/**
 * Feature flag helper functions for testing
 */

export interface FeatureFlagData {
  features: Record<string, string>;
  timestamp: string;
}

/**
 * Helper to compute enabled flags from feature config
 */
export function getEnabledFlags(featureData: FeatureFlagData): string[] {
  if (!featureData.features || typeof featureData.features !== 'object') {
    return [];
  }
  
  return Object.entries(featureData.features)
    .filter(([, value]) => value === 'enabled')
    .map(([flag]) => flag);
}

/**
 * Helper to check if a specific flag is enabled
 */
export function isFeatureEnabled(featureData: FeatureFlagData, flag: string): boolean {
  return featureData.features?.[flag] === 'enabled';
}

/**
 * Helper to fetch feature flags from the API
 * Note: This is a pure function that takes the fetcher as an argument to avoid network side effects in unit tests
 */
export async function fetchFeatureFlags(
  fetcher: (url: string) => Promise<{ ok: boolean; json: () => Promise<unknown>; status: number }>,
  apiBaseUrl: string
): Promise<FeatureFlagData> {
  const featuresUrl = `${apiBaseUrl}/features`;
  
  try {
    const response = await fetcher(featuresUrl);
    if (!response.ok) {
      throw new Error(`Failed to fetch feature flags: ${response.status}`);
    }
    
    const data = await response.json() as FeatureFlagData;
    return data;
  } catch (error) {
    console.error(`[FEATURE FLAGS] Failed to fetch from ${featuresUrl}:`, error);
    throw error;
  }
}