import { FieldValue } from "firebase-admin/firestore";
import { logger } from "firebase-functions";
import { firestore, rtdb } from "../firebase";
import { HttpError } from "../middleware/errors";
import { getGame } from "../repositories/gameRepository";
import { getAllUserVotes, deleteGameVotes } from "../repositories/voteRepository";
import { invalidateStats } from "./statsService";
import { fromTimestamp } from "../types/dateString";
import { DRAW_TEAM_CODE, type Game } from "../types/panit";

export async function processGameEnd(gameId: string): Promise<{ processed: number }> {
  const game = await getGame(gameId);
  if (!game) throw new HttpError(404, `game not found: ${gameId}`);
  return processGameEndWithGame(gameId, game);
}

export async function processGameEndWithGame(
  gameId: string,
  game: Game,
  opts?: { skipInvalidate?: boolean }
): Promise<{ processed: number }> {
  if (game.status !== "completed") throw new HttpError(409, `game status must be completed, got ${game.status}`);

  const date = fromTimestamp(game.time);
  const votes = await getAllUserVotes(gameId);
  const uids = Object.keys(votes);

  // 무승부(`winningTeamCode` 없음): 무승부('DRAW') 투표만 적중, 팀 투표는 오답.
  // 승부가 난 경기: 승리 팀 투표만 적중 — 무승부 투표는 자연히 오답이 된다.
  const isDraw = !game.winningTeamCode;
  const rtdbUpdates: Record<string, unknown> = {};
  for (const uid of uids) {
    const voted = votes[uid].team;
    const result = isDraw
      ? voted === DRAW_TEAM_CODE
      : voted === game.winningTeamCode;
    rtdbUpdates[`/userVotes/${uid}/${date}/${gameId}/team`] = voted;
    rtdbUpdates[`/userVotes/${uid}/${date}/${gameId}/result`] = result;
  }
  if (Object.keys(rtdbUpdates).length > 0) {
    await rtdb.ref().update(rtdbUpdates);
  }

  await deleteGameVotes(gameId);

  // 아카이브 리컨실 경로에선 호출자(dailyArchive)가 유저 단위로 1회 무효화하므로
  // 경기마다 투표자 전원을 다시 무효화하는 fan-out을 건너뛴다(중복 제거).
  if (!opts?.skipInvalidate) {
    await Promise.all(uids.map((uid) => invalidateStats(uid).catch(() => undefined)));
  }

  logger.info(`processGameEnd: ${gameId} processed ${uids.length} votes`);
  return { processed: uids.length };
}

export async function markGameEnded(
  gameId: string,
  winningTeamCode: string
): Promise<{ ok: true; gameId: string }> {
  if (!gameId || !winningTeamCode) {
    throw new HttpError(400, "gameId and winningTeamCode required");
  }
  const ref = firestore.collection("games").doc(gameId);
  const snap = await ref.get();
  if (!snap.exists) throw new HttpError(404, `game not found: ${gameId}`);
  // 'DRAW'는 무승부 수동 처리 — winningTeamCode 없이 completed로 기록한다
  // (판정 규칙상 "winningTeamCode 없음 = 무승부"이므로 남아있는 값도 지운다).
  const isDraw = winningTeamCode === DRAW_TEAM_CODE;
  await ref.update({
    status: "completed",
    winningTeamCode: isDraw ? FieldValue.delete() : winningTeamCode,
    endedAt: FieldValue.serverTimestamp(),
  });
  return { ok: true, gameId };
}