import {
  WebSocketGateway,
  WebSocketServer,
  SubscribeMessage,
  OnGatewayConnection,
  OnGatewayDisconnect,
  ConnectedSocket,
  MessageBody,
} from '@nestjs/websockets';
import { Server, Socket } from 'socket.io';
import { Logger, UseGuards } from '@nestjs/common';
import { JwtService } from '@nestjs/jwt';
import { VoiceService } from './voice.service';
import { TenantDatabaseService } from '../tenant/tenant-database.service';

interface AuthenticatedSocket extends Socket {
  tenantId?: string;
  userId?: string;
  tenantSlug?: string;
}

@WebSocketGateway({
  namespace: 'voice',
  cors: {
    origin: true,
    credentials: true,
  },
})
export class VoiceGateway
  implements OnGatewayConnection, OnGatewayDisconnect
{
  @WebSocketServer()
  server: Server;

  private readonly logger = new Logger(VoiceGateway.name);
  private connectedUsers: Map<string, AuthenticatedSocket> = new Map();
  private activeCallsByUser: Map<string, string> = new Map(); // userId -> callSid

  constructor(
    private readonly jwtService: JwtService,
    private readonly voiceService: VoiceService,
    private readonly tenantDbService: TenantDatabaseService,
  ) {
    // Set gateway reference in service to avoid circular dependency
    this.voiceService.setGateway(this);
  }

  async handleConnection(client: AuthenticatedSocket) {
    try {
      // Extract token from handshake auth
      const token =
        client.handshake.auth.token || client.handshake.headers.authorization?.split(' ')[1];

      if (!token) {
        this.logger.warn('❌ Client connection rejected: No token provided');
        client.disconnect();
        return;
      }

      // Verify JWT token
      const payload = await this.jwtService.verifyAsync(token);
      
      // Extract domain from origin header (e.g., http://tenant1.routebox.co:3001)
      // The domains table stores just the subdomain part (e.g., "tenant1")
      const origin = client.handshake.headers.origin || client.handshake.headers.referer;
      let domain = 'localhost';
      
      if (origin) {
        try {
          const url = new URL(origin);
          const hostname = url.hostname; // e.g., tenant1.routebox.co or localhost
          
          // Extract first part of subdomain as domain
          // tenant1.routebox.co -> tenant1
          // localhost -> localhost
          domain = hostname.split('.')[0];
        } catch (error) {
          this.logger.warn(`Failed to parse origin: ${origin}`);
        }
      }
      
      client.tenantId = domain; // Store the subdomain as tenantId
      client.userId = payload.sub;
      client.tenantSlug = domain; // Same as subdomain

      this.connectedUsers.set(client.userId, client);
      this.logger.log(
        `✓ Client connected: ${client.id} (User: ${client.userId}, Domain: ${domain})`,
      );
      this.logger.log(`Total connected users in ${domain}: ${this.getConnectedUsers(domain).length}`);

      // Send current call state if any active call
      const activeCallSid = this.activeCallsByUser.get(client.userId);
      if (activeCallSid) {
        const callState = await this.voiceService.getCallState(
          activeCallSid,
          client.tenantId,
        );
        client.emit('call:state', callState);
      }
    } catch (error) {
      this.logger.error('❌ Authentication failed', error);
      client.disconnect();
    }
  }

  handleDisconnect(client: AuthenticatedSocket) {
    if (client.userId) {
      this.connectedUsers.delete(client.userId);
      this.logger.log(`✓ Client disconnected: ${client.id} (User: ${client.userId})`);
      this.logger.log(`Remaining connected users: ${this.connectedUsers.size}`);
    }
  }

  /**
   * Initiate outbound call
   */
  @SubscribeMessage('call:initiate')
  async handleInitiateCall(
    @ConnectedSocket() client: AuthenticatedSocket,
    @MessageBody() data: { toNumber: string },
  ) {
    try {
      this.logger.log(`Initiating call from user ${client.userId} to ${data.toNumber}`);

      const result = await this.voiceService.initiateCall({
        tenantId: client.tenantId,
        userId: client.userId,
        toNumber: data.toNumber,
      });

      this.activeCallsByUser.set(client.userId, result.callSid);

      client.emit('call:initiated', {
        callSid: result.callSid,
        toNumber: data.toNumber,
        status: 'queued',
      });

      return { success: true, callSid: result.callSid };
    } catch (error) {
      this.logger.error('Failed to initiate call', error);
      client.emit('call:error', {
        message: error.message || 'Failed to initiate call',
      });
      return { success: false, error: error.message };
    }
  }

