var
	changed = require('gulp-changed'),
	gulp = require('gulp'),
	hljs = require('highlight.js'),
	md = require('jstransformer')(require('jstransformer-markdown-it')),
	md_anchor = require('markdown-it-anchor'),
	md_footnote = require('markdown-it-footnote'),
	md_toc = require('markdown-it-table-of-contents'),
	minifyhtml = require('gulp-minify-html'),
	minifyjs = require('gulp-minify'),
	notify = require('gulp-notify'),
	pug = require('gulp-pug-3'),
	sass = require('gulp-sass-next');

var config = {
	jsPath: './resources/js',
	mdPath: './resources/md',
	pugPath: './resources/pug',
	sassPath: './resources/sass',
}

function css() {
	return gulp.src(config.sassPath + '/style.scss')
		.pipe(sass({
				outputStyle: 'compressed',
				includePaths: [
					'./resources/sass',
					'./node_modules'
				]
			})
			.on('error', notify.onError(function (error) {
				return "Error: " + error.message;
			}))
		)
		.pipe(gulp.dest('./build/assets/css'));
}

function html() {
	var src = config.pugPath + '/finals/**/*.pug',
		dst = './build';

	return gulp.src(src)
		.pipe(changed(dst, {extension: 'html'}))
		.pipe(pug({
			basedir: config.pugPath + '/include',
			filters: {
				markdown: (text, options) => {
					options = Object.assign({
						highlight: (str, lang) => {
							if (lang && hljs.getLanguage(lang)) {
								try {
									return hljs.highlight(str, {language: lang}).value;
								} catch (__) {}
							}

							try {
								return hljs.highlightAuto(str).value;
							} catch (__) {}

							return '';
						},
						html: true,
						langPrefix: 'lang-',
						linkify: true,
						plugins: [
							[md_anchor, {
								permalink: md_anchor.permalink.ariaHidden({
									placement: 'before'
								}),
							}],
							md_footnote,
							[md_toc, {
								containerHeaderHtml: '<h1>Contents</h1>',
							}],
						],
					}, options);
					return md.render(text, options).body;
				}
			}
		}))
		.pipe(minifyhtml())
		.pipe(gulp.dest(dst));
}

function js() {
	var src = [
		'./node_modules/bootstrap-sass/assets/javascripts/bootstrap/collapse.js',
		'./node_modules/bootstrap-sass/assets/javascripts/bootstrap/transition.js',
		'./node_modules/jquery/dist/jquery.slim.min.js',
	];
	var dst = './build/assets/js';

	return gulp.src(src)
		.pipe(minifyjs({
			ext: {
				min: '.min.js'
			},
			ignoreFiles: ['*.min.js'],
			noSource: true,
		}))
		.pipe(gulp.dest(dst));
}

function img() {
	return gulp.src('./resources/img/*')
		.pipe(gulp.dest('./build/assets/img'));
}

function pdf() {
	return gulp.src('./resources/pdf/*')
		.pipe(gulp.dest('./build/assets/pdf'));
}

function fonts() {
	gulp.src('./node_modules/@fortawesome/fontawesome-free/webfonts/fa-brands*')
		.pipe(gulp.dest('./build/assets/webfonts'));
	gulp.src('./node_modules/@fortawesome/fontawesome-free/webfonts/fa-solid*')
		.pipe(gulp.dest('./build/assets/webfonts'));
	gulp.src('./node_modules/academicons/fonts/*')
		.pipe(gulp.dest('./build/assets/fonts'));
	return gulp.src('./resources/fonts/*')
		.pipe(gulp.dest('./build/assets/fonts'));
}

function watch() {
	gulp.watch(config.mdPath + '/**/*.md', html);
	gulp.watch(config.pugPath + '/**/*.pug', html);
	gulp.watch(config.sassPath + '/**/*.scss', css);
}

exports.css = css;
exports.html = html;
exports.img = img;
exports.js = js;
exports.pdf = pdf;
exports.fonts = fonts;
exports.watch = watch;

var build = gulp.parallel(css, html, img, js, pdf, fonts);
gulp.task('build', build);
gulp.task('default', build);