import { beforeEach, describe, expect, it } from "vitest";
import type { DecodedIdToken } from "firebase-admin/auth";
import { firestore, rtdb } from "../../src/firebase";
import {
  checkNickname,
  createMe,
  deleteMe,
  getMe,
  purgeExpiredAccounts,
  PURGE_GRACE_DAYS,
  updateMe,
} from "../../src/services/userService";
import { HttpError } from "../../src/middleware/errors";
import {
  RESERVATION_TTL_MS,
  reserveNickname,
} from "../../src/repositories/nicknameRepository";

const uid = "user-1";

function fakeToken(overrides: Partial<DecodedIdToken> = {}): DecodedIdToken {
  return {
    uid,
    email: "tester@example.com",
    picture: "https://cdn.example.com/p.png",
    firebase: {
      identities: {},
      sign_in_provider: "google.com",
    },
    aud: "test",
    auth_time: 0,
    exp: 0,
    iat: 0,
    iss: "test",
    sub: uid,
    ...overrides,
  } as DecodedIdToken;
}

const validBody = {
  displayName: "유저1",
  favoriteTeamCode: "LG",
  knowledgeLevel: "casual",
};

describe("userService", () => {
  beforeEach(async () => {
    await firestore.recursiveDelete(firestore.collection("users"));
    await rtdb.ref("/nicknames").remove();
    await rtdb.ref("/userNicknames").remove();
  });

  async function createMeWithReservation(
    token = fakeToken(),
    body: Record<string, unknown> = validBody
  ) {
    await reserveNickname(token.uid, body.displayName as string);
    return createMe(token, body);
  }

  describe("getMe", () => {
    it("미존재 유저는 404 + USER_NOT_FOUND", async () => {
      await expect(getMe(fakeToken())).rejects.toMatchObject({
        status: 404,
        code: "USER_NOT_FOUND",
      });
    });

    it("존재하는 유저를 반환한다", async () => {
      await createMeWithReservation();
      const u = await getMe(fakeToken());
      expect(u.displayName).toBe("유저1");
      expect(u.favoriteTeamCode).toBe("LG");
      expect(u.knowledgeLevel).toBe("casual");
    });

    it("토큰의 photoUrl이 바뀌면 자동 동기화한다", async () => {
      await createMeWithReservation();
      const newToken = fakeToken({ picture: "https://cdn.example.com/new.png" });

      const u = await getMe(newToken);
      expect(u.photoUrl).toBe("https://cdn.example.com/new.png");

      // Firestore 저장본도 갱신되었는지 재조회로 확인
      const u2 = await getMe(fakeToken({ picture: "https://cdn.example.com/new.png" }));
      expect(u2.photoUrl).toBe("https://cdn.example.com/new.png");
    });
  });

  describe("응답 직렬화", () => {
    const UTC_ISO = /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z$/;

    it("createMe / getMe / updateMe 모두 createdAt이 UTC ISO 문자열이다", async () => {
      const created = await createMeWithReservation();
      const fetched = await getMe(fakeToken());
      const updated = await updateMe(fakeToken(), { knowledgeLevel: "expert" });

      for (const profile of [created, fetched, updated]) {
        expect(typeof profile.createdAt).toBe("string");
        expect(profile.createdAt).toMatch(UTC_ISO);
      }
    });

    it("응답 JSON에 Firestore Timestamp가 남지 않는다", async () => {
      await createMeWithReservation();
      const json = JSON.stringify(await getMe(fakeToken()));
      expect(json).not.toContain("_seconds");
      expect(json).not.toContain("_nanoseconds");
    });
  });

  describe("createMe", () => {
    it("정상 생성 시 토큰의 email/photo/provider를 사용한다", async () => {
      const u = await createMeWithReservation();
      expect(u.email).toBe("tester@example.com");
      expect(u.photoUrl).toBe("https://cdn.example.com/p.png");
      expect(u.provider).toBe("google");
      expect(u.favoriteTeamCode).toBe("LG");
      expect(u.knowledgeLevel).toBe("casual");
    });

