using Invercargill.DataStructures;
using InvercargillSql;
using InvercargillSql.Migrations;
using InvercargillSql.Dialects;
using InvercargillSql.Orm;

/**
 * Test migrations for testing the migration system
 */
public class V001_CreateUsers : Migration {
    public override int version { get { return 1; } }
    public override string name { get { return "CreateUsers"; } }
    
    public override void up(MigrationBuilder b) throws SqlError {
        b.create_table("users", t => {
            // Type inferred from generic parameter - no redundant type_int() needed
            t.column<int64?>("id")
                .primary_key()
                .auto_increment();
            t.column<string>("name")
                .not_null();
            t.column<string>("email")
                .unique();
            
            // Index created within table builder using fluent API
            t.index("idx_users_email").on_column("email");
        });
    }
    
    public override void down(MigrationBuilder b) throws SqlError {
        b.drop_table("users");  // Indexes dropped automatically with table
    }
}

public class V002_AddAgeColumn : Migration {
    public override int version { get { return 2; } }
    public override string name { get { return "AddAgeColumn"; } }
    
    public override void up(MigrationBuilder b) throws SqlError {
        b.alter_table("users", t => {
            // Type inferred from generic parameter - no redundant type_int() needed
            t.add_column<int?>("age");
        });
    }
    
    public override void down(MigrationBuilder b) throws SqlError {
        b.alter_table("users", t => {
            t.drop_column("age");
        });
    }
}

/**
 * Migration demonstrating index operations in alter table
 */
public class V003_AddIndexOnName : Migration {
    public override int version { get { return 3; } }
    public override string name { get { return "AddIndexOnName"; } }
    
    public override void up(MigrationBuilder b) throws SqlError {
        b.alter_table("users", t => {
            // Create index using alter table builder
            t.create_index("idx_users_name").on_column("name");
        });
    }
    
    public override void down(MigrationBuilder b) throws SqlError {
        b.alter_table("users", t => {
            t.drop_index("idx_users_name");
        });
    }
}

/**
 * Migration tests for Invercargill-Sql library.
 */
public int main(string[] args) {
    print("=== Invercargill-Sql Migration Tests ===\n\n");
    
    try {
        // SQL generation tests
        test_create_table_sql();
        test_drop_table_sql();
        test_create_index_sql();
        test_create_unique_index_sql();
        test_add_column_sql();
        test_drop_column_sql();
        test_rename_column_sql();
        
        // MigrationBuilder tests
        test_migration_builder_create_table();
        test_migration_builder_create_table_with_indexes();
        test_migration_builder_alter_table();
        test_migration_builder_alter_table_with_indexes();
        
        // Index builder tests
        test_index_builder_single_column();
        test_index_builder_composite();
        test_index_builder_unique();
        
        // Foreign Key tests
        test_fk_creation_with_auto_generated_name();
        test_fk_creation_with_explicit_name();
        test_fk_on_delete_actions();
        test_fk_on_update_actions();
        test_fk_in_alter_table_add_column();
        
        // Indexed column tests
        test_indexed_with_auto_generated_name();
        test_indexed_with_custom_name();
        test_unique_indexed_creates_unique_index();
        test_drop_index_on();
        
        // MigrationRunner tests
        test_migration_runner_registration();
        test_migration_runner_migrate_to_latest();
        test_migration_runner_migrate_to_version();
        test_migration_runner_rollback();
        test_migration_runner_rollback_all();
        
        print("\n=== All migration tests passed! ===\n");
        return 0;
    } catch (Error e) {
        printerr("\n=== Test failed: %s ===\n", e.message);
        return 1;
    }
}

void test_create_table_sql() throws SqlError {
    print("Test: CREATE TABLE SQL generation... ");
    
    var dialect = new SqliteDialect();
    var op = new CreateTableOperation() { table_name = "test" };
    op.columns.add(new ColumnDefinition() {
        name = "id",
        column_type = ColumnType.INT_64,
        is_primary_key = true,
        auto_increment = true
    });
    op.columns.add(new ColumnDefinition() {
        name = "name",
        column_type = ColumnType.TEXT,
        is_required = true
    });
    
    var sql = dialect.create_table_sql(op);
    assert("CREATE TABLE test" in sql);
    assert("id" in sql);
    assert("INTEGER" in sql);
    assert("PRIMARY KEY" in sql);
    assert("name" in sql);
    assert("TEXT" in sql);
    assert("NOT NULL" in sql);
    
