// Eryn Wells <eryn@erynwells.me>

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

pub struct DiagramFormatter<'a>(&'a Position);

impl<'a> DiagramFormatter<'a> {
    pub fn new(position: &'a Position) -> DiagramFormatter {
        DiagramFormatter(position)
    }
}

impl<'a> fmt::Display for DiagramFormatter<'a> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "  +-----------------+\n")?;

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

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

            write!(f, "|\n")?;
        }

        write!(f, "  +-----------------+\n")?;
        write!(f, "    a b c d e f g h\n")?;

        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::Position;

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

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

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