    it("apple.com 프로바이더 매핑", async () => {
      const t = fakeToken({
        firebase: { identities: {}, sign_in_provider: "apple.com" },
      });
      const u = await createMeWithReservation(t);
      expect(u.provider).toBe("apple");
    });

    it("중복 생성 시 409 + USER_ALREADY_EXISTS", async () => {
      await createMeWithReservation();
      await expect(createMe(fakeToken(), validBody)).rejects.toMatchObject({
        status: 409,
        code: "USER_ALREADY_EXISTS",
      });
    });

    it.each([
      ["빈 displayName", { ...validBody, displayName: "" }],
      ["11자 displayName", { ...validBody, displayName: "1234567890X" }],
      ["숫자 displayName", { ...validBody, displayName: 123 }],
      ["잘못된 팀코드", { ...validBody, favoriteTeamCode: "XX" }],
      ["잘못된 레벨", { ...validBody, knowledgeLevel: "master" }],
    ])("%s → 400 INVALID_INPUT", async (_label, body) => {
      await expect(createMe(fakeToken(), body as never)).rejects.toMatchObject({
        status: 400,
        code: "INVALID_INPUT",
      });
    });

    it("지원하지 않는 provider → 400", async () => {
      const t = fakeToken({
        firebase: { identities: {}, sign_in_provider: "password" },
      });
      await expect(createMe(t, validBody)).rejects.toBeInstanceOf(HttpError);
    });
  });

  describe("deleteMe (비활성화)", () => {
    it("문서는 남기고 active:false + deactivatedAt만 기록한다 (기록·닉네임 점유 보존)", async () => {
      await createMeWithReservation();
      await firestore
        .collection("users").doc(uid)
        .collection("voteHistory").doc("2026-04-12")
        .set({ data: [] });

      await deleteMe(fakeToken());

      const snap = await firestore.collection("users").doc(uid).get();
      expect(snap.exists).toBe(true);
      expect(snap.data()?.active).toBe(false);
      expect(snap.data()?.deactivatedAt).toBeTruthy();
      // 기록은 파기 전까지 보존된다.
      const sub = await firestore
        .collection("users").doc(uid)
        .collection("voteHistory").get();
      expect(sub.empty).toBe(false);
      // 비활성 계정은 조회 API에서 미존재로 취급 → 재가입(온보딩) 유도.
      await expect(getMe(fakeToken())).rejects.toMatchObject({ code: "USER_NOT_FOUND" });
      // 이미 비활성화된 계정의 중복 탈퇴 요청도 404.
      await expect(deleteMe(fakeToken())).rejects.toMatchObject({ code: "USER_NOT_FOUND" });
    });

    it("미존재 유저는 404 + USER_NOT_FOUND", async () => {
      await expect(
        deleteMe(fakeToken({ uid: "nonexistent", sub: "nonexistent" }))
      ).rejects.toMatchObject({
        status: 404,
        code: "USER_NOT_FOUND",
      });
    });

    it("유예 기간이 지난 계정만 purge가 영구 파기한다", async () => {
      await createMeWithReservation();
      await firestore
        .collection("users").doc(uid)
        .collection("voteHistory").doc("2026-04-12")
        .set({ data: [] });
      await deleteMe(fakeToken());

      // 유예 기간 내 → 파기 대상 아님.
      expect(await purgeExpiredAccounts()).toEqual([]);

      // 유예 기간 +1일 시점 → 파기.
      const later = new Date(
        Date.now() + (PURGE_GRACE_DAYS + 1) * 24 * 60 * 60 * 1000
      );
      expect(await purgeExpiredAccounts(later)).toEqual([uid]);

      const snap = await firestore.collection("users").doc(uid).get();
      expect(snap.exists).toBe(false);
      const sub = await firestore
        .collection("users").doc(uid)
        .collection("voteHistory").get();
      expect(sub.empty).toBe(true);
    });
  });

