import { beforeEach, describe, expect, it } from "vitest";
import { Timestamp } from "firebase-admin/firestore";
import { firestore, rtdb } from "../../src/firebase";
import { getStats } from "../../src/services/statsService";
import {
  addDays,
  todayKst,
  type DateString,
} from "../../src/types/dateString";
import type {
  Game,
  GameStatus,
  StatsResponse,
  User,
} from "../../src/types/panit";

const uid = "stats-uid";

async function seedGames(
  date: DateString,
  specs: Array<{ status: GameStatus; winner?: string }>
): Promise<void> {
  for (let i = 0; i < specs.length; i++) {
    const spec = specs[i];
    const gameId = `${date.replace(/-/g, "")}G${i}`;
    const [y, m, d] = date.split("-").map(Number);
    const doc: Game = {
      time: Timestamp.fromDate(new Date(Date.UTC(y, m - 1, d, 9, 0))),
      stadium: "잠실",
      status: spec.status,
      homeTeamCode: "LG",
      awayTeamCode: "HT",
    };
    if (spec.winner) doc.winningTeamCode = spec.winner;
    await firestore.collection("games").doc(gameId).set(doc);
  }
}

async function seedUser(patch: Partial<User> = {}): Promise<void> {
  await firestore
    .collection("users")
    .doc(uid)
    .set(
      {
        displayName: "stats-user",
        email: "s@e.com",
        provider: "google",
        knowledgeLevel: "beginner",
        createdAt: Timestamp.now(),
        ...patch,
      },
      { merge: true }
    );
}

async function seedCache(
  key: string,
  partial: Partial<StatsResponse>
): Promise<void> {
  await rtdb.ref(`/cache/stats/${uid}/${key}`).set(partial);
}

describe("statsService.getStats — 결석 lazy 보정", () => {
  beforeEach(async () => {
    await firestore.recursiveDelete(firestore.collection("users"));
    await firestore.recursiveDelete(firestore.collection("games"));
    await rtdb.ref(`/cache/stats/${uid}`).remove();
    await rtdb.ref(`/userVotes/${uid}`).remove();
  });

  it("lastJudgedDate가 이틀 이상 이전이고 gap에 실제 경기일이 있으면 streak 0", async () => {
    const today = todayKst();
    const threeDaysAgo = addDays(today, -3);
    const twoDaysAgo = addDays(today, -2);
    await seedUser({
      currentStreak: 5,
      highestStreak: 7,
      lastJudgedDate: threeDaysAgo,
      tierPoints: 100,
    });
    // gap에 실제 경기일을 둔다 → 결석으로 판정되어야 함.
    await seedGames(twoDaysAgo, [
      { status: "completed", winner: "LG" },
      { status: "completed", winner: "LG" },
      { status: "completed", winner: "LG" },
    ]);

    const stats = await getStats(uid);

    expect(stats.streakDays).toBe(0);
    expect(stats.highestStreak).toBe(7); // 최고 streak은 그대로
    expect(stats.forDate).toBe(today);
  });

  it("gap에 실제 경기일이 없으면(전부 휴장) streak 유지", async () => {
    const today = todayKst();
    const threeDaysAgo = addDays(today, -3);
    await seedUser({
      currentStreak: 5,
      highestStreak: 7,
      lastJudgedDate: threeDaysAgo,
    });
    // games 컬렉션 비움 — 모든 gap 날이 0건이므로 skip 처리, 결석 아님.

