import { TableUniqueOptions } from '../options/TableUniqueOptions';
import { UniqueMetadata } from '../../metadata/UniqueMetadata';

/**
 * Database's table unique constraint stored in this class.
 */
export class TableUnique {
	readonly '@instanceof' = Symbol.for('TableUnique');

	// -------------------------------------------------------------------------
	// Public Properties
	// -------------------------------------------------------------------------

	/**
	 * Constraint name.
	 */
	name?: string;

	/**
	 * Columns that contains this constraint.
	 */
	columnNames: string[] = [];

	/**
	 * Set this foreign key constraint as "DEFERRABLE" e.g. check constraints at start
	 * or at the end of a transaction
	 */
	deferrable?: string;

	// -------------------------------------------------------------------------
	// Constructor
	// -------------------------------------------------------------------------

	constructor(options: TableUniqueOptions) {
		this.name = options.name;
		this.columnNames = options.columnNames;
		this.deferrable = options.deferrable;
	}

	// -------------------------------------------------------------------------
	// Public Methods
	// -------------------------------------------------------------------------

	/**
	 * Creates a new copy of this constraint with exactly same properties.
	 */
	clone(): TableUnique {
		return new TableUnique(<TableUniqueOptions>{
			name: this.name,
			columnNames: [...this.columnNames],
			deferrable: this.deferrable,
		});
	}

	// -------------------------------------------------------------------------
	// Static Methods
	// -------------------------------------------------------------------------

	/**
	 * Creates unique from the unique metadata object.
	 */
	static create(uniqueMetadata: UniqueMetadata): TableUnique {
		return new TableUnique(<TableUniqueOptions>{
			name: uniqueMetadata.name,
			columnNames: uniqueMetadata.columns.map((column) => column.databaseName),
			deferrable: uniqueMetadata.deferrable,
		});
	}
}