import pygame
from pygame.locals import *

import math, sys

SCREEN_SIZE_X = 800
SCREEN_SIZE_Y = 600

MAP_SIZE_X = 2000
MAP_SIZE_Y = 2000

RIGHT = 0
LEFT = 1

class Player():
        def __init__(self):
                self.image = pygame.image.load('player.png').convert()
                self.image.set_colorkey((255, 255, 255))
                self.rect = self.image.get_rect()

                self.original = self.image

                self.x, self.y = SCREEN_SIZE_X/2, SCREEN_SIZE_Y/2
                self.virtual_x, self.virtual_y = 567, 456

                self.angle = 90
                self.speed = 5

                self.offset_x, self.offset_y = self.virtual_x - SCREEN_SIZE_X/2, self.virtual_y - SCREEN_SIZE_Y/2

        def change_direction(self, direction):
                if direction == RIGHT:
                        self.angle += 4

                elif direction == LEFT:
                        self.angle -= 4

        def update(self):
                self.rect = self.image.get_rect(center = (self.x, self.y))

                speedx = math.sin(self.angle * (math.pi/180)) * self.speed
                speedy = math.cos(self.angle * (math.pi/180)) * self.speed * -1

                self.virtual_x += speedx
                self.virtual_y += speedy

                if self.virtual_x < MAP_SIZE_X - SCREEN_SIZE_X/2 and self.virtual_x > SCREEN_SIZE_X/2:
                        self.offset_x += speedx

                else:
                        self.x += speedx

                if self.virtual_y < MAP_SIZE_Y - SCREEN_SIZE_Y/2 and self.virtual_y > SCREEN_SIZE_Y/2:
                        self.offset_y += speedy

                else:
                        self.y += speedy

                self.image = pygame.transform.rotate(self.original, self.angle * -1)

        def draw(self, screen):
                screen.blit(self.image, self.rect)

def main():
        pygame.init()

        screen = pygame.display.set_mode((SCREEN_SIZE_X, SCREEN_SIZE_Y), HWSURFACE|DOUBLEBUF)

        background = pygame.image.load('map.png').convert()

        player = Player()

        clock = pygame.time.Clock()

        loop = True
        while loop:
                clock.tick(60)

                for event in pygame.event.get():
                        if event.type == QUIT:
                                loop = False

                        if event.type == KEYDOWN:
                                if event.key == K_ESCAPE:
                                        loop = False

                pygame.event.pump()

                key = pygame.key.get_pressed()

                if key[K_RIGHT]:
                        player.change_direction(RIGHT)

                elif key[K_LEFT]:
                        player.change_direction(LEFT)

                player.update()

                screen.blit(background, (0, 0), area = (player.offset_x, player.offset_y, SCREEN_SIZE_X, SCREEN_SIZE_Y))
                player.draw(screen)

                pygame.display.flip()