const packageJson = require('./package.json');
const autoprefixer = require('autoprefixer');
const babelify = require('babelify'); // eslint-disable-line no-unused-vars
const browserify = require('browserify');
const eventStream = require('event-stream');
const glob = require('glob');
const gulp = require('gulp');
const babel = require('gulp-babel');
const diff = require('gulp-diff');
const gulpif = require('gulp-if');
const notify = require('gulp-notify');
const postcss = require('gulp-postcss');
const sass = require('gulp-sass');
const sourcemaps = require('gulp-sourcemaps');
const uglify = require('gulp-uglify');
const gulpUtil = require('gulp-util');
const path = require('path');
const source = require('vinyl-source-stream');
const buffer = require('vinyl-buffer');
const semver = require('semver');
const sprity = require('sprity');
const watchify = require('watchify');

const isDev = typeof process.env.npm_config_development !== 'undefined';

process.env.NODE_ENV = isDev ? 'development' : 'production';

const PATHS = {
  MODULES: './node_modules',
  ADMIN: './admin',
  ADMIN_IMAGES: './admin/images',
  ADMIN_SCSS: './admin/scss',
  ADMIN_THIRDPARTY: './admin/thirdparty',
  ADMIN_JAVASCRIPT_SRC: './admin/javascript/src',
  ADMIN_JAVASCRIPT_DIST: './admin/javascript/dist',
  FRAMEWORK: '.',
  FRAMEWORK_THIRDPARTY: './thirdparty',
  FRAMEWORK_DEV_INSTALL: './dev/install',
  FRAMEWORK_JAVASCRIPT_SRC: './javascript/src',
  FRAMEWORK_JAVASCRIPT_DIST: './javascript/dist',
};

// Folders which contain both scss and css folders to be compiled
const rootCompileFolders = [PATHS.FRAMEWORK, PATHS.ADMIN, PATHS.FRAMEWORK_DEV_INSTALL];

const browserifyOptions = {
  debug: true,
  paths: [PATHS.ADMIN_JAVASCRIPT_SRC, PATHS.FRAMEWORK_JAVASCRIPT_SRC],
};

const babelifyOptions = {
  presets: ['es2015', 'es2015-ie', 'react'],
  plugins: ['transform-object-assign'],
  ignore: /(node_modules|thirdparty)/,
  comments: false,
};

// Used for autoprefixing css properties (same as Bootstrap Aplha.2 defaults)
const supportedBrowsers = [
  'Chrome >= 35',
  'Firefox >= 31',
  'Edge >= 12',
  'Explorer >= 9',
  'iOS >= 8',
  'Safari >= 8',
  'Android 2.3',
  'Android >= 4',
  'Opera >= 12',
];

const blueimpFileUploadConfig = {
  src: `${PATHS.MODULES}/blueimp-file-upload`,
  dest: PATHS.FRAMEWORK_THIRDPARTY + '/jquery-fileupload',
  files: [
    '/cors/jquery.postmessage-transport.js',
    '/cors/jquery.xdr-transport.js',
    '/jquery.fileupload-ui.js',
    '/jquery.fileupload.js',
    '/jquery.iframe-transport.js'
  ]
};

var blueimpLoadImageConfig = {
  src: PATHS.MODULES + '/blueimp-load-image',
  dest: PATHS.FRAMEWORK_THIRDPARTY + '/javascript-loadimage',
  files: ['/load-image.js']
};

var blueimpTmplConfig = {
  src: PATHS.MODULES + '/blueimp-tmpl',
  dest: PATHS.FRAMEWORK_THIRDPARTY + '/javascript-templates',
  files: ['/tmpl.js']
};

var jquerySizesConfig = {
  src: PATHS.MODULES + '/jquery-sizes',
  dest: PATHS.ADMIN_THIRDPARTY + '/jsizes',
  files: ['/lib/jquery.sizes.js']
};

var tinymceConfig = {
  src: PATHS.MODULES + '/tinymce',
  dest: PATHS.FRAMEWORK_THIRDPARTY + '/tinymce',
  files: [
    '/tinymce.min.js', // Exclude unminified file to keep repository size down
    '/jquery.tinymce.min.js',
    '/themes/**',
    '/skins/**',
    '/plugins/**'
  ]
};

/**
 * Copies files from a source directory to a destination directory.
 *
 * @param object libConfig
 * @param string libConfig.src - The source directory
 * @param string libConfig.dest - The destination directory
 * @param array libConfig.files - The list of files to copy from the source to the destination directory
 */
function copyFiles(libConfig) {
  libConfig.files.forEach(function (file) {
    var dir = path.parse(file).dir;

    gulp.src(libConfig.src + file)
      .pipe(gulp.dest(libConfig.dest + dir));
  });
}

