/**
 * The regular expression to find asset names in a string
 *
 * @type {RegExp}
 */
const defaultAssetRegex = /[{]{2}([^}]+)[}]{2}/g;

/**
 * Replaces asset names with the first of the asset files from a webpack compilation.
 *
 * @param {string} targetSource - a string in which to replace the assets
 * @param {Object} assetFiles - a map of available asset names and their containing files
 * @return {string}
 */
function replaceAssets (targetSource, assetFiles) {
    return targetSource.replace(defaultAssetRegex, function replaceAsset (match, assetName) {
        if (!(assetFiles[assetName] && assetFiles[assetName].length)) {
            console.warn(`no asset for '${assetName}' was found`);
            return match;
        }

        return assetFiles[assetName][0];
    });
}

module.exports = replaceAssets;