import numberAutomat from '../automats/numberAutomat';
import quoteAutomat from '../automats/quoteAutomat';
import orderAutomat from '../automats/orderAutomat';

/**
 * Formats a number pattern given prefix, padding width, and counter.
 *
 * @param {string} [prefix='']
 * @param {number} [padding=0]
 * @param {number} [next=1]
 * @returns {string}
 */
export function formatNumberPattern(prefix, padding, next) {
  const pad = Math.max(0, Number(padding) || 0);
  const num = Math.max(1, Number(next) || 1);
  const numStr = pad > 0 ? String(num).padStart(pad, '0') : String(num);
  return `${prefix ?? ''}${numStr}`;
}

/**
 * Returns the next document number for quote or order based on company sequences.
 *
 * @param {'quote'|'order'|string} kind
 * @returns {string}
 */
export function getNextDocumentNumber(kind) {
  const numbers = numberAutomat.state.items ?? [];
  const seq = numbers.find((r) => r.type === kind);
  if (seq) {
    return formatNumberPattern(seq.prefix, seq.padding, seq.next);
  }

  // Detect style from existing company sequences (sku, delivery, entity)
  const skuSeq = numbers.find((r) => r.type === 'sku');
  const deliverySeq = numbers.find((r) => r.type === 'delivery');
  const entitySeq = numbers.find((r) => r.type === 'entity');
  const refSeq = skuSeq || deliverySeq || entitySeq;

  const pad = refSeq ? Math.max(0, Number(refSeq.padding) || 0) : 6;
  const prefixStyle = refSeq?.prefix ?? '';

  let prefix = '';
  let startNum = 1;

  if (
    prefixStyle.startsWith('ART-') ||
    prefixStyle.startsWith('LS-') ||
    prefixStyle.startsWith('KD-') ||
    prefixStyle.endsWith('-')
  ) {
    // Standard German ERP prefix style (ART-, KD-, LS-, KORR-)
    prefix = kind === 'quote' ? 'ANG-' : (kind === 'order' ? 'AUF-' : '');
  } else if (
    prefixStyle.startsWith('SKU-') ||
    prefixStyle.startsWith('DEL-') ||
    prefixStyle.startsWith('C-')
  ) {
    prefix = kind === 'quote' ? 'Q-' : (kind === 'order' ? 'ORD-' : '');
  } else if (
    prefixStyle.startsWith('A-') ||
    prefixStyle.startsWith('L-') ||
    prefixStyle.startsWith('K-')
  ) {
    prefix = kind === 'quote' ? 'AG-' : (kind === 'order' ? 'AU-' : '');
  } else if (!prefixStyle && refSeq?.next >= 10000) {
    prefix = '';
    startNum = kind === 'quote' ? 40001 : 50001;
  } else {
    prefix = kind === 'quote' ? 'ANG-' : (kind === 'order' ? 'AUF-' : '');
  }

  // Check existing docs from quoteAutomat / orderAutomat to avoid collisions
  const listAutomat = kind === 'quote' ? quoteAutomat : (kind === 'order' ? orderAutomat : null);
  const existingDocs = Array.isArray(listAutomat?.state?.items) ? listAutomat.state.items : [];
  let maxFound = startNum - 1;

  for (const doc of existingDocs) {
    if (!doc || typeof doc !== 'object') continue;
    const docNum = String(doc.number ?? '').trim();
    if (!docNum) continue;
    if (prefix && docNum.startsWith(prefix)) {
      const rest = docNum.slice(prefix.length);
      const parsed = parseInt(rest, 10);
      if (!Number.isNaN(parsed) && parsed > maxFound) {
        maxFound = parsed;
      }
    } else if (!prefix) {
      const parsed = parseInt(docNum, 10);
      if (!Number.isNaN(parsed) && parsed >= startNum && parsed > maxFound) {
        maxFound = parsed;
      }
    }
  }

  const nextVal = maxFound >= startNum ? maxFound + 1 : startNum;
  return formatNumberPattern(prefix, pad, nextVal);
}

/**
 * Asynchronously ensures required stores are loaded, then returns the next document number.
 *
 * @param {'quote'|'order'|string} kind
 * @returns {Promise<string>}
 */
export async function ensureDocumentNumber(kind) {
  const listAutomat = kind === 'quote' ? quoteAutomat : (kind === 'order' ? orderAutomat : null);
  await Promise.all([
    numberAutomat.actions.ensureLoaded().catch(() => {}),
    listAutomat?.actions?.ensureLoaded ? listAutomat.actions.ensureLoaded().catch(() => {}) : Promise.resolve(),
  ]);
  return getNextDocumentNumber(kind);
}