import fs from "node:fs";
import path from "node:path";

export function getRepoRoot(cwd = process.cwd()): string {
  const candidates = [cwd, path.resolve(cwd, ".."), path.resolve(cwd, "../.."), path.resolve(cwd, "../../..")];
  const root = candidates.find(
    (candidate) => fs.existsSync(path.join(candidate, "package.json")) && fs.existsSync(path.join(candidate, "apps/web/app"))
  );

  return root ?? cwd;
}

export function resolveRepoPath(relativePath: string, cwd = process.cwd()): string {
  const repoRoot = getRepoRoot(cwd);
  const normalizedPath = relativePath.replaceAll("\\", "/");
  if (normalizedPath === "app" || normalizedPath.startsWith("app/") || normalizedPath === "public" || normalizedPath.startsWith("public/")) {
    throw new Error(`Use apps/web/${normalizedPath} instead of legacy root ${normalizedPath}`);
  }
  const candidates = [path.join(repoRoot, normalizedPath)];

  return candidates.find((candidate) => fs.existsSync(candidate)) ?? candidates[0];
}

export function repoPathExists(relativePath: string, cwd = process.cwd()): boolean {
  return fs.existsSync(resolveRepoPath(relativePath, cwd));
}

export function readRepoFile(relativePath: string, cwd = process.cwd()): string {
  return fs.readFileSync(resolveRepoPath(relativePath, cwd), "utf8");
}

export function readRepoDir(relativePath: string, cwd = process.cwd()): string[] {
  return fs.readdirSync(resolveRepoPath(relativePath, cwd));
}