var gulp         = require('gulp');
var concat       = require('gulp-concat');
var sort         = require('gulp-sort');
var minify       = require('gulp-minify');
var replace      = require('gulp-string-replace');

gulp.task('build', build);
gulp.task('monitor', monitor);

function build() {
    return gulp.src('./src/r3-*.js')
        .pipe(sort())
        .pipe(concat('r3.js'))
        .pipe(replace('__DATE__', new Date().toString()))
        .pipe(minify({
            ext:{
                src:'.js',
                min:'-min.js'
            }
        }))
        .pipe(gulp.dest('./build/'));
}


function monitor() {
    gulp.watch('src/*.js', build);
}

gulp.task(
    'default',
    gulp.series(
        build,
        monitor
    )
);