import metadataJson from '../public/assets/image-metadata.json';

export interface ImageMeta {
  file: string;
  category: 'pv' | 'wind' | 'fiber' | 'power' | 'battery' | 'unknown';
  environment: 'freies_feld' | 'urban' | 'wald' | 'indoor' | 'unknown';
  quality_score: number;
  description: string;
}

const metadata = metadataJson as Record<string, ImageMeta>;

// Create a deterministic pseudo-random number based on a string
function hashString(str: string): number {
  let hash = 0;
  for (let i = 0; i < str.length; i++) {
    const char = str.charCodeAt(i);
    hash = (hash << 5) - hash + char;
    hash = hash & hash; // Convert to 32bit integer
  }
  return Math.abs(hash);
}

/**
 * Returns a fitting, highly-rated image for a specific project type.
 * It is deterministic based on the seed (e.g. project ID).
 */
export function getImageForProject(seed: string, category: string): string {
  const allImages = Object.values(metadata);
  
  // 1. Filter by category
  let candidates = allImages.filter(img => img.category === category);
  
  // If no candidates for category, fallback to fiber (Kabeltiefbau is safe default for ETIB)
  if (candidates.length === 0) {
    candidates = allImages.filter(img => img.category === 'fiber');
  }

  // Still empty? Just get anything highly rated
  if (candidates.length === 0) {
    candidates = allImages;
  }

  // 2. Sort by quality score (descending)
  candidates.sort((a, b) => b.quality_score - a.quality_score);

  // 3. For PV and Wind, strongly prefer 'freies_feld'
  if (category === 'pv' || category === 'wind') {
    const fieldCandidates = candidates.filter(img => img.environment === 'freies_feld' && img.quality_score >= 6);
    if (fieldCandidates.length > 0) {
      candidates = fieldCandidates;
    }
  } else {
    // For others, just take top 30% quality to have some variation
    candidates = candidates.filter(img => img.quality_score >= 6);
    if (candidates.length === 0) {
      candidates = allImages.filter(img => img.category === category);
    }
  }

  if (candidates.length === 0) {
    return '/assets/logo.png'; // Ultimate fallback
  }

  // 4. Deterministically pick one based on the seed
  const hash = hashString(seed);
  const index = hash % candidates.length;
  
  return candidates[index].file;
}