import { MigrationInterface, QueryRunner } from 'typeorm';

/**
 * Wagons the requester specifically asked for. A transfer request stays
 * count-driven (`quantity` is what must be delivered), but a requester who
 * picked wagons off the yard desk now records WHICH ones — OCC sees the numbers
 * on the queue and the fulfil picker pre-selects them.
 *
 * Stored as a uuid[] column rather than a join table: the list is read and
 * written whole, never queried by wagon, and a preference carries no lifecycle
 * of its own (no FK — a purged wagon simply drops out of the display).
 */
export class TransferRequestPreferredWagons3400000000000
  implements MigrationInterface
{
  public async up(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`
      ALTER TABLE freight.wagon_transfer_requests
        ADD COLUMN IF NOT EXISTS preferred_wagon_ids uuid[]
    `);
  }

  public async down(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`
      ALTER TABLE freight.wagon_transfer_requests
        DROP COLUMN IF EXISTS preferred_wagon_ids
    `);
  }
}