path: root/protocol/src/bridge_engine.rs

use crate::card::{Card, Deal, Suit, RankOrder};
use serde::{Deserialize, Serialize};
use anyhow::{anyhow, bail};
use log::{error, info};
use regex::Regex;
use std::cmp::Ordering;
use std::fmt;
use std::str::FromStr;
use strum::{EnumCount, IntoEnumIterator};
use strum_macros::{EnumCount as EnumCountMacro, EnumIter, FromRepr};

pub const SUIT_DISPLAY_ORDER: [Suit; 4] = [Suit::Diamond, Suit::Club, Suit::Heart, Suit::Spade];

#[derive(PartialEq, Eq, Clone, Copy, Debug, FromRepr, EnumCountMacro, Serialize, Deserialize, EnumIter)]
#[repr(u8)]
pub enum Player {
    West = 0,
    North,
    East,
    South,
}

impl Player {
    pub fn next(&self) -> Self {
        self.many_next(1)
    }

    pub fn many_next(self, i: usize) -> Self {
        Player::from_repr(((self as usize + i) % Player::COUNT) as u8).unwrap()
    }

    pub fn short_str(&self) -> &str {
        match self {
            Self::West => "W",
            Self::North => "N",
            Self::East => "E",
            Self::South => "W",
        }
    }

    pub fn get_cards<'a>(&self, deal: &'a Deal) -> &'a Vec<Card> {
        match self {
            Self::West => &deal.west,
            Self::North => &deal.north,
            Self::East => &deal.east,
            Self::South => &deal.south,
        }
    }

    pub fn get_cards_mut<'a>(&self, deal: &'a mut Deal) -> &'a mut Vec<Card> {
        match self {
            Self::West => &mut deal.west,
            Self::North => &mut deal.north,
            Self::East => &mut deal.east,
            Self::South => &mut deal.south,
        }
    }
}

#[derive(PartialEq, Eq, Debug, Clone, Serialize, Deserialize)]
pub struct Trick {
    pub leader: Player,
    pub cards_played: Vec<Card>,
}

impl Trick {
    pub fn winner(&self) -> Player {
        error!("XXX: Returning incorrect result for winner");
        self.leader
    }
}

#[derive(PartialEq, Eq, Debug, Clone, Serialize, Deserialize)]
pub struct TurnInPlay {
    trick: Trick,
}

#[derive(PartialEq, Eq, Debug)]
pub enum TurnInPlayResult {
    InProgress(TurnInPlay),
    Trick(Trick),
}

impl TurnInPlay {
    pub fn new(p: Player) -> TurnInPlay {
        TurnInPlay {
            trick: Trick {
                leader: p,
                cards_played: Vec::with_capacity(4),
            },
        }
    }

    pub fn suit(&self) -> Option<Suit> {
        self.trick
            .cards_played
            .iter()
            .next()
            .map(|&Card(suit, _)| suit)
    }

    pub fn leader(&self) -> Player {
        self.trick.leader
    }

    pub fn cards_played(&self) -> &[Card] {
        &self.trick.cards_played[..]
    }

    pub fn play(mut self: TurnInPlay, card: Card) -> TurnInPlayResult {
        self.trick.cards_played.push(card);
        if self.trick.cards_played.len() >= 4 {
            return TurnInPlayResult::Trick(self.trick);
        }
        TurnInPlayResult::InProgress(self)
    }

    pub fn next_player(&self) -> Player {
        self.trick.leader.many_next(self.trick.cards_played.len())
    }
}

#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
pub struct DealInPlay {
    deal: Deal,
    tricks_played: Vec<Trick>,
    in_progress: TurnInPlay,
}

