user.js

'use strict';
const request = require('request');
const config = require('./config');
const pg = require('pg');
pg.defaults.ssl = true;

module.exports = {

    addUser: function(callback, userId) {
        request({
            uri: 'https://graph.facebook.com/v2.7/' + userId,
            qs: {
                access_token: config.FB_PAGE_TOKEN
            }

        }, function (error, response, body) {
            if (!error && response.statusCode == 200) {

                var user = JSON.parse(body);


                if (user.first_name.length > 0) {

                    var pool = new pg.Pool(config.PG_CONFIG);
                    pool.connect(function(err, client, done) {
                        if (err) {
                            return console.error('Error acquiring client', err.stack);
                        }
                        var rows = [];

                        client.query(`SELECT id FROM users WHERE fb_id='${userId}' LIMIT 1`,
                            function(err, result) {
                                if (err) {
                                    console.log('Query error: ' + err);
                                } else {
                                    console.log('rows: ' + result.rows.length);
                                    if (result.rows.length === 0) {
                                        let sql = 'INSERT INTO users (fb_id, first_name, last_name, profile_pic, ' +
                                            'locale, timezone, gender) VALUES ($1, $2, $3, $4, $5, $6, $7)';
                                        console.log('sql: ' + sql);
                                        client.query(sql,
                                            [
                                                userId,
                                                user.first_name,
                                                user.last_name,
                                                user.profile_pic,
                                                user.locale,
                                                user.timezone,
                                                user.gender
                                            ]);
                                    }
                                }
                            });
                        

                        callback(user);
                    });
                    pool.end();
                } else {
                    console.log("Cannot get data for fb user with id",
                        userId);
                }
            } else {
                console.error(response.error);
            }

        });
    },

    readAllUsers: function(callback, newstype) {
        var pool = new pg.Pool(config.PG_CONFIG);
        pool.connect(function(err, client, done) {
            if (err) {
                return console.error('Error acquiring client', err.stack);
            }
            client
                .query(
                    'SELECT fb_id, first_name, last_name FROM users WHERE newsletter=$1',
                    [newstype],
                    function(err, result) {
                        if (err) {
                            console.log(err);
                            callback([]);
                        } else {
                            console.log('rows');
                            console.log(result.rows);
                            callback(result.rows);
                        };
                    });
            
        });
        pool.end();
    },

    newsletterSettings: function(callback, setting, userId) {
        var pool = new pg.Pool(config.PG_CONFIG);
        pool.connect(function(err, client, done) {
            if (err) {
                return console.error('Error acquiring client', err.stack);
            }
            client
                .query(
                    'UPDATE users SET newsletter=$1 WHERE fb_id=$2',
                    [setting, userId],
                    function(err, result) {
                        if (err) {
                            console.log(err);
                            callback(false);
                        } else {
                            callback(true);
                        };
                    });
            
        });
        pool.end();
    }

}