Abstract away cache. 2 implementations: redis and memory

src/NadekoBot/Services/strings/impl/MemoryBotStringsProvider.cs

@@ -0,0 +1,38 @@
+#nullable disable
+namespace NadekoBot.Services;
+
+public class MemoryBotStringsProvider : IBotStringsProvider
+{
+    private readonly IStringsSource _source;
+    private IReadOnlyDictionary<string, Dictionary<string, string>> responseStrings;
+    private IReadOnlyDictionary<string, Dictionary<string, CommandStrings>> commandStrings;
+
+    public MemoryBotStringsProvider(IStringsSource source)
+    {
+        _source = source;
+        Reload();
+    }
+
+    public string GetText(string localeName, string key)
+    {
+        if (responseStrings.TryGetValue(localeName, out var langStrings) && langStrings.TryGetValue(key, out var text))
+            return text;
+
+        return null;
+    }
+
+    public void Reload()
+    {
+        responseStrings = _source.GetResponseStrings();
+        commandStrings = _source.GetCommandStrings();
+    }
+
+    public CommandStrings GetCommandStrings(string localeName, string commandName)
+    {
+        if (commandStrings.TryGetValue(localeName, out var langStrings)
+            && langStrings.TryGetValue(commandName, out var strings))
+            return strings;
+
+        return null;
+    }
+}