/*
 * Copyright © 2016-2017 European Support Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

function getTimestampString() {
    let date = new Date();
    let z = n => (n < 10 ? '0' + n : n);
    return `${date.getFullYear()}-${z(date.getMonth())}-${z(
        date.getDate()
    )}_${z(date.getHours())}-${z(date.getMinutes())}`;
}

export default function showFileSaveDialog({
    blob,
    headers,
    defaultFilename,
    addTimestamp
}) {
    let filename;
    let contentDisposition = headers['content-disposition']
        ? headers['content-disposition']
        : '';
    let match = contentDisposition
        ? contentDisposition.match(/filename=(.*?)(;|$)/)
        : false;
    if (match) {
        filename = match[1];
    } else {
        filename = defaultFilename;
    }

    if (addTimestamp) {
        filename = filename.replace(
            /(^.*?)\.([^.]+$)/,
            `$1_${getTimestampString()}.$2`
        );
    }

    let link = document.createElement('a');
    let url = URL.createObjectURL(blob);
    link.href = url;
    link.download = filename;
    link.style.display = 'none';
    document.body.appendChild(link);
    link.click();
    setTimeout(function() {
        document.body.removeChild(link);
        URL.revokeObjectURL(url);
    }, 0);
}