const gulp = require('gulp')
const eslint = require('gulp-eslint')
const stylelint = require('gulp-stylelint')
const sass = require('gulp-sass')

gulp.task('lint:js', () => {
  return gulp.src(['**/*.js','!node_modules/**'])
    .pipe(eslint())
    .pipe(eslint.format())
})

gulp.task('lint:sass', () => {
  const options = {
    reporters: [{formatter: 'string', console: true}]
  }
  return gulp.src('sass/**/*.sass')
    .pipe(stylelint(options))
})

gulp.task('build:dev', () => {
  const options = {
    outputStyle: 'compressed'
  }
  return gulp.src('sass/**/*.sass')
    .pipe(sass(options).on('error', sass.logError))
    .pipe(gulp.dest('temp'))
})

gulp.task('build:prod', () => {
  const options = {
    outputStyle: 'compressed'
  }
  return gulp.src('sass/**/*.sass')
    .pipe(sass(options).on('error', sass.logError))
    .pipe(gulp.dest('css'))
})

gulp.task('generate', ['lint:js', 'lint:sass', 'build:prod'], () => {
  // Generates all *.user.css styles.
  const { bump } = require('./bump.js')
  const klawSync = require('klaw-sync')
  const path = require('path')
  const userCss = require('usercss-creator')

  // Define constants
  const stylesDirectory = path.join(__dirname, 'sass')
  const cssDirectory = path.join(__dirname, 'css')

  // Walk recursively through styles directory
  let files = klawSync(stylesDirectory, {nodir: true})

  // Filter out any files that aren't .json files
  files = files.filter(file => path.extname(file.path) === '.json')

  let style
  let incrementType

  for (const arg of process.argv) {
    if (arg.includes('--bump')) {
      style = arg.substring('--bump='.length, arg.length)
    }
    switch (arg) {
    case '--major':
      incrementType = 'major'
      break
    case '--minor':
      incrementType = 'minor'
      break
    case '--patch':
      incrementType = 'patch'
      break
    }
  }

  // Iterate through all .json files
  for (const file of files) {
    // Requiring the .json file as the descriptor of the style
    const descriptor = require(file.path)
    // Test if the style we want to bump is the one currently generating
    if (style === descriptor.folder) {
      // Bump the style's .json with the increment type
      bump(file.path, incrementType)
    }
    // Create the css path and generate the .user.css file with the options
    const cssPath = path.join(cssDirectory, descriptor.folder, descriptor.entry)
    userCss.create(cssPath, descriptor.options)
  }
})

gulp.task('watch', () => {
  gulp.watch('sass/**/*.sass', ['lint:js', 'lint:sass', 'build:dev'])
})