use std::cmp;

use super::{Cell, Engine, Grid, WHITE, BLACK};

pub struct LifeEngine {
    grid: Grid<bool>,
}


pub fn new(size: usize) -> LifeEngine {
    let mut life = LifeEngine{grid: Grid::new(false, size)};

    // r pemento
    let centery = size/2;
    let centerx = size/2;

    life.grid.set(centery, centerx,true);
    life.grid.set(centery+1, centerx,  true);
    life.grid.set(centery-1, centerx, true);

    life.grid.set(centery-1, centerx-1,  true);
    life.grid.set(centery, centerx+1, true);

    life
}

impl LifeEngine {
    fn nalive(&self, y: usize, x: usize) -> u8 {
        let mut nalive = 0;
        if y > 0 {
            if x > 0 {
                if *self.grid.get(y-1, x-1) {
                    nalive += 1;
                }
            }
            if *self.grid.get(y-1, x) {
                nalive += 1;
            }
            if x < self.grid.size()-1 {
                if *self.grid.get(y-1, x+1) {
                    nalive += 1;
                }
            }
        }

        if x > 0 {
            if *self.grid.get(y, x-1) {
                nalive += 1;
            }
        }

        if x < self.grid.size()-1 {
            if *self.grid.get(y, x+1) {
                nalive += 1;
            }
        }

        if y < self.grid.size()-1 {
            if x > 0 {
                if *self.grid.get(y+1, x-1) {
                    nalive += 1;
                }
            }
            if *self.grid.get(y+1, x) {
                nalive += 1;
            }
            if x < self.grid.size()-1 {
                if *self.grid.get(y+1, x+1) {
                    nalive += 1;
                }
            }
        }
        nalive
    }
}

impl Engine for LifeEngine {
    fn evolve(&mut self) -> super::Grid<Cell> {
        let mut new_render_grid = super::Grid::new(Cell{color: BLACK}, self.grid.size());
        let mut new_life_grid = Grid::new(false, self.grid.size());

        for y in 0..self.grid.size() {
            for x in 0..self.grid.size() {
                let nalive = self.nalive(y, x);

                if *self.grid.get(y, x) {
                    if nalive == 2 || nalive == 3 {
                        new_render_grid.set(y, x, Cell{color: WHITE});
                        new_life_grid.set(y, x,  true);
                    }
                } else if nalive == 3 {
                    new_render_grid.set(y, x, Cell{color: WHITE});
                    new_life_grid.set(y, x, true);
                }
            }
        }

        self.grid = new_life_grid;
        new_render_grid
    }
}