/**
 * Helpers para construir queries OData que entiende el API de BIND.
 *
 * Sintaxis observable en la doc oficial:
 *   /api/Products?$filter=ID eq guid'bbe2cc0c-...'&$skip=0&$top=50&$orderby=Name asc
 *
 * Mantengo el builder muy chico — sólo lo que el MVP necesita.
 */

export type ODataFilter = string;

export interface ODataQuery {
  filter?: ODataFilter;
  top?: number;
  skip?: number;
  orderby?: string;
  select?: string[];
  count?: boolean;
}

export function buildQueryString(q: ODataQuery): string {
  const parts: string[] = [];
  if (q.filter) parts.push(`$filter=${encodeURIComponent(q.filter)}`);
  if (typeof q.top === "number") parts.push(`$top=${q.top}`);
  if (typeof q.skip === "number") parts.push(`$skip=${q.skip}`);
  if (q.orderby) parts.push(`$orderby=${encodeURIComponent(q.orderby)}`);
  if (q.select?.length) parts.push(`$select=${encodeURIComponent(q.select.join(","))}`);
  if (q.count) parts.push(`$count=true`);
  return parts.length ? `?${parts.join("&")}` : "";
}

/**
 * Pequeño helper para escribir filtros legibles. No es un parser OData;
 * solo escapa comillas simples y envuelve guids.
 *
 * Ejemplos:
 *   eq("ID", guid("bbe2..."))           -> "ID eq guid'bbe2...'"
 *   eq("Status", "issued")              -> "Status eq 'issued'"
 *   and(eq("Status","issued"), gt("Total", 1000))
 */
export const guid = (id: string): string => `guid'${id.replaceAll("'", "''")}'`;
export const str = (s: string): string => `'${s.replaceAll("'", "''")}'`;
export const eq = (field: string, value: string | number | boolean): string =>
  `${field} eq ${formatValue(value)}`;
export const ne = (field: string, value: string | number | boolean): string =>
  `${field} ne ${formatValue(value)}`;
export const gt = (field: string, value: string | number): string =>
  `${field} gt ${formatValue(value)}`;
export const lt = (field: string, value: string | number): string =>
  `${field} lt ${formatValue(value)}`;
export const ge = (field: string, value: string | number): string =>
  `${field} ge ${formatValue(value)}`;
export const le = (field: string, value: string | number): string =>
  `${field} le ${formatValue(value)}`;
export const and = (...parts: string[]): string => parts.join(" and ");
export const or = (...parts: string[]): string => `(${parts.join(" or ")})`;

function formatValue(v: string | number | boolean): string {
  if (typeof v === "number" || typeof v === "boolean") return String(v);
  // Si ya viene formateado como guid'...' o '...' (string OData), respétalo.
  if (/^(guid'.*'|'.*')$/.test(v)) return v;
  return str(v);
}