/* ═══════════════════════════════════════════════════════════════════════════
   ML ACADEMY — FEEDBACK STORAGE SYSTEM
   Stocke les feedbacks au format JSON pour traitement ulterieur
   ═══════════════════════════════════════════════════════════════════════════ */

class FeedbackStorage {
  constructor() {
    this.storageKey = 'ml_academy_feedbacks';
    this.feedbacks = this.loadFeedbacks();
  }

  // Charge tous les feedbacks depuis le stockage
  loadFeedbacks() {
    try {
      const stored = localStorage.getItem(this.storageKey);
      return stored ? JSON.parse(stored) : [];
    } catch (e) {
      console.error('Erreur lors du chargement des feedbacks:', e);
      return [];
    }
  }

  // Sauvegarde tous les feedbacks
  saveFeedbacks() {
    try {
      localStorage.setItem(this.storageKey, JSON.stringify(this.feedbacks));
      return true;
    } catch (e) {
      console.error('Erreur lors de la sauvegarde des feedbacks:', e);
      return false;
    }
  }

  // Ajoute un nouveau feedback
  addFeedback(feedbackData) {
    const feedback = {
      id: this.generateId(),
      timestamp: new Date().toISOString(),
      ...feedbackData
    };
    
    this.feedbacks.push(feedback);
    this.saveFeedbacks();
    
    // Exporte automatiquement vers un fichier JSON telechargeable
    this.exportToFile();
    
    return feedback;
  }

  // Genere un ID unique
  generateId() {
    return 'fb_' + Date.now() + '_' + Math.random().toString(36).substr(2, 9);
  }

  // Recupere tous les feedbacks
  getAllFeedbacks() {
    return this.feedbacks;
  }

  // Recupere les feedbacks par date
  getFeedbacksByDateRange(startDate, endDate) {
    return this.feedbacks.filter(fb => {
      const fbDate = new Date(fb.timestamp);
      return fbDate >= startDate && fbDate <= endDate;
    });
  }

  // Recupere les statistiques
  getStatistics() {
    if (this.feedbacks.length === 0) {
      return {
        total: 0,
        averageRating: 0,
        difficultyDistribution: {},
        commonDifficulties: [],
        commonSuggestions: []
      };
    }

    const ratings = this.feedbacks.map(fb => parseInt(fb.rating) || 0);
    const averageRating = ratings.reduce((a, b) => a + b, 0) / ratings.length;

    // Distribution des difficultes
    const difficultyDistribution = {};
    this.feedbacks.forEach(fb => {
      const diff = fb.difficulty || 'non-specifie';
      difficultyDistribution[diff] = (difficultyDistribution[diff] || 0) + 1;
    });

    // Points difficiles communs
    const difficultyCount = {};
    this.feedbacks.forEach(fb => {
      if (fb.difficiles && Array.isArray(fb.difficiles)) {
        fb.difficiles.forEach(d => {
          difficultyCount[d] = (difficultyCount[d] || 0) + 1;
        });
      }
    });
    const commonDifficulties = Object.entries(difficultyCount)
      .sort((a, b) => b[1] - a[1])
      .slice(0, 5);

    // Suggestions communes
    const suggestionCount = {};
    this.feedbacks.forEach(fb => {
      if (fb.suggestions && Array.isArray(fb.suggestions)) {
        fb.suggestions.forEach(s => {
          suggestionCount[s] = (suggestionCount[s] || 0) + 1;
        });
      }
    });
    const commonSuggestions = Object.entries(suggestionCount)
      .sort((a, b) => b[1] - a[1])
      .slice(0, 5);

    return {
      total: this.feedbacks.length,
      averageRating: averageRating.toFixed(2),
      difficultyDistribution,
      commonDifficulties,
      commonSuggestions
    };
  }

  // Exporte les feedbacks vers un fichier JSON
  exportToFile() {
    const data = {
      exportDate: new Date().toISOString(),
      totalFeedbacks: this.feedbacks.length,
      feedbacks: this.feedbacks,
      statistics: this.getStatistics()
    };

    const blob = new Blob([JSON.stringify(data, null, 2)], { type: 'application/json' });
    const url = URL.createObjectURL(blob);
    
    // Stocke l'URL pour telechargement ulterieur
    this.lastExportUrl = url;
    
    return url;
  }

  // Telecharge le fichier JSON
  downloadFeedbacks() {
    const url = this.exportToFile();
    const a = document.createElement('a');
    a.href = url;
    a.download = `ml_academy_feedbacks_${new Date().toISOString().split('T')[0]}.json`;
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
    URL.revokeObjectURL(url);
  }

  // Exporte vers CSV pour Excel
  exportToCSV() {
    if (this.feedbacks.length === 0) return null;

    const headers = [
      'ID', 'Date', 'Nom', 'Email', 'Projet',
      'Note', 'Difficulte', 'Rythme',
      'Parties Utiles', 'Points Difficiles',
      'Question Principale', 'Commentaire'
    ];

    const rows = this.feedbacks.map(fb => [
      fb.id,
      fb.timestamp,
      fb.name || '',
      fb.email || '',
      fb.project || '',
      fb.rating || '',
      fb.difficulty || '',
      fb.rythme || '',
      (fb.utiles || []).join(';'),
      (fb.difficiles || []).join(';'),
      (fb.mainQuestion || '').replace(/"/g, '""'),
      (fb.freeComment || '').replace(/"/g, '""')
    ]);

    const csv = [
      headers.join(','),
      ...rows.map(row => row.map(cell => `"${cell}"`).join(','))
    ].join('\n');

    const blob = new Blob([csv], { type: 'text/csv;charset=utf-8;' });
    const url = URL.createObjectURL(blob);
    
    const a = document.createElement('a');
    a.href = url;
    a.download = `ml_academy_feedbacks_${new Date().toISOString().split('T')[0]}.csv`;
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
    URL.revokeObjectURL(url);
  }

  // Efface tous les feedbacks (avec confirmation)
  clearAll() {
    if (confirm('Attention : Cette action supprimera tous les feedbacks. Continuer ?')) {
      this.feedbacks = [];
      this.saveFeedbacks();
      return true;
    }
    return false;
  }
}

// Instance globale
const feedbackStorage = new FeedbackStorage();

// Fonction pour soumettre un feedback depuis le formulaire
function submitFeedback(formData) {
  const feedback = feedbackStorage.addFeedback(formData);
  console.log('Feedback enregistre:', feedback);
  return feedback;
}

// Fonction pour afficher les statistiques dans la console
function showFeedbackStats() {
  const stats = feedbackStorage.getStatistics();
  console.log('=== Statistiques des Feedbacks ===');
  console.log(`Total: ${stats.total}`);
  console.log(`Note moyenne: ${stats.averageRating}/5`);
  console.log('Distribution des difficultes:', stats.difficultyDistribution);
  console.log('Points difficiles communs:', stats.commonDifficulties);
  console.log('Suggestions communes:', stats.commonSuggestions);
  return stats;
}

// Exporte pour utilisation externe
window.FeedbackStorage = FeedbackStorage;
window.feedbackStorage = feedbackStorage;
window.submitFeedback = submitFeedback;
window.showFeedbackStats = showFeedbackStats;