  describe("checkNickname", () => {
    it("새 예약 성공 → previousReservation: null", async () => {
      const result = await checkNickname(fakeToken(), "닉네임A");
      expect(result).toEqual({ available: true, previousReservation: null });
      const snap = await rtdb.ref("/nicknames/닉네임A").get();
      expect(snap.val()).toMatchObject({ uid });
      const userSnap = await rtdb.ref(`/userNicknames/${uid}`).get();
      expect(userSnap.val()).toBe("닉네임A");
    });

    it("같은 uid 재요청(다른 이름) → 이전 이름 반환 & 이전 경로 제거", async () => {
      await checkNickname(fakeToken(), "닉네임A");
      const result = await checkNickname(fakeToken(), "닉네임B");
      expect(result).toEqual({
        available: true,
        previousReservation: "닉네임A",
      });
      const oldSnap = await rtdb.ref("/nicknames/닉네임A").get();
      expect(oldSnap.exists()).toBe(false);
      const newSnap = await rtdb.ref("/nicknames/닉네임B").get();
      expect(newSnap.val()).toMatchObject({ uid });
      const userSnap = await rtdb.ref(`/userNicknames/${uid}`).get();
      expect(userSnap.val()).toBe("닉네임B");
    });

    it("같은 uid 동일 이름 재요청 → 멱등, previousReservation: null", async () => {
      await checkNickname(fakeToken(), "닉네임A");
      const result = await checkNickname(fakeToken(), "닉네임A");
      expect(result).toEqual({ available: true, previousReservation: null });
    });

    it("타 uid 점유(TTL 이내) → 409 NICKNAME_TAKEN", async () => {
      await checkNickname(
        fakeToken({ uid: "other", sub: "other" }),
        "닉네임A"
      );
      await expect(
        checkNickname(fakeToken(), "닉네임A")
      ).rejects.toMatchObject({
        status: 409,
        code: "NICKNAME_TAKEN",
      });
    });

    it("타 uid 점유(TTL 초과) → 탈취 성공", async () => {
      await rtdb.ref("/nicknames/닉네임A").set({
        uid: "other",
        reservedAt: Date.now() - RESERVATION_TTL_MS - 1000,
      });
      const result = await checkNickname(fakeToken(), "닉네임A");
      expect(result.available).toBe(true);
      const snap = await rtdb.ref("/nicknames/닉네임A").get();
      expect(snap.val()).toMatchObject({ uid });
    });

    it("이미 가입된 유저 → 409 USER_ALREADY_EXISTS", async () => {
      await createMeWithReservation();
      await expect(
        checkNickname(fakeToken(), "닉네임X")
      ).rejects.toMatchObject({
        status: 409,
        code: "USER_ALREADY_EXISTS",
      });
    });

    it("확정된 유저의 displayName이면 타 uid는 409 NICKNAME_TAKEN", async () => {
      // userA 가입 후 RTDB 예약은 소비된 상태
      await createMeWithReservation(fakeToken({ uid: "userA", sub: "userA" }));
      const nameSnap = await rtdb
        .ref(`/nicknames/${validBody.displayName}`)
        .get();
      expect(nameSnap.exists()).toBe(false); // 선결 조건

      // userB가 같은 이름 요청 → Firestore fallback이 차단
      await expect(
        checkNickname(
          fakeToken({ uid: "userB", sub: "userB" }),
          validBody.displayName
        )
      ).rejects.toMatchObject({
        status: 409,
        code: "NICKNAME_TAKEN",
      });
    });

    it("displayName 형식 오류 → 400", async () => {
      await expect(checkNickname(fakeToken(), "")).rejects.toMatchObject({
        status: 400,
        code: "INVALID_INPUT",
      });
    });
  });

  describe("updateMe", () => {
    it("미존재 유저는 404 + USER_NOT_FOUND", async () => {
      await expect(
        updateMe(fakeToken(), { displayName: "새이름" })
      ).rejects.toMatchObject({
        status: 404,
        code: "USER_NOT_FOUND",
      });
    });

