import { MigrationInterface, QueryRunner } from 'typeorm';

/**
 * F4 elimina dos campos heredados de la planificación original de Inspecciones:
 * - title: la Inspección se identifica por su código autogenerado.
 * - planned_end_at: la planificación sólo define la fecha/hora prevista de inicio.
 *
 * La migración conserva una copia técnica de los valores eliminados para que un
 * rollback restaure los datos exactos existentes antes del cambio. Inspecciones
 * creadas después del up() reciben code como title y planned_end_at NULL al bajar.
 *
 * Se conserva un índice sobre planned_start_at porque sigue siendo un criterio de
 * orden y filtro operativo. Ninguna migración histórica se modifica.
 */
export class F4RemoveInspectionLegacyFields1790000500000 implements MigrationInterface {
  name = 'F4RemoveInspectionLegacyFields1790000500000';

  public async up(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`
      CREATE TABLE IF NOT EXISTS f4_inspection_visit_legacy_fields_backup (
        visit_id uuid PRIMARY KEY,
        title varchar(200) NOT NULL,
        planned_end_at timestamptz NULL,
        backed_up_at timestamptz NOT NULL DEFAULT CURRENT_TIMESTAMP
      )
    `);
    await queryRunner.query(`
      INSERT INTO f4_inspection_visit_legacy_fields_backup (
        visit_id,
        title,
        planned_end_at,
        backed_up_at
      )
      SELECT
        id,
        title,
        planned_end_at,
        CURRENT_TIMESTAMP
      FROM inspection_visits
      ON CONFLICT (visit_id) DO UPDATE SET
        title = EXCLUDED.title,
        planned_end_at = EXCLUDED.planned_end_at,
        backed_up_at = EXCLUDED.backed_up_at
    `);

    await queryRunner.query(`DROP INDEX IF EXISTS idx_inspection_visits_planned_dates`);
    await queryRunner.query(`
      ALTER TABLE inspection_visits
      DROP CONSTRAINT IF EXISTS chk_inspection_visits_planned_dates
    `);

    await queryRunner.query(`ALTER TABLE inspection_visits DROP COLUMN IF EXISTS planned_end_at`);
    await queryRunner.query(`ALTER TABLE inspection_visits DROP COLUMN IF EXISTS title`);

    await queryRunner.query(`
      CREATE INDEX IF NOT EXISTS idx_inspection_visits_planned_start_at
      ON inspection_visits (planned_start_at)
    `);
  }

  public async down(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`DROP INDEX IF EXISTS idx_inspection_visits_planned_start_at`);

    await queryRunner.query(`
      ALTER TABLE inspection_visits
      ADD COLUMN IF NOT EXISTS title varchar(200)
    `);
    await queryRunner.query(`
      ALTER TABLE inspection_visits
      ADD COLUMN IF NOT EXISTS planned_end_at timestamptz
    `);

    await queryRunner.query(`
      UPDATE inspection_visits visit
      SET
        title = backup.title,
        planned_end_at = backup.planned_end_at
      FROM f4_inspection_visit_legacy_fields_backup backup
      WHERE backup.visit_id = visit.id
    `);
    await queryRunner.query(`
      UPDATE inspection_visits
      SET title = code
      WHERE title IS NULL
    `);
    await queryRunner.query(`
      ALTER TABLE inspection_visits
      ALTER COLUMN title SET NOT NULL
    `);

    await queryRunner.query(`
      DO $$
      BEGIN
        IF NOT EXISTS (
          SELECT 1
          FROM pg_constraint
          WHERE conname = 'chk_inspection_visits_planned_dates'
            AND conrelid = 'inspection_visits'::regclass
        ) THEN
          ALTER TABLE inspection_visits
          ADD CONSTRAINT chk_inspection_visits_planned_dates CHECK (
            planned_start_at IS NULL
            OR planned_end_at IS NULL
            OR planned_end_at >= planned_start_at
          );
        END IF;
      END
      $$
    `);

    await queryRunner.query(`
      CREATE INDEX IF NOT EXISTS idx_inspection_visits_planned_dates
      ON inspection_visits (planned_start_at, planned_end_at)
    `);

    await queryRunner.query(`DROP TABLE IF EXISTS f4_inspection_visit_legacy_fields_backup`);
  }
}