// Copyright (c) Brock Allen & Dominick Baier. All rights reserved.

// Licensed under the Apache License, Version 2.0. See LICENSE in the project root for license information.

import { Log } from './Log';

import { Global } from './Global';

export class JsonService {

constructor(additionalContentTypes = null, XMLHttpRequestCtor = Global.XMLHttpRequest) {

if (additionalContentTypes && Array.isArray(additionalContentTypes))

{

this._contentTypes = additionalContentTypes.slice();

}

else

{

this._contentTypes = [];

}

this._contentTypes.push('application/json');

this._XMLHttpRequest = XMLHttpRequestCtor;

}

getJson(url, token) {

if (!url){

Log.error("JsonService.getJson: No url passed");

throw new Error("url");

}

Log.debug("JsonService.getJson, url: ", url);

return new Promise((resolve, reject) => {

var req = new this._XMLHttpRequest();

req.open('GET', url);

var allowedContentTypes = this._contentTypes;

req.onload = function() {

Log.debug("JsonService.getJson: HTTP response received, status", req.status);

if (req.status === 200) {

var contentType = req.getResponseHeader("Content-Type");

if (contentType) {

var found = allowedContentTypes.find(item=>{

if (contentType.startsWith(item)) {

return true;

}

});

if (found) {

try {

resolve(JSON.parse(req.responseText));

return;

}

catch (e) {

Log.error("JsonService.getJson: Error parsing JSON response", e.message);

reject(e);

return;

}

}

}

reject(Error("Invalid response Content-Type: " + contentType + ", from URL: " + url));

}

else {

reject(Error(req.statusText + " (" + req.status + ")"));

}

};

req.onerror = function() {

Log.error("JsonService.getJson: network error");

reject(Error("Network Error"));

};

if (token) {

Log.debug("JsonService.getJson: token passed, setting Authorization header");

req.setRequestHeader("Authorization", "Bearer " + token);

}

req.send();

});

}

}