import pygame
from pygame.locals import *
import sys
import random

# Initialize pygame
pygame.init()

# Vector for easy 2D calculations
vec = pygame.math.Vector2

# Screen dimensions
HEIGHT = 450
WIDTH = 400

# Physics constants
ACC = 0.5
FRIC = -0.12

# Frames per second
FPS = 60
FramePerSec = pygame.time.Clock()

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

# Player class
class Player(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__() 
        # Create player surface and rectangle
        self.surf = pygame.Surface((30, 30))
        self.surf.fill((128,255,40))
        self.rect = self.surf.get_rect()
        # Initial position, velocity, and acceleration
        self.pos = vec((10, 360))
        self.vel = vec(0,0)
        self.acc = vec(0,0)
        self.jumping = False

    # Move player
    def move(self):
        self.acc = vec(0,0.5)
        pressed_keys = pygame.key.get_pressed()
        # Apply acceleration based on key presses
        if pressed_keys[K_LEFT]:
            self.acc.x = -ACC
        if pressed_keys[K_RIGHT]:
            self.acc.x = ACC
        # Apply friction
        self.acc.x += self.vel.x * FRIC
        self.vel += self.acc
        self.pos += self.vel + 0.5 * self.acc
        # Wrap around screen edges
        if self.pos.x > WIDTH:
            self.pos.x = 0
        if self.pos.x < 0:
            self.pos.x = WIDTH
        self.rect.midbottom = self.pos

    # Player jump
    def jump(self):
        hits = pygame.sprite.spritecollide(self, platforms, False)
        if hits and not self.jumping:
           self.jumping = True
           self.vel.y = -15

    # Cancel jump if player releases jump key
    def cancel_jump(self):
        if self.jumping:
            if self.vel.y < -3:
                self.vel.y = -3

    # Update player position
    def update(self):
        hits = pygame.sprite.spritecollide(P1 , platforms, False)
        if P1.vel.y > 0:
            if hits:
                if self.pos.y < hits[0].rect.bottom:
                    self.pos.y = hits[0].rect.top + 1
                    self.vel.y = 0
                    self.jumping = False

# Platform class
class Platform(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        # Create platform surface and rectangle
        self.surf = pygame.Surface((random.randint(50,100), 12))
        self.surf.fill((0,255,0))
        self.rect = self.surf.get_rect(center = (random.randint(0,WIDTH-10),
                                                 random.randint(0, HEIGHT-30)))
        
    # Move platform (not used in this game)
    def move(self):
        pass

# Check if platform overlaps with others
def check(platform, groupies):
    if pygame.sprite.spritecollideany(platform,groupies):
        return True
    else:
        for entity in groupies:
            if entity == platform:
                continue
            if (abs(platform.rect.top - entity.rect.bottom) < 50) and (abs(platform.rect.bottom - entity.rect.top) < 50):
                return True
        C = False

# Generate platforms
def plat_gen():
    while len(platforms) < 6 :
        width = random.randrange(50,100)
        p  = Platform()             
        C = True         
        while C:           
             p = Platform()
             p.rect.center = (random.randrange(0, WIDTH - width),
                             random.randrange(-50, 0))
             C = check(p, platforms)
        platforms.add(p)
        all_sprites.add(p)

# Initialize main platform and player
PT1 = Platform()
P1 = Player()

# Customize main platform
PT1.surf = pygame.Surface((WIDTH, 20))
PT1.surf.fill((255,0,0))
PT1.rect = PT1.surf.get_rect(center = (WIDTH/2, HEIGHT - 10))
 
# Create sprite groups
all_sprites = pygame.sprite.Group()
all_sprites.add(PT1)
all_sprites.add(P1)
platforms = pygame.sprite.Group() 
platforms.add(PT1) 

# Generate additional platforms
for x in range(random.randint(4,5)):
    C = True
    pl = Platform()
    while C:
        pl = Platform()
        C = check(pl, platforms)
    platforms.add(pl)
    all_sprites.add(pl)
 
# Main game loop
while True:
    P1.update()
    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()
        if event.type == pygame.KEYUP:    
            if event.key == pygame.K_SPACE:
                P1.cancel_jump()  
 
    # Move player and platforms
    if P1.rect.top <= HEIGHT / 3:
        P1.pos.y += abs(P1.vel.y)
        for plat in platforms:
            plat.rect.y += abs(P1.vel.y)
            if plat.rect.top >= HEIGHT:
                plat.kill()
 
    plat_gen()
    displaysurface.fill((0,0,0))
     
    # Draw sprites and update their positions
    for entity in all_sprites:
        displaysurface.blit(entity.surf, entity.rect)
        entity.move()
 
    pygame.display.update()
    FramePerSec.tick(FPS)