var gulp = require('gulp')
const tsify = require('tsify');
var sourcemaps = require('gulp-sourcemaps');
const rename = require('gulp-rename');
const browserify = require('browserify');
const source = require('vinyl-source-stream');
const buffer = require('vinyl-buffer');
const terser = require('gulp-terser');
const eslint = require('gulp-eslint');
const babelify = require('babelify');
const htmlmin = require('gulp-html-minifier-terser');
const htmlvalidator = require('gulp-html');

const html = () => {
  return gulp.src('src/index.html')
    .pipe(htmlvalidator())
    .pipe(htmlmin({
      removeComments: true,
      collapseWhitespace: true,
      collapseBooleanAttributes: true,
      collapseInlineTagWhitespace: true,
      removeRedundantAttributes: true
    }))
    .pipe(gulp.dest('dist'));
}

const js = () => {
  gulp.src(['src/**/*.ts', '!node_modules/**'])
    .pipe(eslint({quiet: true}))
    .pipe(eslint.results(results => {
    	 // Called once for all ESLint results.
       console.log('ESLint results:\n');
       console.log(`Total Errors: ${results.errorCount}`);
       let output = '';
       results.forEach(file => {
         output += file.filePath + '\n';
         file.messages.forEach(message => {
           output += ' - ' + message.message + ' at ' + message.line + ':' + message.column + '\n';
         });
         output += '\n';
       });
       console.error(output);
    }))
    .pipe(eslint.failAfterError());

  return browserify('src/index.ts')
     .plugin(tsify, { noImplicitAny: true, target: 'es6' })
     .transform(babelify, { extensions: [ '.tsx', '.ts' ] })
     .bundle().on('error', (e) => console.error(e))
     .pipe(source('output.js'))
     .pipe(gulp.dest('dist'))
     .pipe(buffer())
     .pipe(sourcemaps.init())
     .pipe(terser())
     .pipe(rename({ extname: '.min.js' }))
     .pipe(sourcemaps.write()) // Now the sourcemaps are added to the .js file
     .pipe(gulp.dest('dist'));
};

exports.default = gulp.parallel(js, html);