#[derive(Debug)]
pub enum DealInPlayResult {
    InProgress(DealInPlay),
    PlayFinished(Vec<Trick>),
}

impl DealInPlay {
    pub fn new(leader: Player, deal: Deal) -> DealInPlay {
        DealInPlay {
            deal,
            tricks_played: Vec::with_capacity(13),
            in_progress: TurnInPlay::new(leader),
        }
    }

    pub fn tricks(&self) -> &Vec<Trick> {
        &self.tricks_played
    }

    pub fn trick_in_play(&self) -> &TurnInPlay {
        &self.in_progress
    }

    pub fn deal(&self) -> &Deal {
        &self.deal
    }

    pub fn play(mut self: Self, card: Card) -> Result<DealInPlayResult, anyhow::Error> {
        let player = self.in_progress.next_player();
        let player_cards = player.get_cards_mut(&mut self.deal);

        info!(
            "Next player is {:?}, playing card {} from {:?}",
            player, card, player_cards
        );
        let i = player_cards.iter().position(|&c| c == card).ok_or(anyhow!(
            "{:?} does not have {}",
            player,
            card
        ))?;
        player_cards.remove(i);

        Ok(match self.in_progress.play(card) {
            TurnInPlayResult::InProgress(turn) => DealInPlayResult::InProgress(Self {
                in_progress: turn,
                ..self
            }),
            TurnInPlayResult::Trick(trick) => DealInPlayResult::InProgress(Self {
                in_progress: TurnInPlay::new(trick.winner()),
                tricks_played: {
                    let mut tricks = self.tricks_played;
                    tricks.push(trick);
                    tricks
                },
                deal: self.deal,
            }),
        })
    }
}

#[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Copy, EnumIter, Serialize, Deserialize)]
pub enum ContractLevel {
    One = 1,
    Two,
    Three,
    Four,
    Five,
    Six,
    Seven,
}

impl fmt::Display for ContractLevel {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::result::Result<(), std::fmt::Error> {
        write!(f, "{}", *self as u8)
    }
}

impl fmt::Debug for ContractLevel {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::result::Result<(), std::fmt::Error> {
        write!(f, "{}", self)
    }
}

impl FromStr for ContractLevel {
    type Err = anyhow::Error;

    fn from_str(s: &str) -> std::result::Result<Self, <Self as std::str::FromStr>::Err> {
        match s {
            "1" => Ok(ContractLevel::One),
            "2" => Ok(ContractLevel::Two),
            "3" => Ok(ContractLevel::Three),
            "4" => Ok(ContractLevel::Four),
            "5" => Ok(ContractLevel::Five),
            "6" => Ok(ContractLevel::Six),
            "7" => Ok(ContractLevel::Seven),
            _ => Err(anyhow!("invalid string: {}", s)),
        }
    }
}

#[derive(PartialEq, Eq, Clone, Copy, Serialize, Deserialize)]
pub enum Bid {
    Pass,
    Double,
    Redouble,
    Raise(Raise),
}

impl Bid {
    pub fn as_raise(&self) -> Option<Raise> {
        match self {
            Bid::Raise(raise) => Some(*raise),
            _ => None,
        }
    }
}

impl fmt::Display for Bid {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::result::Result<(), std::fmt::Error> {
        match self {
            Bid::Pass => write!(f, "Pass"),
            Bid::Double => write!(f, "Double"),
            Bid::Redouble => write!(f, "Redouble"),
            Bid::Raise(x) => write!(f, "{}", x),
        }
    }
}

impl fmt::Debug for Bid {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::result::Result<(), std::fmt::Error> {
        match self {
            Bid::Pass => write!(f, "Pass"),
            Bid::Double => write!(f, "Double"),
            Bid::Redouble => write!(f, "Redouble"),
            Bid::Raise(x) => write!(f, "Raise({})", x),
        }
    }
}

impl FromStr for Bid {
    type Err = anyhow::Error;
    fn from_str(s: &str) -> std::result::Result<Self, <Self as std::str::FromStr>::Err> {
        match s.trim().to_ascii_lowercase().as_str() {
            "pass" => Ok(Bid::Pass),
            "double" => Ok(Bid::Double),
            "redouble" => Ok(Bid::Redouble),
            x => Ok(Bid::Raise(x.parse()?)),
        }
    }
}

