import { MigrationInterface, QueryRunner } from 'typeorm';

/**
 * F5 makes the physical hierarchy Area-owned. Empresa is never a parent nor a
 * required property of Yacimiento/Instalación/Subinstalación. The current and
 * historical operator/concession truth lives in area_company_relations and is
 * frozen separately by each Inspección/Acta.
 *
 * operator_company_id is retained only as a backwards-compatible creation/
 * historical snapshot. Runtime ownership and search MUST NOT depend on it.
 */
export class F5OperationalContextCompatibility1790087250000 implements MigrationInterface {
  name = 'F5OperationalContextCompatibility1790087250000';

  public async up(queryRunner: QueryRunner): Promise<void> {
    await this.installAreaOwnedGuard(queryRunner);
  }

  public async down(queryRunner: QueryRunner): Promise<void> {
    await this.installLegacyPairedGuard(queryRunner);
  }

  private async installAreaOwnedGuard(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`
      CREATE OR REPLACE FUNCTION enforce_asset_operational_context()
      RETURNS trigger LANGUAGE plpgsql AS $$
      DECLARE
        asset_role asset_type_operational_role;
        area_role asset_type_operational_role;
        company_role asset_type_operational_role;
        active_relation_id uuid;
      BEGIN
        SELECT operational_role INTO asset_role
        FROM asset_types WHERE id=NEW.asset_type_id;

        IF asset_role <> 'GENERIC'::asset_type_operational_role THEN
          IF NEW.operational_area_id IS NOT NULL OR NEW.operator_company_id IS NOT NULL THEN
            RAISE EXCEPTION USING ERRCODE='23514',
              MESSAGE='Área y Empresa no reciben contexto operativo de Inventario';
          END IF;
          RETURN NEW;
        END IF;

        IF NEW.operator_company_id IS NOT NULL AND NEW.operational_area_id IS NULL THEN
          RAISE EXCEPTION USING ERRCODE='23514',
            MESSAGE='Un snapshot de Empresa requiere un Área física';
        END IF;

        -- Once written, an old/current company snapshot cannot be repointed to
        -- simulate physical ownership. Company changes happen in the temporal
        -- Area↔Empresa relation instead.
        IF TG_OP='UPDATE'
           AND NEW.operator_company_id IS DISTINCT FROM OLD.operator_company_id THEN
          RAISE EXCEPTION USING ERRCODE='23514',
            MESSAGE='La Empresa se cambia en la relación temporal del Área, no en el Inventario';
        END IF;

        IF NEW.operational_area_id IS NULL THEN
          RETURN NEW;
        END IF;

        SELECT type.operational_role INTO area_role
        FROM assets area
        JOIN asset_types type ON type.id=area.asset_type_id
        WHERE area.id=NEW.operational_area_id
          AND area.information_status<>'INACTIVE'
          AND type.is_active=true;
        IF area_role IS DISTINCT FROM 'AREA'::asset_type_operational_role THEN
          RAISE EXCEPTION USING ERRCODE='23514',
            MESSAGE='operational area must be an active AREA asset';
        END IF;

        IF NEW.parent_id IS NULL OR NOT EXISTS (
          WITH RECURSIVE ancestors AS (
            SELECT id,parent_id FROM assets WHERE id=NEW.parent_id
            UNION ALL
            SELECT parent.id,parent.parent_id
            FROM assets parent
            JOIN ancestors child ON parent.id=child.parent_id
          )
          SELECT 1 FROM ancestors WHERE id=NEW.operational_area_id LIMIT 1
        ) THEN
          RAISE EXCEPTION USING ERRCODE='23514',
            MESSAGE='operational area must be an ancestor in the physical hierarchy';
        END IF;

