MetadataFetching:

- Jikan (MAL) linking, fetching/updating

API/Schema/MetadataFetchers/MetadataFetcher.cs

@@ -0,0 +1,38 @@
+using System.Diagnostics.CodeAnalysis;
+using API.Schema.Contexts;
+using Microsoft.EntityFrameworkCore;
+
+namespace API.Schema.MetadataFetchers;
+
+[PrimaryKey("MetadataFetcherName")]
+public abstract class MetadataFetcher
+{
+    // ReSharper disable once EntityFramework.ModelValidation.UnlimitedStringLength
+    public string MetadataFetcherName { get; init; }
+
+    protected MetadataFetcher()
+    {
+        this.MetadataFetcherName = this.GetType().Name;
+    }
+    
+    /// <summary>
+    /// EFCORE ONLY!!!
+    /// </summary>
+    internal MetadataFetcher(string metadataFetcherName)
+    {
+        this.MetadataFetcherName = metadataFetcherName;
+    }
+    
+    public abstract MetadataEntry? FindLinkedMetadataEntry(Manga manga);
+
+    public bool TryGetMetadataEntry(Manga manga, [NotNullWhen(true)] out MetadataEntry? metadataEntry)
+    {
+        metadataEntry = FindLinkedMetadataEntry(manga);
+        return metadataEntry != null;
+    }
+
+    /// <summary>
+    /// Updates the Manga linked in the MetadataEntry
+    /// </summary>
+    public abstract void UpdateMetadata(MetadataEntry metadataEntry, PgsqlContext dbContext);
+}