const { src, task, dest, parallel } = require('gulp')
const babel = require('gulp-babel')
const uglify = require('gulp-uglify')
const imagemin = require('gulp-imagemin')

// 加载dotenv模块
// 具体用法可以查看文档
require('dotenv').config()
// console.log(process.env)

const sourceFiles = ['./assets/libs/*.*']
const Copy = cb => {
  src(sourceFiles).pipe(dest('./dist/m/libs'))
  cb()
}

task(Copy)

const mCss = cb => {
  src(['./assets/css/*.css']).pipe(dest('./dist/m/css'))
  cb()
}
task(mCss)

const mJs = cb => {
  src(['./assets/js/*.js', './assets/js/**/*.js'])
    .pipe(
      babel({
        presets: ['@babel/preset-env']
      })
    )
    .pipe(uglify())
    .pipe(dest('./dist/m/js'))
  cb()
}
task(mJs)

const mImg = cb => {
  src('./assets/img/**/*')
    .pipe(
      imagemin([
        imagemin.gifsicle({ interlaced: true }),
        imagemin.mozjpeg({ quality: 75, progressive: true }),
        imagemin.optipng({ optimizationLevel: 5 }),
        imagemin.svgo({
          plugins: [{ removeViewBox: true }, { cleanupIDs: false }]
        })
      ])
    )
    .pipe(dest('./dist/m/img'))
  cb()
}

task(mImg)

exports.buildImg = mImg

exports.build = parallel(Copy, mCss, mJs, mImg)