api: design rest and core

TODO

@@ -0,0 +1,32 @@
+- REST
+    - Models
+    - Preconditions
+    - Endpoints
+	- Channel
+	- Emoji
+	- Guild
+	- Invite
+	- User
+	- Voice
+	- Webhook
+- Gateway
+    - Models
+    - Client
+	- Socket
+	    * Receive
+	    * Compression
+    - Voice (long)
+- Core
+    - CDN
+    - Datastore
+    - Entities
+	- Channel
+	- Emoji
+	- Guild
+	- User
+- Tests
+    - Unit test Gateway stability / deadlockability?
+- Extensions
+    - Commands
+	? design - use finite's or quahu's
+    - Interactivity

src/Discord.Net/Discord.Net.csproj

@@ -4,6 +4,7 @@
     <TargetFramework>netstandard2.1</TargetFramework>
     <LangVersion>8.0</LangVersion>
     <Nullable>enable</Nullable>
+    <RootNamespace>Discord</RootNamespace>
   </PropertyGroup>
 
 </Project>

src/Discord.Net/DiscordClient.cs

@@ -0,0 +1,25 @@
+using Discord.Rest;
+using Discord.Socket;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Discord
+{
+    internal class DiscordClient : IDiscordClient
+    {
+        public DiscordRestApi Rest => _restApi;
+        public DiscordGatewayApi Gateway => _gatewayApi;
+
+        private readonly DiscordConfig _config;
+        private readonly DiscordRestApi _restApi;
+        private readonly DiscordGatewayApi _gatewayApi;
+
+        public DiscordClient(DiscordConfig config, DiscordRestApi restApi, DiscordGatewayApi gatewayApi)
+        {
+            _config = config;
+            _restApi = restApi;
+            _gatewayApi = gatewayApi;
+        }
+    }
+}

src/Discord.Net/DiscordConfig.cs

@@ -0,0 +1,33 @@
+using Discord.Socket;
+using Discord.Socket.Providers;
+using System;
+
+namespace Discord
+{
+    public class DiscordConfig
+    {
+        /// <summary>
+        /// Discord.Net version
+        /// </summary>
+        public const string Version = "3.0.0a0";
+        /// <summary>
+        /// Discord.Net User-Agent
+        /// </summary>
+        public const string UserAgent = "DiscordBot (https://github.com/discord-net/Discord.Net, " + Version + ")";
+
+        /// <summary>
+        /// The default, fallback Gateway URI. This will generally be replaced by <see cref="Rest.IDiscordRestApi.GetGatewayAsync"/>.
+        /// </summary>
+        public static readonly Uri DefaultGatewayUri = new Uri("wss://gateway.discord.gg");
+        /// <summary>
+        /// The base URL for the Rest API.
+        /// </summary>
+        public string RestApiUrl { get; set; } = "https://discordapp.com/api/v6/";
+        /// <summary>
+        /// The URI to use when connecting to the gateway. If specified, this will override the URI Discord instructs us to use.
+        /// </summary>
+        public Uri? GatewayUri = null;
+
+        public SocketFactory SocketFactory { get; set; } = DefaultSocketFactory.Create;
+    }
+}

src/Discord.Net/IDiscordClient.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Threading.Tasks;
+using Discord.Rest;
+using Discord.Socket;
+
+namespace Discord
+{
+    internal interface IDiscordClient
+    {
+        static IDiscordClient Create(DiscordConfig config)
+        {
+            var rest = new DiscordRestApi(config);
+            var gateway = new DiscordGatewayApi(config);
+
+            return new DiscordClient(config, rest, gateway);
+        }
+
+        DiscordRestApi Rest { get; }
+        DiscordGatewayApi Gateway { get; }
+    }
+}

src/Discord.Net/Rest/DiscordRestApi.cs

@@ -0,0 +1,28 @@
+using System.Text.Json;
+using System.Threading.Tasks;
+using Refit;
+using Discord.Rest.Models;
+
+// This is essentially a reimplementation of Wumpus.Net.Rest
+namespace Discord.Rest
+{
+    public class DiscordRestApi : IDiscordRestApi
+    {
+        private readonly IDiscordRestApi _api;
+
+        public DiscordRestApi(DiscordConfig config)
+        {
+            var jsonOptions = new JsonSerializerOptions();
+            var refitSettings = new RefitSettings
+            {
+                ContentSerializer = new JsonContentSerializer(jsonOptions),
+            };
+            _api = RestService.For<IDiscordRestApi>(config.RestApiUrl, refitSettings);
+        }
+
+        public Task<GatewayInfo> GetGatewayInfoAsync()
+        {
+            return _api.GetGatewayInfoAsync();
+        }
+    }
+}