    it("displayName만 변경 성공", async () => {
      await createMeWithReservation();
      const u = await updateMe(fakeToken(), { displayName: "새이름" });
      expect(u.displayName).toBe("새이름");
      expect(u.favoriteTeamCode).toBe("LG");
      expect(u.knowledgeLevel).toBe("casual");
    });

    it("favoriteTeamCode만 변경 성공", async () => {
      await createMeWithReservation();
      const u = await updateMe(fakeToken(), { favoriteTeamCode: "KT" });
      expect(u.favoriteTeamCode).toBe("KT");
      expect(u.displayName).toBe("유저1");
    });

    it("knowledgeLevel만 변경 성공", async () => {
      await createMeWithReservation();
      const u = await updateMe(fakeToken(), { knowledgeLevel: "expert" });
      expect(u.knowledgeLevel).toBe("expert");
    });

    it("favoriteTeamCode를 null로 보내면 필드가 삭제된다", async () => {
      await createMeWithReservation();
      const u = await updateMe(fakeToken(), { favoriteTeamCode: null });
      expect(u.favoriteTeamCode).toBeUndefined();
    });

    it("동일 이름으로 변경 시도 → 400 NAME_CHANGE_DENIED", async () => {
      await createMeWithReservation();
      await expect(
        updateMe(fakeToken(), { displayName: "유저1" })
      ).rejects.toMatchObject({
        status: 400,
        code: "NAME_CHANGE_DENIED",
      });
    });

    it("타인이 사용 중인 닉네임 → 409 NICKNAME_TAKEN", async () => {
      await createMeWithReservation();
      await createMeWithReservation(
        fakeToken({ uid: "other", sub: "other" }),
        { ...validBody, displayName: "타유저" }
      );
      await expect(
        updateMe(fakeToken(), { displayName: "타유저" })
      ).rejects.toMatchObject({
        status: 409,
        code: "NICKNAME_TAKEN",
      });
    });

    it("빈 body → 400 INVALID_INPUT", async () => {
      await createMeWithReservation();
      await expect(updateMe(fakeToken(), {})).rejects.toMatchObject({
        status: 400,
        code: "INVALID_INPUT",
      });
    });

    it.each([
      ["빈 displayName", { displayName: "" }],
      ["11자 displayName", { displayName: "1234567890X" }],
      ["잘못된 팀코드", { favoriteTeamCode: "XX" }],
      ["잘못된 레벨", { knowledgeLevel: "master" }],
    ])("%s → 400 INVALID_INPUT", async (_label, body) => {
      await createMeWithReservation();
      await expect(
        updateMe(fakeToken(), body as never)
      ).rejects.toMatchObject({
        status: 400,
        code: "INVALID_INPUT",
      });
    });

    it("여러 필드를 동시에 변경할 수 있다", async () => {
      await createMeWithReservation();
      const u = await updateMe(fakeToken(), {
        displayName: "새이름",
        favoriteTeamCode: "NC",
        knowledgeLevel: "beginner",
      });
      expect(u.displayName).toBe("새이름");
      expect(u.favoriteTeamCode).toBe("NC");
      expect(u.knowledgeLevel).toBe("beginner");
    });
  });

  describe("createMe 예약 연동", () => {
    it("예약 없이 createMe → 409 RESERVATION_MISSING", async () => {
      await expect(createMe(fakeToken(), validBody)).rejects.toMatchObject({
        status: 409,
        code: "RESERVATION_MISSING",
      });
    });

    it("createMe 성공 후 예약 경로가 소비된다", async () => {
      await createMeWithReservation();
      const nameSnap = await rtdb
        .ref(`/nicknames/${validBody.displayName}`)
        .get();
      expect(nameSnap.exists()).toBe(false);
      const userSnap = await rtdb.ref(`/userNicknames/${uid}`).get();
      expect(userSnap.exists()).toBe(false);
    });

    it("deleteMe 후 예약 잔재 없음", async () => {
      await createMeWithReservation();
      await deleteMe(fakeToken());
      const userSnap = await rtdb.ref(`/userNicknames/${uid}`).get();
      expect(userSnap.exists()).toBe(false);
    });
  });
});