// Eryn Wells <eryn@erynwells.me>

use crate::Board;
use chessfriend_core::{File, Rank, Square};
use std::fmt;

#[must_use]
pub struct DiagramFormatter<'a>(&'a Board);

impl<'a> DiagramFormatter<'a> {
    pub fn new(board: &'a Board) -> Self {
        Self(board)
    }
}

impl<'a> fmt::Display for DiagramFormatter<'a> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        writeln!(f, "  ╔═════════════════╗")?;

        for rank in Rank::ALL.into_iter().rev() {
            write!(f, "{rank} ║ ")?;

            for file in File::ALL {
                let square = Square::from_file_rank(file, rank);
                match self.0.get_piece(square) {
                    Some(piece) => write!(f, "{piece} ")?,
                    None => write!(f, "· ")?,
                }
            }

            writeln!(f, "║")?;
        }

        writeln!(f, "  ╚═════════════════╝")?;
        writeln!(f, "    a b c d e f g h")?;

        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::{test_board, Board};

    #[test]
    #[ignore]
    fn empty() {
        let pos = test_board!(empty);
        let diagram = DiagramFormatter(&pos);
        println!("{diagram}");
    }

    #[test]
    #[ignore]
    fn one_king() {
        let pos = test_board![Black King on H3];
        let diagram = DiagramFormatter(&pos);
        println!("{diagram}");
    }

    #[test]
    #[ignore]
    fn starting() {
        let pos = test_board!(starting);
        let diagram = DiagramFormatter(&pos);
        println!("{diagram}");
    }
}