import {
  GET_BRAND_BY_COMPANY_AND_ID as MSSQL_GET_BRAND,
  UPDATE_BRAND as MSSQL_UPDATE_BRAND,
} from '../../providers/mssql/queries/article.js';
import {
  GET_BRAND_BY_COMPANY_AND_ID as SQLITE_GET_BRAND,
  UPDATE_BRAND as SQLITE_UPDATE_BRAND,
} from '../../providers/sqlite3/queries/article.js';
import { INSERT as MSSQL_INSERT_HISTORY } from '../../providers/mssql/queries/articlehistory.js';
import { INSERT as SQLITE_INSERT_HISTORY } from '../../providers/sqlite3/queries/articlehistory.js';
import queryBySku from './queryBySku.js';
import resolveArticleBySku from './resolveArticleBySku.js';
import makeRunner from '../runner.js';

export default function setBrandIdBySku(provider) {
  const resolve = resolveArticleBySku(provider);
  const load = queryBySku(provider);
  const isSqlite = provider?.dialect === 'sqlite3';

  const getBrandSql = isSqlite ? SQLITE_GET_BRAND : MSSQL_GET_BRAND;
  const updateBrandSql = isSqlite ? SQLITE_UPDATE_BRAND : MSSQL_UPDATE_BRAND;
  const insertHistorySql = isSqlite ? SQLITE_INSERT_HISTORY : MSSQL_INSERT_HISTORY;

  /**
   * Sets (or clears) the brand of an article by its SKU.
   *
   * @param {number} googleAuthId - The id of the Google auth user.
   * @param {string} sku - The article SKU.
   * @param {number|null} brandId - The brand id, or `null` to clear the brand.
   * @param {object} [tx] - Optional transaction.
   * @returns {Promise<object>} The updated article.
   * @throws {Error} If the brand or article is not found.
   *
   * @example
   * const article = await store.article.setBrandIdBySku(42, 'SKU-1', 3);
   * // => { id, sku, name, ... }
   */
  return async (googleAuthId, sku, brandId, tx) => {
    const runner = makeRunner(provider, tx);
    const { articleId, languageId, companyId, companyuserId } = await resolve(
      googleAuthId,
      sku,
      runner,
    );

    if (brandId !== null && (typeof brandId !== 'number' || !Number.isInteger(brandId) || brandId <= 0)) {
      throw new Error('Invalid brandId');
    }

    // Read old brand name (null = no brand assigned)
    const oldBrandRes = await runner.query(
      `SELECT b.name FROM article a LEFT JOIN brand b ON b.id = a.brand_id WHERE a.id = @articleId`,
      { articleId },
    );
    const oldBrandName = oldBrandRes.rows[0]?.name ?? null;

    let resolvedBrandId = null;
    let newBrandName = null;
    if (brandId !== null) {
      // Verify brand belongs to this company
      const brandCheck = await runner.query(getBrandSql, { brandId, companyId });
      if (!brandCheck.rows[0]) {
        throw new Error('Brand not found');
      }
      resolvedBrandId = brandId;

      // GET_BRAND_BY_COMPANY_AND_ID only selects `id`, so fetch name separately
      const brandNameRes = await runner.query(
        'SELECT name FROM brand WHERE id = @brandId',
        { brandId },
      );
      newBrandName = brandNameRes.rows[0]?.name ?? null;
    }

    const result = await runner.query(updateBrandSql, {
      articleId,
      brandId: resolvedBrandId,
    });

    if (!result.rowsAffected) {
      throw new Error('Article not found');
    }

    // null = no brand; treat as distinct sentinel so first assignment is logged
    if (oldBrandName !== newBrandName) {
      await runner.query(insertHistorySql, {
        articleId,
        companyuserId,
        text: `Marke ge\u00e4ndert von "${oldBrandName ?? ''}" auf "${newBrandName ?? ''}"`,
      });
    }

    const article = await load(articleId, languageId, runner);
    if (!article) {
      throw new Error('Article not found');
    }

    return article;
  };
}