import { readFileSync } from "node:fs";
import { fileURLToPath } from "node:url";
import { defineConfig, loadEnv, type Plugin } from "vite";
import react from "@vitejs/plugin-react";
import { VitePWA } from "vite-plugin-pwa";

/** Emits the repo's LICENSE file into the build output. */
function licensePlugin(): Plugin {
  return {
    name: "hermes-pwa-license",
    apply: "build",
    generateBundle() {
      this.emitFile({
        type: "asset",
        fileName: "LICENSE",
        source: readFileSync(fileURLToPath(new URL("../LICENSE", import.meta.url)), "utf-8"),
      });
    },
  };
}

// During `npm run dev` you can point the dev server at a Hermes host to avoid
// CORS entirely: set HERMES_DEV_TARGET=https://hermes.example.com in a .env file
// (or the environment) and the dev server proxies /api/* to it.
export default defineConfig(({ mode }) => {
  const env = loadEnv(mode, ".", "");
  const target = env.HERMES_DEV_TARGET;

  return {
    server: {
      port: 5173,
      proxy: target
        ? Object.fromEntries(
            ["/api", "/v1", "/health"].map((prefix) => [
              prefix,
              {
                target,
                changeOrigin: true,
                secure: false,
                // SSE needs buffering disabled.
                configure: (proxy) => {
                  proxy.on("proxyRes", (proxyRes) => {
                    proxyRes.headers["x-accel-buffering"] = "no";
                  });
                },
              },
            ]),
          )
        : undefined,
    },
    plugins: [
      react(),
      licensePlugin(),
      VitePWA({
        registerType: "autoUpdate",
        includeAssets: ["icons/apple-touch-icon.png", "favicon.svg"],
        manifest: {
          name: "Hermes",
          short_name: "Hermes",
          description: "Chat with your Hermes Agent profiles, sessions, voice and images.",
          theme_color: "#000810",
          background_color: "#000810",
          display: "standalone",
          orientation: "portrait-primary",
          start_url: "/",
          scope: "/",
          icons: [
            { src: "icons/icon-192.png", sizes: "192x192", type: "image/png" },
            { src: "icons/icon-512.png", sizes: "512x512", type: "image/png" },
            {
              src: "icons/maskable-512.png",
              sizes: "512x512",
              type: "image/png",
              purpose: "maskable",
            },
          ],
        },
        workbox: {
          // Never cache API traffic — it is authenticated and dynamic.
          navigateFallbackDenylist: [/^\/api\//],
          runtimeCaching: [
            {
              urlPattern: ({ url }) => url.pathname.startsWith("/api/"),
              handler: "NetworkOnly",
            },
          ],
        },
        devOptions: {
          enabled: false,
        },
      }),
    ],
  };
});