index.ts

/**
 * kong-pdf-api
 * Generic HTML/URL → PDF microservice via Playwright + Bun
 *
 * POST /generate
 * {
 *   url: string                // Required. https://... or file://...
 *   filename?: string          // Output filename (default: page-title.pdf)
 *   format?: "A4" | "Letter"   // Default: A4
 *   landscape?: boolean        // Default: false
 *   printBackground?: boolean  // Default: true
 *   waitUntil?: "load" | "networkidle" | "domcontentloaded"  // Default: networkidle
 *   extraWaitMs?: number       // Extra ms to wait after load (default: 500)
 *   margin?: { top, right, bottom, left }  // Default: see below
 *   pageNumberFooter?: boolean // Default: true — adds "X / N" footer
 *   footerHtml?: string        // Custom footer HTML (overrides pageNumberFooter)
 *   injectCss?: string         // Extra CSS to inject before capture
 * }
 *
 * GET /health → { ok: true, version: "1.0.0" }
 */

import { chromium } from "playwright";
import { tmpdir } from "os";
import { join } from "path";
import { existsSync, unlinkSync } from "fs";

const PORT = parseInt(process.env.PORT ?? "3200");
const API_TOKEN = process.env.KONG_PDF_TOKEN ?? "";
const ALLOWED_ORIGINS = (process.env.ALLOWED_ORIGINS ?? "*").split(",");
const VERSION = "1.0.0";

// ─── Auth middleware ──────────────────────────────────────────────────────────

function isAuthorized(req: Request): boolean {
  if (!API_TOKEN) return true; // no token configured = open
  const auth = req.headers.get("Authorization") ?? "";
  return auth === `Bearer ${API_TOKEN}`;
}

// ─── CORS headers ─────────────────────────────────────────────────────────────

function corsHeaders(origin: string): Record<string, string> {
  const allowed =
    ALLOWED_ORIGINS.includes("*") || ALLOWED_ORIGINS.includes(origin)
      ? origin
      : "";
  return {
    "Access-Control-Allow-Origin": allowed || ALLOWED_ORIGINS[0],
    "Access-Control-Allow-Methods": "POST, GET, OPTIONS",
    "Access-Control-Allow-Headers": "Content-Type, Authorization",
  };
}

// ─── PDF generation ───────────────────────────────────────────────────────────

async function generatePdf(options: {
  url: string;
  format?: string;
  landscape?: boolean;
  printBackground?: boolean;
  waitUntil?: "load" | "networkidle" | "domcontentloaded";
  extraWaitMs?: number;
  margin?: { top?: string; right?: string; bottom?: string; left?: string };
  pageNumberFooter?: boolean;
  footerHtml?: string;
  injectCss?: string;
}): Promise<Buffer> {
  const {
    url,
    format = "A4",
    landscape = false,
    printBackground = true,
    waitUntil = "networkidle",
    extraWaitMs = 500,
    margin,
    pageNumberFooter = true,
    footerHtml,
    injectCss,
  } = options;

  const hasFooter = !!(pageNumberFooter || footerHtml);
  const defaultMargin = {
    top: "0mm",
    right: "0mm",
    bottom: hasFooter ? "14mm" : "0mm",
    left: "0mm",
  };
  const finalMargin = { ...defaultMargin, ...(margin ?? {}) };

  const defaultFooter = pageNumberFooter
    ? `<div style="width:100%;padding:0 8mm;display:flex;justify-content:space-between;
        align-items:center;font-family:Helvetica,Arial,sans-serif;font-size:8pt;color:#9CA3AF;">
        <span></span>
        <span><span class="pageNumber"></span> / <span class="totalPages"></span></span>
       </div>`
    : "<span></span>";

  const browser = await chromium.launch({
    headless: true,
    args: ["--no-sandbox", "--disable-setuid-sandbox", "--disable-dev-shm-usage"],
  });

  try {
    const page = await browser.newPage();
    await page.setViewportSize({ width: 1240, height: 1754 });

    await page.goto(url, { waitUntil, timeout: 30000 });
    await page.evaluate(() => document.fonts.ready);

