BirdsiteLIVE/src/BirdsiteLive/Controllers/WellKnownController.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using BirdsiteLive.Common.Settings;
using BirdsiteLive.Models;
using BirdsiteLive.Twitter;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Options;

namespace BirdsiteLive.Controllers
{
    [ApiController]
    public class WellKnownController : ControllerBase
    {
        private readonly ITwitterService _twitterService;
        private readonly InstanceSettings _settings;

        #region Ctor
        public WellKnownController(IOptions<InstanceSettings> settings, ITwitterService twitterService)
        {
            _twitterService = twitterService;
            _settings = settings.Value;
        }
        #endregion

        [Route("/.well-known/nodeinfo")]
        public IActionResult WellKnownNodeInfo()
        {
            var nodeInfo = new WellKnownNodeInfo
            {
                links = new Link[]
                {
                    new Link()
                    {
                        rel = "http://nodeinfo.diaspora.software/ns/schema/2.0",
                        href = $"https://{_settings.Domain}/nodeinfo/2.0.json"
                    }
                }
            };
            return new JsonResult(nodeInfo);
        }

        [Route("/nodeinfo/2.0.json")]
        public IActionResult NodeInfo()
        {
            var nodeInfo = new NodeInfo
            {
                version = "2.0",
                usage = new Usage()
                {
                    localPosts = 0,
                    users = new Users()
                    {
                        total = 0
                    }
                },
                software = new Software()
                {
                    name = "BirdsiteLive",
                    version = "0.1.0"
                },
                protocols = new []
                {
                    "activitypub"
                },
                openRegistrations = false
            };

            return new JsonResult(nodeInfo);
        }

        [Route("/.well-known/webfinger")]
        public IActionResult Webfinger(string resource = null)
        {
            var acct = resource.Split("acct:")[1].Trim();

            string name = null;
            string domain = null;

            var splitAcct = acct.Split('@', StringSplitOptions.RemoveEmptyEntries);

            var atCount = acct.Count(x => x == '@');
            if (atCount == 1 && acct.StartsWith('@'))
            {
                name = splitAcct[1];
            }
            else if (atCount == 1 || atCount == 2)
            {
                name = splitAcct[0];
                domain = splitAcct[1];
            }
            else
            {
                return BadRequest();
            }

            if (!string.IsNullOrWhiteSpace(domain) && domain != _settings.Domain)
                return NotFound();

            var user = _twitterService.GetUser(name);
            if (user == null)
                return NotFound();

            var result = new WebFingerResult()
            {
                subject = $"acct:{name}@{_settings.Domain}",
                aliases = new[]
                {
                    $"https://{_settings.Domain}/@{name}",
                    $"https://{_settings.Domain}/users/{name}"
                },
                links = new List<WebFingerLink>
                {
                    new WebFingerLink()
                    {
                        rel = "http://webfinger.net/rel/profile-page",
                        type = "text/html",
                        href = $"https://{_settings.Domain}/@{name}"
                    },
                    new WebFingerLink()
                    {
                        rel = "self",
                        type = "application/activity+json",
                        href = $"https://{_settings.Domain}/users/{name}"
                    }
                }
            };

            return new JsonResult(result);
        }
    }

    public class WebFingerResult
    {
        public string subject { get; set; }
        public string[] aliases { get; set; }
        public List<WebFingerLink> links { get; set; } = new List<WebFingerLink>();
    }

    public class WebFingerLink
    {
        public string rel { get; set; }
        public string type { get; set; }
        public string href { get; set; }
    }

    public class WellKnownNodeInfo
    {
        public Link[] links { get; set; }
    }

    public class Link
    {
        public string href { get; set; }
        public string rel { get; set; }
    }

    public class NodeInfo
    {
        public string version { get; set; }
        public string[] protocols { get; set; }
        public Software software { get; set; }
        public Usage usage { get; set; }
        public bool openRegistrations { get; set; }
        public Services services { get; set; }
        public object metadata { get; set; }
    }
    
    public class Services
    {
        public object[] inbound { get; set; }
        public object[] outbound { get; set; }
    }

    public class Software
    {
        public string name { get; set; }
        public string version { get; set; }
    }

    public class Usage
    {
        public int localPosts { get; set; }
        public Users users { get; set; }
    }

    public class Users
    {
        public int total { get; set; }
    }
}