    print("PASSED\n");
}

void test_drop_table_sql() throws SqlError {
    print("Test: DROP TABLE SQL generation... ");
    
    var dialect = new SqliteDialect();
    var op = new DropTableOperation() { table_name = "test" };
    var sql = dialect.drop_table_sql(op);
    assert(sql == "DROP TABLE IF EXISTS test");
    
    print("PASSED\n");
}

void test_create_index_sql() throws SqlError {
    print("Test: CREATE INDEX SQL generation... ");
    
    var dialect = new SqliteDialect();
    var op = new CreateIndexOperation() {
        index_name = "idx_test",
        table_name = "test",
        is_unique = false
    };
    op.columns.add("name");
    var sql = dialect.create_index_sql(op);
    assert("CREATE INDEX idx_test ON test (name)" == sql);
    
    print("PASSED\n");
}

void test_create_unique_index_sql() throws SqlError {
    print("Test: CREATE UNIQUE INDEX SQL generation... ");
    
    var dialect = new SqliteDialect();
    var op = new CreateIndexOperation() {
        index_name = "idx_unique",
        table_name = "test",
        is_unique = true
    };
    op.columns.add("email");
    var sql = dialect.create_index_sql(op);
    assert("CREATE UNIQUE INDEX idx_unique ON test (email)" == sql);
    
    print("PASSED\n");
}

void test_add_column_sql() throws SqlError {
    print("Test: ADD COLUMN SQL generation... ");
    
    var dialect = new SqliteDialect();
    var op = new AddColumnOperation() {
        table_name = "users",
        column = new ColumnDefinition() {
            name = "age",
            column_type = ColumnType.INT_32
        }
    };
    var sql = dialect.add_column_sql(op);
    assert("ALTER TABLE users ADD COLUMN age" in sql);
    assert("INTEGER" in sql);
    
    print("PASSED\n");
}

void test_drop_column_sql() throws SqlError {
    print("Test: DROP COLUMN SQL generation... ");
    
    var dialect = new SqliteDialect();
    var op = new DropColumnOperation() {
        table_name = "users",
        column_name = "age"
    };
    var sql = dialect.drop_column_sql(op);
    assert("ALTER TABLE users DROP COLUMN age" == sql);
    
    print("PASSED\n");
}

void test_rename_column_sql() throws SqlError {
    print("Test: RENAME COLUMN SQL generation... ");
    
    var dialect = new SqliteDialect();
    var op = new RenameColumnOperation() {
        table_name = "users",
        old_name = "old_name",
        new_name = "new_name"
    };
    var sql = dialect.rename_column_sql(op);
    assert("ALTER TABLE users RENAME COLUMN old_name TO new_name" == sql);
    
    print("PASSED\n");
}

void test_migration_builder_create_table() throws SqlError {
    print("Test: MigrationBuilder create_table... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    // Type inferred from generic parameter - cleaner API
    builder.create_table("users", t => {
        t.column<int64?>("id").primary_key().auto_increment();
        t.column<string>("name").not_null();
    });
    
    var ops = builder.get_operations();
    assert(ops.length == 1);
    
    var op = ops[0] as CreateTableOperation;
    assert(op != null);
    assert(op.table_name == "users");
    assert(op.columns.length == 2);
    
    print("PASSED\n");
}

void test_migration_builder_create_table_with_indexes() throws SqlError {
    print("Test: MigrationBuilder create_table with indexes... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    // Create table with indexes defined inline
    builder.create_table("users", t => {
        t.column<int64?>("id").primary_key().auto_increment();
        t.column<string>("email").not_null();
        t.column<string>("name").not_null();
        
        // Single column index
        t.index("idx_email").on_column("email");
        
        // Composite unique index
        t.index("idx_email_name").on_columns("email", "name").unique();
    });
    
    var ops = builder.get_operations();
    // Should have 1 create table + 2 create index operations
    assert(ops.length == 3);
    
    var table_op = ops[0] as CreateTableOperation;
    assert(table_op != null);
    assert(table_op.table_name == "users");
    
    var idx1_op = ops[1] as CreateIndexOperation;
    assert(idx1_op != null);
    assert(idx1_op.index_name == "idx_email");
    assert(idx1_op.is_unique == false);
    
    var idx2_op = ops[2] as CreateIndexOperation;
    assert(idx2_op != null);
    assert(idx2_op.index_name == "idx_email_name");
    assert(idx2_op.is_unique == true);
    
