let gulp = require('gulp'),
    jade = require('gulp-jade'),
    stylus = require('gulp-stylus'),
    rename = require("gulp-rename"),
    plumber = require('gulp-plumber'),
    autoprefixer = require('gulp-autoprefixer'),
    babel = require('rollup-plugin-babel'),
    resolve = require('rollup-plugin-node-resolve'),
    commonjs = require('rollup-plugin-commonjs'),
    replace = require('rollup-plugin-replace'),
    uglify = require('rollup-plugin-uglify'),
    progress = require('rollup-plugin-progress'),
    rollup = require('rollup'),
    browserSync = require('browser-sync').create();

let option = (env) => {
  return {
    entry: './src/main.js',
    plugins: [
      babel({
        exclude: './node_modules/**'
      }),
      commonjs(),
      resolve({
        jsnext: true,
        main: true,
        browser: !env
      }),
      progress({
        clearLine: false
      }),
      replace({
        ENV: JSON.stringify(env || 'development')
      }),
      (env === 'production' && uglify())
    ]
  }
};

let cache = {};

let bundleWrite = (bundle) => {
  console.log('[RD]', 'Writing bundle...')
  cache = bundle;
  bundle.write({
    format: 'iife',
    dest: './dist/main.js',
    sourceMap: 'inline'
  })
};

let rollupfn = (env) => {
  console.log('[RO] INGING ...');
  return rollup.rollup(option(env))
    .then(function(bundle) {
      bundle.write({
        format: 'iife',
        dest: './dist/main.js',
        sourceMap: false
      });
    })
};

// ----------------------- task ------------------------------------------

gulp.task('jade', () => {
  return gulp.src('./src/*.jade')
    .pipe(plumber({
      errorHandler(err) {
        this.emit('end')
      }
    }))
    .pipe(jade({
      pretty: true
    }))
    .pipe(gulp.dest('./dist'));
});

gulp.task('styl', () => {
  return gulp.src('./src/*.styl')
    .pipe(plumber({
      errorHandler(err) {
        this.emit('end')
      }
    }))
    .pipe(stylus({
      compress: true
    }))
    .pipe(autoprefixer({
      browsers: ['last 5 versions', 'Android >= 4.0']
    }))
    // .pipe(rename({
    //   suffix: '.min'
    // }))
    .pipe(gulp.dest('./dist'));
});


// ----------------------- work ------------------------------------------

gulp.task('build', ['jade', 'styl'], () => {
  return rollupfn('production');
});

gulp.task('dev', ['jade', 'styl'], () => {
  browserSync.init({
    server: './dist',
    open: false
  });

  let opd = option();
  rollup.rollup(opd)
    .then(bundleWrite)
    .then(() => {
      gulp.watch('./src/**/*.js').on('change', () => {
        rollup.rollup(Object.assign({}, opd, {
            cache
          }))
          .then(bundleWrite)
      });
    });
  gulp.watch('./src/*.jade', ['jade']);
  gulp.watch('./src/*.styl', ['styl']);
  // gulp.watch('./dist/**').on('change', browserSync.reload);
});