    // Fix: orphaned headings detection
    await page.evaluate(() => {
      const MM_TO_PX = 3.7795;
      const pageHeightPx = 297 * MM_TO_PX;
      const dangerZone = 0.85;
      const headings = Array.from(
        document.querySelectorAll("h2, h3")
      ) as HTMLElement[];
      for (const h of headings) {
        const top = h.getBoundingClientRect().top + window.scrollY;
        if ((top % pageHeightPx) / pageHeightPx >= dangerZone) {
          h.style.breakBefore = "page";
          h.style.pageBreakBefore = "always";
        }
      }
    });

    // Inject @page margins + extra CSS
    const pageCss = `
      @page { margin-top: 10mm; margin-right: 0; margin-left: 0; }
      @page :first { margin-top: 0; }
      ${injectCss ?? ""}
    `;
    await page.addStyleTag({ content: pageCss });

    if (extraWaitMs > 0) await page.waitForTimeout(extraWaitMs);

    // Generate to temp file
    const tmpPath = join(tmpdir(), `kong-pdf-${Date.now()}.pdf`);
    await page.pdf({
      path: tmpPath,
      format: format as "A4" | "Letter",
      landscape,
      printBackground,
      preferCSSPageSize: false,
      margin: finalMargin,
      displayHeaderFooter: hasFooter,
      headerTemplate: "<span></span>",
      footerTemplate: footerHtml ?? defaultFooter,
    });

    const file = Bun.file(tmpPath);
    const buffer = Buffer.from(await file.arrayBuffer());
    if (existsSync(tmpPath)) unlinkSync(tmpPath);
    return buffer;
  } finally {
    await browser.close();
  }
}

// ─── Server ───────────────────────────────────────────────────────────────────

const server = Bun.serve({
  port: PORT,

  async fetch(req) {
    const url = new URL(req.url);
    const origin = req.headers.get("origin") ?? "*";
    const cors = corsHeaders(origin);

    // CORS preflight
    if (req.method === "OPTIONS") {
      return new Response(null, { status: 204, headers: cors });
    }

    // Health check
    if (req.method === "GET" && url.pathname === "/health") {
      return Response.json({ ok: true, version: VERSION }, { headers: cors });
    }

    // PDF generation
    if (req.method === "POST" && url.pathname === "/generate") {
      if (!isAuthorized(req)) {
        return Response.json({ error: "Unauthorized" }, { status: 401, headers: cors });
      }

      let body: Record<string, any>;
      try {
        body = await req.json();
      } catch {
        return Response.json({ error: "Invalid JSON body" }, { status: 400, headers: cors });
      }

      if (!body.url) {
        return Response.json({ error: "Missing required field: url" }, { status: 400, headers: cors });
      }

      const start = Date.now();
      console.log(`[kong-pdf] ${new Date().toISOString()} → ${body.url}`);

      try {
        const pdf = await generatePdf(body);
        const elapsed = ((Date.now() - start) / 1000).toFixed(1);

        // Filename: from body or slug from URL
        const rawName = body.filename ?? new URL(body.url).hostname;
        const filename = rawName.replace(/[^a-z0-9._-]/gi, "-").replace(/-+/g, "-") + ".pdf";

        console.log(`[kong-pdf] ✓ ${filename} — ${(pdf.length / 1024).toFixed(1)} KB — ${elapsed}s`);

        return new Response(pdf, {
          status: 200,
          headers: {
            ...cors,
            "Content-Type": "application/pdf",
            "Content-Disposition": `attachment; filename="${filename}"`,
            "Content-Length": String(pdf.length),
            "X-Generation-Time": `${elapsed}s`,
          },
        });
      } catch (err: any) {
        console.error(`[kong-pdf] ✗ ${err.message}`);
        return Response.json({ error: err.message }, { status: 500, headers: cors });
      }
    }

    return Response.json({ error: "Not found" }, { status: 404, headers: cors });
  },
});

console.log(`\n  👑 kong-pdf-api v${VERSION}`);
console.log(`  ├─ Port:   ${PORT}`);
console.log(`  ├─ Auth:   ${API_TOKEN ? "Bearer token actiu" : "⚠️  sense token (obert)"}`);
console.log(`  ├─ CORS:   ${ALLOWED_ORIGINS.join(", ")}`);
console.log(`  └─ Health: http://localhost:${PORT}/health\n`);