import pygame
import importlib.util
from pocket_friends.hardware.gpio_handler import Constants, GPIOHandler


class InputHandler:
    def __init__(self, pygame_clock):
        self.clock = pygame_clock
        try:
            importlib.util.find_spec('RPi.GPIO')
            import RPi.GPIO as GPIO
            self.on_hardware = True
        except ImportError:
            import pocket_friends.development.FakeGPIO as GPIO
            self.on_hardware = False
        self.last_input_tick = 0

    def create_event(self, pressed_button):
        """
        Creates a pygame event with a given keyboard code
        :param pressed_button:
        """
        # Register a button click so long as the last button click happened no less than two frames ago
        if pygame.time.get_ticks() - self.last_input_tick > self.clock.get_time() * 2 or not self.on_hardware:
            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_gpio(self):
        """
        Handles getting GPIO button presses and making a pygame event when a press is detected.
        """
        for pressed_button in Constants.buttons:
            code = Constants.buttons.get(pressed_button)

            # Check if a button has been pressed. If it has, create a pygame event for it.
            if GPIOHandler.get_press(code):
                self.create_event(code)

    def keyboard_handler(self):
        """
        Simulates key presses to GPIO button presses. Also handles quitting the game.
        """

        # 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(Constants.buttons.get('a'))
                if keyboard_event.key == pygame.K_b:
                    self.create_event(Constants.buttons.get('b'))
                if keyboard_event.key == pygame.K_PERIOD:
                    self.create_event(Constants.buttons.get('j_i'))
                if keyboard_event.key == pygame.K_RIGHT:
                    self.create_event(Constants.buttons.get('j_r'))
                if keyboard_event.key == pygame.K_LEFT:
                    self.create_event(Constants.buttons.get('j_l'))
                if keyboard_event.key == pygame.K_DOWN:
                    self.create_event(Constants.buttons.get('j_d'))
                if keyboard_event.key == pygame.K_UP:
                    self.create_event(Constants.buttons.get('j_u'))
                if keyboard_event.key == pygame.K_ESCAPE:
                    running = False

    def update(self):
        if self.on_hardware:
            self.handle_gpio()
        else:
            self.keyboard_handler()