WebHostMetaDataJson.cs

using System;
using System.Text;
using System.Threading.Tasks;
using Waher.Content.Json;
using Waher.IoTGateway;
using Waher.Networking.HTTP;
 
namespace Waher.Service.IoTBroker.WebServices
{
    public class WebHostMetaDataJson : HttpSynchronousResource, IHttpGetMethod
    {
        public WebHostMetaDataJson()
            : base("/.well-known/host-meta.json")
        {
        }
 
        public override bool HandlesSubPaths => false;
        public override bool UserSessions => false;
        public bool AllowsGET => true;
 
        public Task GET(HttpRequest Request, HttpResponse Response)
        {
            string ContentType = JsonCodec.DefaultContentType;
 
            if (!(Request.Header.Accept is null))
            {
                ContentType = Request.Header.Accept.GetBestAlternative(JsonCodec.JsonContentTypes);
                if (string.IsNullOrEmpty(ContentType))
                    throw new NotAcceptableException();
            }
 
            StringBuilder Json = new StringBuilder();
            int[] HttpsPorts = Gateway.GetConfigPorts("HTTPS");
            int[] HttpPorts = Gateway.GetConfigPorts("HTTP");
 
            Json.Append("{\"links\": [");
 
            if (HttpsPorts.Length > 0 || HttpPorts.Length > 0)
            {
                this.AppendLink(Json, HttpsPorts, HttpPorts, "urn:xmpp:alt-connections:xbosh", "http", "/http-bind");
                this.AppendLink(Json, HttpsPorts, HttpPorts, "urn:xmpp:alt-connections:websocket", "ws", "/xmpp-websocket");
            }
 
            Json.Append("]}");
 
            Response.ContentType = ContentType;
            return Response.Write(Json.ToString());
        }
 
        private void AppendLink(StringBuilder Json, int[] HttpsPorts, int[] HttpPorts,
            string Type, string Protocol, string Resource)
        {
            Json.Append("{\"rel\":\"");
            Json.Append(Type);
            Json.Append("\", \"href\":\"");
            Json.Append(Protocol);
 
            if (HttpsPorts.Length > 0)
            {
                Json.Append("s://");
                Json.Append(Gateway.Domain);
 
                if (Array.IndexOf(HttpsPorts, HttpServer.DefaultHttpsPort) < 0)
                {
                    Json.Append(':');
                    Json.Append(HttpsPorts[0].ToString());
                }
            }
            else
            {
                Json.Append("://");
                Json.Append(Gateway.Domain);
 
                if (Array.IndexOf(HttpPorts, HttpServer.DefaultHttpPort) < 0)
                {
                    Json.Append(':');
                    Json.Append(HttpPorts[0].ToString());
                }
            }
 
            Json.Append(Resource);
            Json.Append("\"}");
        }
 
    }
}