database.service.js

"use strict";
const mongoose = require("mongoose");
const logger = require("./logger.service");
const Q = require("q");

const TAG = "[ DATABASE SERVICE ]";
const env = require("./env.service");

// if DB is defined as an env var, it will go there, elsewise, try local
// you ideally set DB to your database uri that the provider gives you
// it should be easily findable

// DATABASE SERVICE
function getAddressFromEnvironment() {
    return env.isDevelopment()
        ? process.env.DB_ADDRESS_DEV
        : env.isProduction()
        ? process.env.DB_ADDRESS_DEPLOY
        : process.env.DB_ADDRESS_TEST;
}

function getUserFromEnvironment() {
    return env.isDevelopment()
        ? process.env.DB_USER_DEV
        : env.isProduction()
        ? process.env.DB_USER_DEPLOY
        : process.env.DB_USER_TEST;
}

function getPassFromEnvironment() {
    return env.isDevelopment()
        ? process.env.DB_PASS_DEV
        : env.isProduction()
        ? process.env.DB_PASS_DEPLOY
        : process.env.DB_PASS_TEST;
}

module.exports = {
    connect: function(callback) {
        mongoose.Promise = Q.promise;
        const user = getUserFromEnvironment();
        const pass = getPassFromEnvironment();
        const address = getAddressFromEnvironment();
        const url =
            !!user && !!pass
                ? `mongodb://${user}:${pass}@${address}`
                : `mongodb://${address}`;
        logger.info(`${TAG} Connecting to db on ${url}`);
        mongoose
            .connect(url)
            .then(
                function() {
                    logger.info(`${TAG} Connected to database on ${url}`);
                    if (callback) {
                        callback();
                    }
                },
                function(error) {
                    logger.error(
                        `${TAG} Failed to connect to database at ${url}. Error: ${error}`
                    );
                    throw `Failed to connect to database at ${url}`;
                }
            );
    },
    address: getAddressFromEnvironment(),
    readyState: function() {
        return mongoose.connection.readyState;
    }
};