include/confidence/calibration.hpp

#ifndef GAIA_CONFIDENCE_CALIBRATION_HPP
#define GAIA_CONFIDENCE_CALIBRATION_HPP

#include <vector>
#include <cmath>
#include <iostream>

namespace gaia {
namespace confidence {

struct Prediction {
    double predicted;
    double observed;
    double variance;
    double confidence;
};

class Calibration {
public:
    Calibration() : brier_score(0.0) {}
    
    void add_prediction(double predicted, double observed, double variance) {
        Prediction p;
        p.predicted = predicted;
        p.observed = observed;
        p.variance = variance;
        p.confidence = compute_confidence(variance);
        predictions.push_back(p);
    }
    
    double compute_confidence(double variance) {
        double max_variance = 1.0;
        double conf = 1.0 - variance / max_variance;
        return std::max(0.0, std::min(1.0, conf));
    }
    
    void calibrate() {
        double sum = 0.0;
        for (const auto& p : predictions) {
            sum += (p.predicted - p.observed) * (p.predicted - p.observed);
        }
        brier_score = sum / (predictions.size() + 1e-12);
        
        std::cout << "Confidence Calibration:\n";
        std::cout << "Brier score: " << brier_score << "\n";
        if (brier_score < 0.1) std::cout << "✅ Excellent\n";
        else if (brier_score < 0.2) std::cout << "✅ Good\n";
        else if (brier_score < 0.3) std::cout << "⚠️ Moderate\n";
        else std::cout << "❌ Poor\n";
        
        for (const auto& p : predictions) {
            if (p.confidence < 0.7) {
                std::cout << "  Flag: confidence " << p.confidence * 100 << "%\n";
            }
        }
    }

private:
    double brier_score;
    std::vector<Prediction> predictions;
};

} // namespace confidence
} // namespace gaia

#endif