import Fastify from 'fastify';
import dotenv from 'dotenv';
import fastifyFormBody from '@fastify/formbody';
import fastifyWs from '@fastify/websocket';
import { RealtimeAgent, RealtimeSession } from '@openai/agents/realtime';
import { TwilioRealtimeTransportLayer } from '@openai/agents-extensions';
import { RECOMMENDED_PROMPT_PREFIX } from '@openai/agents-core/extensions';

dotenv.config();
const { OPENAI_API_KEY } = process.env;

const fastify = Fastify();
fastify.register(fastifyFormBody);
fastify.register(fastifyWs);

const billingAgent = new RealtimeAgent({ name: 'Billing agent' });
const refundAgent = new RealtimeAgent({ 
  name: 'Refund agent',
  instructions: `${RECOMMENDED_PROMPT_PREFIX}\nYou are Sami a helpful assistant that helps users with refunds.`,
});

const agent = new RealtimeAgent({
  name: 'Triage Agent',
  instructions: 'You are a helpful and friendly triage assistant. Begin each conversation with a creative and engaging greeting. Based on the user\'s request, determine whether their issue is related to billing or refunds. If it is, use the appropriate tool to hand off the conversation to the Billing Agent or the Refund Agent so they can assist further.',
  handoffs: [billingAgent, refundAgent]
});

fastify.all('/twiml', async (request, reply) => {
  const twiml = `
    <Response>
      <Say>O.K. you can start talking!</Say>
      <Connect>
        <Stream url="wss://${request.headers.host}/media-stream" />
      </Connect>
    </Response>`.trim();
  reply.type('text/xml').send(twiml);
});

fastify.register(async (fastify) => {
  fastify.get('/media-stream', { websocket: true }, async (connection) => {
    const twilioTransportLayer = new TwilioRealtimeTransportLayer({
      twilioWebSocket: connection,
    });

    const session = new RealtimeSession(agent, {
      transport: twilioTransportLayer,
    });

    await session.connect({ apiKey: OPENAI_API_KEY });

    session.on('agent_handoff', (_, currentAgent, newAgent) => {
      console.log(`Handoff from ${currentAgent.name} to ${newAgent.name}`);
    });
  });
});

fastify.listen({ port: 5050 });