export interface PredefinedCategory {
  name: string;
  color: string;
  keywords: string[];
  icon: string;
}

export const PREDEFINED_CATEGORIES: PredefinedCategory[] = [
  {
    name: 'Dev',
    color: '#3b82f6', // Blue
    icon: '💻',
    keywords: [
      'code', 'coding', 'development', 'develop', 'dev', 'programming', 'program',
      'bug', 'fix', 'debug', 'feature', 'implement', 'refactor', 'review',
      'api', 'database', 'db', 'frontend', 'backend', 'ui', 'ux',
      'component', 'service', 'function', 'method', 'class',
      'git', 'commit', 'merge', 'pull request', 'pr', 'deploy', 'deployment',
      'test', 'testing', 'unit test', 'integration'
    ]
  },
  {
    name: 'Meeting',
    color: '#8b5cf6', // Purple
    icon: '🤝',
    keywords: [
      'meeting', 'réunion', 'call', 'standup', 'daily', 'retrospective', 'retro',
      'planning', 'demo', 'presentation', 'sync', 'catch up', 'catchup',
      'interview', 'discussion', 'brainstorm', 'workshop', 'session',
      'one on one', '1on1', 'review meeting', 'sprint planning'
    ]
  },
  {
    name: 'Admin',
    color: '#6b7280', // Gray
    icon: '📋',
    keywords: [
      'admin', 'administration', 'paperwork', 'documentation', 'doc', 'docs',
      'report', 'reporting', 'timesheet', 'expense', 'invoice',
      'email', 'mail', 'communication', 'update', 'status',
      'config', 'configuration', 'setup', 'installation', 'maintenance',
      'backup', 'security', 'permission', 'user management'
    ]
  },
  {
    name: 'Learning',
    color: '#10b981', // Green
    icon: '📚',
    keywords: [
      'learning', 'learn', 'study', 'training', 'course', 'tutorial',
      'research', 'reading', 'documentation', 'knowledge', 'skill',
      'certification', 'workshop', 'seminar', 'conference',
      'practice', 'exercise', 'experiment', 'exploration', 'investigate'
    ]
  }
];

export class TaskCategorizationService {
  /**
   * Suggère une catégorie basée sur le titre et la description d'une tâche
   */
  static suggestCategory(title: string, description?: string): PredefinedCategory | null {
    const text = `${title} ${description || ''}`.toLowerCase();
    
    // Compte les matches pour chaque catégorie
    const categoryScores = PREDEFINED_CATEGORIES.map(category => {
      const matches = category.keywords.filter(keyword => 
        text.includes(keyword.toLowerCase())
      ).length;
      
      return {
        category,
        score: matches
      };
    });

    // Trouve la meilleure catégorie
    const bestMatch = categoryScores.reduce((best, current) => 
      current.score > best.score ? current : best
    );

    // Retourne la catégorie seulement s'il y a au moins un match
    return bestMatch.score > 0 ? bestMatch.category : null;
  }

  /**
   * Suggère plusieurs catégories avec leur score de confiance
   */
  static suggestCategoriesWithScore(title: string, description?: string): Array<{
    category: PredefinedCategory;
    score: number;
    confidence: number;
  }> {
    const text = `${title} ${description || ''}`.toLowerCase();
    
    const categoryScores = PREDEFINED_CATEGORIES.map(category => {
      const matches = category.keywords.filter(keyword => 
        text.includes(keyword.toLowerCase())
      );
      
      const score = matches.length;
      const confidence = Math.min((score / 3) * 100, 100); // Max 100% de confiance avec 3+ mots-clés
      
      return {
        category,
        score,
        confidence
      };
    });

    return categoryScores
      .filter(item => item.score > 0)
      .sort((a, b) => b.score - a.score);
  }

  /**
   * Analyse les activités et retourne la répartition par catégorie
   */
  static analyzeActivitiesByCategory(activities: Array<{ title: string; description?: string }>): {
    [categoryName: string]: {
      count: number;
      percentage: number;
      color: string;
      icon: string;
    }
  } {
    const categoryCounts: { [key: string]: number } = {};
    const uncategorized = { count: 0 };

    // Initialiser les compteurs
    PREDEFINED_CATEGORIES.forEach(cat => {
      categoryCounts[cat.name] = 0;
    });

    // Analyser chaque activité
    activities.forEach(activity => {
      const suggestedCategory = this.suggestCategory(activity.title, activity.description);
      
      if (suggestedCategory) {
        categoryCounts[suggestedCategory.name]++;
      } else {
        uncategorized.count++;
      }
    });

    const total = activities.length;
    const result: { [categoryName: string]: { count: number; percentage: number; color: string; icon: string } } = {};

    // Ajouter les catégories prédéfinies
    PREDEFINED_CATEGORIES.forEach(category => {
      const count = categoryCounts[category.name];
      result[category.name] = {
        count,
        percentage: total > 0 ? (count / total) * 100 : 0,
        color: category.color,
        icon: category.icon
      };
    });

    // Ajouter "Autre" si nécessaire
    if (uncategorized.count > 0) {
      result['Autre'] = {
        count: uncategorized.count,
        percentage: total > 0 ? (uncategorized.count / total) * 100 : 0,
        color: '#d1d5db',
        icon: '❓'
      };
    }

    return result;
  }

  /**
   * Retourne les tags suggérés pour une tâche
   */
  static getSuggestedTags(title: string, description?: string): string[] {
    const suggestions = this.suggestCategoriesWithScore(title, description);
    
    return suggestions
      .filter(s => s.confidence >= 30) // Seulement les suggestions avec 30%+ de confiance
      .slice(0, 2) // Maximum 2 suggestions
      .map(s => s.category.name);
  }
}