import { UserProfile } from 'app/common/UserAPI';
import { GristLoginMiddleware, GristServer } from 'app/server/lib/GristServer';
import { Request } from 'express';

/**
 * Return a login system that supports a single hard-coded user.
 */
export async function getMinimalLoginMiddleware(gristServer: GristServer): Promise<GristLoginMiddleware> {
  // Login and logout, redirecting immediately back.  Signup is treated as login,
  // no nuance here.
  return {
    async getLoginRedirectUrl(req: Request, url: URL)  {
      await setSingleUser(req, gristServer);
      return url.href;
    },
    async getLogoutRedirectUrl(req: Request, url: URL) {
      return url.href;
    },
    async getSignUpRedirectUrl(req: Request, url: URL) {
      await setSingleUser(req, gristServer);
      return url.href;
    },
    async addEndpoints() {
      // If working without a login system, make sure default user exists.
      const dbManager = gristServer.getHomeDBManager();
      const profile = getDefaultProfile();
      const user = await dbManager.getUserByLoginWithRetry(profile.email, profile);
      if (user) {
        // No need to survey this user!
        user.isFirstTimeUser = false;
        await user.save();
      }
      return "no-logins";
    }
  };
}

/**
 * Set the user in the current session to the single hard-coded user.
 */
async function setSingleUser(req: Request, gristServer: GristServer) {
  const scopedSession = gristServer.getSessions().getOrCreateSessionFromRequest(req);
  await scopedSession.operateOnScopedSession(async (user) => Object.assign(user, {
    profile: getDefaultProfile()
  }));
}

function getDefaultProfile(): UserProfile {
  return {
    email: process.env.GRIST_DEFAULT_EMAIL || 'you@example.com',
    name: 'You',
  };
}