/**
 * This is an example script which signs and generates an 'ID token' for a user.
 * An 'ID Token' is a JWT that has been signed and encrypted (using 'Nested JWT') and contains patient details
 * It requires the following files to be present in the `./keys` directory:
 * - client-private.pem: The partner's private key for signing the JWT token
 * - emed-public.pem: eMed's public key for encrypting the JWT token
 */
const { JWK, JWE, JWS } = require("node-jose");
const fs = require("fs");
const path = require("path");

const getKey = async (owner, type) => {
  const filepath = `./keys/${owner}-${type}.pem`;
  const keyInput = fs.readFileSync(path.resolve(__dirname, filepath), "utf8");
  return JWK.asKey(keyInput, "pem");
};

const encrypt = async (publicKey, input) => {
  const buffer = Buffer.from(input);
  return JWE.createEncrypt({ format: "compact", contentAlg: "A256GCM", alg: "RSA-OAEP" }, publicKey)
    .update(buffer)
    .final();
};

const sign = async (privateKey, payload) => {
  const opt = { compact: true, fields: { typ: "jwt", alg: "RS256" } };
  const buffer = Buffer.from(payload);
  return JWS.createSign(opt, privateKey).update(buffer).final();
};

async function start() {
  const privateKey = await getKey("partner", "private");
  const emedPublicKey = await getKey("emed", "public");

  // Create a signed JWT token using partner private key
  const signedPayload = await sign(
    privateKey,
    JSON.stringify({
      email: "patient@org-name.co.uk",
      given_name: "Test",
      family_name: "User",
      birthdate: "1990-01-31",
      gender: "female",
      phone_number: "+447909090909",
      iat: Math.floor(Date.now() / 1000),
      exp: Math.floor(Date.now() / 1000) + 30, // ID Tokens with a >30 expiry will be rejected by eMed services
      iss: "org-name-issuer",
      sub: "some-patient-id",
      aud: "https://emed.com",
      nonce: "b02edbfd-fafd-4670-bc18-676b203f7de4",
      org: "org-name",
      address: {
        street_address: "123 Fake Street",
        locality: "Fake Town",
        region: "Fake City",
        postal_code: "SW1A1AA",
      },
    })
  );

  // Get the JWT string and create a JWE token using eMed's public key.
  // The signed JWT string is the payload of this JWE token.
  const encryptedIdToken = await encrypt(emedPublicKey, signedPayload);
  console.log(`encrypted id token:`);
  console.log(`${encryptedIdToken}`);
}

start();

<iframe id="emed-appointment-booking" src="https://embed-uk.preprod.babylontech.co.uk/partners/consultations/new#id_token=CHANGE_ME" frameborder="0" allowfullscreen="1" scrolling="auto" allow="camera *; microphone *"></iframe>