feat: gateway service

Myriad/Cache/HTTPDiscordCache.cs

@@ -0,0 +1,75 @@
+using Serilog;
+using System.Net;
+using System.Text.Json;
+
+using Myriad.Serialization;
+using Myriad.Types;
+
+namespace Myriad.Cache;
+
+public class HttpDiscordCache: IDiscordCache
+{
+    private readonly ILogger _logger;
+    private readonly HttpClient _client;
+    private readonly string _cacheEndpoint;
+    private readonly ulong _ownUserId;
+
+    private readonly JsonSerializerOptions _jsonSerializerOptions;
+
+    public HttpDiscordCache(ILogger logger, HttpClient client, string cacheEndpoint, ulong ownUserId)
+    {
+        _logger = logger;
+        _client = client;
+        _cacheEndpoint = cacheEndpoint;
+        _ownUserId = ownUserId;
+        _jsonSerializerOptions = new JsonSerializerOptions().ConfigureForMyriad();
+    }
+
+    public ValueTask SaveGuild(Guild guild) => default;
+    public ValueTask SaveChannel(Channel channel) => default;
+    public ValueTask SaveUser(User user) => default;
+    public ValueTask SaveSelfMember(ulong guildId, GuildMemberPartial member) => default;
+    public ValueTask SaveRole(ulong guildId, Myriad.Types.Role role) => default;
+    public ValueTask SaveDmChannelStub(ulong channelId) => default;
+    public ValueTask RemoveGuild(ulong guildId) => default;
+    public ValueTask RemoveChannel(ulong channelId) => default;
+    public ValueTask RemoveUser(ulong userId) => default;
+    public ValueTask RemoveRole(ulong guildId, ulong roleId) => default;
+
+    public ulong GetOwnUser() => _ownUserId;
+
+    // todo: cluster
+    private async Task<T?> QueryCache<T>(string endpoint)
+    {
+        var response = await _client.GetAsync($"{_cacheEndpoint}{endpoint}");
+
+        if (response.StatusCode == HttpStatusCode.NotFound)
+            return default;
+
+        if (response.StatusCode != HttpStatusCode.Found)
+            throw new Exception($"failed to query http cache: {response.StatusCode}");
+
+        var plaintext = await response.Content.ReadAsStringAsync();
+        return JsonSerializer.Deserialize<T>(plaintext, _jsonSerializerOptions);
+    }
+
+    public Task<Guild?> TryGetGuild(ulong guildId)
+        => QueryCache<Guild?>($"/guilds/{guildId}");
+
+    public Task<Channel?> TryGetChannel(ulong guildId, ulong channelId)
+        => QueryCache<Channel?>($"/guilds/{guildId}/channels/{channelId}");
+
+    // this should be a GetUserCached method on nirn-proxy (it's always called as GetOrFetchUser)
+    // so just return nothing
+    public Task<User?> TryGetUser(ulong userId)
+        => Task.FromResult<User?>(null);
+
+    public Task<GuildMemberPartial?> TryGetSelfMember(ulong guildId)
+        => QueryCache<GuildMemberPartial?>($"/guilds/{guildId}/members/@me");
+
+    public Task<PermissionSet> BotPermissions(ulong guildId, ulong channelId)
+        => QueryCache<PermissionSet>($"/guilds/{guildId}/channels/{channelId}/permissions/@me");
+
+    public Task<IEnumerable<Channel>> GetGuildChannels(ulong guildId)
+        => QueryCache<IEnumerable<Channel>>($"/guilds/{guildId}/channels");
+}