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

# Initialize Pygame
pygame.init()

# Define constants
vec = pygame.math.Vector2 
HEIGHT = 450
WIDTH = 400
ACC = 0.5
FRIC = -0.12
FPS = 60
FramePerSec = pygame.time.Clock()

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

# Define the Player class
class Player(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__() 
        # Create player surface
        self.surf = pygame.Surface((30, 30))
        self.surf.fill((128,255,40))
        # Set initial position of the player
        self.rect = self.surf.get_rect(center=(10,420))
        # Define player's position, velocity, and acceleration vectors
        self.pos = vec((10, 385))
        self.vel = vec(0,0)
        self.acc = vec(0,0)

    # Method to move the player
    def move(self):
        # Apply gravity
        self.acc = vec(0,0.5)
        # Check for key presses to move left or right
        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
        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    

    # Method to update player position based on collisions
    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
                self.vel.y = 0

    # Method to make the player jump
    def jump(self):
        hits = pygame.sprite.spritecollide(self, platforms, False)
        if hits:
            self.vel.y = -15

# Define the Platform class
class platform(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        # Create platform surface
        self.surf = pygame.Surface((random.randint(50,100), 12))
        self.surf.fill((0,255,0))
        # Set random position for the platform within screen boundaries
        self.rect = self.surf.get_rect(center = (random.randint(0,WIDTH-10),
                                                 random.randint(0, HEIGHT-30)))

# Function to generate platforms
def plat_gen():
    while len(platforms) < 7:
        width = random.randrange(50,100)
        p  = platform()             
        p.rect.center = (random.randrange(0, WIDTH - width), random.randrange(-50, 0))
        platforms.add(p)
        all_sprites.add(p)

# Create instances of Player and Platform classes
PT1 = platform()
P1 = Player()

# Adjust the first platform's properties to act as ground
PT1.surf = pygame.Surface((WIDTH, 20))
PT1.surf.fill((255,0,0))
PT1.rect = PT1.surf.get_rect(center = (WIDTH/2, HEIGHT - 10))

# Group all sprites and platforms
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(5, 6)):
    pl = platform()
    platforms.add(pl)
    all_sprites.add(pl)

# Main game loop
while True:
    # Handle events
    for event in pygame.event.get():
        if event.type == QUIT:
            pygame.quit()
            sys.exit()
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_ESCAPE:
                pygame.quit()
                sys.exit()
        if event.type == pygame.KEYDOWN:    
            if event.key == pygame.K_SPACE:
                P1.jump()
            

    # Check if the player is at the top third of the screen
    if P1.rect.top <= HEIGHT / 3:
        # Move the player and platforms upwards
        P1.pos.y += abs(P1.vel.y)
        for plat in platforms:
            plat.rect.y += abs(P1.vel.y)
            # Remove platforms that have moved off-screen
            if plat.rect.top >= HEIGHT:
                plat.kill()
     
    # Fill the display surface with black color
    displaysurface.fill((0,0,0))

    # Move the player, update its position, and generate platforms
    P1.move()
    P1.update()
    plat_gen()
    
    # Draw all sprites on the display surface
    for entity in all_sprites:
        displaysurface.blit(entity.surf, entity.rect)
    
    # Update the display
    pygame.display.update()
    FramePerSec.tick(FPS)