import type { ChatMessage } from './model';

// The in-game chat is a per-turn reaction, not a running conversation: a player may post
// at most one message on their own turn and none on the opponent's. The turn boundary is
// the move-driven turn start (GameView.lastActivityUnix), so "already wrote this turn" is
// derived from the loaded message list rather than a counter — it survives reopening the
// chat and resets by itself when the turn advances. The backend enforces the same rule.

/**
 * turnMessageLimit is how many chat messages a player may post in the given turn state:
 * one on the player's own turn, none on the opponent's.
 */
export function turnMessageLimit(isMyTurn: boolean): number {
  return isMyTurn ? 1 : 0;
}

/**
 * sentThisTurn counts the chat messages (nudges excluded) that the viewer myId has posted
 * since the current turn began. turnStartUnix is the move-driven turn start in Unix
 * seconds; a message counts toward the current turn when it was created at or after it.
 */
export function sentThisTurn(messages: ChatMessage[], myId: string, turnStartUnix: number): number {
  let n = 0;
  for (const m of messages) {
    if (m.senderId === myId && m.kind === 'message' && m.createdAtUnix >= turnStartUnix) n += 1;
  }
  return n;
}

/**
 * canSendChat reports whether the viewer may still post a chat message this turn: the count
 * already sent is below the turn's limit. It is false on the opponent's turn (limit zero)
 * and once the single own-turn message has been sent.
 */
export function canSendChat(isMyTurn: boolean, sent: number): boolean {
  return sent < turnMessageLimit(isMyTurn);
}