/***********************************************************************************************************************************************************************
 * File Name: passport.config.js
 * Type of Program: Configuration
 * Description: Passport.js strategy configuration.
 *              Registers the Google OAuth 2.0 strategy. On first login via Google
 *              a new user record is auto-created with reg_type="google".
 *              Returns a signed JWT payload after successful authentication.
 * Author: rgrgogu
 * Date Created: Oct. 6, 2025
 ***********************************************************************************************************************************************************************
 * HOW TO USE:
 *   In server.js:
 *     require('./config/passport.config');
 *     app.use(passport.initialize());
 *   In routes:
 *     router.get('/google', passport.authenticate('google', { scope: ['profile', 'email'] }));
 *     router.get('/google/callback', passport.authenticate('google', { session: false }), handler);
 ***********************************************************************************************************************************************************************/
const passport = require('passport');
const { Strategy: GoogleStrategy } = require('passport-google-oauth20');
const mdl_Users = require('../models/users/users.mdl');

passport.use(
  new GoogleStrategy(
    {
      clientID: process.env.GOOGLE_CLIENT_ID,
      clientSecret: process.env.GOOGLE_CLIENT_SECRET,
      callbackURL: process.env.GOOGLE_CALLBACK_URL,
    },
    async (accessToken, refreshToken, profile, done) => {
      try {
        const email = profile.emails?.[0]?.value;
        if (!email) return done(new Error('No email returned from Google'), null);

        let user = await mdl_Users.findOne({ where: { email } });

        if (!user) {
          // Auto-register Google users as 'user' acc_type
          user = await mdl_Users.create({
            email,
            reg_type: 'google',
            acc_type: 'user',
            is_active: true,
            is_verified: true,            // Google accounts are pre-verified
            personal_info: {
              name: {
                given_name: profile.name?.givenName || '',
                last_name: profile.name?.familyName || '',
                full_name: profile.displayName || '',
              },
              avatar: {
                url: profile.photos?.[0]?.value || null,
              },
            },
          });
        }

        if (!user.is_active) {
          return done(null, false, { message: 'Account is deactivated.' });
        }

        return done(null, user);
      } catch (err) {
        return done(err, null);
      }
    }
  )
);

module.exports = passport;