var gulp = require('gulp');
var cp = require('child_process');
var del = require('del');
var concat = require('gulp-concat');
var shell  = require('gulp-shell');
var express = require('express');
var livereload = require('gulp-livereload');
var plumber = require('gulp-plumber');
var notify = require('gulp-notify');
var less = require('gulp-less');
var autoprefixer = require('gulp-autoprefixer');
var minifycss = require('gulp-minify-css');
var imagemin = require('gulp-imagemin');
var jshint = require('gulp-jshint');
var uglify = require('gulp-uglify');
var bundler = process.platform === 'win32' ? 'bundle.bat' : 'bundle';

var onError = function(err) {
    notify.onError({
                title:    'Gulp',
                subtitle: 'Failure!',
                message:  'Error: <%= error.message %>',
                sound:    'Beep'
            })(err);

    this.emit('end');
};

gulp.task('default', ['watch']);

gulp.task('build', ['clean', 'images', 'styles', 'lint', 'scripts', 'styleguide']);

// Run static file server
gulp.task('serve', function () {
    var server = express();
    server.use(express.static('_site'));
    server.listen(3333);
});

// Watch for changed files
gulp.task('watch', ['jekyll', 'serve'], function () {
    // Create LiveReload server
    livereload.listen({ port: 35729, basePath: '_site' });
    // Watch files, reload on change
    gulp.watch('_site/**').on('change', function (file) {
        livereload.changed(file.path);
    });

    gulp.watch('src/images/**/*', ['images']);
    gulp.watch('src/styles/**/*.less', ['styles']);
    gulp.watch('src/scripts/**/*.js', ['scripts']);
    gulp.watch(['src/styles/**/*', 'src/styleguide/**/*'], ['styleguide', 'jekyll']);
    gulp.watch(['*.html', '**/*.html', '**/*.md', '!assets/**', '!src/**', '!_site/**', '!_site/**/*', '!styleguide/**'], ['jekyll']);
});

// Cleanup
gulp.task('clean', function (cb) {
    // Force cleaning first before all other tasks
    del(['_site', 'assets/css/**/*', 'assets/img/**/*', 'assets/js/**/*', 'styleguide'], function (err, deletedFiles) {
        //console.log('Files deleted:', deletedFiles.join(', '));
    });
    cb();
});

// Process images
gulp.task('images', function () {
    return gulp.src('src/images/*')
        .pipe(plumber({errorHandler: onError}))
        .pipe(imagemin({
            progressive: true,
            svgoPlugins: [{removeViewBox: false}]
        }))
        .pipe(gulp.dest('assets/img'))
        .pipe(gulp.dest('_site/assets/img')); // Copy to static dir
});

// Compile style sheets
gulp.task('styles', function () {
    return gulp.src('src/styles/stylesheet.less')
        .pipe(plumber({errorHandler: onError}))
        .pipe(less())
        .pipe(autoprefixer('last 2 version', '> 1%'))
        .pipe(minifycss())
        .pipe(gulp.dest('assets/css'))
        .pipe(gulp.dest('_site/assets/css')); // Copy to static dir
});

// Lint scripts
gulp.task('lint', function () {
    return gulp.src(['gulpfile.js', 'src/js/**/*.js'])
        .pipe(plumber({errorHandler: onError}))
        .pipe(jshint());
});

gulp.task('scripts', ['scripts:jquery', 'scripts:bundle']);

// Compress jquery
gulp.task('scripts:jquery', function() {
    return gulp.src(['components/jquery/dist/jquery.js'])
        .pipe(plumber({errorHandler: onError}))
        .pipe(jshint())
        .pipe(uglify())
        .pipe(gulp.dest('assets/js'))
        .pipe(gulp.dest('_site/assets/js')); // Copy to static dir
});

// Compile all custom scripts and plugins into one bundle
gulp.task('scripts:bundle', function() {
    return gulp.src(['src/scripts/app.js', 'src/scripts/**/*.js'])
        .pipe(plumber({errorHandler: onError}))
        .pipe(jshint())
        .pipe(concat('bundle.js'))
        .pipe(uglify())
        .pipe(gulp.dest('assets/js'))
        .pipe(gulp.dest('_site/assets/js')); // Copy to static dir
});

// Build styleguide docs
gulp.task('styleguide', shell.task([
        // kss-node [source folder of files to parse] [destination folder] --template [location of template files]
        'kss-node <%= source %> <%= destination %> --template <%= template %>'
    ], {
        templateData: {
            template:     'src/styleguide',
            source:       'src/styles',
            destination:  'styleguide'
        }
    }
));

// Compile pages with Jekyll
gulp.task('jekyll', function () {
     return cp.spawn(bundler, ['exec', 'jekyll', 'build', '--drafts', '--quiet'], {stdio: 'inherit'});
});