    print("PASSED\n");
}

void test_migration_builder_alter_table() throws SqlError {
    print("Test: MigrationBuilder alter_table... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    // Type inferred from generic parameter - cleaner API
    builder.alter_table("users", t => {
        t.add_column<string>("email").not_null();
        t.drop_column("old_column");
        t.rename_column("old_name", "new_name");
    });
    
    var ops = builder.get_operations();
    assert(ops.length == 3);
    
    assert(ops[0] is AddColumnOperation);
    assert(ops[1] is DropColumnOperation);
    assert(ops[2] is RenameColumnOperation);
    
    print("PASSED\n");
}

void test_migration_builder_alter_table_with_indexes() throws SqlError {
    print("Test: MigrationBuilder alter_table with indexes... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    builder.alter_table("users", t => {
        t.add_column<string>("phone");
        
        // Create index on new column
        t.create_index("idx_phone").on_column("phone");
        
        // Drop old index
        t.drop_index("idx_old_email");
    });
    
    var ops = builder.get_operations();
    assert(ops.length == 3);
    
    assert(ops[0] is AddColumnOperation);
    assert(ops[1] is CreateIndexOperation);
    assert(ops[2] is DropIndexOperation);
    
    print("PASSED\n");
}

void test_index_builder_single_column() throws SqlError {
    print("Test: IndexBuilder single column... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    builder.create_table("test", t => {
        t.column<string>("name").not_null();
        t.index("idx_name").on_column("name");
    });
    
    var ops = builder.get_operations();
    var idx_op = ops[1] as CreateIndexOperation;
    assert(idx_op != null);
    assert(idx_op.index_name == "idx_name");
    assert(idx_op.columns.length == 1);
    assert(idx_op.columns[0] == "name");
    assert(idx_op.is_unique == false);
    
    print("PASSED\n");
}

void test_index_builder_composite() throws SqlError {
    print("Test: IndexBuilder composite... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    builder.create_table("test", t => {
        t.column<string>("col1").not_null();
        t.column<string>("col2").not_null();
        t.column<string>("col3").not_null();
        
        t.index("idx_composite").on_columns("col1", "col2", "col3");
    });
    
    var ops = builder.get_operations();
    var idx_op = ops[1] as CreateIndexOperation;
    assert(idx_op != null);
    assert(idx_op.index_name == "idx_composite");
    assert(idx_op.columns.length == 3);
    assert(idx_op.columns[0] == "col1");
    assert(idx_op.columns[1] == "col2");
    assert(idx_op.columns[2] == "col3");
    
    print("PASSED\n");
}

void test_index_builder_unique() throws SqlError {
    print("Test: IndexBuilder unique... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    builder.create_table("test", t => {
        t.column<string>("email").not_null();
        t.index("uq_email").on_column("email").unique();
    });
    
    var ops = builder.get_operations();
    var idx_op = ops[1] as CreateIndexOperation;
    assert(idx_op != null);
    assert(idx_op.index_name == "uq_email");
    assert(idx_op.is_unique == true);
    
    print("PASSED\n");
}

void test_migration_runner_registration() throws SqlError {
    print("Test: MigrationRunner registration... ");
    
    var conn = ConnectionFactory.create_and_open("sqlite::memory:");
    var dialect = new SqliteDialect();
    
    var runner = new MigrationRunner(conn, dialect);
    runner.register_migration(new V001_CreateUsers());
    runner.register_migration(new V002_AddAgeColumn());
    
    // Verify migrations are registered - current version should be 0
    var current = runner.get_current_version();
    assert(current == 0); // No migrations applied yet
    
    print("PASSED\n");
    conn.close();
}

void test_migration_runner_migrate_to_latest() throws SqlError {
    print("Test: MigrationRunner migrate_to_latest... ");
    
    var conn = ConnectionFactory.create_and_open("sqlite::memory:");
    var dialect = new SqliteDialect();
    
    var runner = new MigrationRunner(conn, dialect);
    runner.register_migration(new V001_CreateUsers());
    runner.register_migration(new V002_AddAgeColumn());
    
    runner.migrate_to_latest();
    
    var current = runner.get_current_version();
    assert(current == 2);
    
    // Verify table was created
    var cmd = conn.create_command("SELECT name FROM sqlite_master WHERE type='table' AND name='users'");
    var results = cmd.execute_query();
    assert(results.any());
    
    print("PASSED\n");
    conn.close();
}

void test_migration_runner_migrate_to_version() throws SqlError {
    print("Test: MigrationRunner migrate_to_version... ");
    
    var conn = ConnectionFactory.create_and_open("sqlite::memory:");
    var dialect = new SqliteDialect();
    
    var runner = new MigrationRunner(conn, dialect);
    runner.register_migration(new V001_CreateUsers());
    runner.register_migration(new V002_AddAgeColumn());
    
