edr-platform/apps/edr-payment-api/src/migrations/1782200000000-DropActiveReferenceUniqueIndex.ts

import { MigrationInterface, QueryRunner } from "typeorm";

/**
 * Drops the per-reference partial UNIQUE index so a domain order may have MANY intents — including
 * more than one SUCCEEDED (a second real payment is registered as its own row, not blocked by the
 * DB). A plain, non-unique lookup index replaces it for the reference lookups.
 *
 * DATA SAFETY: dropping an index never touches row data — no rows or column values change, and
 * relaxing a constraint cannot conflict with existing rows.
 *
 * ROLLBACK CAVEAT: `down()` re-creates the UNIQUE index on a best-effort basis. Once the new
 * "free initiate" behaviour has produced two active/SUCCEEDED intents for one order, re-creating
 * the unique index WILL FAIL (the duplicates violate it). Roll forward is always safe; rolling
 * back to the strict constraint is only possible while no duplicates exist.
 */
export class DropActiveReferenceUniqueIndex1782200000000
  implements MigrationInterface
{
  name = "DropActiveReferenceUniqueIndex1782200000000";

  public async up(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(
      `DROP INDEX IF EXISTS "edr_payment"."uq_payment_intent_active_reference"`,
    );
    await queryRunner.query(
      `CREATE INDEX IF NOT EXISTS "idx_payment_intent_reference" ON "edr_payment"."payment_intent" ("service", "reference_type", "reference_id")`,
    );
  }

  public async down(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(
      `DROP INDEX IF EXISTS "edr_payment"."idx_payment_intent_reference"`,
    );
    // Best-effort restore — fails if duplicate active/SUCCEEDED intents already exist (see note above).
    await queryRunner.query(
      `CREATE UNIQUE INDEX IF NOT EXISTS "uq_payment_intent_active_reference" ON "edr_payment"."payment_intent" ("service", "reference_type", "reference_id") WHERE status NOT IN ('FAILED','CANCELLED') AND deleted_at IS NULL`,
    );
  }
}