import { readdir, readFile, stat } from "node:fs/promises";
import path from "node:path";

export const repositoryRoot = path.resolve(import.meta.dirname, "..");

const excludedDirectories = new Set([
  ".git",
  ".gradle",
  ".idea",
  "build",
  "node_modules",
]);

export async function walkFiles(directory = repositoryRoot) {
  const result = [];
  const entries = await readdir(directory, { withFileTypes: true });

  for (const entry of entries) {
    if (entry.isDirectory() && excludedDirectories.has(entry.name)) continue;
    const absolutePath = path.join(directory, entry.name);
    if (entry.isDirectory()) {
      result.push(...(await walkFiles(absolutePath)));
    } else if (entry.isFile()) {
      result.push(absolutePath);
    }
  }

  return result;
}

export async function readTextFileIfSmall(file, maximumBytes = 2_000_000) {
  const metadata = await stat(file);
  if (metadata.size > maximumBytes) return null;
  const buffer = await readFile(file);
  if (buffer.includes(0)) return null;
  return buffer.toString("utf8");
}

export function relative(file) {
  return path.relative(repositoryRoot, file).replaceAll(path.sep, "/");
}