feat: add support for applying migrations automatically

Tools/Seeder.cs

@@ -21,6 +21,10 @@ public class Seeder
 
 		Console.WriteLine($"You're running Shadow, commit {ThisAssembly.Git.Commit} of branch {ThisAssembly.Git.Branch} ({ThisAssembly.Git.CommitDate})\n");
 
+		// Check migration status. If we can't proceed, exit now.
+		bool migrationSucceeded = EnsureMigrations(db);
+		if (!migrationSucceeded) return true;
+
 		// Check if this is a clean, first run. If so, run the setup wizard.
 		Global? lastVersion = db.Globals.FirstOrDefault(c => c.Key == "lastVersion");
 		Global? runs = db.Globals.FirstOrDefault(g => g.Key == "runs");
@@ -104,4 +108,73 @@ public class Seeder
 		return shutdown;
 
 	}
+
+	public static bool EnsureMigrations(ApplicationDbContext dbContext)
+	{
+		// Returns true if migrations have been successfully applied.
+		// Otherwise returns false.
+		bool migrationSuccess = false;
+		List<string> availableMigrations = dbContext.Database.GetMigrations().ToList();
+		List<string> appliedMigrations   = dbContext.Database.GetAppliedMigrations().ToList();
+
+		bool hasMissingMigrations = availableMigrations.Count > appliedMigrations.Count;
+		bool doMigrationsMatch = availableMigrations.SequenceEqual(appliedMigrations);
+		if (hasMissingMigrations)
+		{
+			bool userMigrationConsent = false;
+			Console.WriteLine("\n" +
+				"========================================\n" +
+				"[Warn] Database migrations missing!\n" +
+				"========================================");
+			if (appliedMigrations.Count == 0)
+			{
+				Console.WriteLine( "Empty database detected. Applying migrations is recommended, and required if this is the first run of Shadow.");
+				userMigrationConsent = Cli.YesNoPrompt("Do you want to apply migrations automatically? [Y/n]: ", true);
+			}
+			else
+			{
+				Console.WriteLine($"Detected existing {appliedMigrations.Count} migrations. Backing up the database before applying migrations is recommended.");
+				userMigrationConsent = Cli.YesNoPrompt("Do you want to apply migrations automatically? [y/N]: ", false);
+			}
+
+			// Do we have user permission to perform migration?
+			if (userMigrationConsent)
+			{
+				dbContext.Database.Migrate();
+				dbContext.SaveChanges();
+			}
+			else
+			{
+				Console.WriteLine("Exiting...");
+				return migrationSuccess;
+			}
+
+			// Check if migrations match afterwards
+			List<string> newlyAppliedMigrations = dbContext.Database.GetAppliedMigrations().ToList();
+			bool doNewlyAppliedMigrationsMatch = availableMigrations.SequenceEqual(newlyAppliedMigrations);
+			if (doNewlyAppliedMigrationsMatch)
+			{
+				Console.WriteLine("\n" +
+					"==============================\n" +
+					"Migration success!\n" +
+					"==============================\n");
+				migrationSuccess = true;
+			}
+			else
+			{
+				// An error ocurred when applying migrations automatically
+				Console.WriteLine("\n" +
+					"==================================================\n" +
+					"[Error] Failed applying migrations automatically!\n" +
+					"==================================================\n");
+				Console.WriteLine("The list of newly applied migrations does not match the list of planned migrations.\n" +
+					"Shadow cannot operate with missing migrations. Please manually revise the database structure and create backups before altering it.\n");
+				migrationSuccess = false;
+			}
+		}
+		else migrationSuccess = true;
+
+		return migrationSuccess;
+	}
+
 }