import pygame
import sys
from pygame.locals import *

pygame.init()
vec = pygame.math.Vector2  # 2D vector for position and velocity

HEIGHT = 450
WIDTH = 400
ACC = 0.5
FRIC = -0.12
FPS = 60

FramePerSec = pygame.time.Clock()

displaysurface = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Game")

class Player(pygame.sprite.Sprite):
    def jump(self):
        hits = pygame.sprite.spritecollide(self, platforms, False)
        if hits:
            self.vel.y -= 15

    def __init__(self):
        super().__init__()
        self.surf = pygame.Surface((30, 30))
        self.surf.fill((128, 255, 40))
        self.rect = self.surf.get_rect(center=(10, 420))

        self.pos = vec((10, 300))
        self.vel = vec((0, 0))
        self.acc = vec((0, 0))

    def move(self):
        self.acc = vec(0, 0.5)  # gravity effect

        pressed_keys = pygame.key.get_pressed()
        if pressed_keys[K_LEFT]:
            self.acc.x = -ACC
        if pressed_keys[K_RIGHT]:
            self.acc.x = ACC

        # Apply friction to velocity if not moving
        self.acc.x += self.vel.x * FRIC
        self.vel += self.acc  # Update velocity based on acceleration
        self.pos += self.vel + 0.5 * self.acc  # Update position based on velocity and acceleration

        # Wrap around the screen horizontally
        if self.pos.x > WIDTH:
            self.pos.x = 0
        if self.pos.x < 0:
            self.pos.x = WIDTH

        self.rect.midbottom = self.pos

    def update(self):
        hits = pygame.sprite.spritecollide(P1, platforms, False)
        if P1.vel.y > 0:
            if hits:
                self.pos.y = hits[0].rect.top + 1  # Place player on top of platform
                self.vel.y = 0  # Stop vertical velocity when hitting the ground


class Platform(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.surf = pygame.Surface((WIDTH, 20))
        self.surf.fill((255, 0, 0))
        self.rect = self.surf.get_rect(center=(WIDTH / 2, HEIGHT))

# Create player and platform
PT1 = Platform()
P1 = Player()

all_sprites = pygame.sprite.Group()
all_sprites.add(PT1)
all_sprites.add(P1)

platforms = pygame.sprite.Group()
platforms.add(PT1)

while True:
    for event in pygame.event.get():
        if event.type == QUIT:
            pygame.quit()
            sys.exit()
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_SPACE:
                P1.jump()

    # Fill screen with black to clear previous frame
    displaysurface.fill((0, 0, 0))
    
    # Update player movement and position
    P1.move()
    P1.update()

    # Draw all sprites
    for entity in all_sprites:
        displaysurface.blit(entity.surf, entity.rect)

    # Update the display to reflect changes
    pygame.display.update()

    # Maintain frame rate
    FramePerSec.tick(FPS)