const gulp = require('gulp');
const imagemin = require('gulp-imagemin');
const uglify = require('gulp-uglify');
const sass = require('gulp-sass');
const concat = require('gulp-concat');

-- 常用的方法 --

/*
  gulp.task - Define tasks
  gulp.src - Point to files to use
  gulp.dest - Points to folder to output
  gulp.watch - Watch files and folders for changes
*/

// 調(diào)用方法打印

gulp.task('message', function(){
  return console.log('Gulp is running...');
});

// 拷貝所有的html文件

gulp.task('copyHtml', function(){
  gulp.src('src/*.html')
      .pipe(gulp.dest('dist'));
});

// 壓縮圖片

gulp.task('imageMin', () =>
    gulp.src('src/images/*')
        .pipe(imagemin())
        .pipe(gulp.dest('dist/images'))
);

// 壓縮js

gulp.task('minify', function(){ gulp.src('src/js/*.js') 
.pipe(uglify()) .pipe(gulp.dest('dist/js')); });

// 合并scss

gulp.task('sass', function(){
  gulp.src('src/sass/*.scss')
      .pipe(sass().on('error', sass.logError))
      .pipe(gulp.dest('dist/css'));
});

// Scripts

gulp.task('scripts', function(){
  gulp.src('src/js/*.js')
      .pipe(concat('main.js'))
      .pipe(uglify())
      .pipe(gulp.dest('dist/js'));
});

gulp.task('default', ['message', 'copyHtml', 'imageMin', 'sass', 'scripts']);


gulp.task('watch', function(){
    gulp.watch('src/js/*.js', ['scripts']);
    gulp.watch('src/images/*', ['imageMin']);
    gulp.watch('src/sass/*.scss', ['sass']);
    gulp.watch('src/*.html', ['copyHtml']);
});