Adds gzip compression and ETag support for better caching

Implements response compression and ETag headers to optimize asset delivery and enable client-side caching, reducing bandwidth usage and improving load times. Enhances code block styling and syntax highlighting for documentation clarity.

Adds gzip compression, ETag caching, and code block styling

Improves server performance by implementing gzip response compression
and ETag-based caching for static and dynamic content, reducing
bandwidth and enabling efficient client-side caching. Enhances
documentation clarity with improved code block styling and
syntax highlighting support.

src/server/server.ts

@@ -1,11 +1,14 @@
 import { createServer, IncomingMessage, ServerResponse } from "node:http";
 import { promises as fs } from "node:fs";
 import { readFileSync } from "node:fs";
+import { createHash } from "node:crypto";
+import { gzipSync } from "node:zlib";
 import path from "node:path";
 import ejs from "ejs";
 
 const publicDir = path.join(__dirname, "public");
 const viewsDir = path.join(__dirname, "views");
+// Compresión síncrona (rápida para tamaños pequeños de HTML/CSS/JS)
 
 // Cargar metadatos del proyecto para usarlos como variables en las vistas
 let pkg: {
@@ -112,6 +115,29 @@ function applySecurityHeaders(base: Record<string, string> = {}) {
   };
 }
 
+function computeEtag(buf: Buffer): string {
+  // Weak ETag derived from content sha1 and length
+  const hash = createHash("sha1").update(buf).digest("base64");
+  return `W/"${buf.length.toString(16)}-${hash}"`;
+}
+
+function acceptsEncoding(req: IncomingMessage, enc: string): boolean {
+  const ae = (req.headers["accept-encoding"] as string) || "";
+  return ae
+    .split(",")
+    .map((s) => s.trim())
+    .includes(enc);
+}
+
+function shouldCompress(mime: string): boolean {
+  return (
+    mime.startsWith("text/") ||
+    mime.includes("json") ||
+    mime.includes("javascript") ||
+    mime.includes("svg")
+  );
+}
+
 const resolvePath = (pathname: string): string => {
   const decoded = decodeURIComponent(pathname);
   let target = decoded;
@@ -128,6 +154,7 @@ const resolvePath = (pathname: string): string => {
 };
 
 const sendResponse = async (
+  req: IncomingMessage,
   res: ServerResponse,
   filePath: string,
   statusCode = 200
@@ -138,18 +165,49 @@ const sendResponse = async (
     ? "no-cache"
     : "public, max-age=86400, immutable";
 
+  const stat = await fs.stat(filePath).catch(() => undefined);
   const data = await fs.readFile(filePath);
-  res.writeHead(
-    statusCode,
-    applySecurityHeaders({
-      "Content-Type": mimeType,
-      "Cache-Control": cacheControl,
-    })
-  );
-  res.end(data);
+  const etag = computeEtag(data);
+
+  // Conditional requests
+  const inm = (req.headers["if-none-match"] as string) || "";
+  if (inm && inm === etag) {
+    res.writeHead(
+      304,
+      applySecurityHeaders({
+        ETag: etag,
+        "Cache-Control": cacheControl,
+        ...(stat ? { "Last-Modified": stat.mtime.toUTCString() } : {}),
+      })
+    );
+    res.end();
+    return;
+  }
+
+  let body: any = data;
+  const headers: Record<string, string> = {
+    "Content-Type": mimeType,
+    "Cache-Control": cacheControl,
+    ETag: etag,
+    ...(stat ? { "Last-Modified": stat.mtime.toUTCString() } : {}),
+  };
+
+  if (shouldCompress(mimeType) && acceptsEncoding(req, "gzip")) {
+    try {
+      body = gzipSync(data);
+      headers["Content-Encoding"] = "gzip";
+      headers["Vary"] = "Accept-Encoding";
+    } catch {
+      // Si falla compresión, enviar sin comprimir
+    }
+  }
+
+  res.writeHead(statusCode, applySecurityHeaders(headers));
+  res.end(body);
 };
 
 const renderTemplate = async (
+  req: IncomingMessage,
   res: ServerResponse,
   template: string,
   locals: Record<string, any> = {},
@@ -157,7 +215,7 @@ const renderTemplate = async (
 ) => {
   const pageFile = path.join(viewsDir, "pages", `${template}.ejs`);
   const layoutFile = path.join(viewsDir, "layouts", "layout.ejs");
-  const body = await ejs.renderFile(pageFile, locals, { async: true });
+  const pageBody = await ejs.renderFile(pageFile, locals, { async: true });
   const defaultTitle = `${
     locals.appName ?? pkg.name ?? "Amayo Bot"
   } | Guía Completa`;
@@ -168,18 +226,43 @@ const renderTemplate = async (
       scripts: null,
       ...locals,
       title: locals.title ?? defaultTitle,
-      body,
+      body: pageBody,
     },
     { async: true }
   );
-  res.writeHead(
-    statusCode,
-    applySecurityHeaders({
-      "Content-Type": "text/html; charset=utf-8",
-      "Cache-Control": "no-cache",
-    })
-  );
-  res.end(html);
+  const htmlBuffer = Buffer.from(html, "utf8");
+  const etag = computeEtag(htmlBuffer);
+
+  // Conditional ETag for dynamic page (fresh each deploy change)
+  const inm = (req.headers["if-none-match"] as string) || "";
+  if (inm && inm === etag) {
+    res.writeHead(
+      304,
+      applySecurityHeaders({ ETag: etag, "Cache-Control": "no-cache" })
+    );
+    res.end();
+    return;
+  }
+
+  let respBody: any = htmlBuffer;
+  const headers: Record<string, string> = {
+    "Content-Type": "text/html; charset=utf-8",
+    "Cache-Control": "no-cache",
+    ETag: etag,
+  };
+
+  if (acceptsEncoding(req, "gzip")) {
+    try {
+      respBody = gzipSync(htmlBuffer);
+      headers["Content-Encoding"] = "gzip";
+      headers["Vary"] = "Accept-Encoding";
+    } catch {
+      // continuar sin comprimir
+    }
+  }
+
+  res.writeHead(statusCode, applySecurityHeaders(headers));
+  res.end(respBody);
 };
 
 export const server = createServer(
@@ -250,7 +333,7 @@ export const server = createServer(
           year: "numeric",
         });
         const djsVersion = pkg?.dependencies?.["discord.js"] ?? "15.0.0-dev";
-        await renderTemplate(res, "index", {
+        await renderTemplate(req, res, "index", {
           appName: pkg.name ?? "Amayo Bot",
           version: pkg.version ?? "2.0.0",
           djsVersion,
@@ -268,12 +351,12 @@ export const server = createServer(
       }
 
       try {
-        await sendResponse(res, filePath);
+        await sendResponse(req, res, filePath);
       } catch (error: any) {
         if (error.code === "ENOENT") {
           const notFoundPath = path.join(publicDir, "404.html");
           try {
-            await sendResponse(res, notFoundPath, 404);
+            await sendResponse(req, res, notFoundPath, 404);
           } catch {
             res.writeHead(
               404,
@@ -285,7 +368,7 @@ export const server = createServer(
           }
         } else if (error.code === "EISDIR") {
           const indexPath = path.join(filePath, "index.html");
-          await sendResponse(res, indexPath);
+          await sendResponse(req, res, indexPath);
         } else {
           console.error("[Server] Error al servir archivo:", error);
           res.writeHead(