import express from 'express';
import cors from 'cors';

const app = express();
const PORT = process.env.PORT || 3201;

app.use(cors());
app.use(express.json());

const availableHooks = [
  {
    id: 'order-sign-service',
    hook: 'order-sign',
    title: 'Ocean Order Sign Hook',
    description: 'Provides clinical decision support hen signing orders',
    // This is where you specify what data you want from Ocean
    prefetch: {
      patient: 'Patient/
Command 'context.patientId' could not render: There is no placeholder called 'context.patientId'
',
      // Some other available pieces of data
      // questionnaireResponse: 'QuestionnaireResponse?encounter=
Command 'context.encounterId' could not render: There is no placeholder called 'context.encounterId'
'
      // provider: '
Command 'context.userId' could not render: There is no placeholder called 'context.userId'
'
    }
  }
];

// The Discovery Endpoint
app.get('/cds-services', (req, res) => {
  res.json({
    services: availableHooks
  });
});

// Service Endpoint
app.post('/cds-services/order-sign-service', async (req, res) => {
  try {
    const hookRequest = req.body;
    const response = await handleOrderSign(hookRequest);
    res.json(response);
  } catch (error) {
    console.error('Error in order-sign hook:', error);
    res.status(500).json({ error: 'Internal server error' });
  }
});


app.listen(PORT, () => {
  console.log(`CDS Hooks server running on port ${PORT}`);
  console.log(`Discovery endpoint: http://localhost:${PORT}/cds-services`);
  console.log(`Order-sign hook: http://localhost:${PORT}/cds-services/order-sign-service`);
});

export async function handleOrderSign(request) {
  const { prefetch } = request;

  // Extract the first QuestionnaireResponse from the prefetch bundle
  const patient = prefetch?.["patient"];

  const cards = [];

  // Critical error on 50% of submissions
  if (Math.random() > 0.5) {
    cards.push({
      summary: 'Tea break',
      detail: 'We are unable to process submissions right now. The computer is having tea. Please try again.',
      indicator: 'critical',
      source: {
        label: 'Ocean Example CDS Server'
      }
    });
  }

  // Warning for duplicate orders - based on patient demographic
  // Would be connected to an internal request system
  if (hasPotentialDuplicate(patient)) {
    cards.push({
      summary: 'Potential Duplicate Order',
      detail: 'A similar order may have been recently placed for this patient. Please review before signing.',
      indicator: 'warning',
      source: {
        label: 'Ocean Example CDS Server'
      }
    });
  }

  // Informational card applied to all requests

  // Just a static 2 week wait. Should be connected to an internal wait time system
  const twoWeeksLater = new Date();
  twoWeeksLater.setDate(twoWeeksLater.getDate() + 14);
  const twoWeeksLaterStr = twoWeeksLater.toISOString().split("T").at(0);
  cards.push({
    summary: `Request Received! Please do not reach out to us before ${twoWeeksLaterStr}`,
    detail: `There are currently ${Math.floor(Math.random() * 20)} requests ahead of you.`,
    indicator: 'info',
    source: {
      label: 'Ocean Example CDS Server'
    }
  });

  return { cards };
}

function hasPotentialDuplicate(patient) {
  // Simplified duplicate check - would normally check against recent orders in FHIR server
  // Here we are just checking if the patient's name contains 'Dup'
  return JSON.stringify(patient?.name).includes('Dup');
}