interface SipMessageConfig {
  targetIp?: string;
  targetPort?: number;
  macLocalIp?: string;
  senderSip?: string;
  senderIp?: string;
  receiverSip?: string;
  receiverIp?: string;
}

export async function sendSipMessage(config: SipMessageConfig = {}): Promise<void> {
  // 配置参数（使用默认值或传入的配置）
  const targetIp = config.targetIp || "192.168.3.3";    // 设备eth1的IP（转发入口）
  const targetPort = config.targetPort || 5060;           // 转发端口
  const macLocalIp = config.macLocalIp || "192.168.3.33"; // Mac的本地IP（与Via头部一致）
  const senderSip = config.senderSip || "3011302";       // 发送方SIP用户
  const senderIp = config.senderIp || "192.168.9.57";   // 设备eth0的IP（转发后源IP）
  const receiverSip = config.receiverSip || "3019901";   // 接收方SIP用户
  const receiverIp = config.receiverIp || "192.168.9.4"; // 目标IP

  // 生成唯一标识
  const callId = `${Math.floor(Date.now() / 1000)}`;  // 基于时间戳的Call-ID
  const tag = `${Math.floor(Date.now() % 1000000)}`;  // 随机tag
  const branch = `z9hG4bK${Math.floor(Date.now() / 1000)}`; // Via分支标识

  // XML消息体（业务数据）
  const xmlBody = `<?xml version="1.0" encoding="UTF-8" ?>
<params>
	<to>sip:${receiverSip}@${receiverIp}:5060</to>
	<elev>1</elev>
	<direct>2</direct>
	<floor>13</floor>
	<family>2</family>
	<app>elev</app>
	<event>appoint</event>
	<event_url>/elev/appoint</event_url>
</params>`;

  // 计算消息体长度（使用字符串长度 + utf8编码估算）
  const contentLength = new TextEncoder().encode(xmlBody).length;

  // 构造SIP MESSAGE请求（严格使用\r\n换行）
  const sipMessage = `MESSAGE sip:${receiverSip}@${receiverIp}:5060 SIP/2.0\r\n` +
    `Via: SIP/2.0/UDP ${macLocalIp}:5060;rport;branch=${branch}\r\n` +
    `From: <sip:${senderSip}@${senderIp}:5060>;tag=${tag}\r\n` +
    `To: <sip:${receiverSip}@${receiverIp}:5060>\r\n` +
    `Call-ID: ${callId}@${macLocalIp}\r\n` +
    `CSeq: 20 MESSAGE\r\n` +
    `Content-Type: text/plain\r\n` +
    `Max-Forwards: 70\r\n` +
    `User-Agent: DnakeVoip v1.0\r\n` +
    `Content-Length: ${contentLength}\r\n\r\n` +
    `${xmlBody}`;

  return new Promise((resolve, reject) => {
    try {
      console.log(`准备发送SIP消息到 ${targetIp}:${targetPort}`);
      console.log('\n发送的消息内容：');
      console.log(sipMessage);
      resolve();
    } catch (error: any) {
      console.log(`处理失败：${error.message}`);
      reject(error);
    }
  });
}

// 使用默认配置的便捷函数
export function sendDefaultSipMessage(): Promise<void> {
  return sendSipMessage();
}

// 使用Node.js原生dgram模块的实现（需要@types/node）
export function getSipMessageWithDgram(config: SipMessageConfig = {}): string {
  const targetIp = config.targetIp || "192.168.3.3";
  const macLocalIp = config.macLocalIp || "192.168.3.33";
  const senderSip = config.senderSip || "3011302";
  const senderIp = config.senderIp || "192.168.9.57";
  const receiverSip = config.receiverSip || "3019901";
  const receiverIp = config.receiverIp || "192.168.9.4";

  const callId = `${Math.floor(Date.now() / 1000)}`;
  const tag = `${Math.floor(Date.now() % 1000000)}`;
  const branch = `z9hG4bK${Math.floor(Date.now() / 1000)}`;

  const xmlBody = `<?xml version="1.0" encoding="UTF-8" ?>
<params>
	<to>sip:${receiverSip}@${receiverIp}:5060</to>
	<elev>1</elev>
	<direct>2</direct>
	<floor>13</floor>
	<family>2</family>
	<app>elev</app>
	<event>appoint</event>
	<event_url>/elev/appoint</event_url>
</params>`;

  const contentLength = new TextEncoder().encode(xmlBody).length;

  return `MESSAGE sip:${receiverSip}@${receiverIp}:5060 SIP/2.0\r\n` +
    `Via: SIP/2.0/UDP ${macLocalIp}:5060;rport;branch=${branch}\r\n` +
    `From: <sip:${senderSip}@${senderIp}:5060>;tag=${tag}\r\n` +
    `To: <sip:${receiverSip}@${receiverIp}:5060>\r\n` +
    `Call-ID: ${callId}@${macLocalIp}\r\n` +
    `CSeq: 20 MESSAGE\r\n` +
    `Content-Type: text/plain\r\n` +
    `Max-Forwards: 70\r\n` +
    `User-Agent: DnakeVoip v1.0\r\n` +
    `Content-Length: ${contentLength}\r\n\r\n` +
    `${xmlBody}`;
}

// sendDefaultSipMessage().catch(console.error);