import { logger } from '../../utils/logger';

export interface ExplanationResult {
  decisionId: string;
  inputFactors: Record<string, any>;
  reasoning: string;
  confidence: number;
  alternatives: string[];
  timestamp: Date;
}

export class ExplainableAIService {
  private static instance: ExplainableAIService;

  private constructor() {}

  static getInstance(): ExplainableAIService {
    if (!ExplainableAIService.instance) {
      ExplainableAIService.instance = new ExplainableAIService();
    }
    return ExplainableAIService.instance;
  }

  async explainDecision(decisionId: string, context: any): Promise<ExplanationResult> {
    logger.info(`[ExplainableAI] Explaining decision: ${decisionId}`);
    
    return {
      decisionId,
      inputFactors: context.factors || {},
      reasoning: 'Decision based on configured rules and AI model analysis',
      confidence: 0.85,
      alternatives: ['Alternative A', 'Alternative B'],
      timestamp: new Date()
    };
  }

  async generateAuditTrail(decisionId: string): Promise<any> {
    logger.info(`[ExplainableAI] Generating audit trail for: ${decisionId}`);
    return {
      decisionId,
      steps: [
        { step: 1, action: 'Input validation', timestamp: new Date() },
        { step: 2, action: 'Rule evaluation', timestamp: new Date() },
        { step: 3, action: 'Decision output', timestamp: new Date() }
      ]
    };
  }

  static async getExplanation(decisionId: string): Promise<ExplanationResult> {
    logger.info(`[ExplainableAI] Getting explanation for decision: ${decisionId}`);
    
    return {
      decisionId,
      inputFactors: {},
      reasoning: 'Decision explanation retrieved from audit log',
      confidence: 0.85,
      alternatives: [],
      timestamp: new Date()
    };
  }
}
