/* *
 * Mixin for downloading content in the browser
 *
 * (c) 2018 Oystein Moseng
 *
 * License: www.highcharts.com/license
 */

'use strict';

import Highcharts from '../parts/Globals.js';

var win = Highcharts.win,
    nav = win.navigator,
    doc = win.document,
    domurl = win.URL || win.webkitURL || win,
    isEdgeBrowser = /Edge\/\d+/.test(nav.userAgent);

// Convert base64 dataURL to Blob if supported, otherwise returns undefined
Highcharts.dataURLtoBlob = function (dataURL) {
    var parts = dataURL.match(/data:([^;]*)(;base64)?,([0-9A-Za-z+/]+)/);
    if (
        parts &&
        parts.length > 3 &&
        win.atob &&
        win.ArrayBuffer &&
        win.Uint8Array &&
        win.Blob &&
        domurl.createObjectURL
    ) {
        // Try to convert data URL to Blob
        var binStr = win.atob(parts[3]),
            buf = new win.ArrayBuffer(binStr.length),
            binary = new win.Uint8Array(buf),
            blob;

        for (var i = 0; i < binary.length; ++i) {
            binary[i] = binStr.charCodeAt(i);
        }

        blob = new win.Blob([binary], { 'type': parts[1] });
        return domurl.createObjectURL(blob);
    }
};


/**
 * Download a data URL in the browser. Can also take a blob as first param.
 *
 * @private
 * @function Highcharts.downloadURL
 *
 * @param {string|object} dataURL
 *        The dataURL/Blob to download
 *
 * @param {string} filename
 *        The name of the resulting file (w/extension)
 */
Highcharts.downloadURL = function (dataURL, filename) {
    var a = doc.createElement('a'),
        windowRef;

    // IE specific blob implementation
    // Don't use for normal dataURLs
    if (
        typeof dataURL !== 'string' &&
        !(dataURL instanceof String) &&
        nav.msSaveOrOpenBlob
    ) {
        nav.msSaveOrOpenBlob(dataURL, filename);
        return;
    }

    // Some browsers have limitations for data URL lengths. Try to convert to
    // Blob or fall back. Edge always needs that blob.
    if (isEdgeBrowser || dataURL.length > 2000000) {
        dataURL = Highcharts.dataURLtoBlob(dataURL);
        if (!dataURL) {
            throw 'Failed to convert to blob';
        }
    }

    // Try HTML5 download attr if supported
    if (a.download !== undefined) {
        a.href = dataURL;
        a.download = filename; // HTML5 download attribute
        doc.body.appendChild(a);
        a.click();
        doc.body.removeChild(a);
    } else {
        // No download attr, just opening data URI
        try {
            windowRef = win.open(dataURL, 'chart');
            if (windowRef === undefined || windowRef === null) {
                throw 'Failed to open window';
            }
        } catch (e) {
            // window.open failed, trying location.href
            win.location.href = dataURL;
        }
    }
};
