/**
 * SIP URI and SDP body rewriting helpers.
 */

import type { IEndpoint } from './types.ts';

const SIP_URI_RE = /(sips?:)([^@>;,\s]+@)?([^>;,\s:]+)(:\d+)?/g;

/**
 * Replaces the host:port in every `sip:` / `sips:` URI found in `value`.
 */
export function rewriteSipUri(value: string, host: string, port: number): string {
  return value.replace(SIP_URI_RE, (_m, scheme: string, userpart?: string) =>
    `${scheme}${userpart || ''}${host}:${port}`);
}

/**
 * Rewrites the connection address (`c=`) and audio media port (`m=audio`)
 * in an SDP body.  Returns the rewritten body together with the original
 * endpoint that was replaced (if any).
 */
export function rewriteSdp(
  body: string,
  ip: string,
  port: number,
): { body: string; original: IEndpoint | null } {
  let origAddr: string | null = null;
  let origPort: number | null = null;

  const out = body
    .replace(/\r\n/g, '\n')
    .split('\n')
    .map((line) => {
      if (line.startsWith('c=IN IP4 ')) {
        origAddr = line.slice('c=IN IP4 '.length).trim();
        return `c=IN IP4 ${ip}`;
      }
      if (line.startsWith('m=audio ')) {
        const parts = line.split(' ');
        if (parts.length >= 2) {
          origPort = parseInt(parts[1], 10);
          parts[1] = String(port);
        }
        return parts.join(' ');
      }
      return line;
    })
    .join('\r\n');

  return {
    body: out,
    original: origAddr && origPort ? { address: origAddr, port: origPort } : null,
  };
}