Added pubsub to Ellie

src/EllieBot/Common/PubSub/EventPubSub.cs

@@ -0,0 +1,80 @@
+namespace EllieBot.Common;
+
+public class EventPubSub : IPubSub
+{
+    private readonly Dictionary<string, Dictionary<Delegate, List<Func<object, ValueTask>>>> _actions = new();
+    private readonly object _locker = new();
+
+    public Task Sub<TData>(in TypedKey<TData> key, Func<TData, ValueTask> action)
+        where TData : notnull
+    {
+        Func<object, ValueTask> localAction = obj => action((TData)obj);
+        lock (_locker)
+        {
+            if (!_actions.TryGetValue(key.Key, out var keyActions))
+            {
+                keyActions = new();
+                _actions[key.Key] = keyActions;
+            }
+
+            if (!keyActions.TryGetValue(action, out var sameActions))
+            {
+                sameActions = new();
+                keyActions[action] = sameActions;
+            }
+
+            sameActions.Add(localAction);
+
+            return Task.CompletedTask;
+        }
+    }
+
+    public Task Pub<TData>(in TypedKey<TData> key, TData data)
+        where TData : notnull
+    {
+        lock (_locker)
+        {
+            if (_actions.TryGetValue(key.Key, out var actions))
+                // if this class ever gets used, this needs to be properly implemented
+                // 1. ignore all valuetasks which are completed
+                // 2. run all other tasks in parallel
+                return actions.SelectMany(kvp => kvp.Value).Select(action => action(data).AsTask()).WhenAll();
+
+            return Task.CompletedTask;
+        }
+    }
+
+    public Task Unsub<TData>(in TypedKey<TData> key, Func<TData, ValueTask> action)
+    {
+        lock (_locker)
+        {
+            // get subscriptions for this action
+            if (_actions.TryGetValue(key.Key, out var actions))
+            // get subscriptions which have the same action hash code
+            // note: having this as a list allows for multiple subscriptions of
+            //       the same insance's/static method
+            {
+                if (actions.TryGetValue(action, out var sameActions))
+                {
+                    // remove last subscription
+                    sameActions.RemoveAt(sameActions.Count - 1);
+
+                    // if the last subscription was the only subscription
+                    // we can safely remove this action's dictionary entry
+                    if (sameActions.Count == 0)
+                    {
+                        actions.Remove(action);
+
+                        // if our dictionary has no more elements after 
+                        // removing the entry
+                        // it's safe to remove it from the key's subscriptions
+                        if (actions.Count == 0)
+                            _actions.Remove(key.Key);
+                    }
+                }
+            }
+
+            return Task.CompletedTask;
+        }
+    }
+}

src/EllieBot/Common/PubSub/IPubSub.cs

@@ -0,0 +1,10 @@
+namespace EllieBot.Common;
+
+public interface IPubSub
+{
+    public Task Pub<TData>(in TypedKey<TData> key, TData data)
+        where TData : notnull;
+    
+    public Task Sub<TData>(in TypedKey<TData> key, Func<TData, ValueTask> action)
+        where TData : notnull;
+}

src/EllieBot/Common/PubSub/ISeria.cs

@@ -0,0 +1,7 @@
+namespace EllieBot.Common;
+
+public interface ISeria
+{
+    byte[] Serialize<T>(T data);
+    T? Deserialize<T>(byte[]? data);
+}

src/EllieBot/Common/PubSub/JsonSeria.cs

@@ -0,0 +1,27 @@
+using EllieBot.Common.JsonConverters;
+using System.Text.Json;
+
+namespace EllieBot.Common;
+
+public class JsonSeria : ISeria
+{
+    private readonly JsonSerializerOptions _serializerOptions = new()
+    {
+        Converters =
+        {
+            new Rgba32Converter(),
+            new CultureInfoConverter()
+        }
+    };
+
+    public byte[] Serialize<T>(T data)
+        => JsonSerializer.SerializeToUtf8Bytes(data, _serializerOptions);
+
+    public T? Deserialize<T>(byte[]? data)
+    {
+        if (data is null)
+            return default;
+
+        return JsonSerializer.Deserialize<T>(data, _serializerOptions);
+    }
+}

