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use derive_more::{Display, Error};

use crate::card::Card;
use crate::piles::Pile;

#[derive(Debug, Display, Error)]
pub enum SequenceError {
    #[display(fmt = "Cards are out of sequence")]
    OutOfSequence {
        current_index: usize,
        current_card: Card,
        next_card: Card,
    },
}

pub trait CardSequence {
    fn accepts(current_card: Card, next_card: Card) -> bool;
}

pub trait Sequenced {
    fn is_sequential<S>(&self) -> Result<(), SequenceError>
    where
        S: CardSequence;
}

impl Sequenced for [Card] {
    fn is_sequential<S>(&self) -> Result<(), SequenceError>
    where
        S: CardSequence,
    {
        self.iter()
            .copied()
            .enumerate()
            .try_reduce(|current, next| {
                let (current_index, current_card) = current;
                let (_, next_card) = next;

                S::accepts(current_card, next_card).then_some(next).ok_or(
                    SequenceError::OutOfSequence {
                        current_index,
                        current_card,
                        next_card,
                    },
                )
            })?;
        Ok(())
    }
}

impl<P> Sequenced for P
where
    P: Pile,
{
    fn is_sequential<S>(&self) -> Result<(), SequenceError>
    where
        S: CardSequence,
    {
        self.cards().is_sequential::<S>()
    }
}