import { generateResponse } from './llmClient.js';
import Warning, { WarningType, WarningSeverity } from '../models/Warning.js';
import Patient from '../models/Patient.js';
import dotenv from 'dotenv';

dotenv.config();

// Re-export enums for backward compatibility
export { WarningType, WarningSeverity };

class WarningService {
  /**
   * Get all warnings for a patient
   */
  async getPatientWarnings(patientId, includeAcknowledged = false) {
    const warnings = await Warning.findByPatient(patientId, includeAcknowledged);
    return warnings.map(w => w.toResponse());
  }
  
  /**
   * Get all unacknowledged warnings across all patients
   */
  async getAllUnacknowledgedWarnings(limit = 50) {
    const warnings = await Warning.findUnacknowledged(limit);
    return warnings.map(w => w.toResponse());
  }
  
  /**
   * Acknowledge a clinical warning
   */
  async acknowledgeWarning(warningId, userId, notes = null) {
    try {
      const warning = await Warning.findById(warningId);
      
      if (!warning) {
        return null;
      }
      
      await warning.acknowledge(userId, notes);
      return warning.toResponse();
    } catch {
      return null;
    }
  }
  
  /**
   * Create a new clinical warning
   */
  async createWarning(warningData) {
    const warning = new Warning(warningData);
    await warning.save();
    return warning.toResponse();
  }
  
  /**
   * Delete all warnings for a patient
   */
  async deletePatientWarnings(patientId) {
    const result = await Warning.deleteMany({ patient_id: patientId });
    return result.deletedCount;
  }
  
  /**
   * Use AI to analyze patient data and generate clinical warnings
   */
  async analyzePatientForWarnings(patientId, newMedication = null, newCondition = null) {
    const patient = await Patient.findById(patientId);
    
    if (!patient) {
      return [];
    }
    
    // Build the analysis prompt
    const medications = patient.medications || [];
    const medNames = medications
      .filter(m => typeof m === 'object')
      .map(m => m.name || '');
    
    let conditions = patient.medical_history || [];
    
    if (newMedication) {
      medNames.push(`${newMedication} (NEW)`);
    }
    if (newCondition) {
      conditions = [...conditions, `${newCondition} (NEW)`];
    }
    
    const conditionsText = conditions.map(c => {
      if (typeof c === 'string') return c;
      return c.condition || 'Unknown';
    }).join(', ');
    
    const prompt = `You are a clinical decision support AI. Analyze this patient's data for potential clinical warnings.

PATIENT INFORMATION:
- Age: ${patient.age || 'Unknown'}
- Gender: ${patient.gender || 'Unknown'}
- Medical Conditions: ${conditionsText || 'None recorded'}
- Current Medications: ${medNames.join(', ') || 'None recorded'}

Analyze for:
1. DRUG INTERACTIONS - Check if any medications interact negatively with each other
2. CONTRAINDICATIONS - Check if any medications are contraindicated given the patient's conditions
3. ALLERGY RISKS - Common allergy cross-reactions
4. DOSAGE CONCERNS - Age-related dosage considerations
5. DUPLICATE THERAPY - Multiple drugs for the same purpose

Return a JSON array of warnings. Each warning should have:
- warning_type: one of "drug_interaction", "allergy", "contraindication", "abnormal_pattern", "dosage_alert", "duplicate_therapy"
- severity: one of "low", "medium", "high", "critical"
- title: short title (max 50 chars)
- description: detailed explanation
- related_medications: array of medication names involved
- related_conditions: array of conditions involved
- recommendation: suggested action

If there are no warnings, return an empty array [].
Return ONLY valid JSON, no markdown or other text.`;

    try {
      let responseText = await generateResponse(prompt);
      responseText = responseText.trim();
      
      // Remove markdown code blocks if present
      if (responseText.startsWith('```')) {
        responseText = responseText.split('```')[1];
        if (responseText.startsWith('json')) {
          responseText = responseText.substring(4);
        }
      }
      responseText = responseText.trim();
      
      const warningsData = JSON.parse(responseText);
      
      if (!Array.isArray(warningsData)) {
        return [];
      }
      
      // Create warnings in database
      const createdWarnings = [];
      for (const warningData of warningsData) {
        try {
          const warning = new Warning({
            patient_id: patientId,
            warning_type: warningData.warning_type || 'general',
            severity: warningData.severity || 'medium',
            title: (warningData.title || 'Clinical Warning').substring(0, 100),
            description: warningData.description || '',
            related_medications: warningData.related_medications || [],
            related_conditions: warningData.related_conditions || [],
            recommendations: warningData.recommendation ? [warningData.recommendation] : [],
            source: 'ai_analysis'
          });
          
          await warning.save();
          createdWarnings.push(warning.toResponse());
        } catch (error) {
          console.log(`Error creating warning: ${error.message}`);
          continue;
        }
      }
      
      return createdWarnings;
    } catch (error) {
      if (error instanceof SyntaxError) {
        console.log(`JSON parse error: ${error.message}`);
      } else {
        console.log(`Error analyzing patient: ${error.message}`);
      }
      return [];
    }
  }
  
  /**
   * Get warning statistics
   */
  async getWarningStats() {
    return await Warning.getStats();
  }
}

// Singleton instance
export const warningService = new WarningService();