import { fs } from "./fs.js";
import { path } from "./path.js";
/**
 * Finds the number at the end of a filename and increases it
 * If there is no number yet, concatenates '1' to a string
 *
 * E.g.
 *
 * - `hello-world` becomes `hello-world1`
 * - `hello36` becomes `hello37`
 */
export const oneUp = (filename: string): string => {
  const lastNumber = filename.match(/\d+$/)?.[0];
  const newNumber = lastNumber ? String(Number(lastNumber) + 1) : "1";
  return `${filename.slice(
    0,
    filename.length - (lastNumber?.length || 0),
  )}${newNumber}`;
};

export const getFirstAvailableFilename = (absoluteFilePath: string): string => {
  // If that doesn't exist, use that
  if (!fs.existsSync(absoluteFilePath)) {
    return absoluteFilePath;
  }

  const parsedPath = path.parse(absoluteFilePath);

  const newFilename = `${oneUp(parsedPath.name)}${parsedPath.ext}`;
  const newProposedPath = path.join(parsedPath.dir, newFilename);
  return getFirstAvailableFilename(newProposedPath);
};