/**
 * @typedef {{
 *   file: string,
 *   isEntry?: boolean,
 *   imports?: string[]
 * }} ViteManifestEntry
 */

/**
 * Static imports of an entry are part of initial JavaScript. Every remaining
 * JavaScript output is governed by the lazy-chunk budget.
 *
 * @param {Record<string, ViteManifestEntry>} manifest
 */
export function classifyViteJavascript(manifest) {
  const initialFiles = new Set();
  const visitedKeys = new Set();
  const pendingKeys = Object.entries(manifest)
    .filter(([, entry]) => entry.isEntry)
    .map(([key]) => key);
  const missingImports = [];

  while (pendingKeys.length > 0) {
    const key = /** @type {string} */ (pendingKeys.pop());
    if (visitedKeys.has(key)) continue;
    visitedKeys.add(key);
    const entry = manifest[key];
    if (!entry) {
      missingImports.push(key);
      continue;
    }
    if (entry.file.endsWith(".js")) initialFiles.add(entry.file);
    pendingKeys.push(...(entry.imports ?? []));
  }

  const allJavaScript = new Set(
    Object.values(manifest)
      .map((entry) => entry.file)
      .filter((file) => file.endsWith(".js")),
  );
  const lazyFiles = [...allJavaScript].filter(
    (file) => !initialFiles.has(file),
  );
  return Object.freeze({
    initialFiles: Object.freeze([...initialFiles].sort()),
    lazyFiles: Object.freeze(lazyFiles.sort()),
    missingImports: Object.freeze(missingImports.sort()),
  });
}