import Srf from "drachtio-srf";
import logger from "./utils/logger.js";
import config from "./config/default.json" with { type: "json" };

/**
 * NexusVoice SIP Border Controller - Drachtio Implementation
 *
 * This server provides equivalent functionality to the Kamailio configuration:
 * - SIP request validation and security filtering
 * - User registration and location management
 * - Call routing and media handling
 * - Integration with external systems (Asterisk, RTP proxy)
 */
class SipServer {
  /**
   * Ctor
   */
  constructor() {
    this.srf = new Srf();
    this.config = config;
  }

  /**
   * Initialize the SIP server
   */
  async initialize() {
    try {
      logger.info("Initializing NexusVoice SBC...");

      // Configure SIP listening parameters
      const sipConfig = this.config.sip;

      // Connect to drachtio server
      await this.srf.connect({
        host: sipConfig.host,
        port: sipConfig.port,
        transport: sipConfig.transport,
      });

      logger.info(
        "Connected to drachtio server on %s:%s",
        sipConfig.host,
        sipConfig.port,
      );

      logger.info("NexusVoice SBC initialized successfully");
    } catch (error) {
      logger.error("Failed to initialize SBC: %s", error.message);
      throw error;
    }
  }

  /**
   * Start the server
   */
  async start() {
    try {
      await this.initialize();
      logger.info("NexusVoice SBC started successfully");
    } catch (error) {
      logger.error("Failed to start SBC: %s", error.message);
      process.exit(1);
    }
  }

  /**
   * Graceful shutdown
   */
  async shutdown() {
    logger.info("Shutting down NexusVoice SBC...");

    try {
      await this.srf.disconnect();
      logger.info("NexusVoice SBC shutdown complete");
    } catch (error) {
      logger.error("Error during shutdown: %s", error.message);
    }
  }
}

// Create and start the server instance
const server = new SipServer();

// Handle graceful shutdown
process.on("SIGTERM", async () => {
  await server.shutdown();
  process.exit(0);
});

process.on("SIGINT", async () => {
  await server.shutdown();
  process.exit(0);
});

// Start the server
server.start().catch((error) => {
  logger.error("Failed to start server: %s", error.message);
  process.exit(1);
});

export default SipServer;