/*

	Copyright (c) 2020, 2023, The Unified Company.

	This code is part of Unify.

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE,
	as published by the Free Software Foundation.
	See the GNU AFFERO GENERAL PUBLIC LICENSE, for more details.

	https://unifyjs.org 

*/

export default class fileLoader{

	files		= new Array();

	filesExists	= new Array();

	async get( url ) {

		return await this.getFile( url );

	}

	exists( url )
	{

		if( this.filesExists[ url ] ) {

			return this.filesExists[ url ];

		}

		var http = new XMLHttpRequest();

		http.open('HEAD', url, false);

		http.send();

		this.filesExists[ url ]	= http.status != 404;

		return http.status != 404;

	}

	async getFile( url ) {

		if( this.files[ url ] ) {

			return this.files[ url ];

		} else {

			var response 	= await fetch( url );

			var json 		= await response.json();

			this.addFile( url, json );

			return json;

		}

	}

	addFile( url, json ) {

		this.files[ url ] = json;

	}
	
}