docfast/src/index.ts

import express from "express";
import { randomUUID } from "crypto";
import compression from "compression";
import logger from "./services/logger.js";
import helmet from "helmet";
import path from "path";
import { fileURLToPath } from "url";
import rateLimit from "express-rate-limit";
import { convertRouter } from "./routes/convert.js";
import { templatesRouter } from "./routes/templates.js";
import { healthRouter } from "./routes/health.js";
import { signupRouter } from "./routes/signup.js";
import { recoverRouter } from "./routes/recover.js";
import { billingRouter } from "./routes/billing.js";
import { emailChangeRouter } from "./routes/email-change.js";
import { authMiddleware } from "./middleware/auth.js";
import { usageMiddleware, loadUsageData } from "./middleware/usage.js";
import { getUsageStats } from "./middleware/usage.js";
import { pdfRateLimitMiddleware, getConcurrencyStats } from "./middleware/pdfRateLimit.js";
import { initBrowser, closeBrowser } from "./services/browser.js";
import { loadKeys, getAllKeys } from "./services/keys.js";
import { verifyToken, loadVerifications } from "./services/verification.js";
import { initDatabase, pool } from "./services/db.js";

const app = express();
const PORT = parseInt(process.env.PORT || "3100", 10);

app.use(helmet({ crossOriginResourcePolicy: { policy: "cross-origin" } }));

// Request ID + request logging middleware
app.use((req, res, next) => {
  const requestId = (req.headers["x-request-id"] as string) || randomUUID();
  (req as any).requestId = requestId;
  res.setHeader("X-Request-Id", requestId);
  const start = Date.now();
  res.on("finish", () => {
    const ms = Date.now() - start;
    if (req.path !== "/health") {
      logger.info({ method: req.method, path: req.path, status: res.statusCode, ms, requestId }, "request");
    }
  });
  next();
});

// Permissions-Policy header
app.use((_req, res, next) => {
  res.setHeader("Permissions-Policy", "camera=(), microphone=(), geolocation=(), payment=(self)");
  next();
});

// Compression
app.use(compression());

// Differentiated CORS middleware
app.use((req, res, next) => {
  const isAuthBillingRoute = req.path.startsWith('/v1/signup') || 
                             req.path.startsWith('/v1/recover') || 
                             req.path.startsWith('/v1/billing') ||
                             req.path.startsWith('/v1/email-change');
  
  if (isAuthBillingRoute) {
    res.setHeader("Access-Control-Allow-Origin", "https://docfast.dev");
  } else {
    res.setHeader("Access-Control-Allow-Origin", "*");
  }
  
  res.setHeader("Access-Control-Allow-Methods", "GET, POST, OPTIONS");
  res.setHeader("Access-Control-Allow-Headers", "Content-Type, Authorization, X-API-Key");
  res.setHeader("Access-Control-Max-Age", "86400");
  
  if (req.method === "OPTIONS") {
    res.status(204).end();
    return;
  }
  next();
});

// Raw body for Stripe webhook signature verification
app.use("/v1/billing/webhook", express.raw({ type: "application/json" }));
app.use(express.json({ limit: "2mb" }));
app.use(express.text({ limit: "2mb", type: "text/*" }));

// Trust nginx proxy
app.set("trust proxy", 1);

// Global rate limiting - reduced from 10,000 to reasonable limit
const limiter = rateLimit({
  windowMs: 60_000,
  max: 100,
  standardHeaders: true,
  legacyHeaders: false,
});
app.use(limiter);

// Public routes
app.use("/health", healthRouter);
app.use("/v1/signup", signupRouter);
app.use("/v1/recover", recoverRouter);
app.use("/v1/billing", billingRouter);
app.use("/v1/email-change", emailChangeRouter);

// Authenticated routes
app.use("/v1/convert", authMiddleware, usageMiddleware, pdfRateLimitMiddleware, convertRouter);
app.use("/v1/templates", authMiddleware, usageMiddleware, templatesRouter);

// Admin: usage stats
app.get("/v1/usage", authMiddleware, (req: any, res) => {
  res.json(getUsageStats(req.apiKeyInfo?.key));
});

// Admin: concurrency stats
app.get("/v1/concurrency", authMiddleware, (_req, res) => {
  res.json(getConcurrencyStats());
});

