use super::circular_index;
use crate::game_of_life::opts::Opts;
use crate::game_of_life::simulation::plane::Plane;
use std::ops::Index;

/// Game of Life universe struct for running simulations
#[derive(Debug, Clone, PartialEq)]
pub(crate) struct Universe {
    pub opts: Opts,
    pub current: Vec<Plane>,
    pub future: Vec<Plane>,
}

impl Index<isize> for Universe {
    type Output = Plane;
    fn index(&self, idx: isize) -> &Plane {
        let len = self.current.len() as isize;
        &self.current[circular_index(idx, len)]
    }
}

#[cfg(test)]
mod index {
    use super::*;

    #[test]
    fn get_element() {
        let opts = Opts {
            seed: 1337,
            input: None,
            width: 13,
            height: 13,
            live_cell: 'L',
            dead_cell: 'D',
            delay: 13,
        };
        let u = Universe {
            opts,
            current: vec![
                Plane(vec![false; 5]),
                Plane(vec![false, false, true, false, false]),
                Plane(vec![false; 5]),
            ],
            future: vec![Plane(vec![])],
        };

        assert_eq!(u[-3][0], false);
        assert_eq!(u[-3][1], false);
        assert_eq!(u[-3][3], false);
        assert_eq!(u[-3][4], false);
        assert_eq!(u[0][0], false);
        assert_eq!(u[0][1], false);
        assert_eq!(u[0][3], false);
        assert_eq!(u[0][4], false);
        assert_eq!(u[2][0], false);
        assert_eq!(u[2][1], false);
        assert_eq!(u[2][3], false);
        assert_eq!(u[2][4], false);
        assert_eq!(u[5][0], false);
        assert_eq!(u[5][1], false);
        assert_eq!(u[5][3], false);
        assert_eq!(u[5][4], false);

        assert_eq!(u[-2][-3], true);
        assert_eq!(u[-2][2], true);
        assert_eq!(u[-2][7], true);
        assert_eq!(u[1][-3], true);
        assert_eq!(u[1][2], true);
        assert_eq!(u[1][7], true);
        assert_eq!(u[4][-3], true);
        assert_eq!(u[4][2], true);
        assert_eq!(u[4][7], true);
    }
}

impl Universe {
    /// Return the neighboring cells to the cell in index (Y,X) on a plane
    ///
    /// given a cell "C" in a universe of cells "." the immediate neighbors would be "x" as in
    /// the following different examples
    ///
    ///     .....  |  .xxx.  |  .xCx.  |  xCx..  |  Cx..x  |  xx..x  |
    ///     .xxx.  |  .xCx.  |  .xxx.  |  xxx..  |  xx..x  |  Cx..x  |
    ///     .xCx.  |  .xxx.  |  .....  |  .....  |  .....  |  xx..x  |
    ///     .xxx.  |  .....  |  .....  |  .....  |  .....  |  .....  |
    ///     .....  |  .....  |  .xxx.  |  xxx..  |  xx..x  |  .....  |
    ///
    pub(crate) fn neighbors(self, y: isize, x: isize) -> Vec<bool> {
        vec![
            self[y - 1][x - 1],
            self[y - 1][x],
            self[y - 1][x + 1],
            self[y][x - 1],
            self[y][x + 1],
            self[y + 1][x - 1],
            self[y + 1][x],
            self[y + 1][x + 1],
        ]
    }

}

#[cfg(test)]
mod neighbors {
    use super::*;

    fn opts() -> Opts {
        Opts {
            seed: 1337,
            input: None,
            width: 13,
            height: 13,
            live_cell: 'L',
            dead_cell: 'D',
            delay: 13,
        }
    }

    #[test]
    fn center() {
        let u = Universe {
            opts: opts(),
            future: vec![Plane(vec![])],
            current: vec![
                Plane(vec![false, false, false, false, false]),
                Plane(vec![false, true, true, true, false]),
                Plane(vec![false, true, true, true, false]),
                Plane(vec![false, true, true, true, false]),
                Plane(vec![false, false, false, false, false]),
            ],
        };
        assert_eq!(u.neighbors(2,2), vec![true; 8]);
    }

    #[test]
    fn top_edge() {
        let u = Universe {
            opts: opts(),
            future: vec![Plane(vec![])],
            current: vec![
                Plane(vec![false, true, true, true, false]),
                Plane(vec![false, true, true, true, false]),
                Plane(vec![false, false, false, false, false]),
                Plane(vec![false, false, false, false, false]),
                Plane(vec![false, true, true, true, false]),
            ],
        };
        assert_eq!(u.neighbors(0,2), vec![true; 8]);
    }

    #[test]
    fn bottom_edge() {
        let u = Universe {
            opts: opts(),
            future: vec![Plane(vec![])],
            current: vec![
                Plane(vec![false, true, true, true, false]),
                Plane(vec![false, false, false, false, false]),
                Plane(vec![false, false, false, false, false]),
                Plane(vec![false, true, true, true, false]),
                Plane(vec![false, true, true, true, false]),
            ],
        };
        assert_eq!(u.neighbors(4,2), vec![true; 8]);
    }

    #[test]
    fn left_edge() {
        let u = Universe {
            opts: opts(),
            future: vec![Plane(vec![])],
            current: vec![
                Plane(vec![false, false, false, false, false]),
                Plane(vec![true, true, false, false, true]),
                Plane(vec![true, true, false, false, true]),
                Plane(vec![true, true, false, false, true]),
                Plane(vec![false, false, false, false, false]),
            ],
        };
        assert_eq!(u.neighbors(2,0), vec![true; 8]);
    }

    #[test]
    fn right_edge() {
        let u = Universe {
            opts: opts(),
            future: vec![Plane(vec![])],
            current: vec![
                Plane(vec![false, false, false, false, false]),
                Plane(vec![true, false, false, true, true]),
                Plane(vec![true, false, false, true, true]),
                Plane(vec![true, false, false, true, true]),
                Plane(vec![false, false, false, false, false]),
            ],
        };
        assert_eq!(u.neighbors(2,4), vec![true; 8]);
    }

    #[test]
    fn bottom_corner_edge() {
        let u = Universe {
            opts: opts(),
            future: vec![Plane(vec![])],
            current: vec![
                Plane(vec![true, false, false, true, true]),
                Plane(vec![false, false, false, false, false]),
                Plane(vec![false, false, false, false, false]),
                Plane(vec![true, false, false, true, true]),
                Plane(vec![true, false, false, true, true]),
            ],
        };
        assert_eq!(u.neighbors(4,4), vec![true; 8]);
    }

    #[test]
    fn top_corner_edge() {
        let u = Universe {
            opts: opts(),
            future: vec![Plane(vec![])],
            current: vec![
                Plane(vec![true, true, false, false, true]),
                Plane(vec![true, true, false, false, true]),
                Plane(vec![false, false, false, false, false]),
                Plane(vec![false, false, false, false, false]),
                Plane(vec![true, true, false, false, true]),
            ],
        };
        assert_eq!(u.neighbors(0,0), vec![true; 8]);
    }
}