import os
import pygame

from display import Scaling, INTERNAL_WIDTH, INTERNAL_HEIGHT

from stats import Stats

DEBUG = os.getenv("DEBUG")

class FieldSprite(pygame.sprite.Sprite):
    def __init__(self, area: tuple ):
        super().__init__()
        self.area = area
        self.update()
        
    def update(self):
        self.rect = Scaling.area_to_rect(self.area)
        self.image = pygame.Surface(self.rect.size)
        self.image.fill("green")
        

class Field():
    initial_area = (320_000, 220_000)

    def __init__(self):
        self.sprites = pygame.sprite.Group()
        self.sprites.add(FieldSprite( (0, 0, *__class__.initial_area) ))
        self.area_full = __class__.initial_area[0] * __class__.initial_area[1]
        self.area_current = self.area_full
        self.percentage = 100
        
    def coordinates_inside_area(self, area, x, y) -> bool:
        """ Test if coordinates are inside area """
        if x < area[0]:
            return False
        if y < area[1]:
            return False
        if x >= area[0]+area[2]:
            return False
        if y >= area[1]+area[3]:
            return False
        return True
        
    def update_area(self):
        """ calculates remaining area and remaining percentage """
        self.area_current = sum( s.area[2]*s.area[3] for s in self.sprites )
        Stats.percent = 100 * self.area_current / self.area_full
        if DEBUG:
            print(
                    f"FIELD: {self.area_full}/{self.area_current}, "
                    f"{self.percentage}")

    def slice(
            self,
            pos: tuple,
            direction: bool,
            thickness: int) -> pygame.Rect:
        """ Slice one area into two areas """

        # Find the overlapping area
        for field in self.sprites:
            if self.coordinates_inside_area(field.area, pos[0], pos[1]):
                break
        else:
            return None

        # remove current area
        ax, ay, aw, ah = field.area
        field.remove(self.sprites)

        # create new areas if there is any space

        if direction:
            x1 = ax
            x2 = pos[0] - thickness
            x3 = pos[0] + thickness
            x4 = ax + aw
            
            if x2 > x1:
                self.sprites.add(FieldSprite( (x1, ay, x2-x1, ah) ))
            if x4 > x3:
                self.sprites.add(FieldSprite( (x3, ay, x4-x3, ah) ))
            self.update_area()
            return Scaling.area_to_rect((x2, ay, x3-x2, ah))
        y1 = ay
        y2 = pos[1] - thickness
        y3 = pos[1] + thickness
        y4 = ay + ah

        if y2 > y1:
            self.sprites.add(FieldSprite( (ax, y1, aw, y2-y1) ))
        if y4 > y3:
            self.sprites.add(FieldSprite( (ax, y3, aw, y4-y3) ))
        self.update_area()
        return Scaling.area_to_rect((ax, y2, aw, y3-y2))
        
    def update(self, dt):
        """ Update sprites basis of dt. dt = milliseconds from last update """
        pass