#[derive(PartialEq, Eq, Clone, Copy, Serialize, Deserialize)]
pub struct Raise {
    pub level: ContractLevel,
    pub suit: Option<Suit>,
}

impl Raise {
    pub fn all_raises() -> Vec<Raise> {
        let mut result = Vec::with_capacity(7 * 5);
        for level in ContractLevel::iter() {
            for suit in Suit::iter() {
                result.push(Raise {
                    level,
                    suit: Some(suit),
                });
            }
            result.push(Raise { level, suit: None });
        }
        result
    }
}

impl PartialOrd<Self> for Raise {
    fn partial_cmp(&self, o: &Self) -> Option<Ordering> {
        if self.level != o.level {
            return self.level.partial_cmp(&o.level);
        }
        if self.suit != o.suit {
            if self.suit == None {
                return Some(Ordering::Greater);
            }
            if o.suit == None {
                return Some(Ordering::Less);
            }
            return self.suit.partial_cmp(&o.suit);
        }
        return Some(Ordering::Equal);
    }
}

impl Ord for Raise {
    fn cmp(&self, o: &Self) -> std::cmp::Ordering {
        self.partial_cmp(o).unwrap()
    }
}

impl fmt::Display for Raise {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::result::Result<(), std::fmt::Error> {
        write!(
            f,
            "{}{}",
            self.level,
            self.suit
                .map_or("NT".to_string(), |suit| format!("{}", suit))
        )
    }
}

impl fmt::Debug for Raise {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::result::Result<(), std::fmt::Error> {
        write!(f, "{}", self)
    }
}

impl FromStr for Raise {
    type Err = anyhow::Error;
    fn from_str(s: &str) -> std::result::Result<Self, <Self as std::str::FromStr>::Err> {
        lazy_static::lazy_static! {
            static ref RE: Regex = Regex::new(r#"\s*(.[0-9]*)\s*(.*)"#).unwrap();
        };
        let caps = RE.captures(s).ok_or(anyhow!("invalid raise: {}", s))?;
        info!("caps: {:?}", caps);
        let level = caps[1].parse()?;
        let suit = match caps[2].to_ascii_uppercase().as_str() {
            "NT" => None,
            x => Some(x.parse()?),
        };
        Ok(Raise { level, suit })
    }
}

#[derive(Debug, PartialEq, Eq, Copy, Clone, Serialize, Deserialize)]
pub enum ContractModifier {
    None,
    Doubled,
    Redoubled,
}

impl fmt::Display for ContractModifier {
    fn fmt(&self, f: &mut fmt::Formatter) -> std::result::Result<(), std::fmt::Error> {
        match self {
            ContractModifier::None => Ok(()),
            ContractModifier::Doubled => write!(f, "x"),
            ContractModifier::Redoubled => write!(f, "xx"),
        }
    }
}

#[derive(Debug, PartialEq, Eq, Copy, Clone, Serialize, Deserialize)]
pub struct Contract {
    declarer: Player,
    highest_bid: Raise,
    modifier: ContractModifier,
}

impl fmt::Display for Contract {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> std::result::Result<(), fmt::Error> {
        write!(
            f,
            "{}{}{}",
            self.highest_bid,
            self.declarer.short_str(),
            self.modifier
        )
    }
}

#[derive(Debug, PartialEq, Eq, Clone, Serialize, Deserialize)]
pub struct Bidding {
    pub dealer: Player,
    pub bids: Vec<Bid>,
}

impl Bidding {
    pub fn new(dealer: Player) -> Bidding {
        Bidding {
            dealer,
            bids: vec![],
        }
    }

    fn declarer(&self) -> Player {
        // Bids are: [..., winning bid, pass, pass, pass].
        self.dealer.many_next(self.bids.len() - 4)
    }

    pub fn highest_bid(&self) -> Option<Raise> {
        for bid in self.bids.iter().rev() {
            if let Some(raise) = bid.as_raise() {
                return Some(raise);
            }
        }
        None
    }

