ETV (Estimated Traffic Value)

// Calcul de l'ETV à partir des données DataForSEO
interface KeywordData {
  keyword: string;
  position: number;
  searchVolume: number;
  cpc: number;
}

function computeETV(keywords: KeywordData[]): number {
  const ctrByPosition: Record<number, number> = {
    1: 0.316, 2: 0.241, 3: 0.189,
    4: 0.110, 5: 0.088, 6: 0.067,
    7: 0.052, 8: 0.041, 9: 0.033, 10: 0.028
  };
  
  return keywords.reduce((total, kw) => {
    const ctr = ctrByPosition[kw.position] || 0.01;
    const estimatedTraffic = kw.searchVolume * ctr;
    return total + (estimatedTraffic * kw.cpc);
  }, 0);
}