src/saveDemo.ts

import "dotenv/config";
import { mkdirSync, rmSync, writeFileSync } from "fs";
import {
  ARC_EXPLORER_URL,
  createArcPaymentClient,
  getClientPrivateKey,
} from "./arc.js";

const SERVER_URL = process.env.SERVER_URL || "http://localhost:3001";
const EVM_PRIVATE_KEY = getClientPrivateKey();
const targetUrl =
  process.argv[2] || process.env.DEMO_URL || "https://x.com/circle";
const outputDir = "docs/demoOutput";

if (!EVM_PRIVATE_KEY) {
  console.error("ERROR: EVM_PRIVATE_KEY or ARC_PRIVATE_KEY not set in .env");
  process.exit(1);
}

const { client, httpClient } = createArcPaymentClient(EVM_PRIVATE_KEY);

interface CaptureLogResponse {
  title?: string;
  description?: string;
  captureTimeMs?: number;
  content?: string;
  headings?: Array<{
    level?: string;
    text?: string;
  }>;
  links?: Array<{
    text?: string;
    href?: string;
  }>;
  refund?: unknown;
}

function now(): string {
  return new Date().toISOString();
}

function preview(text?: string | null, max = 3000): string {
  if (!text) return "(empty)";
  return text.length > max ? `${text.slice(0, max)}\n... [truncated]` : text;
}

async function recordPlainFetch(url: string): Promise<string> {
  const started = Date.now();
  const response = await fetch(url, {
    headers: {
      "user-agent": "eyezDemo/1.0",
    },
  });
  const body = await response.text();
  const elapsed = Date.now() - started;

  return [
    `# Plain fetch demo`,
    `Recorded: ${now()}`,
    `Target: ${url}`,
    `Command: fetch("${url}")`,
    ``,
    `Status: ${response.status} ${response.statusText}`,
    `Final URL: ${response.url}`,
    `Content-Type: ${response.headers.get("content-type") || "(none)"}`,
    `Elapsed: ${elapsed}ms`,
    `Body length: ${body.length} chars`,
    ``,
    `## Body preview`,
    preview(body),
    ``,
  ].join("\n");
}

async function recordPaidCapture(url: string): Promise<string> {
  const endpoint = `${SERVER_URL}/capture?url=${encodeURIComponent(url)}`;
  const log = [
    `# eyez paid capture demo`,
    `Recorded: ${now()}`,
    `Target: ${url}`,
    `Endpoint: ${endpoint}`,
    ``,
  ];

  const firstTry = await fetch(endpoint);
  log.push(`Initial response: ${firstTry.status} ${firstTry.statusText}`);

  if (firstTry.status !== 402) {
    const body = await firstTry.text();
    log.push(`Expected 402 Payment Required but got ${firstTry.status}.`);
    log.push(``, `## Response body`, preview(body), ``);
    return log.join("\n");
  }

  const paymentRequired = httpClient.getPaymentRequiredResponse((name) =>
    firstTry.headers.get(name),
  );
  const requirement = paymentRequired.accepts[0];
  if (!requirement) {
    throw new Error("Payment required response did not include any accepted payments");
  }

  log.push(`x402 version: ${paymentRequired.x402Version}`);
  log.push(`Scheme: ${requirement.scheme}`);
  log.push(`Network: ${requirement.network}`);
  log.push(`Asset: ${requirement.asset}`);
  log.push(`Amount: ${requirement.amount}`);
  log.push(`Pay to: ${requirement.payTo}`);
  log.push(``, `Creating payment payload...`);

  const paymentPayload = await client.createPaymentPayload(paymentRequired);
  const headers = httpClient.encodePaymentSignatureHeader(paymentPayload);
  const started = Date.now();
  const paidResponse = await fetch(endpoint, { headers });
  const elapsed = Date.now() - started;

  log.push(`Paid response: ${paidResponse.status} ${paidResponse.statusText}`);
  log.push(`Paid elapsed: ${elapsed}ms`);

  try {
    const settlement = httpClient.getPaymentSettleResponse((name) =>
      paidResponse.headers.get(name),
    );
    log.push(`Settlement success: ${settlement.success}`);
    log.push(`Settlement tx: ${settlement.transaction}`);
    log.push(`Settlement network: ${settlement.network}`);
    if (settlement.transaction) {
      log.push(`Explorer: ${ARC_EXPLORER_URL}/tx/${settlement.transaction}`);
    }
  } catch {
    log.push(`Settlement header: (missing)`);
  }

  const data = (await paidResponse.json()) as CaptureLogResponse;
  log.push(``, `## Capture result`);
  log.push(`Title: ${data.title || "(none)"}`);
  if (data.description) log.push(`Description: ${data.description}`);
  log.push(`Capture time: ${data.captureTimeMs}ms`);
  log.push(`Content length: ${data.content?.length || 0} chars`);

  if (data.headings?.length) {
    log.push(``, `## Headings`);
    for (const heading of data.headings.slice(0, 10)) {
      log.push(`${heading.level}: ${heading.text}`);
    }
  }

  if (data.links?.length) {
    log.push(``, `## Links`);
    for (const link of data.links.slice(0, 10)) {
      log.push(`${link.text?.slice(0, 80) || "(untitled)"} -> ${link.href}`);
    }
  }

  if (data.refund) {
    log.push(``, `## Refund`);
    log.push(JSON.stringify(data.refund, null, 2));
  }

  log.push(``, `## Content preview`, preview(data.content), ``);
  return log.join("\n");
}

rmSync(outputDir, { recursive: true, force: true });
mkdirSync(outputDir, { recursive: true });

console.log(`Recording plain fetch demo for ${targetUrl}...`);
writeFileSync(`${outputDir}/plainFetch.log`, await recordPlainFetch(targetUrl));

console.log(`Recording paid eyez capture demo for ${targetUrl}...`);
writeFileSync(`${outputDir}/eyezCapture.log`, await recordPaidCapture(targetUrl));

writeFileSync(
  `${outputDir}/README.md`,
  [
    `# Demo Output`,
    ``,
    `Generated by \`node dist/saveDemo.js ${targetUrl}\`.`,
    ``,
    `- \`plainFetch.log\`: direct Node fetch against the target URL.`,
    `- \`eyezCapture.log\`: x402 paid eyez capture against the same URL.`,
    ``,
  ].join("\n"),
);

console.log(`Done. Logs written to ${outputDir}/`);