/**
 * Diffs files in a source directory against a destination directory.
 *
 * @param object libConfig
 * @param string libConfig.src - The source directory
 * @param string libConfig.dest - The destination directory
 * @param array libConfig.files - The list of files to copy from the source to the destination directory
 */
function diffFiles(libConfig) {
  libConfig.files.forEach(function (file) {
    var dir = path.parse(file).dir;

    gulp.src(libConfig.src + file)
      .pipe(diff(libConfig.dest + dir))
      .pipe(diff.reporter({ fail: true, quiet: true }))
      .on('error', function (error) {
        console.error(new Error('Sanity check failed. \'' + libConfig.dest + file + '\' has been modified.'));
        process.exit(1);
      });
  });
}

/**
 * Transforms the passed JavaScript files to UMD modules.
 *
 * @param array files - The files to transform.
 * @param string dest - The output directory.
 * @return object
 */
function transformToUmd(files, dest) {
  return eventStream.merge(files.map(function (file) {
    return gulp.src(file)
      .pipe(babel({
        presets: ['es2015'],
        moduleId: 'ss.' + path.parse(file).name,
        plugins: ['transform-es2015-modules-umd'],
        comments: false
      }))
      .on('error', notify.onError({
        message: 'Error: <%= error.message %>',
      }))
      .pipe(gulp.dest(dest));
  }));
}

// Make sure the version of Node being used is valid.
if (!semver.satisfies(process.versions.node, packageJson.engines.node)) {
  console.error('Invalid Node.js version. You need to be using ' + packageJson.engines.node + '. If you want to manage multiple Node.js versions try https://github.com/creationix/nvm');
  process.exit(1);
}

if (isDev) {
  browserifyOptions.cache = {};
  browserifyOptions.packageCache = {};
  browserifyOptions.plugin = [watchify];
}

gulp.task('build', ['umd', 'bundle']);

gulp.task('bundle', ['bundle-lib', 'bundle-legacy', 'bundle-framework']);

gulp.task('bundle-lib', function bundleLib() {
  var bundleFileName = 'bundle-lib.js';

  return browserify(Object.assign({}, browserifyOptions, { entries: PATHS.ADMIN_JAVASCRIPT_SRC + '/bundles/lib.js' }))
    .on('update', bundleLib)
    .on('log', function (msg) { gulpUtil.log('Finished', 'bundled ' + bundleFileName + ' ' + msg) })
    .transform('babelify', babelifyOptions)
    .require('deep-freeze', { expose: 'deep-freeze' })
    .require('react', { expose: 'react' })
    .require('react-addons-css-transition-group', { expose: 'react-addons-css-transition-group' })
    .require('react-addons-test-utils', { expose: 'react-addons-test-utils' })
    .require('react-dom', { expose: 'react-dom' })
    .require('react-redux', { expose: 'react-redux' })
    .require('redux', { expose: 'redux' })
    .require('redux-thunk', { expose: 'redux-thunk' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/components/form/index', { expose: 'components/form/index' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/components/form-action/index', { expose: 'components/form-action/index' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/components/form-builder/index', { expose: 'components/form-builder/index' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/components/grid-field/index', { expose: 'components/grid-field/index' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/components/grid-field/cell', { expose: 'components/grid-field/cell/index' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/components/grid-field/header', { expose: 'components/grid-field/header' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/components/grid-field/header-cell', { expose: 'components/grid-field/header-cell' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/components/grid-field/row', { expose: 'components/grid-field/row' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/components/grid-field/table', { expose: 'components/grid-field/table' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/components/hidden-field/index', { expose: 'components/hidden-field/index' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/components/text-field/index', { expose: 'components/text-field/index' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/components/north-header/index', { expose: 'components/north-header/index' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/components/north-header-breadcrumbs/index', { expose: 'components/north-header-breadcrumbs/index' })
    .require(PATHS.FRAMEWORK_JAVASCRIPT_SRC + '/i18n.js', { expose: 'i18n' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/config.js', { expose: 'config' })
    .require(PATHS.FRAMEWORK_JAVASCRIPT_SRC + '/jQuery.js', { expose: 'jQuery' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/reducer-register.js', { expose: 'reducer-register' })
    .require(PATHS.FRAMEWORK_JAVASCRIPT_SRC + '/router.js', { expose: 'router' })
    .require(PATHS.ADMIN_JAVASCRIPT_SRC + '/silverstripe-component', { expose: 'silverstripe-component' })
    .bundle()
    .on('error', notify.onError({ message: bundleFileName + ': <%= error.message %>' }))
    .pipe(source(bundleFileName))
    .pipe(buffer())
    .pipe(sourcemaps.init({ loadMaps: true }))
    .pipe(uglify())
    .pipe(sourcemaps.write('./'))
    .pipe(gulp.dest(PATHS.ADMIN_JAVASCRIPT_DIST));
});


gulp.task('bundle-legacy', function bundleLeftAndMain() {
  var bundleFileName = 'bundle-legacy.js';