    // Migrate to version 1 only
    runner.migrate_to(1);
    assert(runner.get_current_version() == 1);
    
    // Then migrate to version 2
    runner.migrate_to(2);
    assert(runner.get_current_version() == 2);
    
    print("PASSED\n");
    conn.close();
}

void test_migration_runner_rollback() throws SqlError {
    print("Test: MigrationRunner rollback... ");
    
    var conn = ConnectionFactory.create_and_open("sqlite::memory:");
    var dialect = new SqliteDialect();
    
    var runner = new MigrationRunner(conn, dialect);
    runner.register_migration(new V001_CreateUsers());
    runner.register_migration(new V002_AddAgeColumn());
    
    runner.migrate_to_latest();
    assert(runner.get_current_version() == 2);
    
    // Rollback one step
    runner.rollback(1);
    assert(runner.get_current_version() == 1);
    
    print("PASSED\n");
    conn.close();
}

void test_migration_runner_rollback_all() throws SqlError {
    print("Test: MigrationRunner rollback_all... ");
    
    var conn = ConnectionFactory.create_and_open("sqlite::memory:");
    var dialect = new SqliteDialect();
    
    var runner = new MigrationRunner(conn, dialect);
    runner.register_migration(new V001_CreateUsers());
    runner.register_migration(new V002_AddAgeColumn());
    
    runner.migrate_to_latest();
    assert(runner.get_current_version() == 2);
    
    // Rollback all
    runner.rollback_all();
    assert(runner.get_current_version() == 0);
    
    print("PASSED\n");
    conn.close();
}

// ========== Foreign Key Tests ==========

void test_fk_creation_with_auto_generated_name() throws SqlError {
    print("Test: FK creation with auto-generated name... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    builder.create_table("orders", t => {
        t.column<int64?>("id").primary_key().auto_increment();
        t.column<int64?>("user_id")
            .not_null()
            .references("users", "id");
    });
    
    var ops = builder.get_operations();
    assert(ops.length == 1);
    
    var table_op = ops[0] as CreateTableOperation;
    assert(table_op != null);
    
    // Debug: print constraint count
    if (table_op.constraints.length != 1) {
        print("\n  DEBUG: constraints.length = %u (expected 1)\n", table_op.constraints.length);
    }
    
    assert(table_op.constraints.length == 1);
    
    var constraint = table_op.constraints.get(0);
    assert(constraint.constraint_type == "FOREIGN KEY");
    assert(constraint.name == "fk_orders_user_id");  // Auto-generated name
    assert(constraint.reference_table == "users");
    assert(constraint.reference_columns.get(0) == "id");
    assert(constraint.columns.get(0) == "user_id");
    
    // Verify SQL contains proper FOREIGN KEY clause
    var sql = dialect.create_table_sql(table_op);
    assert("FOREIGN KEY" in sql);
    assert("REFERENCES users (id)" in sql);
    assert("fk_orders_user_id" in sql);
    
    print("PASSED\n");
}

void test_fk_creation_with_explicit_name() throws SqlError {
    print("Test: FK creation with explicit name... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    builder.create_table("orders", t => {
        t.column<int64?>("id").primary_key().auto_increment();
        t.column<int64?>("user_id")
            .not_null()
            .references("users", "id")
                .name("custom_fk_orders_users");
    });
    
    var ops = builder.get_operations();
    var table_op = ops[0] as CreateTableOperation;
    assert(table_op != null);
    
    var constraint = table_op.constraints.get(0);
    assert(constraint.name == "custom_fk_orders_users");  // Custom name
    
    var sql = dialect.create_table_sql(table_op);
    assert("custom_fk_orders_users" in sql);
    
    print("PASSED\n");
}

void test_fk_on_delete_actions() throws SqlError {
    print("Test: FK ON DELETE actions... ");
    
    var dialect = new SqliteDialect();
    
    // Test CASCADE
    var builder = new MigrationBuilder(dialect);
    builder.create_table("orders", t => {
        t.column<int64?>("user_id")
            .references("users", "id")
                .on_delete_cascade();
    });
    var ops = builder.get_operations();
    var table_op = ops[0] as CreateTableOperation;
    var constraint = table_op.constraints.get(0);
    assert(constraint.on_delete_action == ReferentialAction.CASCADE);
    var sql = dialect.create_table_sql(table_op);
    assert("ON DELETE CASCADE" in sql);
    
