Fix metadata

VoidCat/Model/VoidFileMeta.cs

@@ -3,15 +3,25 @@ using VoidCat.Services.Abstractions;
 
 namespace VoidCat.Model;
 
+/// <summary>
+/// Base metadata must contain version number
+/// </summary>
+public interface IVoidFileMeta
+{
+    const int CurrentVersion = 3;
+    
+    int Version { get; init; }
+}
+
 /// <summary>
 /// File metadata which is managed by <see cref="IFileMetadataStore"/>
 /// </summary>
-public record VoidFileMeta
+public record VoidFileMeta : IVoidFileMeta
 {
     /// <summary>
     /// Metadata version
     /// </summary>
-    public int Version { get; init; } = 2;
+    public int Version { get; init; } = IVoidFileMeta.CurrentVersion;
     
     /// <summary>
     /// Filename

VoidCat/Services/LocalDiskFileMetadataStore.cs

@@ -7,7 +7,7 @@ namespace VoidCat.Services;
 
 public class LocalDiskFileMetadataStore : IFileMetadataStore
 {
-    private const string MetadataDir = "metadata-v2";
+    private const string MetadataDir = "metadata-v3";
     private readonly VoidSettings _settings;
     
     public LocalDiskFileMetadataStore(VoidSettings settings)

VoidCat/Services/Migrations/20220218_FixMigration.cs

@@ -0,0 +1,46 @@
+using Newtonsoft.Json;
+using VoidCat.Model;
+
+namespace VoidCat.Services.Migrations;
+
+public class FixMigration_20220218 : MetadataMigrator<WrongFile, WrongMeta>
+{
+    public FixMigration_20220218(VoidSettings settings, ILogger<MetadataMigrator<WrongFile, WrongMeta>> logger) : base(settings, logger)
+    {
+    }
+    
+    protected override string OldPath => "metadata-v2";
+    protected override string NewPath => "metadata-v3";
+    
+    protected override bool ShouldMigrate(string json)
+    {
+        var metaBase = JsonConvert.DeserializeObject<WrongFile>(json);
+        return metaBase?.Metadata?.Version == 2 && metaBase?.Metadata?.Size > 0;
+    }
+
+    protected override WrongMeta MigrateModel(WrongFile old)
+    {
+        return old.Metadata!;
+    }
+}
+
+public class WrongFile
+{
+    [JsonConverter(typeof(Base58GuidConverter))]
+    public Guid Id { get; init; }
+    public WrongMeta? Metadata { get; init; }
+    public Paywall? Paywall { get; init; }
+}
+
+public class WrongMeta
+{
+    public int Version { get; init; } = 2;
+    public string? Name { get; init; }
+    public ulong Size { get; init; }
+    public DateTimeOffset Uploaded { get; init; } = DateTimeOffset.UtcNow;
+    public string? Description { get; init; }
+    public string? MimeType { get; init; }
+    public string? Digest { get; init; }
+    [JsonConverter(typeof(Base58GuidConverter))]
+    public Guid EditSecret { get; init; }
+}

VoidCat/Services/Migrations/IMigration.cs

@@ -10,6 +10,7 @@ public static class Migrations
     public static IServiceCollection AddVoidMigrations(this IServiceCollection svc)
     {
         svc.AddTransient<IMigration, MigrateMetadata_20220217>();
+        svc.AddTransient<IMigration, FixMigration_20220218>();
         return svc;
     }
 }

VoidCat/Services/Migrations/MetadataMigrator.cs

@@ -0,0 +1,66 @@
+using Newtonsoft.Json;
+using VoidCat.Model;
+
+namespace VoidCat.Services.Migrations;
+
+public abstract class MetadataMigrator<TOld, TNew> : IMigration
+{
+    private readonly VoidSettings _settings;
+    private readonly ILogger<MetadataMigrator<TOld, TNew>> _logger;
+
+    protected MetadataMigrator(VoidSettings settings, ILogger<MetadataMigrator<TOld, TNew>> logger)
+    {
+        _settings = settings;
+        _logger = logger;
+    }
+    
+    public async ValueTask Migrate()
+    {
+        var newMeta = Path.Combine(_settings.DataDirectory, OldPath);
+        if (!Directory.Exists(newMeta))
+        {
+            Directory.CreateDirectory(newMeta);
+        }
+        
+        foreach (var fe in Directory.EnumerateFiles(_settings.DataDirectory))
+        {
+            var filename = Path.GetFileNameWithoutExtension(fe);
+            if (!Guid.TryParse(filename, out var id)) continue;
+
+            var fp = MapOldMeta(id);
+            if (File.Exists(fp))
+            {
+                _logger.LogInformation("Migrating metadata for {file}", fp);
+                try
+                {
+                    var oldJson = await File.ReadAllTextAsync(fp);
+                    if (!ShouldMigrate(oldJson)) continue;
+                    
+                    var old = JsonConvert.DeserializeObject<TOld>(oldJson);
+                    if(old == null) continue;
+                    
+                    var newObj = MigrateModel(old);
+                    await File.WriteAllTextAsync(MapNewMeta(id), JsonConvert.SerializeObject(newObj));
+                    
+                    // delete old metadata
+                    File.Delete(fp);
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogError(ex, "Error migrating metadata: {Message}", ex.Message);
+                }
+            }
+        }
+    }
+
+    protected abstract string OldPath { get; }
+    protected abstract string NewPath { get; }
+
+    protected abstract bool ShouldMigrate(string json);
+    protected abstract TNew MigrateModel(TOld old);
+    
+    private string MapOldMeta(Guid id) =>
+        Path.ChangeExtension(Path.Join(_settings.DataDirectory, OldPath, id.ToString()), ".json");
+    private string MapNewMeta(Guid id) =>
+        Path.ChangeExtension(Path.Join(_settings.DataDirectory, NewPath, id.ToString()), ".json");
+}