// agent-402-client.js
//
// Drop-in example: agent-side AERE402 client. Calls a paid endpoint,
// receives 402, signs the quote via the agent's signing key, retries.
//
// Run:
//   yarn add ethers
//   AGENT_PRIVATE_KEY=0x... AGENT_ID=1234 ENDPOINT=http://localhost:3000/v1/inference node agent-402-client.js
//
// Prereq: the agent's signing key (AGENT_PRIVATE_KEY) must already be
// registered on AereAgent with sufficient prepaid balance + un-exceeded
// rate limits.

const { ethers } = require('ethers');

const AGENT_PK = process.env.AGENT_PRIVATE_KEY;
const AGENT_ID = process.env.AGENT_ID;
const ENDPOINT = process.env.ENDPOINT ?? 'http://localhost:3000/v1/inference';

if (!AGENT_PK || !AGENT_ID) {
  console.error('AGENT_PRIVATE_KEY + AGENT_ID env required');
  process.exit(1);
}

const signer = new ethers.Wallet(AGENT_PK);

(async () => {
  console.log(`agent ${AGENT_ID} calling ${ENDPOINT}...`);

  // 1. Unpaid request.
  const r1 = await fetch(ENDPOINT);
  if (r1.status !== 402) {
    console.log(`unexpected status ${r1.status} on first call`);
    console.log(await r1.text());
    return;
  }
  const quoteJson = r1.headers.get('x-aere402-quote');
  if (!quoteJson) throw new Error('server did not return X-AERE402-Quote');
  const quote = JSON.parse(quoteJson);
  console.log('  received quote:', quote);

  // 2. Build EIP-712 domain + types.
  const domain = {
    name: 'AERE402Facilitator',
    version: '1',
    chainId: quote.chainId,
    verifyingContract: quote.facilitator,
  };
  const types = {
    PaymentAuth: [
      { name: 'agentId',    type: 'uint256' },
      { name: 'token',      type: 'address' },
      { name: 'payee',      type: 'address' },
      { name: 'amount',     type: 'uint256' },
      { name: 'resourceId', type: 'bytes32' },
      { name: 'nonce',      type: 'uint256' },
      { name: 'deadline',   type: 'uint256' },
    ],
  };
  const value = {
    agentId: BigInt(AGENT_ID),
    token: quote.token,
    payee: quote.payee,
    amount: BigInt(quote.amount),
    resourceId: quote.resourceId,
    nonce: BigInt(quote.nonce),
    deadline: BigInt(quote.deadline),
  };

  // 3. Sign.
  const signature = await signer.signTypedData(domain, types, value);
  console.log(`  signed: ${signature.slice(0, 18)}...`);

  // 4. Retry with the signature.
  const r2 = await fetch(ENDPOINT, {
    headers: {
      'X-AERE402-Sig': signature,
      'X-AERE402-AgentId': AGENT_ID,
      'X-AERE402-Quote': quoteJson,
    },
  });
  console.log(`  retry status: ${r2.status}`);
  console.log(`  tx hash:      ${r2.headers.get('x-aere402-txhash')}`);
  console.log('  body:', await r2.json());
})();