'use strict';

const gulp    = require('gulp');
const babel   = require('gulp-babel');
const argv    = require('yargs').argv;

const jsSrc   = 'src/**/*.js';
const jsonSrc = 'src/*.json';
const dist    = 'dist';


// Transpile from ES6 to ES5
gulp.task( 'transpile', () => {
    return gulp
        .src( jsSrc )
        .pipe( babel( {
            presets: [ 'es2015' ]
        }))
        .pipe( gulp.dest( dist ) );
});

// Copy JSON files
gulp.task( 'copy-json-files', () => {
    return gulp
        .src( jsonSrc )
        .pipe( gulp.dest( dist ) )
});

// Check if --watch true was passed to the command line
if( typeof argv.watch !== 'undefined' && !!argv.watch ){
    console.log('Watching enabled!');

    gulp.task('default',[ 'transpile' ], () => {
        return gulp.watch( jsSrc, ['transpile']);
    });

    gulp.task('default',[ 'copy-json-files' ], () => {
        return gulp.watch( jsonSrc, ['copy-json-files']);
    });
}
else {
    gulp.task('default',[ 'transpile', 'copy-json-files' ]);
}