ecs-observable/examples/blackjack/components.ts

import { defineComponent } from "../../src/component";
import type { World, Entity } from "../../src/index";
import { query } from "../../src/query";
import { SUITS, RANKS, isBlackjack, type CardData } from "./game";

// ── Component definitions ────────────────────────────

/** Each card is its own entity. `order` tracks position within its collection. */
export const Card = defineComponent("card", {
  rank: "A",
  suit: "♠",
  order: 0,
});

// ── Tag components — mark which collection a card belongs to ─
export const InDeck = defineComponent("inDeck", {});
export const InPlayerHand = defineComponent("inPlayerHand", {});
export const InDealerHand = defineComponent("inDealerHand", {});

// ── Dealer state ─────────────────────────────────────
/** When present (as singleton), the dealer's hole card is hidden. */
export const HoleHidden = defineComponent("holeHidden", {});

// ── Score / state ────────────────────────────────────
export const Score = defineComponent("score", {
  wins: 0,
  losses: 0,
  pushes: 0,
  chips: 100,
});

export const Bet = defineComponent("bet", {
  amount: 10,
});

/** Current phase of the game. */
export type Phase = "betting" | "playerTurn" | "dealerTurn" | "roundOver";

export const GamePhase = defineComponent("gamePhase", {
  phase: "betting" as Phase,
  message: "",
});

// ── Card helpers ─────────────────────────────────────

export function createCardHelpers(world: World) {
  return {
    /** Create all 52 card entities with the InDeck tag. */
    buildDeck(): void {
      let order = 0;
      for (const suit of SUITS) {
        for (const rank of RANKS) {
          const e = world.spawn();
          world.add(e, Card, { rank, suit, order });
          world.add(e, InDeck);
          order++;
        }
      }
    },

    /** Shuffle the deck: collect all InDeck entities, shuffle, reassign order. */
    shuffleDeck(): void {
      const entities = [...world.query(query(Card, InDeck))];
      for (let i = entities.length - 1; i > 0; i--) {
        const j = Math.floor(Math.random() * (i + 1));
        [entities[i], entities[j]] = [entities[j], entities[i]];
      }
      for (let i = 0; i < entities.length; i++) {
        world.get(entities[i], Card).order = i;
      }
    },

    /** Draw the top card from the deck (highest order). Returns entity or null. */
    drawCard(): Entity | null {
      const cards = [...world.query(query(Card, InDeck))];
      if (cards.length === 0) return null;
      let top = cards[0];
      let topOrder = world.get(top, Card).order;
      for (let i = 1; i < cards.length; i++) {
        const o = world.get(cards[i], Card).order;
        if (o > topOrder) {
          top = cards[i];
          topOrder = o;
        }
      }
      world.remove(top, InDeck);
      return top;
    },

    /** Move a card entity to a hand tag, assigning the next order. */
    dealTo(cardEntity: Entity, tag: typeof InPlayerHand): void {
      const existing = [...world.query(query(Card, tag))];
      const nextOrder =
        existing.length === 0
          ? 0
          : Math.max(...existing.map((e) => world.get(e, Card).order)) + 1;
      world.add(cardEntity, tag);
      world.get(cardEntity, Card).order = nextOrder;
    },

    /** Collect CardData from a hand tag, sorted by order. */
    getHand(tag: typeof InPlayerHand): CardData[] {
      return [...world.query(query(Card, tag))]
        .map((e) => {
          const c = world.get(e, Card);
          return { rank: c.rank, suit: c.suit, order: c.order };
        })
        .sort((a, b) => a.order - b.order)
        .map(({ rank, suit }) => ({ rank, suit }));
    },

    /** Remove all cards from a hand tag (destroy the card entities). */
    clearHand(tag: typeof InPlayerHand): void {
      for (const e of world.query(query(Card, tag))) {
        world.destroy(e);
      }
    },

    /** Count cards remaining in the deck. */
    deckCount(): number {
      return [...world.query(query(Card, InDeck))].length;
    },

    /** Deal initial 4 cards and start a round. */
    startRound(): void {
      const bet = world.getSingleton(Bet);
      const score = world.getSingleton(Score);

      score.chips -= bet.amount;

      if (this.deckCount() < 15) {
        const remaining = [...world.query(query(Card, InDeck))];
        for (const e of remaining) {
          world.remove(e, InDeck);
        }
        for (const e of remaining) {
          world.add(e, InDeck);
        }
        this.shuffleDeck();
      }

      this.clearHand(InPlayerHand);
      this.clearHand(InDealerHand);
      world.removeSingleton(HoleHidden);

      const c1 = this.drawCard();
      const c2 = this.drawCard();
      const c3 = this.drawCard();
      const c4 = this.drawCard();
      if (c1) this.dealTo(c1, InPlayerHand);
      if (c2) this.dealTo(c2, InDealerHand);
      if (c3) this.dealTo(c3, InPlayerHand);
      if (c4) this.dealTo(c4, InDealerHand);

      const playerCards = this.getHand(InPlayerHand);
      const dealerCards = this.getHand(InDealerHand);

      if (isBlackjack(playerCards)) {
        world.removeSingleton(HoleHidden);

        if (isBlackjack(dealerCards)) {
          score.chips += bet.amount;
          score.pushes++;
          world.setSingleton(GamePhase, {
            phase: "roundOver",
            message: "Both have Blackjack — Push! Press N for new round.",
          });
        } else {
          const winnings = payout("blackjack", bet.amount);
          score.chips += bet.amount + winnings;
          score.wins++;
          world.setSingleton(GamePhase, {
            phase: "roundOver",
            message: "Blackjack! You win 3:2! Press N for new round.",
          });
        }
      } else {
        world.addSingleton(HoleHidden);
        world.setSingleton(GamePhase, {
          phase: "playerTurn",
          message: "Your turn — H to hit, S to stand.",
        });
      }
    },
  };
}

// ── Internal ─────────────────────────────────────────

function payout(outcome: string, bet: number): number {
  switch (outcome) {
    case "blackjack":
      return Math.floor(bet * 1.5);
    case "win":
      return bet;
    case "push":
      return 0;
    case "lose":
      return -bet;
    default:
      return 0;
  }
}