import pygame
from collections import deque

class InputHandler:
    """
    Class that is implemented into surfaces in order to control the
    pressing of buttons on both the real hardware and on a keyboard.

    Attributes:
        clock (pygame.time.Clock): Pygame clock used for input time calculations.
        last_input_tick (int): The tick that the last input was registered on.

    """

    def __init__(self, pygame_clock, tick_check=True):
        """
        Create a InputHandler object using a given Pygame clock.

        Args:
            pygame_clock (:obj:`pygame.time.Clock`): A pygame clock to use as the clock for input time calculations.
            tick_check (bool, optional): Bool to ignore inputs that happen to quickly after another. Defaults to True.

        """
        self.clock = pygame_clock
        self.tick_check = tick_check
        self.last_input_tick = 0
        self.dev_check = deque()
        self.dev_code = deque()
        for button in [pygame.K_DOWN, pygame.K_DOWN, pygame.K_UP, pygame.K_UP, pygame.K_DOWN, pygame.K_LEFT,
                       pygame.K_RIGHT, pygame.K_LEFT, pygame.K_a]:
            self.dev_code.append(button)
        self.dev_found = False

    def create_event(self, pressed_button):
        """
        Create a pygame event given a GPIO code and post it to the pygame event handler.
        Args:
            pressed_button (int): The GPIO code to be registered and pressed.

        """
        # Register a button click so long as the last button click happened no less than two frames ago
        if self.tick_check:
            if pygame.time.get_ticks() - self.last_input_tick > self.clock.get_time() * 2:
                pygame.event.post(pygame.event.Event(pygame.KEYDOWN, {'key': pressed_button}))
                pygame.event.post(pygame.event.Event(pygame.KEYUP, {'key': pressed_button}))
                self.dev_check.append(pressed_button)
                if len(self.dev_check) > len(self.dev_code):
                    self.dev_check.popleft()
        else:
            pygame.event.post(pygame.event.Event(pygame.KEYDOWN, {'key': pressed_button}))
            pygame.event.post(pygame.event.Event(pygame.KEYUP, {'key': pressed_button}))
        self.last_input_tick = pygame.time.get_ticks()

    def handle_keyboard(self):
        """Handle keyboard presses and generate corresponding GPIO codes to create events."""

        # Checks if a corresponding keyboard key has been pressed. If it has, emulate a button press.
        for keyboard_event in pygame.event.get():
            if keyboard_event.type == pygame.QUIT:
                running = False
            if keyboard_event.type == pygame.KEYDOWN:
                if keyboard_event.key == pygame.K_a:
                    self.create_event(pygame.K_a)
                if keyboard_event.key == pygame.K_b:
                    self.create_event(pygame.K_b)
                if keyboard_event.key == pygame.K_KP_ENTER:
                    self.create_event(pygame.K_KP_ENTER)
                if keyboard_event.key == pygame.K_RIGHT:
                    self.create_event(pygame.K_RIGHT)
                if keyboard_event.key == pygame.K_LEFT:
                    self.create_event(pygame.K_LEFT)
                if keyboard_event.key == pygame.K_DOWN:
                    self.create_event(pygame.K_DOWN)
                if keyboard_event.key == pygame.K_UP:
                    self.create_event(pygame.K_UP)
                if keyboard_event.key == pygame.K_ESCAPE:
                    running = False

    def update(self):
        """Run either the GPIO handler or the keyboard handler to check for input and create events."""
        self.handle_keyboard()
        if self.dev_code == self.dev_check:
            self.dev_found = True