manageConfig.js

const fs = require( 'fs' );
const { resolve } = require( 'path' );
const path = require( 'path' );

const configSample = fs.readFileSync(
	path.join( __dirname, 'config.json.sample' )
);
const configSampleJSON = JSON.parse( configSample );
const configPath = path.join( __dirname, 'config.json' );

function confirmOptionsAvail( config, sample ) {
	// Loop through each element of the sample and add it if it's missing
	for ( element in sample ) {
		if ( ! config.hasOwnProperty( element ) ) {
			config[ element ] = sample[ element ];
		}
		// If we encounter a nested object, loop through each of its elements as well
		if ( typeof sample[ element ] === 'object' ) {
			config[ element ] = confirmOptionsAvail(
				config[ element ],
				sample[ element ]
			);
		}
	}
	return config;
}
function getUserConfig() {
	return new Promise( ( resolve ) => {
		// Generate a config file if one does not already exist
		fs.writeFile( configPath, configSample, { flag: 'wx' }, ( error ) => {
			if ( error ) {
				// An error code of -17 means the file already exists, and we should confirm all values are present.
				// All other errors should throw.
				if ( error.errno === -17 ) {
					// Confirm that all configSample elements are present, and add any that are missing
					updatedConfig = confirmOptionsAvail(
						JSON.parse( fs.readFileSync( configPath ) ),
						configSampleJSON
					);
					// If any values needed updating, write the new config to the file
					if (
						updatedConfig !==
						JSON.parse( fs.readFileSync( configPath ) )
					) {
						fs.writeFileSync(
							configPath,
							JSON.stringify( updatedConfig, null, 4 ),
							{ flag: 'w' },
							function ( err ) {
								if ( err ) throw err;
							}
						);
					}
					resolve( JSON.parse( fs.readFileSync( configPath ) ) );
				} else {
					throw error;
				}
			}
		} );
	} );
}

module.exports = { getUserConfig };