import pygame
import math
from queue import PriorityQueue
WIDTH=800
WIN=pygame.display.set_mode((WIDTH,WIDTH))
pygame.display.set_caption("Path Finding")
RED=(255,0,0)
GREEN=(0,255,0)
BLUE=(0,0,255)
WHITE=(255,255,255)
YELLOW=(255,255,0)
BLACK=(0,0,0)
PURPLE=(128,0,128)
ORANGE=(255,165,0)
GREY=(128,128,128)
TURQUIOSE=(64,224,208)

class Spot:
    def __init__(self,row,col,width,total_rows):
        self.row = row
        self.col = col
        self.x= row*width
        self.y= col*width
        self.color=WHITE
        self.neighbors=[]
        self.width=width
        self.total_rows=total_rows
    def get_pos(self):
        return self.row,self.col
    def is_closed(self):
        return self.color == RED
    def is_opened(self):
        return self.color == GREEN
    def is_barrier(self):
        return self.color == BLACK
    def is_start(self):
        return self.color == ORANGE
    def is_end(self):
        return self.color == TURQUIOSE
    def reset(self):
        self.color=WHITE
    def make_closed(self):
        self.color=RED
    def make_start(self):
        self.color=ORANGE
    def make_open(self):
        self.color=GREEN
    def make_barrier(self):
        self.color=BLACK
    def make_end(self):
        self.color=TURQUIOSE
    def make_path(self):
        self.color=PURPLE
    def draw(self,win):
        pygame.draw.rect(win,self.color,(self.x,self.y,self.width,self.width))
    def update_neighbours(self,grid):
        self.neighbors=[]
        if self.row < self.total_rows-1 and not grid[self.row+1][self.col].is_barrier():
            self.neighbors.append(grid[self.row+1][self.col])
        if self.row > 0 and not grid[self.row-1][self.col].is_barrier():
            self.neighbors.append(grid[self.row-1][self.col])
        if self.col < self.total_rows-1 and not grid[self.row][self.col+1].is_barrier():
            self.neighbors.append(grid[self.row][self.col+1])
        if self.col > 0 and not grid[self.row][self.col-1].is_barrier():
            self.neighbors.append(grid[self.row][self.col-1])

    def __lt__(self,other):
        return False
def h(p1,p2):
    x1,y1=p1
    x2,y2=p2
    return abs(x1-x2)+abs(y1-y2)
def reconstruct_path(came_from,current,draw):
    while current in came_from:
        current=came_from[current]
        current.make_path()
        draw()
def algoritham(draw,grid,start,end):
    c=0
    open_set=PriorityQueue()
    open_set.put((0,c,start))
    came_from={}
    g_score={spot:float("inf") for row in grid for spot in row}
    g_score[start]=0
    f_score={spot:float("inf") for row in grid for spot in row}
    f_score[start]=h(start.get_pos(),end.get_pos())
    open_set_hash={start}
    while not open_set.empty():
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
        current =open_set.get()[2]
        open_set_hash.remove(current)
        if(current == end):
            reconstruct_path(came_from,end,draw)
            start.make_start()
            end.make_end()
            return True
        for neighbor in current.neighbors:
            temp_g_score = g_score[current]+1
            if temp_g_score<g_score[neighbor]:
                came_from[neighbor]=current
                g_score[neighbor]=temp_g_score
                f_score[neighbor]=temp_g_score+h(neighbor.get_pos(),end.get_pos())
                if neighbor not in open_set_hash:
                    c=c+1
                    open_set.put((f_score[neighbor],c,neighbor))
                    open_set_hash.add(neighbor)
                    neighbor.make_open()
        draw()
        if current!=start:
            current.make_closed()
    return None

def make_grid(rows,width):
    grid=[]
    gap=width//rows
    for i in range(rows):
        grid.append([])
        for j in range(rows):
            spot=Spot(i,j,gap,rows)
            grid[i].append(spot)
    return grid
def draw_grid(win,rows,width):
    gap=width//rows
    for i in range(rows):
        pygame.draw.line(win,GREY,(0,i*gap),(width,i*gap))
        for j in range(rows):
            pygame.draw.line(win,GREY,(j*gap,0),(j*gap,width))
def draw(win ,grid,rows,width):
    win.fill(WHITE)
    for row in grid:
        for spot in row:
            spot.draw(win)
    draw_grid(win,rows,width)
    pygame.display.update()
def get_clicked_postion(pos,rows,width):
    gap=width//rows
    y,x=pos
    row=y//gap
    col=x//gap
    return row,col
def main(win,width):
    ROWS= 50
    grid=make_grid(ROWS,width)
    start=None
    end=None
    run=True

    while run:
        draw(win,grid,ROWS,width)
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                run=False

            if pygame.mouse.get_pressed()[0]:
                pos=pygame.mouse.get_pos()
                row,col =get_clicked_postion(pos,ROWS,width)
                spot =grid[row][col]
                if not start and spot!=end:
                    start=spot
                    start.make_start()
                elif not end and spot!=start:
                    end=spot
                    end.make_end()
                elif spot!= end and spot !=start:
                    spot.make_barrier()
            elif pygame.mouse.get_pressed()[2]:
                pos=pygame.mouse.get_pos()
                row,col =get_clicked_postion(pos,ROWS,width)
                spot =grid[row][col]
                spot.reset()
                if spot==start:
                    start=None
                elif spot==end:
                    end=None
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_SPACE and start and end:
                    for row in grid:
                        for spot in row:
                            spot.update_neighbours(grid)
                    algoritham(lambda:draw(win,grid,ROWS,width),grid,start,end)
                if event.key == pygame.K_c:
                    start=None
                    end=None
                    grid=make_grid(ROWS,width)


    pygame.quit()
main(WIN,WIDTH)