alien_invasion.py

import sys
import pygame
from time import sleep
from settings import Settings
from button import Button
from scoreboard import Scoreboard
from ship import Ship
from fleet import Fleet

class AlienInvasion:
    """Overall class to manage game assets and behavior."""

    def __init__(self):
        """Initialize the game."""
        # Initialize game display
        pygame.init()
        self.settings = Settings()
        if self.settings.fullscreen:
            self.screen = pygame.display.set_mode((0, 0), pygame.FULLSCREEN)
            self.settings.screen_width = self.screen.get_rect().width
            self.settings.screen_height = self.screen.get_rect().height
        else:
            self.screen = pygame.display.set_mode(
                (self.settings.screen_width, self.settings.screen_height))
        pygame.display.set_caption("Alien Invasion")

        # Game is paused initiallly
        self.active = False

        # Initialize basic logic variables
        self.level = 1
        self.ships_remaining = self.settings.ship_limit

        # Initialize game elements
        self.player_ship = Ship(self)
        self.fleet = Fleet(self)
        self.play_button = Button(self, "Play")
        self.scoreboard = Scoreboard(self)

    def run(self):
        """Start the main game loop."""
        while True:
            # Check for keyboard/mouse events
            self._check_events()

            # Update player ship and alien fleet, if game is active
            if self.active:
                self.player_ship.update()
                self.fleet.update()

            # Draw the game
            self._draw()

    def _draw(self):
        """Draw the game screen and all elements."""

        # Redraw the background
        self.screen.fill(self.settings.bg_color)

        # Redraw the player ship
        self.player_ship.draw()

        # Redraw the alien fleet
        self.fleet.draw()

        # Redraw the scoreboard
        self.scoreboard.draw()

        # Redraw play button if game is inactive
        if not self.active:
            self.play_button.draw()

        # Make the most recently drawn screen visible
        pygame.display.flip()

    def _start_game(self):
        """Start a new game."""
        # Reset game
        self.level = 1
        self.ships_remaining = self.settings.ship_limit
        self.scoreboard.reset()
        self.settings.initialize_dynamic_settings()
        self.fleet = Fleet(self)
        self.player_ship.reset()

        # Hide cursor
        pygame.mouse.set_visible(False)

        # Start game
        self.active = True

    def kill_player(self):
        """Handle player death."""
        if self.ships_remaining > 0:
            # Decrement number of ships remaining
            self.ships_remaining -= 1
            self.scoreboard.reset()

            # Create new fleet and ship
            self.fleet = Fleet(self)
            self.player_ship.reset()

            # Pause
            sleep(0.5)
        else:
            self.active = False
            pygame.mouse.set_visible(True)

    def kill_alien(self):
        """Handle alien kills."""
        self.scoreboard.set_score(self.scoreboard.score + self.settings.alien_points)

        # Create a new fleet if all aliens are gone
        if not self.fleet.aliens:
            self.player_ship.reset()
            self.fleet = Fleet(self)
            # Increment speed (difficulty)
            self.settings.increase_speed()
            # Increment level
            self.level += 1
            self.scoreboard.prep_level()

    def _check_events(self):
        """Respond to keyboard and mouse events."""
        for event in pygame.event.get():
            # Exit when the game window is closed
            if event.type == pygame.QUIT:
                self.scoreboard.save_high_score()
                sys.exit()
            # Respond to mouse events
            if event.type == pygame.MOUSEBUTTONDOWN:
                mouse_pos = pygame.mouse.get_pos()
                self._check_play_button(mouse_pos)
            # Respond to key events
            elif event.type == pygame.KEYDOWN:
                self._check_keydown_event(event)
            elif event.type == pygame.KEYUP:
                self._check_keyup_event(event)

    def _check_keydown_event(self, event):
        """Respond to keypresses."""
        if event.key == pygame.K_RIGHT:
            self.player_ship.moving_right = True
        elif event.key == pygame.K_LEFT:
            self.player_ship.moving_left = True
        elif event.key == pygame.K_SPACE:
            self.player_ship.fire_bullet()
        elif event.key == pygame.K_q:
            self.scoreboard.save_high_score()
            sys.exit()
        elif event.key == pygame.K_p and not self.active:
            self._start_game()

    def _check_keyup_event(self, event):
        """Respond to key releases."""
        if event.key == pygame.K_RIGHT:
            self.player_ship.moving_right = False
        elif event.key == pygame.K_LEFT:
            self.player_ship.moving_left = False

    def _check_play_button(self, mouse_pos):
        """Start a new game when the player clicks Play."""
        button_clicked = self.play_button.rect.collidepoint(mouse_pos)
        if button_clicked and not self.active:
            self._start_game()

if __name__ == '__main__':
    # Make a game instance and run it
    game = AlienInvasion()
    game.run()