    fn passed_out(&self) -> bool {
        let mut passes = 0;
        for b in self.bids.iter().rev().take(3) {
            if b == &Bid::Pass {
                passes += 1
            }
        }
        passes == 3
    }

    fn contract(&self) -> Option<Contract> {
        match self.highest_bid() {
            None => None,
            Some(highest_bid) => Some(Contract {
                declarer: self.declarer(),
                highest_bid,
                modifier: ContractModifier::None,
            }),
        }
    }

    pub fn bid(mut self, bid: Bid) -> Result<BiddingResult, anyhow::Error> {
        // TODO: Need logic for double and redouble here.
        if bid.as_raise().is_some() && bid.as_raise() <= self.highest_bid() {
            bail!(
                "bid too low: {:?} <= {:?}",
                bid.as_raise(),
                self.highest_bid()
            );
        }
        self.bids.push(bid);
        if self.passed_out() {
            Ok(BiddingResult::Contract(self.contract(), self))
        } else {
            Ok(BiddingResult::InProgress(self))
        }
    }
}

#[derive(Debug, Clone)]
pub enum BiddingResult {
    InProgress(Bidding),
    Contract(Option<Contract>, Bidding),
}

impl BiddingResult {
    pub fn new(dealer: Player) -> Self {
        BiddingResult::InProgress(Bidding::new(dealer))
    }

    pub fn bidding(&self) -> &Bidding {
        match self {
            BiddingResult::InProgress(bidding) => bidding,
            BiddingResult::Contract(_, bidding) => bidding,
        }
    }
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
pub enum GameState {
    Bidding {
        dealer: Player,
        deal: Deal,
    },
    PassedOut {
        dealer: Player,
        deal: Deal,
        bidding: Bidding,
    },
    Play {
        dealer: Player,
        playing_deal: DealInPlay,
        contract: Contract,
        bidding: Bidding,
    },
}

impl GameState {
    pub fn deal(&self) -> &Deal {
        match self {
            Self::Bidding { deal, .. } => deal,
            Self::PassedOut { deal, .. } => deal,
            Self::Play { playing_deal, .. } => &playing_deal.deal(),
        }
    }

    pub fn dealer(&self) -> Player {
        match *self {
            Self::Bidding { dealer, .. } => dealer,
            Self::PassedOut { dealer, .. } => dealer,
            Self::Play { dealer, .. } => dealer,
        }
    }
}

pub fn deal() -> Deal {
    let mut rng = rand::thread_rng();
    let mut deal = crate::card::deal(&mut rng);
    deal.sort(&SUIT_DISPLAY_ORDER, RankOrder::Descending);
    deal
}

#[derive(Serialize, Deserialize, PartialEq, Eq, Clone, Debug)]
pub struct TableView {
    pub dealer: Player,
    pub player_position: Player,
    pub hand: Vec<Card>,
}

impl TableView {
    pub fn from_game_state(game_state: &GameState, player_position: Player) -> Self {
        TableView {
            dealer: game_state.dealer(),
            player_position,
            hand: player_position.get_cards(game_state.deal()).clone(),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use log::info;

    fn as_bidding(r: BiddingResult) -> Bidding {
        match r {
            BiddingResult::InProgress(bidding) => bidding,
            _ => panic!("expected BiddingResult::InProgress(): {:?}", r),
        }
    }

    fn as_contract(r: BiddingResult) -> Option<Contract> {
        match r {
            BiddingResult::Contract(contract, _) => contract,
            _ => panic!("expected BiddingResult::Contract(): {:?}", r),
        }
    }

