import os from 'os';
import path from 'path';

function readPathEnv(key: string): string | null {
  const value = process.env[key]?.trim();
  return value ? path.resolve(value) : null;
}

export function getClaudeCredentialsPath(
  accountIndex: number,
  options: { allowHomeFallback?: boolean } = {},
): string | null {
  const explicitPath = readPathEnv('CLAUDE_CREDENTIALS_PATH');
  if (accountIndex === 0 && explicitPath) return explicitPath;

  const explicitAccountsDir = readPathEnv('CLAUDE_ACCOUNTS_DIR');
  if (accountIndex > 0 && explicitAccountsDir) {
    return path.join(
      explicitAccountsDir,
      String(accountIndex),
      '.credentials.json',
    );
  }

  if (options.allowHomeFallback === false) return null;

  if (accountIndex === 0) {
    return path.join(os.homedir(), '.claude', '.credentials.json');
  }
  return path.join(
    os.homedir(),
    '.claude-accounts',
    String(accountIndex),
    '.credentials.json',
  );
}

export function hasExplicitClaudeCredentialsPath(): boolean {
  return Boolean(readPathEnv('CLAUDE_CREDENTIALS_PATH'));
}