use crate::chess::piece::Piece;
use crate::chess::square::Square;
use crate::chess::moves::Move;
use log::trace;


#[derive(Debug)]
pub struct Castling {
    king_side: bool,
    queen_side: bool,
}

#[derive(Debug)]
pub struct Position {
    rows: [[Option<Piece>; 8]; 8],
    whites_turn: bool,
    castling: [Castling; 2],
    en_pessant: Option<Square>
}


// |-----------------------------------------------|
// | 0;0 | 1;0 | 2;0 | 3;0 | 4;0 | 5;0 | 6;0 | 7;0 |
// |-----------------------------------------------|
// | 0;1 | 1;1 | 2;1 | 3;1 | 4;1 | 5;1 | 6;1 | 7;1 | Black
// |-----------------------------------------------|
// | 0;2 | 1;2 | 2;2 | 3;2 | 4;2 | 5;2 | 6;2 | 7;2 |
// |-----------------------------------------------|
// | 0;3 | 1;3 | 2;3 | 3;3 | 4;3 | 5;3 | 6;3 | 7;3 |
// |-----------------------------------------------|
// | 0;4 | 1;4 | 2;4 | 3;4 | 4;4 | 5;4 | 6;4 | 7;4 |
// |-----------------------------------------------|
// | 0;5 | 1;5 | 2;5 | 3;5 | 4;5 | 5;5 | 6;5 | 7;5 |
// |-----------------------------------------------|
// | 0;6 | 1;6 | 2;6 | 3;6 | 4;6 | 5;6 | 6;6 | 7;6 | White
// |-----------------------------------------------|
// | 0;7 | 1;7 | 2;7 | 3;7 | 4;7 | 5;7 | 6;7 | 7;7 |
// |-----------------------------------------------|
// Chess board repesented in code
//
// NOTE: capture left/right is implemented relative to color
// TODO: make this a doc comment

impl Default for Position {
    fn default() -> Self {
        Position {
            rows: [
               [None, None, None, None, None, None, None, None],
               [None, None, None, None, None, None, None, None],
               [None, None, None, None, None, None, None, None],
               [None, None, None, None, None, None, None, None],
               [None, None, None, None, None, None, None, None],
               [None, None, None, None, None, None, None, None],
               [None, None, None, None, None, None, None, None],
               [None, None, None, None, None, None, None, None],
            ],
            whites_turn: true,
            castling: [
                Castling { king_side: false, queen_side: false },
                Castling { king_side: false, queen_side: false },
            ],
            en_pessant: None
        }
    }
}


/// Creating Position
impl Position {
    pub fn new() -> Self {
        Position::default()
    }

    pub fn from_fen(fen: String) -> Self {
        trace!("{fen}");
        let mut pos = Position::default();
        let mut parts = fen.split_ascii_whitespace();

        trace!("{:?}", parts);
        // parse board
        parts.next().unwrap().split('/').enumerate().for_each(|(y, row)| {
            let mut x = 0;
            row.chars().for_each(|c| {
            if c.is_ascii_digit() {
                x += c.to_digit(10).unwrap();
            } else {
                pos.rows[y][x as usize] = Piece::from_fen(c);
                x += 1;
            }
            });
        });

        // parse active color
        parts.next().unwrap();
        trace!("{:?}", parts);
        pos
    }

    /*
    TODO: Decide if Position should be mutable or not
    pub fn set_rows(mut self, rows: [[Option<Piece>; 8]; 8]) -> Self {
        self.rows = rows;
        self
    }
    pub fn set_whites_turn(mut self, whites_turn: bool) -> Self {
        self.whites_turn = whites_turn;
        self
    }
    pub fn set_castling(mut self, castling: [Castling; 2]) -> Self {
        self.castling = castling;
        self
    }
    pub fn set_en_passent(mut self, en_passent: Option<Square>) -> Self {
        self.en_pessant = en_passent;
        self
    }
    */
}

/// Exposing position fields
impl Position {
    pub fn rows(self) -> [[Option<Piece>; 8]; 8] {
        self.rows
    }

    pub fn whites_turn(self) -> bool {
        self.whites_turn
    }

    pub fn castling(self) -> [Castling; 2] {
        self.castling
    }

    pub fn en_passent(self) -> Option<Square> {
        self.en_pessant
    }
}

/// Use position
impl Position {
    pub fn get_moves(self) -> Vec<Move> {
        todo!("finish")
    }
}