/**
 * Projection helpers that turn the full table state into safe views.
 *
 * The full state (including every hole card and the deck order) must never
 * leave the server; clients only ever receive these views. Hole cards are
 * hidden except for the viewer's own seats and for live hands at showdown.
 */

import { getLegalActions } from "./betting";
import type {
  Card,
  PokerSeatId,
  PokerTableState,
  PrivatePlayerView,
  PublicPlayerView,
  PublicTableView,
} from "./types";

function sumCommitted(state: PokerTableState): number {
  return state.players.reduce((total, player) => total + player.committed, 0);
}

function projectPlayer(
  state: PokerTableState,
  player: PokerTableState["players"][number],
  viewerSeat: PokerSeatId | null,
): PublicPlayerView {
  const isViewer = viewerSeat !== null && player.seatId === viewerSeat;
  const reveal = (state.phase === "showdown" && !player.folded) || isViewer;
  const holeCards: readonly Card[] | null = reveal && player.holeCards.length > 0
    ? player.holeCards
    : null;
  return {
    seatId: player.seatId,
    name: player.name,
    stack: player.stack,
    committed: player.committed,
    totalCommitted: player.totalCommitted,
    folded: player.folded,
    allIn: player.allIn,
    hasActed: player.hasActed,
    eliminated: player.eliminated,
    holeCards,
    cardCount: player.holeCards.length,
  };
}

/**
 * Public view of the table. Pass `viewerSeat` to also reveal that seat's own
 * hole cards; pass null for a fully spectator-safe view.
 */
export function buildPublicView(
  state: PokerTableState,
  viewerSeat: PokerSeatId | null,
): PublicTableView {
  return {
    players: state.players.map((player) => projectPlayer(state, player, viewerSeat)),
    buttonSeat: state.buttonSeat,
    smallBlindSeat: state.smallBlindSeat,
    bigBlindSeat: state.bigBlindSeat,
    street: state.street,
    phase: state.phase,
    potTotal: state.collectedPot + sumCommitted(state),
    communityCards: state.communityCards,
    currentBet: state.currentBet,
    toActSeat: state.toActSeat,
    handNumber: state.handNumber,
    config: state.config,
    showdown: state.showdown,
    finalPlacements: state.finalPlacements,
  };
}

/** Everything one seated player is allowed to know, including their options. */
export function buildPrivateView(state: PokerTableState, seatId: PokerSeatId): PrivatePlayerView {
  const viewer = state.players[seatId];
  const publicView = buildPublicView(state, seatId);
  return {
    ...publicView,
    viewerSeat: seatId,
    yourHoleCards: viewer?.holeCards ?? [],
    legalActions: getLegalActions(state, seatId),
    yourTurn: state.phase === "betting" && state.toActSeat === seatId,
  };
}