chore: remove legacy C# DatabaseMigrator

PluralKit.Core/Database/Database.cs

@@ -23,18 +23,16 @@ internal partial class Database: IDatabase
     private readonly ILogger _logger;
     private readonly IMetrics _metrics;
     private readonly DbConnectionCountHolder _countHolder;
-    private readonly DatabaseMigrator _migrator;
 
     private readonly NpgsqlDataSource _dataSource;
     private readonly NpgsqlDataSource _dataSourceMessages;
 
     public Database(CoreConfig config, DbConnectionCountHolder countHolder, ILogger logger,
-                    IMetrics metrics, DatabaseMigrator migrator)
+                    IMetrics metrics)
     {
         _config = config;
         _countHolder = countHolder;
         _metrics = metrics;
-        _migrator = migrator;
         _logger = logger.ForContext<Database>();
 
         string connectionString(string src)
@@ -121,12 +119,6 @@ internal partial class Database: IDatabase
         return conn;
     }
 
-    public async Task ApplyMigrations()
-    {
-        using var conn = await Obtain();
-        await _migrator.ApplyMigrations(conn);
-    }
-
     private class PassthroughTypeHandler<T>: SqlMapper.TypeHandler<T>
     {
         public override void SetValue(IDbDataParameter parameter, T value) => parameter.Value = value;

PluralKit.Core/Database/IDatabase.cs

@@ -6,7 +6,6 @@ namespace PluralKit.Core;
 
 public interface IDatabase
 {
-    Task ApplyMigrations();
     Task<IPKConnection> Obtain(bool messages = false);
     Task Execute(Func<IPKConnection, Task> func);
     Task<T> Execute<T>(Func<IPKConnection, Task<T>> func);

PluralKit.Core/Database/Utils/DatabaseMigrator.cs

@@ -1,81 +0,0 @@
-using System.Data;
-
-using Dapper;
-
-using Serilog;
-
-namespace PluralKit.Core;
-
-internal class DatabaseMigrator
-{
-    private const string RootPath = "PluralKit.Core.Database"; // "resource path" root for SQL files
-    private const int TargetSchemaVersion = 52;
-    private readonly ILogger _logger;
-
-    public DatabaseMigrator(ILogger logger)
-    {
-        _logger = logger;
-    }
-
-    public async Task ApplyMigrations(IPKConnection conn)
-    {
-        // Run everything in a transaction
-        await using var tx = await conn.BeginTransactionAsync();
-
-        // Before applying migrations, clean out views/functions to prevent type errors
-        await ExecuteSqlFile($"{RootPath}.clean.sql", conn, tx);
-
-        // Apply all migrations between the current database version and the target version
-        await ApplyMigrations(conn, tx);
-
-        // Now, reapply views/functions (we deleted them above, no need to worry about conflicts)
-        await ExecuteSqlFile($"{RootPath}.Views.views.sql", conn, tx);
-        await ExecuteSqlFile($"{RootPath}.Functions.functions.sql", conn, tx);
-
-        // Finally, commit tx
-        await tx.CommitAsync();
-    }
-
-    private async Task ApplyMigrations(IPKConnection conn, IDbTransaction tx)
-    {
-        var currentVersion = await GetCurrentDatabaseVersion(conn);
-        _logger.Information("Current schema version: {CurrentVersion}", currentVersion);
-        for (var migration = currentVersion + 1; migration <= TargetSchemaVersion; migration++)
-        {
-            _logger.Information("Applying schema migration {MigrationId}", migration);
-            await ExecuteSqlFile($"{RootPath}.Migrations.{migration}.sql", conn, tx);
-        }
-    }
-
-    private async Task ExecuteSqlFile(string resourceName, IPKConnection conn, IDbTransaction tx = null)
-    {
-        await using var stream = typeof(Database).Assembly.GetManifestResourceStream(resourceName);
-        if (stream == null) throw new ArgumentException($"Invalid resource name  '{resourceName}'");
-
-        using var reader = new StreamReader(stream);
-        var query = await reader.ReadToEndAsync();
-
-        await conn.ExecuteAsync(query, transaction: tx);
-
-        // If the above creates new enum/composite types, we must tell Npgsql to reload the internal type caches
-        // This will propagate to every other connection as well, since it marks the global type mapper collection dirty.
-        ((PKConnection)conn).ReloadTypes();
-    }
-
-    private async Task<int> GetCurrentDatabaseVersion(IPKConnection conn)
-    {
-        // First, check if the "info" table exists (it may not, if this is a *really* old database)
-        var hasInfoTable =
-            await conn.QuerySingleOrDefaultAsync<int>(
-                "select count(*) from information_schema.tables where table_name = 'info'") == 1;
-
-        // If we have the table, read the schema version
-        if (hasInfoTable)
-            return await conn.QuerySingleOrDefaultAsync<int>("select schema_version from info");
-
-        // If not, we return version "-1"
-        // This means migration 0 will get executed, getting us into a consistent state
-        // Then, migration 1 gets executed, which creates the info table and sets version to 1
-        return -1;
-    }
-}

PluralKit.Core/Modules/DataStoreModule.cs

@@ -10,7 +10,6 @@ public class DataStoreModule: Module
     protected override void Load(ContainerBuilder builder)
     {
         builder.RegisterType<DbConnectionCountHolder>().SingleInstance();
-        builder.RegisterType<DatabaseMigrator>().SingleInstance();
         builder.RegisterType<Database>().As<IDatabase>().SingleInstance();
         builder.RegisterType<ModelRepository>().AsSelf().SingleInstance();