    // Test SET NULL
    builder = new MigrationBuilder(dialect);
    builder.create_table("orders", t => {
        t.column<int64?>("user_id")
            .references("users", "id")
                .on_delete_set_null();
    });
    ops = builder.get_operations();
    table_op = ops[0] as CreateTableOperation;
    constraint = table_op.constraints.get(0);
    assert(constraint.on_delete_action == ReferentialAction.SET_NULL);
    sql = dialect.create_table_sql(table_op);
    assert("ON DELETE SET NULL" in sql);
    
    // Test SET DEFAULT
    builder = new MigrationBuilder(dialect);
    builder.create_table("orders", t => {
        t.column<int64?>("user_id")
            .references("users", "id")
                .on_delete_set_default();
    });
    ops = builder.get_operations();
    table_op = ops[0] as CreateTableOperation;
    constraint = table_op.constraints.get(0);
    assert(constraint.on_delete_action == ReferentialAction.SET_DEFAULT);
    sql = dialect.create_table_sql(table_op);
    assert("ON DELETE SET DEFAULT" in sql);
    
    // Test NO ACTION
    builder = new MigrationBuilder(dialect);
    builder.create_table("orders", t => {
        t.column<int64?>("user_id")
            .references("users", "id")
                .on_delete_no_action();
    });
    ops = builder.get_operations();
    table_op = ops[0] as CreateTableOperation;
    constraint = table_op.constraints.get(0);
    assert(constraint.on_delete_action == ReferentialAction.NO_ACTION);
    
    // Test RESTRICT
    builder = new MigrationBuilder(dialect);
    builder.create_table("orders", t => {
        t.column<int64?>("user_id")
            .references("users", "id")
                .on_delete_restrict();
    });
    ops = builder.get_operations();
    table_op = ops[0] as CreateTableOperation;
    constraint = table_op.constraints.get(0);
    assert(constraint.on_delete_action == ReferentialAction.RESTRICT);
    sql = dialect.create_table_sql(table_op);
    assert("ON DELETE RESTRICT" in sql);
    
    print("PASSED\n");
}

void test_fk_on_update_actions() throws SqlError {
    print("Test: FK ON UPDATE actions... ");
    
    var dialect = new SqliteDialect();
    
    // Test CASCADE
    var builder = new MigrationBuilder(dialect);
    builder.create_table("orders", t => {
        t.column<int64?>("user_id")
            .references("users", "id")
                .on_update_cascade();
    });
    var ops = builder.get_operations();
    var table_op = ops[0] as CreateTableOperation;
    var constraint = table_op.constraints.get(0);
    assert(constraint.on_update_action == ReferentialAction.CASCADE);
    var sql = dialect.create_table_sql(table_op);
    assert("ON UPDATE CASCADE" in sql);
    
    // Test SET NULL
    builder = new MigrationBuilder(dialect);
    builder.create_table("orders", t => {
        t.column<int64?>("user_id")
            .references("users", "id")
                .on_update_set_null();
    });
    ops = builder.get_operations();
    table_op = ops[0] as CreateTableOperation;
    constraint = table_op.constraints.get(0);
    assert(constraint.on_update_action == ReferentialAction.SET_NULL);
    sql = dialect.create_table_sql(table_op);
    assert("ON UPDATE SET NULL" in sql);
    
    // Test SET DEFAULT
    builder = new MigrationBuilder(dialect);
    builder.create_table("orders", t => {
        t.column<int64?>("user_id")
            .references("users", "id")
                .on_update_set_default();
    });
    ops = builder.get_operations();
    table_op = ops[0] as CreateTableOperation;
    constraint = table_op.constraints.get(0);
    assert(constraint.on_update_action == ReferentialAction.SET_DEFAULT);
    sql = dialect.create_table_sql(table_op);
    assert("ON UPDATE SET DEFAULT" in sql);
    
    // Test NO ACTION
    builder = new MigrationBuilder(dialect);
    builder.create_table("orders", t => {
        t.column<int64?>("user_id")
            .references("users", "id")
                .on_update_no_action();
    });
    ops = builder.get_operations();
    table_op = ops[0] as CreateTableOperation;
    constraint = table_op.constraints.get(0);
    assert(constraint.on_update_action == ReferentialAction.NO_ACTION);
    
