import {
  ACCESS_TOKEN,
  AUTH_LOGIN_REDIRECT_URL,
  AUTH_USER_ID,
  CLAIM_NAME,
  ENDPOINT,
} from "@/shared/config";
import {
  type AuthPayload,
  type AuthService,
  getRemainingMs,
} from "@common/auth";

import {
  clearRefreshTimer,
  removeToken,
  setToken,
  setupRefreshTimer,
  tokenManager,
} from "../lib/token-manager";

function resolveLoginError(message: string | undefined): string {
  switch (message) {
    case "Invalid Credentials":
      return "아이디와 비밀번호가 일치하지 않습니다.";
    case "User not found":
      return "존재하지 않는 아이디입니다.";
    case "User is not active":
      return "활성화되지 않은 계정입니다.";
    case "User is not verified":
      return "이메일 인증이 필요합니다.";
    default:
      return message ?? "로그인에 실패했습니다.";
  }
}

async function login(payload: AuthPayload): Promise<void> {
  const response = await fetch(`/api/proxy${ENDPOINT.USER_SERVICE.LOGIN}`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify(payload),
  });

  const data = await response.json();

  if (!response.ok) {
    throw new Error(resolveLoginError(data?.message));
  }

  const accessToken = data[ACCESS_TOKEN] as string | undefined;
  const tokenId = data[AUTH_USER_ID] as string | undefined;

  if (!accessToken || !tokenId) {
    throw new Error("인증 토큰을 받지 못했습니다.");
  }

  setToken(CLAIM_NAME, accessToken);
  setToken(AUTH_USER_ID, tokenId);

  const remainingMs = getRemainingMs(accessToken);
  if (remainingMs > 0) {
    setupRefreshTimer(silentRefresh, remainingMs);
  }
}

async function silentRefresh(): Promise<void> {
  console.log(`[silentRefresh] Called at ${new Date().toISOString()}`);
  try {
    const response = await fetch(
      `/api/proxy${ENDPOINT.USER_SERVICE.SILENT_REFRESH}`,
      { method: "PUT" },
    );

    const data = await response.json();

    if (!response.ok) {
      throw new Error(data?.message ?? "토큰 갱신에 실패했습니다.");
    }

    const accessToken = data[ACCESS_TOKEN] as string | undefined;
    const tokenId = data[AUTH_USER_ID] as string | undefined;

    if (!accessToken || !tokenId) {
      throw new Error("갱신된 인증 토큰을 받지 못했습니다.");
    }

    setToken(CLAIM_NAME, accessToken);
    setToken(AUTH_USER_ID, tokenId);

    const remainingMs = getRemainingMs(accessToken);
    if (remainingMs > 0) {
      setupRefreshTimer(silentRefresh, remainingMs);
    }
  } catch (error) {
    console.error(
      `[silentRefresh] Failed at ${new Date().toISOString()}`,
      error,
    );
    tokenManager.clearAuthToken();
    if (typeof window !== "undefined") {
      window.dispatchEvent(new CustomEvent("auth:logout"));
    }
    // re-throw하지 않음: setupRefreshTimer 콜백의 catch와 이중 처리 방지
  }
}

async function logout(): Promise<void> {
  try {
    await fetch("/api/auth/logout", {
      method: "POST",
      credentials: "include",
    });
  } catch (error) {
    console.error("Logout API failed:", error);
  }

  tokenManager.clearAuthToken();
  removeToken("site-id-key");
  removeToken("site-theme-key");

  if (typeof window !== "undefined") {
    window.dispatchEvent(new CustomEvent("auth:logout"));
    window.location.href = AUTH_LOGIN_REDIRECT_URL;
  }
}

export const authService: AuthService = {
  login,
  silentRefresh,
  declineSessionExtend: clearRefreshTimer,
  logout,
};