/** Groups that are not sales customers (filter client-side). */
export const EXCLUDED_CUSTOMER_GROUP_NAMES = new Set(['Lieferanten', 'POS']);

export function entityDisplayName(entity) {
  if (!entity) return '';
  return [entity.firstName, entity.name].filter(Boolean).join(' ');
}

export function sortEntities(entities) {
  return [...entities].sort((a, b) => {
    const byName = String(a.name).localeCompare(String(b.name), 'de');
    if (byName !== 0) return byName;
    return String(a.firstName ?? '').localeCompare(String(b.firstName ?? ''), 'de');
  });
}

/**
 * Customers = entities whose customergroup.name is not Lieferanten/POS.
 */
export function filterCustomerEntities(entities, groups) {
  const excludedIds = new Set(
    groups
      .filter((g) => EXCLUDED_CUSTOMER_GROUP_NAMES.has(g.name))
      .map((g) => g.id),
  );
  return sortEntities(
    entities.filter((e) => !excludedIds.has(e.customergroupId)),
  );
}

export function sortSuppliers(suppliers) {
  return [...suppliers].sort((a, b) =>
    String(a.name).localeCompare(String(b.name), 'de'),
  );
}

export function sortDocs(docs) {
  return [...docs].sort((a, b) => String(b.date).localeCompare(String(a.date)));
}

export function formatDate(iso) {
  const d = new Date(iso);
  if (Number.isNaN(d.getTime())) return iso;
  return d.toLocaleDateString('de-DE');
}

/**
 * Delivery documents have a server-allocated, read-only `number` plus an
 * optional user-entered `externalNumber`. Returns the display value for a
 * field, defaulting to a dash when empty.
 */
export function numberDisplay(value) {
  if (value == null || String(value).trim() === '') return '–';
  return String(value);
}

export function dateInputValue(iso) {
  if (!iso) return '';
  const d = new Date(iso);
  if (Number.isNaN(d.getTime())) return String(iso).slice(0, 10);
  return d.toISOString().slice(0, 10);
}

export function emptyLine() {
  return {
    key: `${Date.now()}-${Math.random().toString(36).slice(2, 8)}`,
    amount: '',
    sku: '',
    tax: '',
    rebate: '',
    net: '',
    name: '',
    pu: '',
    unit: '',
    netprice: '',
    taxrate: '',
  };
}

export function lineFromApi(row) {
  return {
    key: `line-${row.id ?? `${Date.now()}-${Math.random().toString(36).slice(2, 8)}`}`,
    amount: row.amount == null ? '' : String(row.amount),
    sku: row.sku ?? '',
    tax: row.tax == null ? '' : String(row.tax),
    rebate: row.rebate == null ? '' : String(row.rebate),
    net: row.net == null ? '' : String(row.net),
    name: row.name ?? '',
    pu: row.pu == null ? '' : String(row.pu),
    unit: row.unit ?? '',
    netprice: row.netprice != null ? String(row.netprice) : row.net != null ? String(row.net) : '',
    taxrate: row.taxrate != null ? String(row.taxrate) : row.tax != null ? String(row.tax) : '',
  };
}

function parseNum(value) {
  if (value == null || value === '') return null;
  const n = Number(String(value).trim().replace(',', '.'));
  return Number.isFinite(n) ? n : null;
}

/** Build create/update line array. Throws Error on client validation. */
export function buildLines(lines, { requireAtLeastOne }) {
  const outLines = [];
  for (const line of lines) {
    const sku = String(line.sku ?? '').trim();
    const amount = parseNum(line.amount);
    const net = parseNum(line.net ?? line.netprice);
    const tax = parseNum(line.tax ?? line.taxrate);
    const rebate = parseNum(line.rebate);
    const blank =
      !sku && amount == null && net == null && tax == null && rebate == null;
    if (blank) continue;
    if (!sku || amount == null || net == null || tax == null) {
      throw new Error('Jede Zeile braucht SKU, Amount, Net und Tax.');
    }
    const row = { sku, amount, net, tax };
    if (rebate != null) row.rebate = rebate;
    if (line.name) row.name = line.name;
    if (line.pu != null) row.pu = line.pu;
    if (line.unit) row.unit = line.unit;
    outLines.push(row);
  }
  if (requireAtLeastOne && outLines.length === 0) {
    throw new Error('Mindestens eine Artikelzeile nötig.');
  }
  return outLines;
}

