var webRoot = 'https://localhost:8080/';

if(typeof window !== 'undefined'){
  webRoot = 'https://' + window.location.host + '/';
  if (window.location.hostname == 'localhost'
	  || window.location.hostname == '127.0.0.1'
	  || ((window.location.port != "") && (window.location.port > 1023))) {
		// We're probably running against the DevAppServer
		webRoot = 'http://' + window.location.host.replace("8081","8080") + '/';
  }
}
var apiRoot =  webRoot + '_ah/api';

var ApiLoader = function(config){
  this.config = config;	
  this.scopes = config.scopes;
  var me = this;
  this.apis = config.apis;
  if(!this.apis){
  	this.apis = [];	
  }
  this.reload = function(){
  	if(!gapi.auth2){
  		console.error("not init yet");
  		return;
  	}
  	var user = getUserInfo();
	if(me.config.callback){
		me.config.callback(user);
	}
	setUserElements(user);
  }
  var getUserInfo = function(){
  	var defaultUser = {isSignedIn:false};
	var googleAuth = gapi.auth2.getAuthInstance();
	if(!googleAuth){
		return defaultUser;
	}
	var user = googleAuth.currentUser.get().getBasicProfile();
	if(!user){
		return defaultUser;
	}
	user.isSignedIn = googleAuth.isSignedIn.get();
	return user;
  }
  this.signIn = function(options){
	var googleAuth = gapi.auth2.getAuthInstance();
	if(!options){
		options = {};
	}
	options.scope = me.scopes.join(" ");
	options.ux_mode = "redirect";
	localStorage.urlBeforeSignIn = window.location.href;
	
	return googleAuth.signIn(options).then(()=>{		
			me.reload();  		
  	});

  }
  this.signInWithPrompt = function(options){
  	//return gapi.auth2.getAuthInstance().disconnect().then(()=>{
	  	return this.signIn({"prompt":"select_account"});
	//});
  }
  this.load = function(){
	gapi.load('client:auth2', ()=>{
			var discoveryDocs = me.apis.select(api=>{
				var discoveryDoc = api.setRoot  ? apiRoot + "/" : "https://www.googleapis.com/";
				discoveryDoc += `discovery/v1/apis/${api.name}/${api.version}/rest`;
				return discoveryDoc;
			});
		var options = {
			discoveryDocs: discoveryDocs,
			clientId: me.config.clientId,
		};
		options.scope = me.scopes.join(" ");
		return gapi.client.init(options).then(()=>{
			console.log("Done loading APIs!");
			if(me.config.callback){				
			  	if(localStorage.urlBeforeSignIn){
			  		var location = localStorage.urlBeforeSignIn;
			  		delete localStorage.urlBeforeSignIn;
			  		window.location.href = location;
			  		return;
			  	}
				var user = getUserInfo();
				if(!user.isSignedIn){
					if(me.config.autoSignIn){
						me.signIn();
					}else{
						me.config.callback(user);
					}		
				}else{
					setUserElements(user);
					me.config.callback(user);	
				}
			}
		});
	});
  }
  var setUserElements = function(user){
  	if(!user || !user.isSignedIn){
  		return;
  	}
	if(me.config.elementSwitchAccounts){
		var element = document.getElementById(me.config.elementSwitchAccounts);
		if(element){
			if(element.tagName == "IMG"){
				element.src = user.getImageUrl();
			}
			element.onclick = e =>  apiLoader.signInWithPrompt();
			element.style.cursor = "pointer";							
		}
	}
	if(me.config.elementUserName){
		var element = document.getElementById(me.config.elementUserName);
		if(element){
			element.innerHTML = user.getName();	
		}
	}
  }
	this.getURLParameter = function(name) {
		var url = window.location.href;
		var value = decodeURIComponent((new RegExp('[?|&]' + name + '=' + '([^&;]+?)(&|#|;|$)').exec(url)||[,""])[1].replace(/\+/g, '%20'))||null;
		/*if(value && url.indexOf(this.config.clientId) < 0){
			localStorage[name] = value;
		}else{
			value = localStorage[name];
		}*/
		return value;
	}
}