import { MigrationInterface, QueryRunner } from 'typeorm';

/**
 * Bulk contract templates gain trade direction, so the unique key becomes
 * (cargo type, direction, customs option) instead of (cargo type, customs).
 *
 * Intercity is domestic and crosses no border, so it has no customs variant at
 * all: with_customs stays NULL there, enforced by ck_bulk_intercity_no_customs.
 * The unique index coalesces that NULL so two intercity templates for the same
 * cargo type still collide (plain NULLs never do).
 *
 * No backfill: staff-created bulk templates are keyed by cargo_type_id and no
 * such row exists yet — the seeded direction-keyed bulk rows were retired by
 * 3320000000000 and carry a NULL cargo_type_id. The five system container
 * templates are untouched: cargo_type_id IS NULL keeps them out of both the
 * index and the check.
 */
export class BulkTemplateTradeDirection3420000000000 implements MigrationInterface {
  public async up(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`
      ALTER TABLE freight.contract_templates
        ADD COLUMN IF NOT EXISTS trade_direction varchar(20)
    `);

    await queryRunner.query(
      `DROP INDEX IF EXISTS freight.uq_contract_templates_cargo_customs`,
    );

    await queryRunner.query(`
      CREATE UNIQUE INDEX IF NOT EXISTS uq_contract_templates_cargo_dir_customs
        ON freight.contract_templates
           (cargo_type_id, trade_direction, COALESCE(with_customs, false))
        WHERE deleted_at IS NULL AND cargo_type_id IS NOT NULL
    `);

    await queryRunner.query(`
      ALTER TABLE freight.contract_templates
        DROP CONSTRAINT IF EXISTS ck_bulk_intercity_no_customs
    `);
    await queryRunner.query(`
      ALTER TABLE freight.contract_templates
        ADD CONSTRAINT ck_bulk_intercity_no_customs CHECK (
          cargo_type_id IS NULL
          OR (
            trade_direction IN ('IMPORT', 'EXPORT', 'INTERCITY')
            AND (trade_direction = 'INTERCITY') = (with_customs IS NULL)
          )
        )
    `);
  }

  public async down(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`
      ALTER TABLE freight.contract_templates
        DROP CONSTRAINT IF EXISTS ck_bulk_intercity_no_customs
    `);
    await queryRunner.query(
      `DROP INDEX IF EXISTS freight.uq_contract_templates_cargo_dir_customs`,
    );
    await queryRunner.query(`
      CREATE UNIQUE INDEX IF NOT EXISTS uq_contract_templates_cargo_customs
        ON freight.contract_templates (cargo_type_id, with_customs)
        WHERE deleted_at IS NULL AND cargo_type_id IS NOT NULL
    `);
    await queryRunner.query(`
      ALTER TABLE freight.contract_templates DROP COLUMN IF EXISTS trade_direction
    `);
  }
}