PublisherAvatar.cs

using System;
using System.Threading.Tasks;
using System.Web;
using Waher.IoTGateway;
using Waher.Networking.HTTP;
using Waher.Networking.XMPP.Avatar;
using Waher.Networking.XMPP.Server;
using Waher.Persistence;
using Waher.Service.IoTBroker.PubSub;
 
namespace Waher.Service.IoTBroker.WebServices
{
    public class PublisherAvatar : HttpSynchronousResource, IHttpGetMethod
    {
        public PublisherAvatar()
            : base("/PublisherAvatar")
        {
        }
 
        public override bool HandlesSubPaths
        {
            get
            {
                return false;
            }
        }
 
        public override bool UserSessions
        {
            get
            {
                return true;
            }
        }
 
        public bool AllowsGET => true;
 
        public async Task GET(HttpRequest Request, HttpResponse Response)
        {
            if (!Request.Header.TryGetQueryParameter("c", out string s) ||
                Request.Header.Referer is null)
            {
                throw new BadRequestException("Missing parameters.");
            }
 
            CaseInsensitiveString Contact = s;
            Uri Uri = new Uri(Request.Header.Referer.Value);
 
            s = Uri.AbsolutePath;
            if (s.StartsWith("/"))
                s = s[1..];
 
            int i = s.IndexOf('/');
            if (i < 0)
                i = s.Length;
 
            CaseInsensitiveString NodeName = s[..i];
 
            PubSubNode Node = await XmppServerModule.PubSub.GetNodeAsync(CaseInsensitiveString.Empty, NodeName, null, XmppAddress.Empty, null)
                ?? throw new NotFoundException("Node not found: " + NodeName);
 
            if (!Node.PublishOnWeb)
                throw new BadRequestException("Node is not a web node.");
 
            s = s[i..];
            if (string.IsNullOrEmpty(s) || s == "/")
            {
                if ((Node.Creator != Contact) &&
                    (Node.Contact is null || Array.IndexOf(Node.Contact, Contact) < 0) &&
                    (Node.Publishers is null || Array.IndexOf(Node.Publishers, Contact) < 0) &&
                    (Node.PublishersOnly is null || Array.IndexOf(Node.PublishersOnly, Contact) < 0))
                {
                    throw new ForbiddenException(Request, "Access to avatar not granted: " + Contact + " is not a publisher of " + NodeName + ".");
                }
            }
            else
            {
                PubSubItem Item = await XmppServerModule.PubSub.LoadItem(CaseInsensitiveString.Empty, NodeName, s);
                if (Item is null && s.StartsWith("/"))
                    Item = await XmppServerModule.PubSub.LoadItem(CaseInsensitiveString.Empty, NodeName, s[1..]);
 
                if (Item is null)
                {
                    string s2 = HttpUtility.UrlDecode(s);
 
                    if (s != s2)
                    {
                        s = s2;
                        Item = await XmppServerModule.PubSub.LoadItem(CaseInsensitiveString.Empty, NodeName, s);
 
                        if (Item is null && s.StartsWith("/"))
                            Item = await XmppServerModule.PubSub.LoadItem(CaseInsensitiveString.Empty, NodeName, s[1..]);
                    }
 
                    if (Item is null)
                        throw new NotFoundException("Item not found on node: " + s);
                }
 
                if (Contact != Item.Publisher)
                    throw new ForbiddenException(Request, Contact + " not the publisher of " + s);
            }
 
            HttpRequestHeader Header = Request.Header;
            Avatar Avatar = await Gateway.AvatarClient.GetAvatarAsync(Contact);
 
            if (!(Header.IfNoneMatch is null) && Header.IfNoneMatch.Value == Avatar.Hash)
            {
                Response.StatusCode = 304;
                Response.StatusMessage = "Not Modified";
            }
            else
            {
                Response.StatusCode = 200;
                Response.StatusMessage = "OK";
                Response.ContentType = Avatar.ContentType;
                Response.SetHeader("ETag", "\"" + Avatar.Hash + "\"");
                await Response.Write(true, Avatar.Binary);
            }
        }
 
    }
}