import { readFile } from 'node:fs/promises';
import path from 'node:path';
import process from 'node:process';
import { pathToFileURL } from 'node:url';
import { extractEntryAssetPath } from './verify-public-build.shared.mjs';

export async function verifyPlanningEntry(distDir = path.resolve(process.cwd(), 'dist')) {
  const indexHtmlPath = path.join(distDir, 'index.html');
  const indexHtml = await readFile(indexHtmlPath, 'utf8');
  const entryAssetPath = extractEntryAssetPath(indexHtml);

  if (!entryAssetPath) {
    throw new Error(`No module entry asset found in ${indexHtmlPath}`);
  }

  const entryChunkPath = path.join(distDir, entryAssetPath.replace(/^\//, ''));
  const entryChunk = await readFile(entryChunkPath, 'utf8');

  const planningRouteIndex = entryChunk.indexOf('/planning');
  if (planningRouteIndex === -1) {
    throw new Error(`The entry chunk ${path.basename(entryChunkPath)} does not contain a /planning route.`);
  }

  const planningWindow = entryChunk.slice(
    Math.max(0, planningRouteIndex - 600),
    Math.min(entryChunk.length, planningRouteIndex + 1400),
  );

  const planningRouteRedirectPattern =
    /path:\s*[`'"]\/planning[`'"]\s*,\s*element:\s*[^{}]{0,220}?to:\s*[`'"]\/planning\//;

  if (planningRouteRedirectPattern.test(planningWindow)) {
    throw new Error(
      `The built entry chunk ${path.basename(entryChunkPath)} still redirects /planning into a child page.`,
    );
  }

  return {
    distDir,
    entryAssetPath,
    entryChunkPath,
  };
}

async function main() {
  const distArg = process.argv[2];
  const distDir = distArg ? path.resolve(process.cwd(), distArg) : path.resolve(process.cwd(), 'dist');
  const result = await verifyPlanningEntry(distDir);
  process.stdout.write(
    `Verified planning entry in ${result.entryAssetPath} (${path.relative(process.cwd(), result.distDir)})\n`,
  );
}

const isDirectExecution = process.argv[1]
  ? pathToFileURL(path.resolve(process.argv[1])).href === import.meta.url
  : false;

if (isDirectExecution) {
  main().catch((error) => {
    process.stderr.write(`${error.message}\n`);
    process.exitCode = 1;
  });
}