Static Files Plugin

import { Elysia } from "elysia";
import { staticPlugin } from "@elysiajs/static";

/**
 * Static file serving configuration
 */
export interface StaticConfig {
  /** Base path for static files (default: /public) */
  prefix?: string;
  /** Directory to serve files from (default: public) */
  assets?: string;
  /** Enable directory listing (default: false) */
  alwaysStatic?: boolean;
  /** Ignore patterns */
  ignorePatterns?: string[];
  /** Cache control max age in seconds (default: 86400 = 1 day) */
  maxAge?: number;
  /** Enable etag (default: true) */
  etag?: boolean;
}

/**
 * Setup static file serving with production-ready defaults
 */
export const setupStatic = (config: StaticConfig = {}) => {
  const isProd = process.env.NODE_ENV === "production";
  const maxAge = config.maxAge ?? (isProd ? 86400 : 0);

  return new Elysia({ name: "static-plugin" })
    .use(
      staticPlugin({
        prefix: config.prefix ?? "/public",
        assets: config.assets ?? "public",
        alwaysStatic: config.alwaysStatic ?? false,
        ignorePatterns: config.ignorePatterns ?? [
          ".*",
          "*.ts",
          "*.tsx",
          "node_modules/**",
        ],
      })
    )
    .onAfterHandle(({ set, request }) => {
      const url = new URL(request.url);
      
      // Add cache headers for static assets
      if (url.pathname.startsWith(config.prefix ?? "/public")) {
        if (maxAge > 0) {
          set.headers["Cache-Control"] = `public, max-age=${maxAge}`;
        } else {
          set.headers["Cache-Control"] = "no-cache";
        }
      }
    });
};

/**
 * Serve single page application (SPA)
 */
export const setupSPA = (config: {
  /** Directory containing the SPA build (default: dist) */
  assets?: string;
  /** Fallback file for client-side routing (default: index.html) */
  fallback?: string;
} = {}) => {
  const assets = config.assets ?? "dist";
  const fallback = config.fallback ?? "index.html";

  return new Elysia({ name: "spa-plugin" })
    .use(
      staticPlugin({
        assets,
        prefix: "/",
        alwaysStatic: false,
      })
    )
    .get("*", async ({ set }) => {
      const file = Bun.file(`${assets}/${fallback}`);
      if (await file.exists()) {
        set.headers["Content-Type"] = "text/html";
        return file;
      }
      set.status = 404;
      return { error: "Not found" };
    });
};

/* USAGE:

import { Elysia } from "elysia";
import { setupStatic, setupSPA } from "./plugins/static";

// Basic static file serving
const app = new Elysia()
  .use(setupStatic())
  .get("/", () => "Hello World")
  .listen(3000);

// Files in /public directory are served at /public/*
// e.g., public/images/logo.png -> /public/images/logo.png

// Custom configuration
const app = new Elysia()
  .use(setupStatic({
    prefix: "/assets",
    assets: "static",
    maxAge: 604800, // 1 week
    ignorePatterns: ["*.md", "*.txt"],
  }))
  .listen(3000);

// Serve SPA (React, Vue, etc.)
const app = new Elysia()
  // API routes first
  .group("/api", (app) =>
    app
      .get("/users", () => [])
      .get("/posts", () => [])
  )
  // Then SPA fallback
  .use(setupSPA({
    assets: "dist",
    fallback: "index.html",
  }))
  .listen(3000);

*/