import { defineConfig } from "vite";
import react from "@vitejs/plugin-react";
import tailwindcss from "@tailwindcss/vite";

import { viteModuleInventoryPlugin } from "./scripts/lib/vite-module-inventory.ts";

/**
 * §6.1. One sub-path, declared once.
 *
 * `VITE_ROUTER_BASE_PATH` already drives the router and the Service Worker
 * scope. Vite's asset `base` was left at its default, so a build served from
 * `/app/` emitted root-absolute asset URLs and loaded nothing: the three
 * consumers of the same setting disagreed. They are read from one value here so
 * a sub-path deployment is coherent or fails at build time.
 */
function routerBasePath(environment: NodeJS.ProcessEnv): string {
  const declared = environment["VITE_ROUTER_BASE_PATH"];
  if (declared === undefined || declared === "") return "/";
  if (!declared.startsWith("/") || !declared.endsWith("/")) {
    throw new Error(
      `VITE_ROUTER_BASE_PATH must start and end with "/"; received ${declared}`,
    );
  }
  return declared;
}

export default defineConfig({
  base: routerBasePath(process.env),
  plugins: [react(), tailwindcss(), viteModuleInventoryPlugin()],
  build: {
    manifest: true,
    sourcemap: false,
  },
});