    #[test]
    fn bidding() {
        crate::tests::test_setup();
        let bidding = Bidding::new(Player::South);
        let bidding = as_bidding(bidding.bid(Bid::Pass).unwrap());
        let bidding = as_bidding(bidding.bid(Bid::Raise("1♦".parse().unwrap())).unwrap());
        let bidding = as_bidding(bidding.bid(Bid::Pass).unwrap());
        let bidding = as_bidding(bidding.bid(Bid::Pass).unwrap());
        let contract = as_contract(bidding.bid(Bid::Pass).unwrap());
        assert_eq!(
            Some(Contract {
                declarer: Player::West,
                highest_bid: "1♦".parse().unwrap(),
                modifier: ContractModifier::None
            }),
            contract
        );
    }

    #[test]
    fn bid_conversion() {
        crate::tests::test_setup();
        let bid1d = Raise {
            level: ContractLevel::One,
            suit: Some(Suit::Diamond),
        };
        assert_eq!("1♢", format!("{}", bid1d));
        assert_eq!("1♢", format!("{:?}", bid1d));
        assert_eq!(bid1d, Raise::from_str("1D").unwrap());

        assert_eq!(Bid::Pass, Bid::from_str("pass").unwrap());

        let mut checked_raises = 0;
        for bid in Raise::all_raises() {
            assert_eq!(bid, Raise::from_str(format!("{}", bid).as_str()).unwrap());
            assert_eq!(
                Bid::Raise(bid),
                Bid::from_str(format!("{}", bid).as_str()).unwrap()
            );
            checked_raises += 1;
        }
        assert_eq!(checked_raises, 35);
    }

    #[test]
    fn fmt_contract() {
        assert_eq!(
            format!(
                "{}",
                Contract {
                    declarer: Player::West,
                    highest_bid: "1♥".parse().unwrap(),
                    modifier: ContractModifier::None
                }
            ),
            "1♡W"
        );

        assert_eq!(
            format!(
                "{}",
                Contract {
                    declarer: Player::East,
                    highest_bid: "1♥".parse().unwrap(),
                    modifier: ContractModifier::Doubled
                }
            ),
            "1♡Ex"
        );
    }

    #[test]
    fn bid_ord() {
        let bid = |s| Raise::from_str(s).unwrap();
        assert!(bid("2♦") < bid("3♦"));
        assert!(bid("3♦") < bid("3♥"));
        assert!(bid("1♠") < bid("2♣"));
        assert!(bid("1♠") < bid("1NT"));
        for bid in Raise::all_raises() {
            assert_eq!(bid, bid);
        }
    }

    #[test]
    fn contract_level_conversion() {
        crate::tests::test_setup();
        assert_eq!("2", format!("{}", ContractLevel::Two));
        assert_eq!("3", format!("{:?}", ContractLevel::Three));

        let result = ContractLevel::from_str("8");
        info!("{:?}", result);
        assert!(result.unwrap_err().to_string().contains("invalid"));
        assert_eq!(ContractLevel::Seven, "7".parse().unwrap());
    }

    #[test]
    fn next_player() {
        let next_players = vec![Player::North, Player::East, Player::South, Player::West]
            .iter()
            .map(Player::next)
            .collect::<Vec<_>>();
        assert_eq!(
            next_players,
            vec![Player::East, Player::South, Player::West, Player::North]
        );
    }

    #[test]
    fn many_next_player() {
        assert_eq!(Player::South, Player::South.many_next(4 * 1234567890));
    }

    fn as_turn(p: TurnInPlayResult) -> TurnInPlay {
        if let TurnInPlayResult::InProgress(t) = p {
            t
        } else {
            panic!("expected PlayResult::InProgress(): {:?}", p);
        }
    }

    fn as_trick(p: TurnInPlayResult) -> Trick {
        if let TurnInPlayResult::Trick(t) = p {
            t
        } else {
            panic!("expected PlayResult::Trick(): {:?}", p);
        }
    }