  /**
   * Accept incoming call
   */
  @SubscribeMessage('call:accept')
  async handleAcceptCall(
    @ConnectedSocket() client: AuthenticatedSocket,
    @MessageBody() data: { callSid: string },
  ) {
    try {
      this.logger.log(`User ${client.userId} accepting call ${data.callSid}`);

      await this.voiceService.acceptCall({
        callSid: data.callSid,
        tenantId: client.tenantId,
        userId: client.userId,
      });

      this.activeCallsByUser.set(client.userId, data.callSid);

      client.emit('call:accepted', { callSid: data.callSid });

      return { success: true };
    } catch (error) {
      this.logger.error('Failed to accept call', error);
      return { success: false, error: error.message };
    }
  }

  /**
   * Reject incoming call
   */
  @SubscribeMessage('call:reject')
  async handleRejectCall(
    @ConnectedSocket() client: AuthenticatedSocket,
    @MessageBody() data: { callSid: string },
  ) {
    try {
      this.logger.log(`User ${client.userId} rejecting call ${data.callSid}`);

      await this.voiceService.rejectCall(data.callSid, client.tenantId);

      client.emit('call:rejected', { callSid: data.callSid });

      return { success: true };
    } catch (error) {
      this.logger.error('Failed to reject call', error);
      return { success: false, error: error.message };
    }
  }

  /**
   * End active call
   */
  @SubscribeMessage('call:end')
  async handleEndCall(
    @ConnectedSocket() client: AuthenticatedSocket,
    @MessageBody() data: { callSid: string },
  ) {
    try {
      this.logger.log(`User ${client.userId} ending call ${data.callSid}`);

      await this.voiceService.endCall(data.callSid, client.tenantId);

      this.activeCallsByUser.delete(client.userId);

      client.emit('call:ended', { callSid: data.callSid });

      return { success: true };
    } catch (error) {
      this.logger.error('Failed to end call', error);
      return { success: false, error: error.message };
    }
  }

  /**
   * Send DTMF tones
   */
  @SubscribeMessage('call:dtmf')
  async handleDtmf(
    @ConnectedSocket() client: AuthenticatedSocket,
    @MessageBody() data: { callSid: string; digit: string },
  ) {
    try {
      await this.voiceService.sendDtmf(
        data.callSid,
        data.digit,
        client.tenantId,
      );

      return { success: true };
    } catch (error) {
      this.logger.error('Failed to send DTMF', error);
      return { success: false, error: error.message };
    }
  }

  /**
   * Emit incoming call notification to specific user
   */
  async notifyIncomingCall(userId: string, callData: any) {
    const socket = this.connectedUsers.get(userId);
    if (socket) {
      socket.emit('call:incoming', callData);
      this.logger.log(`Notified user ${userId} of incoming call`);
    } else {
      this.logger.warn(`User ${userId} not connected to receive call notification`);
    }
  }

  /**
   * Emit call status update to user
   */
  async notifyCallUpdate(userId: string, callData: any) {
    const socket = this.connectedUsers.get(userId);
    if (socket) {
      socket.emit('call:update', callData);
    }
  }

  /**
   * Emit AI transcript to user
   */
  async notifyAiTranscript(userId: string, data: { callSid: string; transcript: string; isFinal: boolean }) {
    const socket = this.connectedUsers.get(userId);
    if (socket) {
      socket.emit('ai:transcript', data);
    }
  }

  /**
   * Emit AI suggestion to user
   */
  async notifyAiSuggestion(userId: string, data: any) {
    const socket = this.connectedUsers.get(userId);
    if (socket) {
      socket.emit('ai:suggestion', data);
    }
  }

  /**
   * Emit AI action result to user
   */
  async notifyAiAction(userId: string, data: any) {
    const socket = this.connectedUsers.get(userId);
    if (socket) {
      socket.emit('ai:action', data);
    }
  }

  /**
   * Get connected users for a tenant
   */
  getConnectedUsers(tenantDomain?: string): string[] {
    const userIds: string[] = [];
    
    for (const [userId, socket] of this.connectedUsers.entries()) {
      // If tenantDomain specified, filter by tenant
      if (!tenantDomain || socket.tenantSlug === tenantDomain) {
        userIds.push(userId);
      }
    }
    
    return userIds;
  }
}