/**
 * WebRTC Globals Initialization
 *
 * Single initialization point for WebRTC globals.
 * Handles both browser and Node.js environments.
 */

// Track initialization state
let isInitialized = false;
let initializationPromise: Promise<void> | null = null;

/**
 * Ensures WebRTC globals are available in the current environment.
 * In browsers, these are already available globally.
 * In Node.js, we polyfill them from @roamhq/wrtc.
 *
 * This function is idempotent - safe to call multiple times.
 */
export async function ensureWebRTCGlobals(): Promise<boolean> {
  // Already initialized
  if (isInitialized) {
    return true;
  }

  // Already tried and failed
  if (initializationPromise !== null) {
    return false;
  }

  // Initialization in progress - wait for it
  if (initializationPromise) {
    await initializationPromise;
    return isInitialized;
  }

  initializationPromise = doInitialize();
  await initializationPromise;
  return isInitialized;
}

async function doInitialize(): Promise<void> {
  // Browser environment - WebRTC is already available
  if (typeof window !== 'undefined') {
    if (typeof RTCPeerConnection === 'undefined') {
      throw new Error('WebRTC is not supported in this browser');
    }
    isInitialized = true;
    return;
  }

  // Node.js environment - need to polyfill
  try {
    const wrtc = require('@roamhq/wrtc');

    if (typeof global.MediaStream === 'undefined' && wrtc.MediaStream) {
      global.MediaStream = wrtc.MediaStream;
    }

    if (typeof (global as any).RTCDataChannel === 'undefined' && wrtc.RTCDataChannel) {
      (global as any).RTCDataChannel = wrtc.RTCDataChannel;
    }

    if (typeof global.RTCPeerConnection === 'undefined' && wrtc.RTCPeerConnection) {
      global.RTCPeerConnection = wrtc.RTCPeerConnection;
    }

    if (typeof global.RTCSessionDescription === 'undefined' && wrtc.RTCSessionDescription) {
      global.RTCSessionDescription = wrtc.RTCSessionDescription;
    }

    if (typeof global.RTCIceCandidate === 'undefined' && wrtc.RTCIceCandidate) {
      global.RTCIceCandidate = wrtc.RTCIceCandidate;
    }

    if (typeof (global as any).RTCVideoSource === 'undefined' && wrtc.nonstandard?.RTCVideoSource) {
      (global as any).RTCVideoSource = wrtc.nonstandard.RTCVideoSource;
    }

    if (typeof (global as any).RTCAudioSource === 'undefined' && wrtc.nonstandard?.RTCAudioSource) {
      (global as any).RTCAudioSource = wrtc.nonstandard.RTCAudioSource;
    }

    if (typeof (global as any).RTCAudioSink === 'undefined' && wrtc.nonstandard?.RTCAudioSink) {
      (global as any).RTCAudioSink = wrtc.nonstandard.RTCAudioSink;
    }

    isInitialized = true;
  } catch (error) {
    // In Bun compiled binaries, native addons like @roamhq/wrtc are not available.
    // Log warning and continue — WebRTC features will be unavailable but won't crash the process.
    console.warn(`WebRTC native module (@roamhq/wrtc) not available: ${error}. ` + `WebRTC features will be disabled.`);
    isInitialized = false;
  }
}

/**
 * Check if WebRTC globals have been initialized.
 */
export function isWebRTCInitialized(): boolean {
  return isInitialized;
}

/**
 * Check if WebRTC is available in the current environment.
 * Does not initialize - just checks availability.
 */
export function isWebRTCAvailable(): boolean {
  if (typeof window !== 'undefined') {
    return typeof RTCPeerConnection !== 'undefined';
  }

  // In Node.js, check if already initialized or if wrtc is available
  if (isInitialized) {
    return true;
  }

  try {
    require.resolve('@roamhq/wrtc');
    return true;
  } catch {
    return false;
  }
}