Initial MVP: DocFast PDF API

- HTML/Markdown to PDF conversion via Puppeteer
- Invoice and receipt templates
- API key auth + rate limiting
- Dockerfile for deployment

src/services/browser.ts

@@ -0,0 +1,54 @@
+import puppeteer, { Browser, Page } from "puppeteer";
+
+let browser: Browser | null = null;
+
+export async function initBrowser(): Promise<void> {
+  browser = await puppeteer.launch({
+    headless: true,
+    args: ["--no-sandbox", "--disable-setuid-sandbox", "--disable-gpu"],
+  });
+  console.log("Browser pool ready");
+}
+
+export async function closeBrowser(): Promise<void> {
+  if (browser) await browser.close();
+}
+
+export async function renderPdf(
+  html: string,
+  options: {
+    format?: string;
+    landscape?: boolean;
+    margin?: { top?: string; right?: string; bottom?: string; left?: string };
+    printBackground?: boolean;
+    headerTemplate?: string;
+    footerTemplate?: string;
+    displayHeaderFooter?: boolean;
+  } = {}
+): Promise<Buffer> {
+  if (!browser) throw new Error("Browser not initialized");
+
+  const page: Page = await browser.newPage();
+  try {
+    await page.setContent(html, { waitUntil: "networkidle0", timeout: 15_000 });
+
+    const pdf = await page.pdf({
+      format: (options.format as any) || "A4",
+      landscape: options.landscape || false,
+      printBackground: options.printBackground !== false,
+      margin: options.margin || {
+        top: "20mm",
+        right: "15mm",
+        bottom: "20mm",
+        left: "15mm",
+      },
+      headerTemplate: options.headerTemplate,
+      footerTemplate: options.footerTemplate,
+      displayHeaderFooter: options.displayHeaderFooter || false,
+    });
+
+    return Buffer.from(pdf);
+  } finally {
+    await page.close();
+  }
+}