    const stats = await getStats(uid);

    expect(stats.streakDays).toBe(5);
  });

  it("lastJudgedDate가 어제(D-1)면 streak 유지", async () => {
    const today = todayKst();
    const yesterday = addDays(today, -1);
    await seedUser({
      currentStreak: 5,
      highestStreak: 5,
      lastJudgedDate: yesterday,
    });

    const stats = await getStats(uid);

    expect(stats.streakDays).toBe(5);
  });

  it("lastJudgedDate가 D-2여도 어제분 userVotes가 남아 있으면 archive 대기로 보고 streak 보호", async () => {
    const today = todayKst();
    const yesterday = addDays(today, -1);
    const twoDaysAgo = addDays(today, -2);
    await seedUser({
      currentStreak: 5,
      highestStreak: 5,
      lastJudgedDate: twoDaysAgo,
    });
    // 어제 투표는 했으나 아직 dailyArchive가 안 돈 상황을 시뮬레이트.
    await rtdb
      .ref(`/userVotes/${uid}/${yesterday}/g1`)
      .set({ team: "LG" });

    const stats = await getStats(uid);

    expect(stats.streakDays).toBe(5);
  });

  it("어제 경기가 있었는데 userVotes 비어 있으면(진짜 결석) streak 0", async () => {
    const today = todayKst();
    const yesterday = addDays(today, -1);
    const twoDaysAgo = addDays(today, -2);
    await seedUser({
      currentStreak: 5,
      highestStreak: 5,
      lastJudgedDate: twoDaysAgo,
    });
    // 어제 실제 경기가 있었음 + userVotes 없음 = 진짜 결석.
    await seedGames(yesterday, [
      { status: "completed", winner: "LG" },
      { status: "completed", winner: "LG" },
      { status: "completed", winner: "LG" },
    ]);

    const stats = await getStats(uid);

    expect(stats.streakDays).toBe(0);
  });

  it("lastJudgedDate가 없는 신규 유저는 streak 0", async () => {
    await seedUser({
      tierPoints: 0,
    });

    const stats = await getStats(uid);

    expect(stats.streakDays).toBe(0);
  });
});

describe("statsService.getStats — 캐시 forDate 검증", () => {
  beforeEach(async () => {
    await firestore.recursiveDelete(firestore.collection("users"));
    await rtdb.ref(`/cache/stats/${uid}`).remove();
    await rtdb.ref(`/userVotes/${uid}`).remove();
  });

  it("캐시 forDate가 오늘이면 그대로 반환한다", async () => {
    const today = todayKst();
    await seedUser({ currentStreak: 99, lastJudgedDate: today });
    // 일부러 streakDays를 비현실적인 값으로 캐시에 저장 → 캐시 hit이면 그대로 노출
    await seedCache("current", {
      streakDays: 12345,
      highestStreak: 12345,
      weeklyResults: [null, null, null, null, null, null, null],
      winRates: { overall: 0, weekly: 0, monthly: 0, season: 0 },
      totalPredictions: 0,
      totalCorrect: 0,
      weeklyPredictions: 0,
      currentLevel: 1,
      progress: 0,
      tier: "bronze",
      tierPoints: 0,
      tickets: { dailyAllKill: 0, weeklyMaster: 0 },
      updatedAt: Date.now(),
      forDate: today,
    });

    const stats = await getStats(uid);

    expect(stats.streakDays).toBe(12345);
  });

  it("캐시 forDate가 어제면 무효화하고 재계산한다", async () => {
    const today = todayKst();
    const yesterday = addDays(today, -1);
    await seedUser({ currentStreak: 3, lastJudgedDate: yesterday });
    // 어제 날짜의 stale 캐시를 심어둔다.
    await seedCache("current", {
      streakDays: 99,
      highestStreak: 99,
      weeklyResults: [null, null, null, null, null, null, null],
      winRates: { overall: 0, weekly: 0, monthly: 0, season: 0 },
      totalPredictions: 0,
      totalCorrect: 0,
      weeklyPredictions: 0,
      currentLevel: 1,
      progress: 0,
      tier: "bronze",
      tierPoints: 0,
      tickets: { dailyAllKill: 0, weeklyMaster: 0 },
      updatedAt: Date.now() - 86_400_000,
      forDate: yesterday,
    });

    const stats = await getStats(uid);

    expect(stats.forDate).toBe(today);
    expect(stats.streakDays).toBe(3); // user doc 기준으로 재계산
  });
});