'use strict';

// Directory name inside the patterns repo
var site = 'codesignd';

////////////////////////////////////////////////////////////////////////////////

// Node dependencies
var fs   = require('fs');
var path = require('path');

// gulp and gulp plugins
var gulp         = require('gulp');
var autoprefixer = require('gulp-autoprefixer');
var cleanCSS     = require('gulp-clean-css');
var concat       = require('gulp-concat');
var header       = require('gulp-header');
var include      = require('gulp-include');
var preservetime = require('gulp-preservetime');
var refresh      = require('gulp-refresh');
var rename       = require('gulp-rename');
var gulpSass     = require('gulp-sass');
var sass         = gulpSass.compiler;
var uglify       = require('gulp-uglify');

// Other npm modules
var del = require('del');

// Load package.json of the patterns repo
var packageData = require('./site/patterns/package.json');

////////////////////////////////////////////////////////////////////////////////

var helpers = {};

/**
 * Returns a banner for asset files
 *
 * @param  {string} type File type of the generated file
 * @return {object}
 */
helpers.banner = function(type) {
	var banner = [
		'/*!',
		' * <%= pkg.description %>',
		' * @link <%= pkg.homepage %>',
		' * @copyright <%= pkg.copyright %>',
		' * @license <%= pkg.license' + type + ' || pkg.license %>',
		' */',
		''
	].join('\n');
	
	return header(banner, {pkg: packageData});
};

/**
 * Builds the CSS of the specified site
 *
 * @param  {string}  site   Site name, defaults to "shared" if not given
 * @param  {boolean} minify Whether to minify using clean-css
 * @return {stream}
 */
helpers.buildCSS = function(site, minify) {
	if(!site)   site   = 'shared';
	if(!minify) minify = false;
	
	var sassOptions = {
		functions: {
			'-cdd-cachebuster($filepath)': function(filepath, done) {
				var pathString = filepath.getValue();
				
				fs.stat(__dirname + pathString, function(err, stats) {
					if(err) throw err;
					
					var mtime = Math.round(Date.parse(stats.mtime) / 1000);
					
					var parsed = path.parse(pathString);
					var filepath = parsed.dir + '/' + parsed.name + '.' + mtime + parsed.ext;
					done(sass.types.String(filepath));
				});
			}
		},
		outputStyle: 'expanded'
	};
	
	// Compile the SCSS file
	var stream = gulp.src('site/patterns/' + site + '/' + site + '.scss')
	                 .pipe(gulpSass(sassOptions).on('error', gulpSass.logError))
	                 .pipe(autoprefixer({browsers: ['> 1%']}))
	                 .pipe(rename('index.css'))
	                 .pipe(helpers.banner('CSS'))
	                 .pipe(gulp.dest('assets/css'));
	
	// Minify CSS if required
	if(minify) {
		stream = stream.pipe(rename('index.min.css'))
		               .pipe(cleanCSS())
		               .pipe(gulp.dest('assets/css'));
	}
	
	// Trigger LiveReload
	return stream.pipe(refresh());
};

/**
 * Builds the JS of the specified site
 *
 * @param  {string}  site   Site name, defaults to "shared" if not given
 * @param  {boolean} minify Whether to minify using UglifyJS
 * @return {stream}
 */
helpers.buildJS = function(site, minify) {
	if(!site)   site   = 'shared';
	if(!minify) minify = false;
	
	var src = ['site/patterns/shared/**/*.js', '!site/patterns/shared/polyfills.js'];
	if(site !== 'shared') {
		src.push('site/patterns/'  + site + '/**/*.js');
		src.push('!site/patterns/' + site + '/polyfills.js');
	}

	// Concat the JS files
	var stream = gulp.src(src)
	                 .pipe(concat('index.js'))
	                 .pipe(include({includePaths: __dirname + '/node_modules'}))
	                 .pipe(helpers.banner('JS'))
	                 .pipe(gulp.dest('assets/js'));
	
	// Minify JS if required
	if(minify) {
		stream = stream.pipe(rename('index.min.js'))
		               .pipe(uglify({output: {comments: 'some'}}))
		               .pipe(gulp.dest('assets/js'));
	}

	// Trigger LiveReload
	return stream.pipe(refresh());
};
	
/**
 * Builds the polyfills JS of the specified site
 *
 * @param  {string}  site   Site name, defaults to "shared" if not given
 * @param  {boolean} minify Whether to minify using UglifyJS
 * @return {stream}
 */
helpers.buildPolyfillsJS = function(site, minify) {
	if(!site)   site   = 'shared';
	if(!minify) minify = false;

	var src = ['site/patterns/shared/polyfills.js'];
	if(site !== 'shared') src.push('site/patterns/' + site + '/polyfills.js');