// Email verification endpoint
app.get("/verify", (req, res) => {
  const token = req.query.token as string;
  if (!token) {
    res.status(400).send(verifyPage("Invalid Link", "No verification token provided.", null));
    return;
  }

  const result = verifyToken(token);

  switch (result.status) {
    case "ok":
      res.send(verifyPage("Email Verified! 🚀", "Your DocFast API key is ready:", result.verification!.apiKey));
      break;
    case "already_verified":
      res.send(verifyPage("Already Verified", "This email was already verified. Here's your API key:", result.verification!.apiKey));
      break;
    case "expired":
      res.status(410).send(verifyPage("Link Expired", "This verification link has expired (24h). Please sign up again.", null));
      break;
    case "invalid":
      res.status(404).send(verifyPage("Invalid Link", "This verification link is not valid.", null));
      break;
  }
});

function verifyPage(title: string, message: string, apiKey: string | null): string {
  return `<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport" content="width=device-width,initial-scale=1">
<title>${title} — DocFast</title>
<link rel="icon" href="data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'><text y='.9em' font-size='90'>⚡</text></svg>">
<link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700;800&display=swap" rel="stylesheet">
<style>
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:'Inter',sans-serif;background:#0b0d11;color:#e4e7ed;min-height:100vh;display:flex;align-items:center;justify-content:center;padding:24px}
.card{background:#151922;border:1px solid #1e2433;border-radius:16px;padding:48px;max-width:520px;width:100%;text-align:center}
h1{font-size:1.8rem;margin-bottom:12px;font-weight:800}
p{color:#7a8194;margin-bottom:24px;line-height:1.6}
.key-box{background:#0b0d11;border:1px solid #34d399;border-radius:8px;padding:16px;font-family:monospace;font-size:0.82rem;word-break:break-all;margin:16px 0;cursor:pointer;transition:background 0.2s;position:relative}
.key-box:hover{background:#12151c}
.key-box::after{content:'Click to copy';position:absolute;top:-24px;right:0;font-size:0.7rem;color:#7a8194;font-family:'Inter',sans-serif}
.warning{background:rgba(251,191,36,0.06);border:1px solid rgba(251,191,36,0.15);border-radius:8px;padding:12px 16px;font-size:0.85rem;color:#fbbf24;margin-bottom:16px;text-align:left}
.links{margin-top:24px;color:#7a8194;font-size:0.9rem}
.links a{color:#34d399;text-decoration:none}
.links a:hover{color:#5eead4}
</style></head><body>
<div class="card">
<h1>${title}</h1>
<p>${message}</p>
${apiKey ? `
<div class="warning">⚠️ Save your API key securely. You can recover it via email if needed.</div>
<div class="key-box" onclick="navigator.clipboard.writeText('${apiKey}');this.style.borderColor='#5eead4';setTimeout(()=>this.style.borderColor='#34d399',1500)">${apiKey}</div>
<div class="links">100 free PDFs/month · <a href="/docs">Read the docs →</a></div>
` : `<div class="links"><a href="/">← Back to DocFast</a></div>`}
</div></body></html>`;
}

// Landing page
const __dirname = path.dirname(fileURLToPath(import.meta.url));

// Favicon route
app.get("/favicon.ico", (_req, res) => {
  res.setHeader('Content-Type', 'image/svg+xml');
  res.setHeader('Cache-Control', 'public, max-age=604800');
  res.sendFile(path.join(__dirname, "../public/favicon.svg"));
});

app.use(express.static(path.join(__dirname, "../public"), { 
  maxAge: "1d", 
  etag: true,
  setHeaders: (res) => {
    res.setHeader('Cache-Control', 'public, max-age=86400');
  }
}));

// Docs page (clean URL)
app.get("/docs", (_req, res) => {
  res.setHeader('Cache-Control', 'public, max-age=86400');
  res.sendFile(path.join(__dirname, "../public/docs.html"));
});

// Legal pages (clean URLs)
app.get("/impressum", (_req, res) => {
  res.setHeader('Cache-Control', 'public, max-age=86400');
  res.sendFile(path.join(__dirname, "../public/impressum.html"));
});

app.get("/privacy", (_req, res) => {
  res.setHeader('Cache-Control', 'public, max-age=86400');
  res.sendFile(path.join(__dirname, "../public/privacy.html"));
});

app.get("/terms", (_req, res) => {
  res.setHeader('Cache-Control', 'public, max-age=86400');
  res.sendFile(path.join(__dirname, "../public/terms.html"));
});