  return browserify(Object.assign({}, browserifyOptions, { entries: PATHS.ADMIN_JAVASCRIPT_SRC + '/bundles/legacy.js' }))
    .on('update', bundleLeftAndMain)
    .on('log', function (msg) { gulpUtil.log('Finished', 'bundled ' + bundleFileName + ' ' + msg) })
    .transform('babelify', babelifyOptions)
    .external('config')
    .external('jQuery')
    .external('i18n')
    .external('router')
    .bundle()
	.on('update', bundleLeftAndMain)
    .on('error', notify.onError({ message: bundleFileName + ': <%= error.message %>' }))
    .pipe(source(bundleFileName))
    .pipe(buffer())
    .pipe(sourcemaps.init({ loadMaps: true }))
    .pipe(uglify())
    .pipe(sourcemaps.write('./'))
    .pipe(gulp.dest(PATHS.ADMIN_JAVASCRIPT_DIST));
});

gulp.task('bundle-framework', function bundleBoot() {
  var bundleFileName = 'bundle-framework.js';

  return browserify(Object.assign({}, browserifyOptions, { entries: PATHS.ADMIN_JAVASCRIPT_SRC + '/boot/index.js' }))
    .on('update', bundleBoot)
    .on('log', function (msg) { gulpUtil.log('Finished', 'bundled ' + bundleFileName + ' ' + msg) })
    .transform('babelify', babelifyOptions)
    .external('components/action-button/index')
	  .external('components/north-header/index')
	  .external('components/form-builder/index')
    .external('deep-freeze')
    .external('components/grid-field/index')
    .external('i18n')
    .external('jQuery')
    .external('page.js')
    .external('react-addons-test-utils')
    .external('react-dom')
    .external('react-redux')
    .external('react')
    .external('reducer-register')
    .external('redux-thunk')
    .external('redux')
    .external('silverstripe-component')
    .bundle()
	.on('update', bundleBoot)
    .on('error', notify.onError({ message: bundleFileName + ': <%= error.message %>' }))
    .pipe(source(bundleFileName))
    .pipe(buffer())
    .pipe(sourcemaps.init({ loadMaps: true }))
    .pipe(uglify())
    .pipe(sourcemaps.write('./'))
    .pipe(gulp.dest(PATHS.ADMIN_JAVASCRIPT_DIST));
});

gulp.task('sanity', function () {
  diffFiles(blueimpFileUploadConfig);
  diffFiles(blueimpLoadImageConfig);
  diffFiles(blueimpTmplConfig);
  diffFiles(jquerySizesConfig);
  diffFiles(tinymceConfig);
});

gulp.task('thirdparty', function () {
  copyFiles(blueimpFileUploadConfig);
  copyFiles(blueimpLoadImageConfig);
  copyFiles(blueimpTmplConfig);
  copyFiles(jquerySizesConfig);
  copyFiles(tinymceConfig);
});

gulp.task('umd', ['umd-admin', 'umd-framework'], function () {
  if (isDev) {
    gulp.watch(PATHS.ADMIN_JAVASCRIPT_SRC + '/*.js', ['umd-admin']);
    gulp.watch(PATHS.FRAMEWORK_JAVASCRIPT_SRC + '/*.js', ['umd-framework']);
  }
});

gulp.task('umd-admin', function () {
  var files = glob.sync(PATHS.ADMIN_JAVASCRIPT_SRC + '/*.js', { ignore: PATHS.ADMIN_JAVASCRIPT_SRC + '/LeftAndMain.!(Ping).js' });

  return transformToUmd(files, PATHS.ADMIN_JAVASCRIPT_DIST);
});

gulp.task('umd-framework', function () {
  return transformToUmd(glob.sync(PATHS.FRAMEWORK_JAVASCRIPT_SRC + '/*.js'), PATHS.FRAMEWORK_JAVASCRIPT_DIST);
});

/*
 * Takes individual images and compiles them together into sprites
 */
gulp.task('sprites', function () {
  return sprity.src({
    src: PATHS.ADMIN_IMAGES + '/sprites/src/**/*.{png,jpg}',
    cssPath: '../images/sprites/dist',
    style: './_spritey.scss',
    processor: 'sass',
    split: true,
    margin: 0
  })
  .pipe(gulpif('*.png', gulp.dest(PATHS.ADMIN_IMAGES + '/sprites/dist'), gulp.dest(PATHS.ADMIN_SCSS)))
});

gulp.task('css', ['compile:css'], function () {
  if (isDev) {
    rootCompileFolders.forEach(function (folder) {
      gulp.watch(folder + '/scss/**/*.scss', ['compile:css']);
    });

    // Watch the .scss files in react components
    gulp.watch('./admin/javascript/src/**/*.scss', ['compile:css']);
  }
})

/*
 * Compiles scss into css
 * Watches for changes if --development flag is given
 */
gulp.task('compile:css', function () {
  var outputStyle = isDev ? 'expanded' : 'compressed';

  var tasks = rootCompileFolders.map(function(folder) {
    return gulp.src(folder + '/scss/**/*.scss')
      .pipe(sourcemaps.init())
      .pipe(sass({ outputStyle: outputStyle })
        .on('error', notify.onError({
          message: 'Error: <%= error.message %>'
        }))
      )
      .pipe(postcss([autoprefixer({ browsers: supportedBrowsers })]))
      .pipe(sourcemaps.write())
      .pipe(gulp.dest(folder + '/css'))
  });

  return tasks;
});