import fs from "fs";
import os from "os";
import path from "path";

export function getFileSystemSuggestions(pathPrefix: string): Array<string> {
  if (!pathPrefix) {
    return [];
  }

  try {
    const sep = path.sep;
    const hasTilde = pathPrefix === "~" || pathPrefix.startsWith("~" + sep);
    const expanded = hasTilde
      ? path.join(os.homedir(), pathPrefix.slice(1))
      : pathPrefix;

    const normalized = path.normalize(expanded);
    const isDir = pathPrefix.endsWith(path.sep);
    const base = path.basename(normalized);

    const dir =
      normalized === "." && !pathPrefix.startsWith("." + sep) && !hasTilde
        ? process.cwd()
        : path.dirname(normalized);

    const readDir = isDir ? path.join(dir, base) : dir;

    return fs
      .readdirSync(readDir)
      .filter((item) => isDir || item.startsWith(base))
      .map((item) => {
        const fullPath = path.join(readDir, item);
        const isDirectory = fs.statSync(fullPath).isDirectory();
        if (isDirectory) {
          return path.join(fullPath, sep);
        }
        return fullPath;
      });
  } catch {
    return [];
  }
}