// API root
app.get("/api", (_req, res) => {
  res.json({
    name: "DocFast API",
    version: "0.2.1",
    endpoints: [
      "POST /v1/signup/free — Get a free API key",
      "POST /v1/convert/html",
      "POST /v1/convert/markdown",
      "POST /v1/convert/url",
      "POST /v1/templates/:id/render",
      "GET  /v1/templates",
      "POST /v1/billing/checkout — Start Pro subscription",
    ],
  });
});

// 404 handler - must be after all routes
app.use((req, res) => {
  // Check if it's an API request
  const isApiRequest = req.path.startsWith('/v1/') || req.path.startsWith('/api') || req.path.startsWith('/health');
  
  if (isApiRequest) {
    // JSON 404 for API paths
    res.status(404).json({
      error: "Not Found",
      message: `The requested endpoint ${req.method} ${req.path} does not exist`,
      statusCode: 404,
      timestamp: new Date().toISOString()
    });
  } else {
    // HTML 404 for browser paths
    res.status(404).send(`<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>404 - Page Not Found | DocFast</title>
  <link rel="icon" href="data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'><text y='.9em' font-size='90'>⚡</text></svg>">
  <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap" rel="stylesheet">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body { font-family: 'Inter', sans-serif; background: #0b0d11; color: #e4e7ed; min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 24px; }
    .container { background: #151922; border: 1px solid #1e2433; border-radius: 16px; padding: 48px; max-width: 520px; width: 100%; text-align: center; }
    h1 { font-size: 3rem; margin-bottom: 12px; font-weight: 700; color: #34d399; }
    h2 { font-size: 1.5rem; margin-bottom: 16px; font-weight: 600; }
    p { color: #7a8194; margin-bottom: 24px; line-height: 1.6; }
    a { color: #34d399; text-decoration: none; font-weight: 600; }
    a:hover { color: #5eead4; }
    .emoji { font-size: 4rem; margin-bottom: 24px; }
  </style>
</head>
<body>
  <div class="container">
    <div class="emoji">⚡</div>
    <h1>404</h1>
    <h2>Page Not Found</h2>
    <p>The page you're looking for doesn't exist or has been moved.</p>
    <p><a href="/">← Back to DocFast</a> | <a href="/docs">Read the docs</a></p>
  </div>
</body>
</html>`);
  }
});



async function start() {
  // Initialize PostgreSQL
  await initDatabase();
  
  // Load data from PostgreSQL
  await loadKeys();
  await loadVerifications();
  await loadUsageData();
  
  await initBrowser();
  logger.info(`Loaded ${getAllKeys().length} API keys`);
  const server = app.listen(PORT, () => logger.info(`DocFast API running on :${PORT}`));

  let shuttingDown = false;
  const shutdown = async (signal: string) => {
    if (shuttingDown) return;
    shuttingDown = true;
    logger.info(`Received ${signal}, starting graceful shutdown...`);

    // 1. Stop accepting new connections, wait for in-flight requests (max 10s)
    await new Promise<void>((resolve) => {
      const forceTimeout = setTimeout(() => {
        logger.warn("Forcing server close after 10s timeout");
        resolve();
      }, 10_000);
      server.close(() => {
        clearTimeout(forceTimeout);
        logger.info("HTTP server closed (all in-flight requests completed)");
        resolve();
      });
    });

    // 2. Close Puppeteer browser pool
    try {
      await closeBrowser();
      logger.info("Browser pool closed");
    } catch (err) {
      logger.error({ err }, "Error closing browser pool");
    }

    // 3. Close PostgreSQL connection pool
    try {
      await pool.end();
      logger.info("PostgreSQL pool closed");
    } catch (err) {
      logger.error({ err }, "Error closing PostgreSQL pool");
    }

    logger.info("Graceful shutdown complete");
    process.exit(0);
  };
  process.on("SIGTERM", () => shutdown("SIGTERM"));
  process.on("SIGINT", () => shutdown("SIGINT"));
}

start().catch((err) => {
  logger.error({ err }, "Failed to start");
  process.exit(1);
});

export { app };