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

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

const techLogRouteChunks = Object.freeze({
  "/public/pages/home-page.tsx": "route-tech-log-home",
  "/public/pages/explore-page.tsx": "route-tech-log-explore",
  "/public/pages/explore-kind-page.tsx": "route-tech-log-explore-kind",
  "/public/pages/case-page.tsx": "route-tech-log-case",
  "/public/pages/reference-page.tsx": "route-tech-log-reference",
  "/public/pages/question-page.tsx": "route-tech-log-question",
  "/public/pages/topic-page.tsx": "route-tech-log-topic",
  "/public/pages/projects-page.tsx": "route-tech-log-projects",
  "/public/pages/project-overview-page.tsx": "route-tech-log-project",
  "/public/pages/project-records-page.tsx": "route-tech-log-project-records",
  "/public/pages/project-decisions-page.tsx": "route-tech-log-project-decisions",
  "/public/pages/project-activity-page.tsx": "route-tech-log-project-activity",
  "/public/pages/releases-page.tsx": "route-tech-log-releases",
  "/public/pages/release-page.tsx": "route-tech-log-release",
  "/public/pages/profile-page.tsx": "route-tech-log-profile",
  "/public/pages/search-page.tsx": "route-tech-log-search",
  "/studio/pages/studio-home-page.tsx": "route-tech-log-studio-home",
  "/studio/pages/documents-page.tsx": "route-tech-log-studio-documents",
  "/studio/pages/new-document-page.tsx": "route-tech-log-studio-document-new",
  "/studio/pages/document-edit-page.tsx": "route-tech-log-studio-document-edit",
  "/studio/pages/document-validation-page.tsx": "route-tech-log-studio-document-validation",
  "/studio/pages/document-preview-page.tsx": "route-tech-log-studio-document-preview",
  "/studio/pages/document-publish-page.tsx": "route-tech-log-studio-document-publish",
  "/studio/pages/publications-page.tsx": "route-tech-log-studio-publications",
  "/studio/pages/publication-preview-page.tsx": "route-tech-log-studio-publication-preview",
  "/studio/pages/assets-page.tsx": "route-tech-log-studio-assets",
  "/studio/pages/taxonomy-page.tsx": "route-tech-log-studio-taxonomy",
  "/studio/pages/project-edit-page.tsx": "route-tech-log-studio-project-edit",
  "/studio/pages/releases-page.tsx": "route-tech-log-studio-releases",
  "/studio/pages/studio-not-found-page.tsx": "route-tech-log-studio-not-found",
  "/public/pages/public-not-found-page.tsx": "route-not-found",
} as const);

function routeChunkName(moduleId: string): string | undefined {
  const normalized = moduleId.replaceAll("\\", "/");
  const featurePath = "/src/features/tech-log/presentation";
  const featureIndex = normalized.lastIndexOf(featurePath);
  if (featureIndex < 0) return undefined;
  const routePath = normalized.slice(featureIndex + featurePath.length);
  return techLogRouteChunks[routePath as keyof typeof techLogRouteChunks];
}

/**
 * §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,
    rolldownOptions: {
      output: {
        manualChunks: routeChunkName,
      },
    },
  },
});