import { XMLParser } from "fast-xml-parser";

export const xmlParser = new XMLParser({
  ignoreAttributes: false,
  attributeNamePrefix: "@_",
  textNodeName: "#text",
  cdataPropName: "__cdata",
  trimValues: true,
  parseTagValue: false,
  parseAttributeValue: false,
  processEntities: true,
  htmlEntities: true,
  removeNSPrefix: false,
});

export function parseXml(text: string): Record<string, unknown> {
  // Strip BOM and leading junk some feeds emit before the prolog.
  const cleaned = text.replace(/^/, "").replace(/^[^<]+/, "");
  return xmlParser.parse(cleaned) as Record<string, unknown>;
}

export function asArray<T>(v: T | T[] | undefined | null): T[] {
  if (v === undefined || v === null) return [];
  return Array.isArray(v) ? v : [v];
}

/** Text of an XML node that may be string, cdata object or {#text}. */
export function textOf(v: unknown): string {
  if (v === undefined || v === null) return "";
  if (typeof v === "string") return v.trim();
  if (typeof v === "number" || typeof v === "boolean") return String(v);
  if (typeof v === "object") {
    const o = v as Record<string, unknown>;
    if (typeof o.__cdata === "string") return o.__cdata.trim();
    if (typeof o["#text"] === "string") return (o["#text"] as string).trim();
    if (o.__cdata && typeof o.__cdata === "object") return textOf(o.__cdata);
    if (typeof o["@_href"] === "string") return o["@_href"].trim();
  }
  return "";
}

export function stripHtml(s: string): string {
  return s
    .replace(/<script[\s\S]*?<\/script>/gi, " ")
    .replace(/<style[\s\S]*?<\/style>/gi, " ")
    .replace(/<[^>]+>/g, " ")
    .replace(/&nbsp;/g, " ")
    .replace(/&amp;/g, "&")
    .replace(/&lt;/g, "<")
    .replace(/&gt;/g, ">")
    .replace(/&quot;/g, '"')
    .replace(/&#39;|&apos;/g, "'")
    .replace(/\s+/g, " ")
    .trim();
}

export function parseDate(v: unknown): Date | null {
  const s = textOf(v);
  if (!s) return null;
  const d = new Date(s);
  if (!Number.isNaN(d.getTime())) return d;
  // RFC 822 variants with odd zones like "PST"/"EDT" are handled by Date; try trimming
  const d2 = new Date(s.replace(/\s+[A-Z]{3,4}$/, ""));
  return Number.isNaN(d2.getTime()) ? null : d2;
}