src/EllieBot/Common/PubSub/RedisPubSub.cs

@@ -0,0 +1,52 @@
+using StackExchange.Redis;
+
+namespace EllieBot.Common;
+
+public sealed class RedisPubSub : IPubSub
+{
+    private readonly IBotCredentials _creds;
+    private readonly ConnectionMultiplexer _multi;
+    private readonly ISeria _serializer;
+
+    public RedisPubSub(ConnectionMultiplexer multi, ISeria serializer, IBotCredentials creds)
+    {
+        _multi = multi;
+        _serializer = serializer;
+        _creds = creds;
+    }
+
+    public Task Pub<TData>(in TypedKey<TData> key, TData data)
+        where TData : notnull
+    {
+        var serialized = _serializer.Serialize(data);
+        return _multi.GetSubscriber()
+                     .PublishAsync($"{_creds.RedisKey()}:{key.Key}", serialized, CommandFlags.FireAndForget);
+    }
+
+    public Task Sub<TData>(in TypedKey<TData> key, Func<TData, ValueTask> action)
+        where TData : notnull
+    {
+        var eventName = key.Key;
+
+        async void OnSubscribeHandler(RedisChannel _, RedisValue data)
+        {
+            try
+            {
+                var dataObj = _serializer.Deserialize<TData>(data);
+                if (dataObj is not null)
+                    await action(dataObj);
+                else
+                {
+                    Log.Warning("Publishing event {EventName} with a null value. This is not allowed",
+                        eventName);
+                }
+            }
+            catch (Exception ex)
+            {
+                Log.Error("Error handling the event {EventName}: {ErrorMessage}", eventName, ex.Message);
+            }
+        }
+
+        return _multi.GetSubscriber().SubscribeAsync($"{_creds.RedisKey()}:{eventName}", OnSubscribeHandler);
+    }
+}

src/EllieBot/Common/PubSub/TypedKey.cs

@@ -0,0 +1,30 @@
+namespace EllieBot.Common;
+
+public readonly struct TypedKey<TData>
+{
+    public string Key { get; }
+
+    public TypedKey(in string key)
+        => Key = key;
+
+    public static implicit operator TypedKey<TData>(in string input)
+        => new(input);
+
+    public static implicit operator string(in TypedKey<TData> input)
+        => input.Key;
+
+    public static bool operator ==(in TypedKey<TData> left, in TypedKey<TData> right)
+        => left.Key == right.Key;
+
+    public static bool operator !=(in TypedKey<TData> left, in TypedKey<TData> right)
+        => !(left == right);
+
+    public override bool Equals(object? obj)
+        => obj is TypedKey<TData> o && o == this;
+
+    public override int GetHashCode()
+        => Key?.GetHashCode() ?? 0;
+
+    public override string ToString()
+        => Key;
+}

src/EllieBot/Common/PubSub/YamlSeria.cs

@@ -0,0 +1,39 @@
+using EllieBot.Common.Configs;
+using EllieBot.Common.Yml;
+using System.Text.RegularExpressions;
+using YamlDotNet.Serialization;
+
+namespace EllieBot.Common;
+
+public class YamlSeria : IConfigSeria
+{
+    private static readonly Regex _codePointRegex =
+        new(@"(\\U(?<code>[a-zA-Z0-9]{8})|\\u(?<code>[a-zA-Z0-9]{4})|\\x(?<code>[a-zA-Z0-9]{2}))",
+            RegexOptions.Compiled);
+
+    private readonly IDeserializer _deserializer;
+    private readonly ISerializer _serializer;
+
+    public YamlSeria()
+    {
+        _serializer = Yaml.Serializer;
+        _deserializer = Yaml.Deserializer;
+    }
+
+    public string Serialize<T>(T obj)
+        where T : notnull
+    {
+        var escapedOutput = _serializer.Serialize(obj);
+        var output = _codePointRegex.Replace(escapedOutput,
+            me =>
+            {
+                var str = me.Groups["code"].Value;
+                var newString = YamlHelper.UnescapeUnicodeCodePoint(str);
+                return newString;
+            });
+        return output;
+    }
+
+    public T Deserialize<T>(string data)
+        => _deserializer.Deserialize<T>(data);
+}