/**
 * @param {{ number: string, externalNumber?: string, date: string, partyId: number|null, lines: object[] }} form
 * @param {{ partyField: 'supplierId'|'entityId', requireAtLeastOne: boolean, externalNumber?: boolean }} opts
 */
export function buildManifestBody(
  form,
  { partyField, requireAtLeastOne, externalNumber: useExternalNumber },
) {
  const date = form.date;
  if (!date) throw new Error('Datum fehlt.');

  let body;
  if (useExternalNumber) {
    // Delivery: number is server-allocated/read-only. The caller-supplied
    // reference goes in externalNumber (nullable; empty string → null).
    const externalNumber = String(form.externalNumber ?? '').trim();
    body = {
      externalNumber: externalNumber || null,
      date,
      lines: buildLines(form.lines, { requireAtLeastOne }),
    };
  } else {
    const number = String(form.number ?? '').trim();
    if (!number) throw new Error('Nummer fehlt.');
    body = {
      number,
      date,
      lines: buildLines(form.lines, { requireAtLeastOne }),
    };
  }
  if (form.partyId != null) body[partyField] = form.partyId;
  else if (!requireAtLeastOne) body[partyField] = null;
  return body;
}

export const LINE_COLUMNS = [
  { id: 'amount', label: 'Amount', width: 88, align: 'right', type: 'number' },
  { id: 'sku', label: 'SKU', width: 140, align: 'left', type: 'text' },
  { id: 'tax', label: 'Tax', width: 80, align: 'right', type: 'number' },
  { id: 'rebate', label: 'Rebate', width: 88, align: 'right', type: 'number' },
  { id: 'net', label: 'Net', width: 104, align: 'right', type: 'number' },
];

export const DELIVERY_LINE_COLUMNS = [
  { id: 'sku', label: 'SKU', width: 130, align: 'left', type: 'text' },
  { id: 'name', label: 'Name', width: 220, align: 'left', type: 'text' },
  { id: 'amount', label: 'Amount', width: 88, align: 'right', type: 'number' },
  { id: 'pu', label: 'PU', width: 80, align: 'right', type: 'number' },
  { id: 'taxrate', label: 'Tax', width: 80, align: 'right', type: 'number' },
  { id: 'netprice', label: 'Net', width: 104, align: 'right', type: 'number' },
];

/** @typedef {'delivery'|'quote'|'order'} ManifestKind */

/**
 * Load party options for Autocomplete / list name lookup.
 * @param {ManifestKind} kind
 * @param {object} ctx StorageManager instance
 */
export async function loadParties(kind, ctx) {
  if (kind === 'delivery') {
    const list = ctx.suppliers ?? (await ctx.supplierPromise);
    return sortSuppliers(list);
  }
  const [entities, groups] = await Promise.all([
    ctx.entities ?? ctx.entityPromise,
    ctx.customergroups ?? ctx.customergroupPromise,
  ]);
  return filterCustomerEntities(entities, groups);
}

export function partyDisplayName(kind, party) {
  if (!party) return '';
  if (kind === 'delivery') return String(party.name ?? '');
  return entityDisplayName(party);
}

