import { MigrationInterface, QueryRunner } from 'typeorm';

function quoteIdentifier(identifier: string): string {
  return `"${identifier.replaceAll('"', '""')}"`;
}

export class PhaseD52FindingCatalogAdministration1787335200000 implements MigrationInterface {
  name = 'PhaseD52FindingCatalogAdministration1787335200000';

  public async up(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`
      CREATE TABLE finding_catalog_item_versions (
        id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
        item_id uuid NOT NULL,
        revision integer NOT NULL,
        snapshot jsonb NOT NULL,
        actor_user_id uuid,
        actor_username varchar(80),
        created_at timestamptz NOT NULL DEFAULT CURRENT_TIMESTAMP,
        CONSTRAINT uq_finding_catalog_item_versions_revision
          UNIQUE (item_id, revision),
        CONSTRAINT chk_finding_catalog_item_versions_revision
          CHECK (revision > 0),
        CONSTRAINT chk_finding_catalog_item_versions_snapshot
          CHECK (jsonb_typeof(snapshot) = 'object'),
        CONSTRAINT fk_finding_catalog_item_versions_item FOREIGN KEY (item_id)
          REFERENCES finding_catalog_items(id) ON DELETE RESTRICT,
        CONSTRAINT fk_finding_catalog_item_versions_actor FOREIGN KEY (actor_user_id)
          REFERENCES users(id) ON DELETE SET NULL
      )
    `);
    await queryRunner.query(`
      CREATE INDEX idx_finding_catalog_item_versions_item_revision
      ON finding_catalog_item_versions (item_id, revision DESC)
    `);
    await queryRunner.query(`
      CREATE INDEX idx_finding_catalog_item_versions_created_at
      ON finding_catalog_item_versions (created_at DESC)
    `);

    await queryRunner.query(`
      INSERT INTO finding_catalog_item_versions (
        item_id, revision, snapshot, actor_username, created_at
      )
      SELECT
        item.id,
        item.revision,
        JSONB_BUILD_OBJECT(
          'id', item.id,
          'categoryId', category.id,
          'categoryCode', category.code,
          'categoryName', category.name,
          'code', item.code,
          'sourceNumber', item.source_number,
          'title', item.title,
          'legalBasis', item.legal_basis,
          'glossary', item.glossary,
          'importNote', item.import_note,
          'revision', item.revision,
          'isActive', item.is_active
        ),
        'migration:D5.2',
        item.updated_at
      FROM finding_catalog_items item
      INNER JOIN finding_categories category ON category.id = item.category_id
    `);

    const appRole = process.env.DB_APP_USER;
    if (!appRole) throw new Error('Missing required environment variable: DB_APP_USER');
    const roleRows = (await queryRunner.query(
      'SELECT 1 FROM pg_roles WHERE rolname = $1',
      [appRole],
    )) as unknown[];
    if (roleRows.length !== 1) throw new Error('Configured DB_APP_USER does not exist');
    const applicationRole = quoteIdentifier(appRole);
    await queryRunner.query(`
      GRANT SELECT, INSERT ON TABLE finding_catalog_item_versions
      TO ${applicationRole}
    `);
    await queryRunner.query(`
      REVOKE UPDATE, DELETE ON TABLE finding_catalog_item_versions
      FROM ${applicationRole}
    `);
  }

  public async down(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query('DROP TABLE finding_catalog_item_versions');
  }
}