import { defineConfig, type Plugin } from "vite";
import react from "@vitejs/plugin-react";
// @ts-expect-error The runtime is Node; this project intentionally avoids a browser dependency on Node types.
import fs from "node:fs";
// @ts-expect-error The runtime is Node; this project intentionally avoids a browser dependency on Node types.
import path from "node:path";

const isolationHeaders = {
  "Cross-Origin-Opener-Policy": "same-origin",
  "Cross-Origin-Embedder-Policy": "require-corp",
  "Cross-Origin-Resource-Policy": "same-origin",
};

function preserveIsolationHeaders(): Plugin {
  const install = (server: { middlewares: { use: (handler: (request: unknown, response: { setHeader: (name: string, value: string) => void }, next: () => void) => void) => void } }) => {
    server.middlewares.use((_request, response, next) => {
      for (const [name, value] of Object.entries(isolationHeaders)) response.setHeader(name, value);
      next();
    });
  };
  return {
    name: "preserve-isolation-headers",
    configureServer: install,
    configurePreviewServer: install,
  };
}

function localVDBFixture(): Plugin {
  const resourceRoot = (globalThis as { process?: { env?: Record<string, string | undefined> } }).process?.env?.VDB_RESOURCE_ROOT ?? "/home/mes123456/resource-library/blender-web-vdb";
  const files = new Map([
    ["/__vdb_fixture__/manifest", { path: path.join(resourceRoot, "manifests/generated-smoke.nanovdb.json"), type: "application/json" }],
    ["/__vdb_fixture__/report", { path: path.join(resourceRoot, "reports/generated-smoke-conversion.json"), type: "application/json" }],
    ["/__vdb_fixture__/bundle", { path: path.join(resourceRoot, "nanovdb/generated-smoke.nvdb"), type: "application/x-nanovdb" }],
    ["/assets/volumes/generated-smoke.nanovdb.json", { path: path.join(resourceRoot, "manifests/generated-smoke.nanovdb.json"), type: "application/json" }],
    ["/assets/volumes/generated-smoke.nvdb", { path: path.join(resourceRoot, "nanovdb/generated-smoke.nvdb"), type: "application/x-nanovdb" }],
    ["/volumes/generated-smoke.nanovdb.json", { path: path.join(resourceRoot, "manifests/generated-smoke.nanovdb.json"), type: "application/json" }],
    ["/volumes/generated-smoke.nvdb", { path: path.join(resourceRoot, "nanovdb/generated-smoke.nvdb"), type: "application/x-nanovdb" }],
  ]);
  return {
    name: "local-vdb-fixture",
    configureServer(server) {
      server.middlewares.use((request, response, next) => {
        const nodeRequest = request as unknown as { url?: string; headers: { range?: string } };
        const pathname = nodeRequest.url?.split("?", 1)[0] ?? "";
        const fixture = files.get(pathname);
        if (!fixture || !fs.existsSync(fixture.path)) { next(); return; }
        const stat = fs.statSync(fixture.path);
        response.setHeader("Content-Type", fixture.type);
        response.setHeader("Accept-Ranges", "bytes");
        response.setHeader("Cache-Control", "no-store");
        response.setHeader("ETag", `"vdb-${stat.size}-${Math.trunc(stat.mtimeMs)}"`);
        const match = nodeRequest.headers.range?.match(/^bytes=(\d+)-(\d+)$/);
        if (match) {
          const start = Number(match[1]);
          const end = Number(match[2]);
          if (!Number.isSafeInteger(start) || !Number.isSafeInteger(end) || start < 0 || end < start || end >= stat.size) { response.writeHead(416); response.end(); return; }
          response.statusCode = 206;
          response.setHeader("Content-Range", `bytes ${start}-${end}/${stat.size}`);
          response.setHeader("Content-Length", end - start + 1);
          fs.createReadStream(fixture.path, { start, end }).pipe(response);
          return;
        }
        response.setHeader("Content-Length", stat.size);
        fs.createReadStream(fixture.path).pipe(response);
      });
    },
  };
}

export default defineConfig({
  root: "app",
  plugins: [preserveIsolationHeaders(), localVDBFixture(), react()],
  server: {
    port: 5173,
    strictPort: false,
    headers: {
      ...isolationHeaders,
    },
  },
  preview: {
    headers: {
      ...isolationHeaders,
    },
  },
  build: {
    outDir: "../dist",
    emptyOutDir: true,
  },
});