const fs = require("fs-extra");
const path = require("node:path");

/**
 * Attempt to find the project root by walking up from startDir
 * Looks for common project markers like .git, package.json, pyproject.toml, etc.
 * @param {string} startDir
 * @returns {Promise<string|null>} project root directory or null if not found
 */
async function findProjectRoot(startDir) {
  try {
    let dir = path.resolve(startDir);
    const root = path.parse(dir).root;
    const markers = [
      ".git",
      "package.json",
      "pnpm-workspace.yaml",
      "yarn.lock",
      "pnpm-lock.yaml",
      "pyproject.toml",
      "requirements.txt",
      "go.mod",
      "Cargo.toml",
      "composer.json",
      ".hg",
      ".svn",
    ];

    while (true) {
      const exists = await Promise.all(
        markers.map((m) => fs.pathExists(path.join(dir, m))),
      );
      if (exists.some(Boolean)) {
        return dir;
      }
      if (dir === root) break;
      dir = path.dirname(dir);
    }
    return null;
  } catch {
    return null;
  }
}

module.exports = { findProjectRoot };