    // Test RESTRICT
    builder = new MigrationBuilder(dialect);
    builder.create_table("orders", t => {
        t.column<int64?>("user_id")
            .references("users", "id")
                .on_update_restrict();
    });
    ops = builder.get_operations();
    table_op = ops[0] as CreateTableOperation;
    constraint = table_op.constraints.get(0);
    assert(constraint.on_update_action == ReferentialAction.RESTRICT);
    sql = dialect.create_table_sql(table_op);
    assert("ON UPDATE RESTRICT" in sql);
    
    print("PASSED\n");
}

void test_fk_in_alter_table_add_column() throws SqlError {
    print("Test: FK in ALTER TABLE add column... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    builder.alter_table("orders", t => {
        t.add_column<int64?>("product_id")
            .not_null()
            .references("products", "id")
                .on_delete_restrict();
    });
    
    var ops = builder.get_operations();
    assert(ops.length == 1);
    
    var add_col_op = ops[0] as AddColumnOperation;
    assert(add_col_op != null);
    assert(add_col_op.foreign_key_constraint != null);
    
    var fk = add_col_op.foreign_key_constraint;
    assert(fk.constraint_type == "FOREIGN KEY");
    assert(fk.reference_table == "products");
    assert(fk.reference_columns.get(0) == "id");
    assert(fk.on_delete_action == ReferentialAction.RESTRICT);
    
    // Verify SQL contains inline REFERENCES clause
    var sql = dialect.add_column_sql(add_col_op);
    assert("REFERENCES products (id)" in sql);
    assert("ON DELETE RESTRICT" in sql);
    
    print("PASSED\n");
}

// ========== Indexed Column Tests ==========

void test_indexed_with_auto_generated_name() throws SqlError {
    print("Test: indexed() with auto-generated name... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    builder.create_table("users", t => {
        t.column<int64?>("id").primary_key().auto_increment();
        t.column<string>("email")
            .not_null()
            .indexed();
    });
    
    var ops = builder.get_operations();
    // Should have 1 create table + 1 create index operation
    assert(ops.length == 2);
    
    var table_op = ops[0] as CreateTableOperation;
    assert(table_op != null);
    
    var idx_op = ops[1] as CreateIndexOperation;
    assert(idx_op != null);
    assert(idx_op.index_name == "idx_users_email");  // Auto-generated name
    assert(idx_op.table_name == "users");
    assert(idx_op.columns.length == 1);
    assert(idx_op.columns.get(0) == "email");
    assert(idx_op.is_unique == false);
    
    print("PASSED\n");
}

void test_indexed_with_custom_name() throws SqlError {
    print("Test: indexed() with custom name... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    builder.create_table("users", t => {
        t.column<int64?>("id").primary_key().auto_increment();
        t.column<string>("email")
            .not_null()
            .indexed("idx_users_email_address");
    });
    
    var ops = builder.get_operations();
    assert(ops.length == 2);
    
    var idx_op = ops[1] as CreateIndexOperation;
    assert(idx_op != null);
    assert(idx_op.index_name == "idx_users_email_address");  // Custom name
    
    print("PASSED\n");
}

void test_unique_indexed_creates_unique_index() throws SqlError {
    print("Test: unique().indexed() creates UNIQUE index... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    builder.create_table("users", t => {
        t.column<int64?>("id").primary_key().auto_increment();
        t.column<string>("email")
            .not_null()
            .unique()
            .indexed();
    });
    
    var ops = builder.get_operations();
    assert(ops.length == 2);
    
    var idx_op = ops[1] as CreateIndexOperation;
    assert(idx_op != null);
    assert(idx_op.is_unique == true);  // Uniqueness inferred from column's unique() flag
    
    var sql = dialect.create_index_sql(idx_op);
    assert("CREATE UNIQUE INDEX" in sql);
    
    print("PASSED\n");
}

void test_drop_index_on() throws SqlError {
    print("Test: drop_index_on() generates correct DropIndexOperation... ");
    
    var dialect = new SqliteDialect();
    var builder = new MigrationBuilder(dialect);
    
    builder.alter_table("users", t => {
        t.drop_index_on("email");
    });
    
    var ops = builder.get_operations();
    assert(ops.length == 1);
    
    var drop_op = ops[0] as DropIndexOperation;
    assert(drop_op != null);
    assert(drop_op.index_name == "idx_users_email");  // Auto-generated name
    assert(drop_op.table_name == "users");
    
    print("PASSED\n");
}