export interface TenantLaunchInput {
  query?: Record<string, unknown>;
  referrerExtraData?: Record<string, unknown>;
}

function normalizedTenantCode(value: unknown) {
  if (typeof value !== 'string') return '';
  const normalized = value.trim();
  return /^[A-Za-z0-9._-]{2,64}$/.test(normalized) ? normalized : '';
}

function tenantCodeFromScene(value: unknown) {
  if (typeof value !== 'string' || !value.trim()) return '';
  let decoded = value.trim();
  try {
    decoded = decodeURIComponent(decoded);
  } catch {
    return '';
  }
  if (!decoded.includes('=')) return normalizedTenantCode(decoded);
  for (const segment of decoded.split('&')) {
    const separator = segment.indexOf('=');
    if (separator < 0) continue;
    const key = segment.slice(0, separator).trim();
    if (key !== 'tenantCode' && key !== 'tenant') continue;
    return normalizedTenantCode(segment.slice(separator + 1));
  }
  return '';
}

export function tenantCodeFromLaunch(input: TenantLaunchInput) {
  const query = input.query || {};
  const extraData = input.referrerExtraData || {};
  return normalizedTenantCode(query.tenantCode)
    || normalizedTenantCode(query.tenant)
    || tenantCodeFromScene(query.scene)
    || normalizedTenantCode(extraData.tenantCode)
    || normalizedTenantCode(extraData.tenant)
    || '';
}