How to manage multiple themes in a Pimcore project using the CoreShop Theme Bundle

webpack_encore:
   output_path: '%kernel.project_dir%/public/build/base'
   builds:
       admin: '%kernel.project_dir%/public/build/admin'
       base: '%kernel.project_dir%/public/build/base'
       # Example for an additional theme
       #portal: '%kernel.project_dir%/public/build/portal'

const Encore = require('@symfony/webpack-encore');

/**
 *
 * @param {string} name
 * @param {string} outputPath
 * @param {string} publicPath
 * @param {Array.<{name:string, src:string}>} entries
 * @param {Array.<{name:string, src:string}>} styleEntries
 * @param {Array.<{from:string, to:string}>} copyFiles
 * @param {Array.<Plugin>} plugins
 * @param {boolean} defaults
 * @param {boolean} mangle
 * @returns {webpack.Configuration}
 */
function getConfig({
                       name,
                       outputPath,
                       publicPath,
                       entries = [],
                       styleEntries = [],
                       copyFiles = [],
                       plugins = [],
                       defaults = true,
                       mangle = true
                   }) {
    Encore.reset();

    if (!mangle) {
        Encore.configureTerserPlugin((options) => {
            return {
                terserOptions: {
                    mangle: false,
                }
            };
        })
    }

    Encore
    // directory where all compiled assets will be stored
    .setOutputPath(outputPath)

    // what's the public path to this directory (relative to your project's document root dir)
    .setPublicPath(publicPath)

    .cleanupOutputBeforeBuild()

    // allow sass/scss files to be processed
    .enableSassLoader()

    .enablePostCssLoader((options) => {
        options.postcssOptions = {
            path: 'postcss.config.js'
        };
    })
    .enableSingleRuntimeChunk()
    .enableSourceMaps(!Encore.isProduction())
    .enableVersioning(Encore.isProduction())
    .enableTypeScriptLoader()
    ;
    // ##########################################################################################
    // ### default integrations for all configs
    // ##########################################################################################
    if (defaults) {
        // Put your default js includes here, if needed
        /*Encore
        .addEntry('js/base', './themes/base/assets/js/base.js')
        ;*/
    }

    entries.forEach(entry => {
        if (entry.name && entry.src) {
            Encore.addEntry(entry.name, entry.src);
        }
    })

    styleEntries.forEach(entry => {
        if (entry.name && entry.src) {
            Encore.addStyleEntry(entry.name, entry.src);
        }
    })

    if (defaults) {
        // Put your default copyFiles here, if needed
        /*copyFiles = [
            ...[
                {
                    from: './themes/base/assets/images',
                    to: 'images/[path][name].[ext]',
                }, {
                    from: './themes/base/assets/fonts',
                    to: 'fonts/[path][name].[ext]',
                }
            ],
            ...copyFiles
        ];*/
    }

    Encore
    .copyFiles(copyFiles)

    plugins.forEach(plugin => {
        Encore.addPlugin(plugin);
    })

    const config = Encore.getWebpackConfig();
    config.name = name;
    return config;
}

// export the final configuration
const admin = getConfig({
    name: 'admin',
    outputPath: 'public/build/admin',
    publicPath: '/build/admin',
    defaults: false,
    mangle: false,
    styleEntries: [
        {
            name: 'css/admin/edit',
            src: './themes/base/admin/assets/css/edit.scss'
        }
    ],
    copyFiles: [
        {
            from: './themes/base/admin/assets/js',
            to: 'js/[path][name].[ext]',
        },
    ]
});
const base = getConfig(require('./themes/base/webpack-web.config.js'));
const portal = getConfig(require('./themes/portal/webpack-web.config.js'));

module.exports = [admin, base, portal];