/* Include Guard */
#ifndef CVE_INCLUDE_GUARD_H_
#define CVE_INCLUDE_GUARD_H_

#include <string.h> // `mem*` functions.
#include <math.h>   // sqrt, exp, ...

#include <R.h>
#include <Rinternals.h>
#include <R_ext/BLAS.h>
#include <R_ext/Lapack.h>

#define CVE_MEM_CHUNK_SIZE 2032
#define CVE_MEM_CHUNK_SMALL 1016

/* Bis masks for method types */
#define CVE_METHOD_WEIGHTED 1

// typedef struct {
//     unsigned int nrow;
//     unsigned int ncol;
//     unsigned int memsize;
//     double *data;
// } mat;

// mat* Matrix(const unsigned int nrow, const unsigned int ncol);

void cve_sub(const int n, const int p, const int q,
             const double *X, const double *Y, const double h,
             const unsigned int method,
             const double momentum,
             const double tau_init, const double tol_init,
             const double slack, const double gamma,
             const int maxIter, int attempts,
             double *V, double *L,
             SEXP logger, SEXP loggerEnv);

void callLogger(SEXP logger, SEXP env,
                const int attempt, const int epoch,
                const double* L, const int lenL,
                const double* V, const int nrowV, const int ncolV,
                const double tau);

/* CVE sub-routines */
int getWorkLen(const int n, const int p, const int q);
double cost(const unsigned int method,
            const int n,
            const double *Y,
            const double *vecK,
            const double *colSums,
            double *y1, double *L);
void scaling(const unsigned int method,
             const int n,
             const double *Y, const double *y1, const double *L,
             const double *vecD, const double *vecK,
             const double *colSums,
             double *vecS);

/* rStiefel */
void rStiefel(const int p, const int q, double *V,
              double *workMem, int workLen);

/* MATRIX */
double sum(const double *A, const int nelem);

double norm(const double *A, const int nrow, const int ncol,
            const char *type);

void matrixprod(const double *A, const int nrowA, const int ncolA,
                const double *B, const int nrowB, const int ncolB,
                double *C);

void crossprod(const double *A, const int nrowA, const int ncolA,
               const double *B, const int nrowB, const int ncolB,
               double *C);

void skew(const int nrow, const int ncol,
          double alpha, const double *A, const double *B,
          double beta,
          double *C);

void nullProj(const double *B, const int nrowB, const int ncolB,
              double *Q);

void scale(const double s, double *A, const int nelem);

void cayleyTransform(const int p, const int q,
                     const double *A, const double *B,
                     double *X, double *workMem);

/* Row and column opperations. */
void rowSums(const double *A, const int nrow, const int ncol,
             double *sum);

void colSums(const double *A, const int nrow, const int ncol,
             double *sum);

void rowSquareSums(const double *A, const int nrow, const int ncol,
                   double *sum);

void rowSumsSymVec(const double *Avec, const int nrow,
                   const double diag,
                   double *sum);

void rowDiffs(const double* X, const int nrow, const int ncol,
              double *diffs);

void rowDiffSquareSums(const double* X, const int nrow, const int ncol,
                       double *sum);

/* SWEEP */
void rowSweep(const double *A, const int nrow, const int ncol,
              const char* op,
              const double *v, // vector of length nrow
              double *C);

#endif /* CVE_INCLUDE_GUARD_H_ */