    #[test]
    fn play_turn() {
        let turn = TurnInPlay::new(Player::South);
        assert_eq!(turn.next_player(), Player::South);
        let turn = as_turn(turn.play("♣4".parse().unwrap()));
        assert_eq!(turn.next_player(), Player::West);
        let turn = as_turn(turn.play("♥A".parse().unwrap()));
        assert_eq!(turn.next_player(), Player::North);
        let turn = as_turn(turn.play("♣4".parse().unwrap()));
        assert_eq!(turn.next_player(), Player::East);
        let trick = as_trick(turn.play("♣A".parse().unwrap()));
        assert_eq!(
            trick,
            Trick {
                leader: Player::South,
                cards_played: ["♣4", "♥A", "♣4", "♣A"]
                    .into_iter()
                    .map(|c| c.parse().unwrap())
                    .collect()
            }
        );
    }

    #[test]
    fn lead_suit() {
        let turn = TurnInPlay::new(Player::South);
        assert_eq!(turn.suit(), None);
        let turn = as_turn(turn.play("♣4".parse().unwrap()));
        assert_eq!(turn.suit(), Some("♣".parse().unwrap()));
    }

    fn mkcard(s: &str) -> Card {
        Card::from_str(s).unwrap()
    }

    fn mkcards(s: &str) -> Vec<Card> {
        s.split(" ").map(mkcard).collect()
    }

    fn _example_deal() -> Deal {
        Deal {
            west: mkcards("♠5 ♢10 ♡K ♣4 ♡J ♣5 ♢5 ♠9 ♢3 ♠2 ♣2 ♡4 ♠Q"),
            north: mkcards("♢Q ♡9 ♠7 ♠8 ♠A ♡A ♡5 ♠6 ♢9 ♣3 ♡3 ♣9 ♢J"),
            east: mkcards("♣10 ♡7 ♢A ♣6 ♡8 ♣Q ♠K ♡10 ♣K ♠3 ♡Q ♣J ♢4"),
            south: mkcards("♢K ♡6 ♣8 ♢6 ♢7 ♢8 ♣A ♡2 ♣7 ♠10 ♠4 ♠J ♢2"),
        }
    }

    fn mini_deal() -> Deal {
        Deal {
            west: mkcards("♢A ♡Q"),
            north: mkcards("♢Q ♡9"),
            east: mkcards("♢7 ♡K"),
            south: mkcards("♢9 ♠9"),
        }
    }

    #[test]
    fn table_view() {
        crate::tests::test_setup();
        let game_state = GameState::Bidding { dealer: Player::East, deal: mini_deal() };
        info!("Game state: {game_state:?}");
        for p in Player::iter() {
            info!("Testing view for {p:?}");
            let view = TableView::from_game_state(&game_state, p);
            assert_eq!(view.player_position, p);
            assert_eq!(view.dealer, Player::East);
            assert_eq!(&view.hand, p.get_cards_mut(&mut mini_deal()));
        }
    }

    fn as_playing_hand(result: DealInPlayResult) -> DealInPlay {
        match result {
            DealInPlayResult::InProgress(r) => r,
            DealInPlayResult::PlayFinished(_) => {
                panic!("expected PlayingDealResult::InProgress(): {:?}", result)
            }
        }
    }

    #[test]
    fn play_hand() {
        let deal = DealInPlay::new(Player::West, mini_deal());
        assert_eq!(deal.tricks_played, vec!());
        {
            let err = deal.clone().play(mkcard("♥9")).unwrap_err().to_string();
            assert_eq!(err, "West does not have ♡9");
        }

        let deal = as_playing_hand(deal.play(mkcard("♢A")).unwrap());
        assert_eq!(deal.in_progress.trick.cards_played, vec!(mkcard("♢A")));

        let deal = as_playing_hand(deal.play(mkcard("♢Q")).unwrap());
        let deal = as_playing_hand(deal.play(mkcard("♥K")).unwrap());
        let deal = as_playing_hand(deal.play(mkcard("♢9")).unwrap());
        assert_eq!(deal.in_progress.trick.cards_played, []);
        assert_eq!(
            deal.tricks_played,
            vec!(Trick {
                leader: Player::West,
                cards_played: mkcards("♢A ♢Q ♡K ♢9"),
            })
        );
    }
}