#ifndef RLS_H
#define RLS_H

#include <stdint.h>

#define RLS_MAX_ORDER 4u

typedef struct
{
    uint8_t order;
    uint8_t initialized;
    float lambda;
    float theta[RLS_MAX_ORDER];
    float covariance[RLS_MAX_ORDER][RLS_MAX_ORDER];
    float gain[RLS_MAX_ORDER];
    float last_prediction;
    float last_error;
} RLSInstance;

void RLSInit(RLSInstance *rls, uint8_t order, float lambda, float init_covariance, const float *initial_theta);
float RLSPredict(const RLSInstance *rls, const float *x);
float RLSUpdate(RLSInstance *rls, const float *x, float y);
const float *RLSGetTheta(const RLSInstance *rls);

#endif