app/lib/risk_engine/hazard_ratios.dart

import '../models/models.dart';

/// Hazard ratios based on conservative estimates from meta-analyses.
/// All HRs are relative to optimal baseline (HR = 1.0).

double getSmokingHR(SmokingStatus status, int cigarettesPerDay) {
  switch (status) {
    case SmokingStatus.never:
      return 1.0;
    case SmokingStatus.former:
      return 1.3;
    case SmokingStatus.current:
      if (cigarettesPerDay < 10) return 1.8;
      if (cigarettesPerDay <= 20) return 2.2;
      return 2.8;
  }
}

double getAlcoholHR(AlcoholLevel level) {
  switch (level) {
    case AlcoholLevel.none:
    case AlcoholLevel.light:
      return 1.0;
    case AlcoholLevel.moderate:
      return 1.1;
    case AlcoholLevel.heavy:
      return 1.3;
    case AlcoholLevel.veryHeavy:
      return 1.6;
  }
}

double getSleepHR(double hours, bool consistent) {
  double hr;
  if (hours >= 7 && hours <= 8) {
    hr = 1.0;
  } else if (hours >= 6 && hours < 7) {
    hr = 1.05;
  } else if (hours < 6) {
    hr = 1.15;
  } else {
    // > 8 hours
    hr = 1.10;
  }

  // Inconsistent sleep schedule adds additional risk
  if (!consistent) {
    hr *= 1.05;
  }

  return hr;
}

double getActivityHR(ActivityLevel level) {
  switch (level) {
    case ActivityLevel.high:
      return 1.0;
    case ActivityLevel.moderate:
      return 1.05;
    case ActivityLevel.light:
      return 1.15;
    case ActivityLevel.sedentary:
      return 1.4;
  }
}

double getBmiHR(double bmi) {
  if (bmi >= 18.5 && bmi < 25) return 1.0;
  if (bmi >= 25 && bmi < 30) return 1.1;
  if (bmi >= 30 && bmi < 35) return 1.2;
  if (bmi >= 35 && bmi < 40) return 1.4;
  if (bmi >= 40) return 1.8;
  // Underweight
  return 1.15;
}

double getDrivingHR(DrivingExposure level) {
  switch (level) {
    case DrivingExposure.low:
      return 1.0;
    case DrivingExposure.moderate:
      return 1.02;
    case DrivingExposure.high:
      return 1.04;
    case DrivingExposure.veryHigh:
      return 1.08;
  }
}

double getWorkHoursHR(WorkHoursLevel level) {
  switch (level) {
    case WorkHoursLevel.normal:
      return 1.0;
    case WorkHoursLevel.elevated:
      return 1.05;
    case WorkHoursLevel.high:
      return 1.15;
    case WorkHoursLevel.extreme:
      return 1.3;
  }
}

/// Existing conditions modify baseline mortality but are NOT modifiable.
double getDiagnosisHR(Set<Diagnosis> diagnoses) {
  double hr = 1.0;
  for (final diagnosis in diagnoses) {
    switch (diagnosis) {
      case Diagnosis.cardiovascular:
        hr *= 1.5;
        break;
      case Diagnosis.diabetes:
        hr *= 1.4;
        break;
      case Diagnosis.cancer:
        hr *= 2.0;
        break;
      case Diagnosis.copd:
        hr *= 1.6;
        break;
      case Diagnosis.hypertension:
        hr *= 1.2;
        break;
    }
  }
  return hr;
}

/// Confidence levels for each behavior based on evidence quality.
Confidence getConfidenceForBehavior(String behaviorKey) {
  switch (behaviorKey) {
    case 'smoking':
    case 'alcohol':
    case 'activity':
      return Confidence.high;
    case 'sleep':
    case 'workHours':
      return Confidence.moderate;
    case 'driving':
      return Confidence.emerging;
    default:
      return Confidence.moderate;
  }
}

/// Display names for behaviors.
String getDisplayName(String behaviorKey) {
  switch (behaviorKey) {
    case 'smoking':
      return 'Smoking';
    case 'alcohol':
      return 'Alcohol Consumption';
    case 'sleep':
      return 'Sleep';
    case 'activity':
      return 'Physical Activity';
    case 'driving':
      return 'Driving Exposure';
    case 'workHours':
      return 'Work Hours';
    default:
      return behaviorKey;
  }
}