import { MigrationInterface, QueryRunner } from 'typeorm';

export class F51CleanManualInventory1790087400000 implements MigrationInterface {
  name = 'F51CleanManualInventory1790087400000';

  public async up(queryRunner: QueryRunner): Promise<void> {
    // F5.1 is an intentional clean-start cut. The deployment process creates a
    // full database backup before migrations, so old domain data is recovered
    // from that backup rather than by pretending a destructive migration can
    // reconstruct historical rows.
    await queryRunner.query('DROP TRIGGER IF EXISTS trg_f5_canonical_asset_hierarchy ON assets');

    // Remove all operational/domain instances and every table that depends on
    // them (visits, acts, findings, reports, versions, media, relations, etc.).
    // Users/roles/permissions and technical configuration are deliberately not
    // part of this TRUNCATE.
    await queryRunner.query('TRUNCATE TABLE assets CASCADE');

    // Imported territorial/source material must not silently repopulate or
    // influence the new manually curated structure.
    await queryRunner.query('TRUNCATE TABLE administrative_departments CASCADE');
    await queryRunner.query('TRUNCATE TABLE source_documents CASCADE');

    // Start the classification ↔ finding applicability review from zero while
    // preserving both master catalogs themselves.
    await queryRunner.query('TRUNCATE TABLE finding_catalog_item_inventory_families');

    // Explicitly clear audit history, including authentication/admin events
    // accumulated during development. New events continue to be recorded after
    // this migration.
    await queryRunner.query('TRUNCATE TABLE audit_events');

    // Import/reconciliation tables can contain rows not connected to a current
    // Asset. Clear every asset_import_* data table without coupling this cut to
    // one historical import implementation.
    await queryRunner.query(`
      DO $$
      DECLARE table_name text;
      BEGIN
        FOR table_name IN
          SELECT tablename
          FROM pg_tables
          WHERE schemaname = current_schema()
            AND tablename LIKE 'asset_import_%'
        LOOP
          EXECUTE format('TRUNCATE TABLE %I CASCADE', table_name);
        END LOOP;
      END $$;
    `);

    // F5.1 decouples the physical Inventory tree from Empresa. A structural
    // Asset may therefore inherit an Area while no operator has been assigned
    // yet. Keep the useful invariant that an operator can never exist without
    // an Area, but remove the old all-or-nothing pair requirement.
    await queryRunner.query(`
      ALTER TABLE asset_context_history
      DROP CONSTRAINT IF EXISTS chk_asset_context_history_context_pair
    `);
    await queryRunner.query(`
      ALTER TABLE asset_context_history
      ADD CONSTRAINT chk_asset_context_history_context_pair
      CHECK (operator_company_id IS NULL OR operational_area_id IS NOT NULL)
    `);

    // Departamento becomes the real root of the physical Inventory tree.
    await queryRunner.query(`
      INSERT INTO asset_types(code,name,description,can_be_root,is_active,operational_role)
      SELECT 'departamento','Departamento','Departamento administrativo que contiene Áreas.',true,true,'GENERIC'
      WHERE NOT EXISTS (
        SELECT 1 FROM asset_types WHERE lower(code)='departamento'
      )
    `);
    await queryRunner.query(`
      UPDATE asset_types
      SET name='Departamento',
          description='Departamento administrativo que contiene Áreas.',
          can_be_root=true,
          is_active=true,
          operational_role='GENERIC',
          updated_at=CURRENT_TIMESTAMP
      WHERE lower(code)='departamento'
    `);
    await queryRunner.query(`
      UPDATE asset_types
      SET can_be_root=false,updated_at=CURRENT_TIMESTAMP
      WHERE lower(code)='area'
    `);

    // Area has exactly one canonical structural parent kind: Departamento.
    await queryRunner.query(`
      DELETE FROM asset_type_parent_rules rule
      USING asset_types child
      WHERE rule.child_type_id=child.id AND lower(child.code)='area'
    `);
    await queryRunner.query(`
      INSERT INTO asset_type_parent_rules(child_type_id,parent_type_id)
      SELECT child.id,parent.id
      FROM asset_types child CROSS JOIN asset_types parent
      WHERE lower(child.code)='area' AND lower(parent.code)='departamento'
      ON CONFLICT (child_type_id,parent_type_id) DO NOTHING
    `);

    // Database-level guard: UI/API bugs cannot create an invalid physical tree.
    await queryRunner.query(`
      CREATE OR REPLACE FUNCTION enforce_f5_canonical_asset_hierarchy()
      RETURNS trigger LANGUAGE plpgsql AS $$
      DECLARE child_code text; parent_code text;
      BEGIN
        SELECT lower(code) INTO child_code FROM asset_types WHERE id=NEW.asset_type_id;

        IF child_code IN ('empresa','organizacion','departamento') THEN
          IF NEW.parent_id IS NOT NULL THEN
            RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='Empresa y Departamento son maestros raíz independientes';
          END IF;
          RETURN NEW;
        END IF;

        IF child_code NOT IN ('area','yacimiento','instalacion','subinstalacion') THEN
          RETURN NEW;
        END IF;

        IF NEW.parent_id IS NULL THEN
          RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='La estructura requiere Departamento → Área → Yacimiento → Instalación → Subinstalación';
        END IF;

        SELECT lower(type.code) INTO parent_code
        FROM assets parent
        JOIN asset_types type ON type.id=parent.asset_type_id
        WHERE parent.id=NEW.parent_id;

        IF (child_code='area' AND parent_code<>'departamento')
          OR (child_code='yacimiento' AND parent_code<>'area')
          OR (child_code='instalacion' AND parent_code<>'yacimiento')
          OR (child_code='subinstalacion' AND parent_code<>'instalacion') THEN
          RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='Jerarquía inválida: Departamento → Área → Yacimiento → Instalación → Subinstalación';
        END IF;
        RETURN NEW;
      END $$;
    `);
    await queryRunner.query(`
      CREATE TRIGGER trg_f5_canonical_asset_hierarchy
      BEFORE INSERT OR UPDATE OF asset_type_id,parent_id ON assets
      FOR EACH ROW EXECUTE FUNCTION enforce_f5_canonical_asset_hierarchy()
    `);

    const rows = (await queryRunner.query(`
      SELECT
        (SELECT COUNT(*)::integer FROM assets) AS assets,
        (SELECT COUNT(*)::integer FROM audit_events) AS audits,
        (SELECT COUNT(*)::integer FROM finding_catalog_item_inventory_families) AS applicability,
        (SELECT COUNT(*)::integer FROM asset_types WHERE lower(code)='departamento' AND can_be_root=true AND is_active=true) AS departments,
        (SELECT COUNT(*)::integer
           FROM asset_type_parent_rules rule
           JOIN asset_types child ON child.id=rule.child_type_id
           JOIN asset_types parent ON parent.id=rule.parent_type_id
          WHERE lower(child.code)='area' AND lower(parent.code)='departamento') AS area_rules
    `)) as Array<{ assets: number; audits: number; applicability: number; departments: number; area_rules: number }>;
    const check = rows[0];
    if (!check || Number(check.assets) !== 0 || Number(check.audits) !== 0 || Number(check.applicability) !== 0
      || Number(check.departments) !== 1 || Number(check.area_rules) !== 1) {
      throw new Error(`F5.1 clean-start verification failed: ${JSON.stringify(check ?? {})}`);
    }
  }

  public async down(): Promise<void> {
    throw new Error('F5.1 is an intentional destructive clean-start migration. Restore the pre-deploy database backup to recover previous data.');
  }
}