/**
 * @param {ManifestKind} kind
 */
export function manifestConfig(kind) {
  if (kind === 'delivery') {
    return {
      kind: 'delivery',
      api: 'delivery',
      listField: 'deliveries',
      docField: 'delivery',
      partyField: 'supplierId',
      listPath: '/lieferung',
      createPath: '/lieferung/neu',
      editPath: (id) => `/lieferung/${id}`,
      dateLabel: 'Lieferdatum',
      partyLabel: 'Lieferant',
      emptyList: 'Noch keine Lieferungen.',
      createButton: 'Neue Lieferung',
      createdMsg: 'Lieferung angelegt.',
      savedMsg: 'Lieferung gespeichert.',
      deletedMsg: 'Lieferung gelöscht.',
      confirmDelete: (number) => `Lieferung „${number}“ wirklich löschen?`,
      invalidId: 'Ungültige Lieferungs-ID.',
      partyGateMessage: 'Lieferant wählen, um Artikel zu erfassen.',
      getPathLabel: 'GET /api/delivery/:id',
      postPathLabel: 'POST /api/delivery',
      patchPathLabel: 'PATCH /api/delivery/:id',
      listColor: '#fed7aa',
      headerColor: '#fed7aa',
      linesColor: '#bbf7d0',
      requirePartyBeforeLines: true,
      updateCache: 'updateDelivery',
      listPromise: (ctx) => ctx.deliveries ?? ctx.deliveryPromise,
      partiesByIdFromList: (parties) =>
        Object.fromEntries(parties.map((row) => [row.id, row])),
      // Delivery uses a server-allocated read-only number plus an optional
      // caller-supplied external reference.
      externalNumber: true,
      columns: DELIVERY_LINE_COLUMNS,
    };
  }
  if (kind === 'quote') {
    return {
      kind: 'quote',
      api: 'quote',
      listField: 'quotes',
      docField: 'quote',
      partyField: 'entityId',
      listPath: '/auftrag',
      createPath: '/auftrag/neu',
      editPath: (id) => `/auftrag/${id}`,
      dateLabel: 'Gültig bis',
      partyLabel: 'Kunde',
      emptyList: 'Noch keine Angebote.',
      createButton: 'Neues Angebot',
      createdMsg: 'Angebot angelegt.',
      savedMsg: 'Angebot gespeichert.',
      deletedMsg: 'Angebot gelöscht.',
      confirmDelete: (number) => `Angebot „${number}“ wirklich löschen?`,
      invalidId: 'Ungültige Angebots-ID.',
      partyGateMessage: null,
      getPathLabel: 'GET /api/quote/:id',
      postPathLabel: 'POST /api/quote',
      patchPathLabel: 'PATCH /api/quote/:id',
      listColor: '#fde68a',
      headerColor: '#fde68a',
      linesColor: '#bbf7d0',
      requirePartyBeforeLines: false,
      updateCache: 'updateQuote',
      listPromise: (ctx) => ctx.quotes ?? ctx.quotePromise,
      partiesByIdFromList: (parties) =>
        Object.fromEntries(parties.map((row) => [row.id, row])),
      columns: LINE_COLUMNS,
    };
  }
  if (kind === 'order') {
    return {
      kind: 'order',
      api: 'order',
      listField: 'orders',
      docField: 'order',
      partyField: 'entityId',
      listPath: '/auftrag/bestellung',
      createPath: '/auftrag/bestellung/neu',
      editPath: (id) => `/auftrag/bestellung/${id}`,
      dateLabel: 'Lieferdatum',
      partyLabel: 'Kunde',
      emptyList: 'Noch keine Bestellungen.',
      createButton: 'Neue Bestellung',
      createdMsg: 'Bestellung angelegt.',
      savedMsg: 'Bestellung gespeichert.',
      deletedMsg: 'Bestellung gelöscht.',
      confirmDelete: (number) => `Bestellung „${number}“ wirklich löschen?`,
      invalidId: 'Ungültige Bestellungs-ID.',
      partyGateMessage: null,
      getPathLabel: 'GET /api/order/:id',
      postPathLabel: 'POST /api/order',
      patchPathLabel: 'PATCH /api/order/:id',
      listColor: '#c4b5fd',
      headerColor: '#c4b5fd',
      linesColor: '#bbf7d0',
      requirePartyBeforeLines: false,
      updateCache: 'updateOrder',
      listPromise: (ctx) => ctx.orders ?? ctx.orderPromise,
      partiesByIdFromList: (parties) =>
        Object.fromEntries(parties.map((row) => [row.id, row])),
      columns: LINE_COLUMNS,
    };
  }
  throw new Error(`Unknown manifest kind: ${kind}`);
}