import type { QName } from "@/worker/xml/namespaces";
import { DAV_NS } from "@/worker/xml/namespaces";

export interface PropValue {
  qname: QName;
  valueXml: string;
}

export interface Propstat {
  status: number;
  props: PropValue[];
}

export interface MultistatusResponse {
  href: string;
  status?: number;
  propstats: Propstat[];
}

const REASON: Record<number, string> = {
  200: "OK",
  201: "Created",
  204: "No Content",
  207: "Multi-Status",
  400: "Bad Request",
  403: "Forbidden",
  404: "Not Found",
  409: "Conflict",
  412: "Precondition Failed",
  423: "Locked",
  424: "Failed Dependency",
  507: "Insufficient Storage",
};

export function escapeXml(value: string): string {
  return value
    .replaceAll("&", "&amp;")
    .replaceAll("<", "&lt;")
    .replaceAll(">", "&gt;")
    .replaceAll('"', "&quot;")
    .replaceAll("'", "&apos;");
}

export function statusLine(status: number): string {
  return `HTTP/1.1 ${status} ${REASON[status] ?? "Status"}`;
}

function prefixedName(qname: QName): string {
  return qname.nsUri === DAV_NS ? `D:${qname.localName}` : `x:${qname.localName}`;
}

function namespaceAttribute(qname: QName): string {
  return qname.nsUri === DAV_NS ? "" : ` xmlns:x="${escapeXml(qname.nsUri)}"`;
}

function propXml(prop: PropValue): string {
  if (prop.valueXml === "") {
    return `<${prefixedName(prop.qname)}${namespaceAttribute(prop.qname)}/>`;
  }
  if (prop.qname.nsUri === DAV_NS) return `<D:${prop.qname.localName}>${prop.valueXml}</D:${prop.qname.localName}>`;
  return prop.valueXml;
}

export function buildMultistatus(responses: MultistatusResponse[], options: { syncToken?: string } = {}): string {
  const body = responses
    .map((response) => {
      const status = response.status ? `<D:status>${statusLine(response.status)}</D:status>` : "";
      const propstats = response.propstats
        .filter((propstat) => propstat.props.length > 0)
        .map(
          (propstat) =>
            `<D:propstat><D:prop>${propstat.props.map(propXml).join("")}</D:prop><D:status>${statusLine(
              propstat.status,
            )}</D:status></D:propstat>`,
        )
        .join("");
      return `<D:response><D:href>${escapeXml(response.href)}</D:href>${status}${propstats}</D:response>`;
    })
    .join("");
  // RFC 6578 3.4: sync-token is emitted after all response elements inside multistatus.
  const syncToken = options.syncToken ? `<D:sync-token>${escapeXml(options.syncToken)}</D:sync-token>` : "";
  return `<?xml version="1.0" encoding="utf-8"?><D:multistatus xmlns:D="DAV:">${body}${syncToken}</D:multistatus>`;
}

export function emptyProp(qname: QName): PropValue {
  return { qname, valueXml: "" };
}