import type { ISignalingMessage } from '../interfaces/IWebRTCClient.ts';

export class SubscriberRTCManager {
  private peerConnection: RTCPeerConnection | null = null;
  private remoteVideo: HTMLVideoElement | null = null;
  private onStreamReceived?: (stream: MediaStream) => void;
  private onConnectionStateChange?: (state: string) => void;

  private rtcConfiguration: RTCConfiguration = {
    iceServers: [
      { urls: 'stun:stun.l.google.com:19302' },
      { urls: 'stun:stun1.l.google.com:19302' }
    ]
  };

  constructor(
    videoElementId: string,
    onStreamReceived?: (stream: MediaStream) => void,
    onConnectionStateChange?: (state: string) => void
  ) {
    this.remoteVideo = document.getElementById(videoElementId) as HTMLVideoElement;
    this.onStreamReceived = onStreamReceived;
    this.onConnectionStateChange = onConnectionStateChange;
  }

  async handleOffer(offer: RTCSessionDescriptionInit): Promise<RTCSessionDescriptionInit> {
    this.createPeerConnection();
    
    if (!this.peerConnection) {
      throw new Error('Failed to create peer connection');
    }

    await this.peerConnection.setRemoteDescription(offer);
    const answer = await this.peerConnection.createAnswer();
    await this.peerConnection.setLocalDescription(answer);
    
    return answer;
  }

  async handleIceCandidate(candidate: RTCIceCandidateInit): Promise<void> {
    if (this.peerConnection && candidate) {
      await this.peerConnection.addIceCandidate(candidate);
    }
  }

  disconnect(): void {
    if (this.peerConnection) {
      this.peerConnection.close();
      this.peerConnection = null;
    }

    if (this.remoteVideo) {
      this.remoteVideo.srcObject = null;
    }
  }

  private createPeerConnection(): void {
    this.peerConnection = new RTCPeerConnection(this.rtcConfiguration);

    this.peerConnection.onicecandidate = (event) => {
      if (event.candidate) {
        this.onIceCandidate?.(event.candidate);
      }
    };

    this.peerConnection.ontrack = (event) => {
      console.log('Received remote stream');
      const [remoteStream] = event.streams;
      
      if (this.remoteVideo) {
        this.remoteVideo.srcObject = remoteStream;
      }

      if (this.onStreamReceived) {
        this.onStreamReceived(remoteStream);
      }
    };

    this.peerConnection.onconnectionstatechange = () => {
      const state = this.peerConnection?.connectionState || 'unknown';
      console.log('Connection state changed:', state);
      
      if (this.onConnectionStateChange) {
        this.onConnectionStateChange(state);
      }
    };

    this.peerConnection.onicegatheringstatechange = () => {
      console.log('ICE gathering state:', this.peerConnection?.iceGatheringState);
    };
  }

  private onIceCandidate?: (candidate: RTCIceCandidate) => void;

  setOnIceCandidate(handler: (candidate: RTCIceCandidate) => void): void {
    this.onIceCandidate = handler;
  }
}