import {
  DELETE_PRICE,
  GET_BY_ID_AND_ARTICLE_ID,
  UPDATE as UPDATE_ARTICLE_SUPPLIER,
  UPDATE_PRICE,
} from '../../sql/articlesupplier.js';
import { CREATE as CREATE_PRICE } from '../../sql/price.js';
import request from '../request.js';
import resolveArticleBySku from '../article/resolveArticleBySku.js';
import ensureLieferantenGroup from '../supplier/ensureLieferantenGroup.js';
import taxEnsure from '../tax/ensure.js';
import {
  optionalString,
  resolveCompanyDefaultTax,
  shapeArticleSupplier,
} from './helpers.js';

export default function update(pool) {
  const resolve = resolveArticleBySku(pool);
  const ensureTax = taxEnsure(pool);

  /**
   * Updates an existing supplier assignment and its associated purchase price.
   *
   * @param {number} googleAuthId - The id of the Google auth user.
   * @param {string} sku - The article SKU.
   * @param {number} id - The id of the articlesupplier record.
   * @param {object} patch - The fields to update.
   * @param {string|null} [patch.sku] - The supplier's item number/SKU.
   * @param {number} [patch.pu] - Packaging unit (> 0).
   * @param {number|null} [patch.stock] - Current stock at the supplier.
   * @param {number|null} [patch.netPrice] - Net purchase price.
   * @param {number} [patch.taxId] - The tax id for the purchase price.
   * @param {number} [patch.taxRate] - The tax rate in percent.
   * @returns {Promise<{id: number, articleId: number, entityId: number, supplierName: string|null, sku: string|null, pu: number, stock: number|null, priceId: number|null, price: {net: number, taxId: number, taxRate?: number}|null}>} The updated assignment.
   * @throws {Error} If input is invalid or supplier assignment is not found.
   *
   * @example
   * const updated = await store.articlesupplier.update(42, 'SKU-1', 12, {
   *   sku: 'MET-44910-B',
   *   pu: 6,
   *   netPrice: 22.50,
   * });
   * // => { id, articleId, entityId, supplierName, sku, pu, stock, priceId, price }
   */
  return async (googleAuthId, sku, id, patch = {}) => {
    if (id == null || !Number.isFinite(id)) {
      throw new Error('Supplier assignment not found');
    }

    if (patch.pu !== undefined) {
      if (!Number.isFinite(patch.pu) || patch.pu <= 0) {
        throw new Error('Invalid pu');
      }
    }

    if (patch.stock !== undefined && patch.stock !== null) {
      if (!Number.isFinite(patch.stock)) {
        throw new Error('Invalid stock');
      }
    }

    if (patch.netPrice !== undefined && patch.netPrice !== null) {
      if (!Number.isFinite(patch.netPrice)) {
        throw new Error('Invalid price');
      }
    }

    const { articleId, companyId } = await resolve(googleAuthId, sku);

    const existingRes = await pool
      .request()
      .input('id', id)
      .input('articleId', articleId)
      .input('companyId', companyId)
      .query(GET_BY_ID_AND_ARTICLE_ID);

    const existing = existingRes.recordset[0];
    if (!existing) {
      throw new Error('Supplier assignment not found');
    }

    const tx = pool.transaction();
    await tx.begin();

    try {
      let priceId = existing.priceId;

      if (patch.netPrice !== undefined) {
        if (patch.netPrice === null) {
          if (priceId != null) {
            const oldPriceId = priceId;
            priceId = null;

            await request(pool, tx)
              .input('id', id)
              .input('articleId', articleId)
              .input('sku', existing.sku)
              .input('stock', existing.stock)
              .input('pu', existing.pu)
              .input('priceId', null)
              .query(UPDATE_ARTICLE_SUPPLIER);

            await request(pool, tx)
              .input('id', oldPriceId)
              .input('articleId', articleId)
              .query(DELETE_PRICE);
          }
        } else {
          // netPrice is a valid number
          if (priceId != null) {
            let taxId = patch.taxId;
            if (taxId == null || !Number.isFinite(taxId)) {
              if (patch.taxRate != null && Number.isFinite(patch.taxRate)) {
                taxId = await ensureTax(patch.taxRate, tx);
              } else {
                taxId = existing.priceTaxId;
              }
            }

            await request(pool, tx)
              .input('id', priceId)
              .input('articleId', articleId)
              .input('net', patch.netPrice)
              .input('taxId', taxId)
              .query(UPDATE_PRICE);
          } else {
            // create new price row
            let taxId = patch.taxId;
            if (taxId == null || !Number.isFinite(taxId)) {
              if (patch.taxRate != null && Number.isFinite(patch.taxRate)) {
                taxId = await ensureTax(patch.taxRate, tx);
              } else {
                const defaultTaxId = await resolveCompanyDefaultTax(
                  pool,
                  tx,
                  companyId,
                );
                taxId = defaultTaxId != null ? defaultTaxId : await ensureTax(0, tx);
              }
            }

            const customerGroupId = await ensureLieferantenGroup(
              pool,
              companyId,
              tx,
            );

            const priceRes = await request(pool, tx)
              .input('taxId', taxId)
              .input('articleId', articleId)
              .input('minmultiplier', 1)
              .input('customerGroupId', customerGroupId)
              .input('net', patch.netPrice)
              .query(CREATE_PRICE);

            priceId = priceRes.recordset[0].id;
          }
        }
      }

      const nextSku =
        patch.sku !== undefined ? optionalString(patch.sku) : existing.sku;
      const nextStock =
        patch.stock !== undefined
          ? patch.stock === null
            ? null
            : patch.stock
          : existing.stock;
      const nextPu = patch.pu !== undefined ? patch.pu : existing.pu;

      await request(pool, tx)
        .input('id', id)
        .input('articleId', articleId)
        .input('sku', nextSku)
        .input('stock', nextStock)
        .input('pu', nextPu)
        .input('priceId', priceId)
        .query(UPDATE_ARTICLE_SUPPLIER);

      await tx.commit();

      const loadRes = await pool
        .request()
        .input('id', id)
        .input('articleId', articleId)
        .input('companyId', companyId)
        .query(GET_BY_ID_AND_ARTICLE_ID);

      return shapeArticleSupplier(loadRes.recordset[0]);
    } catch (err) {
      try {
        await tx.rollback();
      } catch {
        // ignore
      }
      throw err;
    }
  };
}