Abstract away cache. 2 implementations: redis and memory

src/NadekoBot/Services/Impl/LocalDataCache.cs

@@ -0,0 +1,82 @@
+using NadekoBot.Common.Pokemon;
+using NadekoBot.Modules.Games.Common.Trivia;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace NadekoBot.Services;
+
+public sealed class LocalDataCache : ILocalDataCache, INService
+{
+    private const string POKEMON_ABILITIES_FILE = "data/pokemon/pokemon_abilities.json";
+    private const string POKEMON_LIST_FILE = "data/pokemon/pokemon_list.json";
+    private const string POKEMON_MAP_PATH = "data/pokemon/name-id_map.json";
+    private const string QUESTIONS_FILE = "data/trivia_questions.json";
+
+    private readonly IBotCache _cache;
+
+    private readonly JsonSerializerOptions _opts = new JsonSerializerOptions()
+    {
+        AllowTrailingCommas = true,
+        NumberHandling = JsonNumberHandling.AllowReadingFromString,
+        PropertyNameCaseInsensitive = true
+    };
+
+    public LocalDataCache(IBotCache cache)
+        => _cache = cache;
+
+    private async Task<T?> GetOrCreateCachedDataAsync<T>(
+        TypedKey<T> key,
+        string fileName)
+        => await _cache.GetOrAddAsync(key,
+            async () =>
+            {
+                if (!File.Exists(fileName))
+                {
+                    Log.Warning($"{fileName} is missing. Relevant data can't be loaded");
+                    return default;
+                }
+
+                try
+                {
+                    await using var stream = File.OpenRead(fileName);
+                    return await JsonSerializer.DeserializeAsync<T>(stream, _opts);
+                }
+                catch (Exception ex)
+                {
+                    Log.Error(ex,
+                        "Error reading {FileName} file: {ErrorMessage}",
+                        fileName,
+                        ex.Message);
+
+                    return default;
+                }
+            });
+
+
+    private static TypedKey<IReadOnlyDictionary<string, SearchPokemon>> _pokemonListKey
+        = new("pokemon:list");
+
+    public async Task<IReadOnlyDictionary<string, SearchPokemon>?> GetPokemonsAsync()
+        => await GetOrCreateCachedDataAsync(_pokemonListKey, POKEMON_LIST_FILE);
+
+
+    private static TypedKey<IReadOnlyDictionary<string, SearchPokemonAbility>> _pokemonAbilitiesKey
+        = new("pokemon:abilities");
+
+    public async Task<IReadOnlyDictionary<string, SearchPokemonAbility>?> GetPokemonAbilitiesAsync()
+        => await GetOrCreateCachedDataAsync(_pokemonAbilitiesKey, POKEMON_ABILITIES_FILE);
+
+
+    private static TypedKey<PokemonNameId[]> _pokeMapKey
+        = new("pokemon:ab_map");
+
+    public async Task<PokemonNameId[]?> GetPokemonMapAsync()
+        => await GetOrCreateCachedDataAsync(_pokeMapKey, POKEMON_MAP_PATH);
+
+
+    private static TypedKey<TriviaQuestionModel[]> _triviaKey
+        = new("trivia:questions");
+
+    public async Task<TriviaQuestionModel[]?> GetTriviaQuestionsAsync()
+        => await GetOrCreateCachedDataAsync(_triviaKey, QUESTIONS_FILE);
+}