src/Discord.Net/Rest/IDiscordRestApi.cs

@@ -0,0 +1,12 @@
+using System.Threading.Tasks;
+using Refit;
+using Discord.Rest.Models;
+
+namespace Discord.Rest
+{
+    public interface IDiscordRestApi
+    {
+        [Get("/gateway/bot")]
+        Task<GatewayInfo> GetGatewayInfoAsync();
+    }
+}

src/Discord.Net/Rest/JsonContentSerializer.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Net.Http;
+using System.Net.Http.Headers;
+using System.Text;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.Threading.Tasks;
+using Refit;
+
+// https://blog.martincostello.com/refit-and-system-text-json/
+
+namespace Discord.Rest
+{
+    public class JsonContentSerializer : IContentSerializer
+    {
+        private static readonly MediaTypeHeaderValue _jsonMediaType = new MediaTypeHeaderValue("application/json") { CharSet = Encoding.UTF8.WebName };
+        private readonly JsonSerializerOptions _serializerOptions;
+
+        public JsonContentSerializer(JsonSerializerOptions serializerOptions)
+        {
+            _serializerOptions = serializerOptions;
+        }
+
+        public async Task<T> DeserializeAsync<T>(HttpContent content)
+        {
+            using var json = await content.ReadAsStreamAsync().ConfigureAwait(false);
+            return await JsonSerializer.DeserializeAsync<T>(json, _serializerOptions).ConfigureAwait(false);
+        }
+
+        public async Task<HttpContent> SerializeAsync<T>(T data)
+        {
+            var stream = new MemoryStream();
+            try
+            {
+                await JsonSerializer.SerializeAsync<T>(stream, data, _serializerOptions).ConfigureAwait(false);
+                await stream.FlushAsync();
+
+                var content = new StreamContent(stream);
+                content.Headers.ContentType = _jsonMediaType;
+
+                return content;
+            }
+            catch
+            {
+                await stream.DisposeAsync().ConfigureAwait(false);
+                throw;
+            }
+        }
+    }
+}

src/Discord.Net/Rest/Models/GatewayInfo.cs

@@ -0,0 +1,25 @@
+#pragma warning disable CS8618 // Uninitialized NRT expected in models
+using System.Text.Json.Serialization;
+
+namespace Discord.Rest.Models
+{
+    public class GatewayInfo
+    {
+        [JsonPropertyName("url")]
+        public string Url { get; set; }
+        [JsonPropertyName("shards")]
+        public int Shards { get; set; }
+        [JsonPropertyName("session_start_limit")]
+        public GatewaySessionStartInfo SessionStartInfo { get; set; }
+    }
+
+    public class GatewaySessionStartInfo
+    {
+        [JsonPropertyName("total")]
+        public int Total { get; set; }
+        [JsonPropertyName("remaining")]
+        public int Remaining { get; set; }
+        [JsonPropertyName("reset_after")]
+        public int ResetAfter { get; set; }
+    }
+}

src/Discord.Net/Socket/Gateway.cs → src/Discord.Net/Socket/DiscordGatewayApi.cs

@@ -2,17 +2,17 @@ using System;
 using System.Threading;
 using System.Threading.Tasks;
 
-namespace Discord.Net.Socket
+namespace Discord.Socket
 {
-    public class Gateway
+    public class DiscordGatewayApi
     {
         static readonly Uri DefaultGatewayUri = new Uri("wss://gateway.discord.gg");
 
         ISocket Socket { get; set; }
 
-        public Gateway(SocketFactory socketFactory)
+        public DiscordGatewayApi(DiscordConfig config)
         {
-            Socket = socketFactory(OnAborted, OnPacket);
+            Socket = config.SocketFactory(OnAborted, OnPacket);
         }
 
         public async Task ConnectAsync(Uri? gatewayUri)

src/Discord.Net/Socket/ISocket.cs

@@ -2,7 +2,7 @@ using System;
 using System.Threading;
 using System.Threading.Tasks;
 
-namespace Discord.Net.Socket
+namespace Discord.Socket
 {
     public delegate ISocket SocketFactory(OnAbortionHandler abortionHandler, OnPacketHandler packetHandler);
 

src/Discord.Net/Socket/Providers/DefaultSocket.cs

@@ -3,7 +3,7 @@ using System.Net.WebSockets;
 using System.Threading;
 using System.Threading.Tasks;
 
-namespace Discord.Net.Socket.Providers
+namespace Discord.Socket.Providers
 {
     public static class DefaultSocketFactory
     {