self.last_frame_time = current_time

            if self.fixed_dt:
                self.tick(1 / self.fps, *self.args)
            else:
                self.tick(dt, *self.args)

            sleep_time = (1 / self.fps) - (time.time() - self.last_frame_time)
            if sleep_time > 0:
                time.sleep(sleep_time)

    def start(self):
        self.running = True
        self.thread.start()

    def stop(self):
        self.running = False

    def default_tick(self, dt):
        print('ticked. Last tick was %.2f seconds ago' % dt)
        time.sleep(random.choice([0.4, 0.5, 0.6, 1.4, 2.1]) * 1/self.fps)