	// Concat the JS files
	var stream = gulp.src(src, {allowEmpty: true})
	                 .pipe(concat('polyfills.js'))
	                 .pipe(include({includePaths: __dirname + '/node_modules'}))
	                 .pipe(helpers.banner('JS'))
	                 .pipe(gulp.dest('assets/js'));

	// Minify JS if required
	if(minify) {
		stream = stream.pipe(rename('polyfills.min.js'))
		               .pipe(uglify({output: {comments: 'some'}}))
		               .pipe(gulp.dest('assets/js'));
	}

	// Trigger LiveReload
	return stream.pipe(refresh());
};

/**
 * Copies all files matching a specified pattern to the assets dir
 * Removes folder hierarchies so make sure that each file has a unique name!
 *
 * @param  {string} site    Site name, defaults to "shared" if not given
 * @param  {string} pattern Something like "*.{jpg,svg}"
 * @param  {string} dest    Either "fonts" or "img"
 * @return {stream}
 */
helpers.copyFiles = function(site, pattern, dest) {
	if(!site) site = 'shared';
	
	var src = ['site/patterns/shared/**/' + pattern];
	if(site !== 'shared') src.push('site/patterns/' + site + '/**/' + pattern);
	
	return gulp.src(src, {since: gulp.lastRun(dest)})
	           .pipe(rename({dirname: ''})) // Flat hierarchy
	           .pipe(gulp.dest('assets/' + dest))
	           .pipe(preservetime())
	           .pipe(refresh());
};

////////////////////////////////////////////////////////////////////////////////

/**
 * Compiles the CSS file of the current site
 */
gulp.task('css', function() {
	return helpers.buildCSS(site);
});

/**
 * Compiles and minifies the CSS file of the current site
 */
gulp.task('css.min', function() {
	return helpers.buildCSS(site, true);
});

/**
 * Combines the JS files of the current site
 */
gulp.task('js', function() {
	return helpers.buildJS(site);
});

/**
 * Combines and minifies the JS files of the current site
 */
gulp.task('js.min', function() {
	return helpers.buildJS(site, true);
});

/**
 * Combines the polyfills JS files of the current site
 */
gulp.task('polyfills', function() {
	return helpers.buildPolyfillsJS(site);
});

/**
 * Combines and minifies the polyfills JS files of the current site
 */
gulp.task('polyfills.min', function() {
	return helpers.buildPolyfillsJS(site, true);
});

/**
 * Copies all webfonts to assets/fonts
 */
gulp.task('fonts', function() {
	return helpers.copyFiles(site, '*.{woff,woff2,eot}', 'fonts');
});

/**
 * Copies all images to assets/img
 */
gulp.task('img', function() {
	return helpers.copyFiles(site, '*.{jpg,png,svg,ico}', 'img');
});

/**
 * Copies prism.js components to assets/js/prism
 */
gulp.task('prismjs', function() {
	return gulp.src('node_modules/prismjs/components/*')
	           .pipe(gulp.dest('assets/js/prism'));
});

/**
 * Builds everything except the minified files for local development
 */
gulp.task('default', gulp.series(gulp.parallel('fonts', 'img'), gulp.parallel('css', 'js', 'polyfills', 'prismjs')));

/**
 * Watches for changes
 */
function watchwait() {
	refresh.listen();
	
	gulp.watch('site/patterns/**/*.scss', gulp.series('css'));
	gulp.watch('site/patterns/**/*.js', gulp.series('js'));
	gulp.watch('site/patterns/*/polyfills.js', gulp.series('polyfills'));
	gulp.watch('site/patterns/**/*.{woff,woff2,eot}', gulp.series('fonts'));
	gulp.watch('site/patterns/**/*.{jpg,png,svg,ico}', gulp.series('img'));
	
	gulp.watch(['content/**/*.txt', 'site/**/*.{php,yml}']).on('change', refresh.changed);
}
gulp.task('watch', gulp.series('default', watchwait));

/**
 * Cleans built files
 */
gulp.task('clean', function() {
	return del('assets/*/*');
});

/**
 * Builds everything for production
 * WARNING: Deletes some source files, only run this after committing your files
 */
function prodclean() {
	return del(['node_modules', 'gulpfile.js', 'site/patterns/*/', '!site/patterns/{shared,' + site + '}']);
}
gulp.task('prod', gulp.series('clean', gulp.parallel('fonts', 'img'), gulp.parallel('css.min', 'js.min', 'polyfills.min', 'prismjs'), prodclean));