Moved to Lazy<T> and a static class for handling Redis connections with some methods to make it easier to work with JSON. Completely untested.

KfChatDotNetBot/Services/Redis.cs

@@ -0,0 +1,110 @@
+using KfChatDotNetBot.Settings;
+using System.Text.Json;
+using NLog;
+using StackExchange.Redis;
+
+namespace KfChatDotNetBot.Services;
+
+public static class Redis
+{
+    public static bool IsAvailable => LazyMultiplexer.IsValueCreated;
+    // Claude told me this will act like a singleton ConnectionMultiplexer
+    // while keeping things nice and convenient with static methods
+    // FYI the exception will be thrown once, cached for the lifetime of the application
+    // If you configure a Redis connection string, you MUST restart the application
+    // https://learn.microsoft.com/en-us/dotnet/api/system.lazy-1?view=net-10.0#:~:text=Exception%20caching,-When
+    private static readonly Lazy<ConnectionMultiplexer> LazyMultiplexer =
+        new(() =>
+        {
+            var logger = LogManager.GetCurrentClassLogger();
+            var connectionString = SettingsProvider.GetValueAsync(BuiltIn.Keys.BotRedisConnectionString).Result.Value;
+            if (string.IsNullOrEmpty(connectionString))
+            {
+                logger.Error($"Could not initiate the lazy connection multiplexer for the Redis service as the " +
+                             $"connection string is not configured in {BuiltIn.Keys.BotRedisConnectionString}. " +
+                             $"Redis won't be available to anything that relies on it. " +
+                             $"If you do configure {BuiltIn.Keys.BotRedisConnectionString}, YOU MUST RESTART THE BOT");
+                throw new InvalidOperationException();
+            }
+
+            try
+            {
+                return ConnectionMultiplexer.Connect(
+                    SettingsProvider.GetValueAsync(BuiltIn.Keys.BotRedisConnectionString).Result.Value ??
+                    throw new InvalidOperationException(
+                        $"{BuiltIn.Keys.BotRedisConnectionString} not defined, cannot connect to Redis"));
+            }
+            catch (Exception e)
+            {
+                logger.Error($"Caught an exception when connecting to Redis at {connectionString}");
+                logger.Error(e);
+                throw;
+            }
+        });
+
+    // You can just grab this from wherever if you want a ready to go Redis connection
+    // ReSharper disable once MemberCanBePrivate.Global
+    public static ConnectionMultiplexer Multiplexer => LazyMultiplexer.Value;
+
+    private static IDatabase Db => Multiplexer.GetDatabase();
+
+    /// <summary>
+    /// Fetches a key from Redis asynchronously and deserializes its JSON value to T.
+    /// Returns default(T) if the key doesn't exist.
+    /// </summary>
+    /// <param name="key">Redis key</param>
+    public static async Task<T?> GetJsonAsync<T>(string key)
+    {
+        var value = await Db.StringGetAsync(key);
+        if (value.IsNullOrEmpty)
+            return default;
+
+        return JsonSerializer.Deserialize<T>(value.ToString());
+    }
+
+    /// <summary>
+    /// Fetches a key from Redis synchronously and deserializes its JSON value to T.
+    /// Returns default(T) if the key doesn't exist.
+    /// </summary>
+    /// <param name="key">Redis key</param>
+    public static T? GetJson<T>(string key)
+    {
+        var value = Db.StringGet(key);
+        if (value.IsNullOrEmpty)
+            return default;
+
+        return JsonSerializer.Deserialize<T>(value.ToString());
+    }
+
+    /// <summary>
+    /// Asynchronously set a key to a given object serialized using JSON
+    /// </summary>
+    /// <param name="key">Redis key</param>
+    /// <param name="value">Object that you wish to serialize</param>
+    /// <param name="expires">Expiration (null means never expires)</param>
+    /// <param name="when">Redis behavior whether the key has a value or not
+    /// When.Always = set the value regardless of whether the key has a value
+    /// When.Exists = only set the value if the key has a value already
+    /// When.NotExists = only set the value if the key has no value
+    /// </param>
+    public static async Task SetJsonAsync(string key, object value, TimeSpan? expires = null, When when = When.Always)
+    {
+        await Db.StringSetAsync(key, JsonSerializer.Serialize(value), expires, when);
+    }
+    
+    /// <summary>
+    /// Synchronously set a key to a given object serialized using JSON
+    /// </summary>
+    /// <param name="key">Redis key</param>
+    /// <param name="value">Object that you wish to serialize</param>
+    /// <param name="expires">Expiration (null means never expires)</param>
+    /// <param name="when">Redis behavior whether the key has a value or not
+    /// When.Always = set the value regardless of whether the key has a value
+    /// When.Exists = only set the value if the key has a value already
+    /// When.NotExists = only set the value if the key has no value
+    /// </param>
+    public static void SetJson(string key, object value, TimeSpan? expires = null, When when = When.Always)
+    {
+        Db.StringSet(key, JsonSerializer.Serialize(value), expires, when);
+    }
+}