use nd_array::Array;
use crate::system::Position;

pub trait Storage {
    fn at(&self, position: &Position) -> bool;
    fn deposit(&mut self, position: &Position);
}

pub struct VectorStorage {
    backing: Vec<bool>,
    grid_size: u32,
    dim: u32,
}

impl VectorStorage {
    pub fn new(grid_size: u32, dim: u32) -> VectorStorage {
        VectorStorage { grid_size, dim, backing: vec![false; grid_size.pow(dim) as usize] }
    }

    pub fn linear_index(&self, position: &Position) -> usize {
        assert!(position.0 <= self.grid_size as i32 && -(self.grid_size as i32) <= position.0);
        assert!(position.1 <= self.grid_size as i32 && -(self.grid_size as i32) <= position.1);

        let x = (position.0 + (self.grid_size as i32) / 2) as usize;
        let y = (position.1 + (self.grid_size as i32) / 2) as usize;

        return self.grid_size as usize * y + x
    }

    /*
     * Convenience function for c-binding
     * */
    pub fn write(&mut self, position: &Position, val: bool) {
        let index = self.linear_index(position);
        self.backing[index] = val;
    }
}

impl Storage for VectorStorage {
    fn at(&self, position: &Position) -> bool {
        return self.backing[self.linear_index(position)]
    }

    fn deposit(&mut self, position: &Position) {
        let index = self.linear_index(position);
        self.backing[index] = true;
    }
}