edr-platform/apps/edr-freight-api/src/migrations/3610000000000-MultipleMiscClearanceCharges.ts

import { MigrationInterface, QueryRunner } from 'typeorm';

/**
 * Clearance charges are no longer one-of-each in a fixed order: GL Ethiopia
 * may raise several MISCELLANEOUS charges, and either level may be created
 * first. Port charges stay unique per booking (one port bill per shipment),
 * enforced by a partial index instead of the old blanket (booking_id, type)
 * uniqueness that also capped miscellaneous at one.
 */
export class MultipleMiscClearanceCharges3610000000000
  implements MigrationInterface
{
  name = 'MultipleMiscClearanceCharges3610000000000';

  public async up(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`
      DROP INDEX IF EXISTS "freight"."uq_booking_clearance_charge_booking_type"
    `);
    await queryRunner.query(`
      CREATE UNIQUE INDEX IF NOT EXISTS "uq_booking_clearance_charge_port"
        ON "freight"."booking_clearance_charge" ("booking_id")
        WHERE "type" = 'PORT_CHARGES' AND "deleted_at" IS NULL
    `);
    await queryRunner.query(`
      CREATE INDEX IF NOT EXISTS "idx_booking_clearance_charge_booking"
        ON "freight"."booking_clearance_charge" ("booking_id")
    `);
  }

  public async down(queryRunner: QueryRunner): Promise<void> {
    // No-op on the uniqueness: restoring the blanket (booking_id, type) index
    // would fail on any booking that has since raised a second miscellaneous
    // charge, which is exactly what this migration set out to allow.
    await queryRunner.query(`
      DROP INDEX IF EXISTS "freight"."uq_booking_clearance_charge_port"
    `);
  }
}