        -- A company value is allowed only as the context snapshot that was valid
        -- at creation time. It is never used to decide future membership.
        IF NEW.operator_company_id IS NOT NULL THEN
          SELECT type.operational_role INTO company_role
          FROM assets company
          JOIN asset_types type ON type.id=company.asset_type_id
          WHERE company.id=NEW.operator_company_id
            AND company.information_status<>'INACTIVE'
            AND type.is_active=true;
          IF company_role IS DISTINCT FROM 'COMPANY'::asset_type_operational_role THEN
            RAISE EXCEPTION USING ERRCODE='23514',
              MESSAGE='operator snapshot must reference an active COMPANY-role asset';
          END IF;

          IF TG_OP='INSERT' THEN
            SELECT relation.id INTO active_relation_id
            FROM area_company_relations relation
            WHERE relation.area_id=NEW.operational_area_id
              AND relation.company_id=NEW.operator_company_id
              AND relation.relation_role='OPERATOR'::area_organization_role
              AND relation.valid_until IS NULL
            FOR KEY SHARE;
            IF active_relation_id IS NULL THEN
              RAISE EXCEPTION USING ERRCODE='23514',
                MESSAGE='creation operator snapshot must be active for the selected Area';
            END IF;
          END IF;
        END IF;

        RETURN NEW;
      END $$;
    `);
  }

  /** Restores the production F4-era paired Area+Empresa guard on rollback. */
  private async installLegacyPairedGuard(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`
      CREATE OR REPLACE FUNCTION enforce_asset_operational_context()
      RETURNS trigger LANGUAGE plpgsql AS $$
      DECLARE
        asset_role asset_type_operational_role;
        area_role asset_type_operational_role;
        company_role asset_type_operational_role;
        active_relation_id uuid;
      BEGIN
        IF NEW.operational_area_id IS NULL AND NEW.operator_company_id IS NULL THEN
          RETURN NEW;
        END IF;
        IF NEW.operational_area_id IS NULL OR NEW.operator_company_id IS NULL THEN
          RAISE EXCEPTION USING ERRCODE='23514',
            MESSAGE='operational area and organization must be assigned together';
        END IF;

        SELECT operational_role INTO asset_role FROM asset_types WHERE id=NEW.asset_type_id;
        IF asset_role <> 'GENERIC'::asset_type_operational_role THEN
          RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='area and organization assets cannot receive an operational assignment';
        END IF;

        SELECT type.operational_role INTO area_role
        FROM assets area JOIN asset_types type ON type.id=area.asset_type_id
        WHERE area.id=NEW.operational_area_id AND area.information_status<>'INACTIVE' AND type.is_active=true;
        SELECT type.operational_role INTO company_role
        FROM assets company JOIN asset_types type ON type.id=company.asset_type_id
        WHERE company.id=NEW.operator_company_id AND company.information_status<>'INACTIVE' AND type.is_active=true;
        IF area_role IS DISTINCT FROM 'AREA'::asset_type_operational_role THEN
          RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='operational area must be an active AREA asset';
        END IF;
        IF company_role IS DISTINCT FROM 'COMPANY'::asset_type_operational_role THEN
          RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='operator organization must be an active COMPANY-role asset';
        END IF;

        SELECT relation.id INTO active_relation_id
        FROM area_company_relations relation
        WHERE relation.area_id=NEW.operational_area_id
          AND relation.company_id=NEW.operator_company_id
          AND relation.relation_role='OPERATOR'::area_organization_role
          AND relation.valid_until IS NULL
        FOR KEY SHARE;
        IF active_relation_id IS NULL THEN
          RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='operational area and organization do not have an active OPERATOR relation';
        END IF;

        IF NEW.parent_id IS NULL OR NOT EXISTS (
          WITH RECURSIVE ancestors AS (
            SELECT id,parent_id FROM assets WHERE id=NEW.parent_id
            UNION ALL
            SELECT parent.id,parent.parent_id FROM assets parent JOIN ancestors child ON parent.id=child.parent_id
          ) SELECT 1 FROM ancestors WHERE id=NEW.operational_area_id LIMIT 1
        ) THEN
          RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='operational area must be an ancestor in the physical hierarchy';
        END IF;
        RETURN NEW;
      END $$;
    `);
  }
}