#include "rb_lapack.h"

extern VOID ssbgvx_(char* jobz, char* range, char* uplo, integer* n, integer* ka, integer* kb, real* ab, integer* ldab, real* bb, integer* ldbb, real* q, integer* ldq, real* vl, real* vu, integer* il, integer* iu, real* abstol, integer* m, real* w, real* z, integer* ldz, real* work, integer* iwork, integer* ifail, integer* info);


static VALUE
rblapack_ssbgvx(int argc, VALUE *argv, VALUE self){
  VALUE rblapack_jobz;
  char jobz; 
  VALUE rblapack_range;
  char range; 
  VALUE rblapack_uplo;
  char uplo; 
  VALUE rblapack_ka;
  integer ka; 
  VALUE rblapack_kb;
  integer kb; 
  VALUE rblapack_ab;
  real *ab; 
  VALUE rblapack_bb;
  real *bb; 
  VALUE rblapack_vl;
  real vl; 
  VALUE rblapack_vu;
  real vu; 
  VALUE rblapack_il;
  integer il; 
  VALUE rblapack_iu;
  integer iu; 
  VALUE rblapack_abstol;
  real abstol; 
  VALUE rblapack_q;
  real *q; 
  VALUE rblapack_m;
  integer m; 
  VALUE rblapack_w;
  real *w; 
  VALUE rblapack_z;
  real *z; 
  VALUE rblapack_work;
  real *work; 
  VALUE rblapack_iwork;
  integer *iwork; 
  VALUE rblapack_ifail;
  integer *ifail; 
  VALUE rblapack_info;
  integer info; 
  VALUE rblapack_ab_out__;
  real *ab_out__;
  VALUE rblapack_bb_out__;
  real *bb_out__;

  integer ldab;
  integer n;
  integer ldbb;
  integer ldq;
  integer ldz;

  VALUE rblapack_options;
  if (argc > 0 && TYPE(argv[argc-1]) == T_HASH) {
    argc--;
    rblapack_options = argv[argc];
    if (rb_hash_aref(rblapack_options, sHelp) == Qtrue) {
      printf("%s\n", "USAGE:\n  q, m, w, z, work, iwork, ifail, info, ab, bb = NumRu::Lapack.ssbgvx( jobz, range, uplo, ka, kb, ab, bb, vl, vu, il, iu, abstol, [:usage => usage, :help => help])\n\n\nFORTRAN MANUAL\n      SUBROUTINE SSBGVX( JOBZ, RANGE, UPLO, N, KA, KB, AB, LDAB, BB, LDBB, Q, LDQ, VL, VU, IL, IU, ABSTOL, M, W, Z, LDZ, WORK, IWORK, IFAIL, INFO )\n\n*  Purpose\n*  =======\n*\n*  SSBGVX computes selected eigenvalues, and optionally, eigenvectors\n*  of a real generalized symmetric-definite banded eigenproblem, of\n*  the form A*x=(lambda)*B*x.  Here A and B are assumed to be symmetric\n*  and banded, and B is also positive definite.  Eigenvalues and\n*  eigenvectors can be selected by specifying either all eigenvalues,\n*  a range of values or a range of indices for the desired eigenvalues.\n*\n\n*  Arguments\n*  =========\n*\n*  JOBZ    (input) CHARACTER*1\n*          = 'N':  Compute eigenvalues only;\n*          = 'V':  Compute eigenvalues and eigenvectors.\n*\n*  RANGE   (input) CHARACTER*1\n*          = 'A': all eigenvalues will be found.\n*          = 'V': all eigenvalues in the half-open interval (VL,VU]\n*                 will be found.\n*          = 'I': the IL-th through IU-th eigenvalues will be found.\n*\n*  UPLO    (input) CHARACTER*1\n*          = 'U':  Upper triangles of A and B are stored;\n*          = 'L':  Lower triangles of A and B are stored.\n*\n*  N       (input) INTEGER\n*          The order of the matrices A and B.  N >= 0.\n*\n*  KA      (input) INTEGER\n*          The number of superdiagonals of the matrix A if UPLO = 'U',\n*          or the number of subdiagonals if UPLO = 'L'.  KA >= 0.\n*\n*  KB      (input) INTEGER\n*          The number of superdiagonals of the matrix B if UPLO = 'U',\n*          or the number of subdiagonals if UPLO = 'L'.  KB >= 0.\n*\n*  AB      (input/output) REAL array, dimension (LDAB, N)\n*          On entry, the upper or lower triangle of the symmetric band\n*          matrix A, stored in the first ka+1 rows of the array.  The\n*          j-th column of A is stored in the j-th column of the array AB\n*          as follows:\n*          if UPLO = 'U', AB(ka+1+i-j,j) = A(i,j) for max(1,j-ka)<=i<=j;\n*          if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+ka).\n*\n*          On exit, the contents of AB are destroyed.\n*\n*  LDAB    (input) INTEGER\n*          The leading dimension of the array AB.  LDAB >= KA+1.\n*\n*  BB      (input/output) REAL array, dimension (LDBB, N)\n*          On entry, the upper or lower triangle of the symmetric band\n*          matrix B, stored in the first kb+1 rows of the array.  The\n*          j-th column of B is stored in the j-th column of the array BB\n*          as follows:\n*          if UPLO = 'U', BB(ka+1+i-j,j) = B(i,j) for max(1,j-kb)<=i<=j;\n*          if UPLO = 'L', BB(1+i-j,j)    = B(i,j) for j<=i<=min(n,j+kb).\n*\n*          On exit, the factor S from the split Cholesky factorization\n*          B = S**T*S, as returned by SPBSTF.\n*\n*  LDBB    (input) INTEGER\n*          The leading dimension of the array BB.  LDBB >= KB+1.\n*\n*  Q       (output) REAL array, dimension (LDQ, N)\n*          If JOBZ = 'V', the n-by-n matrix used in the reduction of\n*          A*x = (lambda)*B*x to standard form, i.e. C*x = (lambda)*x,\n*          and consequently C to tridiagonal form.\n*          If JOBZ = 'N', the array Q is not referenced.\n*\n*  LDQ     (input) INTEGER\n*          The leading dimension of the array Q.  If JOBZ = 'N',\n*          LDQ >= 1. If JOBZ = 'V', LDQ >= max(1,N).\n*\n*  VL      (input) REAL\n*  VU      (input) REAL\n*          If RANGE='V', the lower and upper bounds of the interval to\n*          be searched for eigenvalues. VL < VU.\n*          Not referenced if RANGE = 'A' or 'I'.\n*\n*  IL      (input) INTEGER\n*  IU      (input) INTEGER\n*          If RANGE='I', the indices (in ascending order) of the\n*          smallest and largest eigenvalues to be returned.\n*          1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0.\n*          Not referenced if RANGE = 'A' or 'V'.\n*\n*  ABSTOL  (input) REAL\n*          The absolute error tolerance for the eigenvalues.\n*          An approximate eigenvalue is accepted as converged\n*          when it is determined to lie in an interval [a,b]\n*          of width less than or equal to\n*\n*                  ABSTOL + EPS *   max( |a|,|b| ) ,\n*\n*          where EPS is the machine precision.  If ABSTOL is less than\n*          or equal to zero, then  EPS*|T|  will be used in its place,\n*          where |T| is the 1-norm of the tridiagonal matrix obtained\n*          by reducing A to tridiagonal form.\n*\n*          Eigenvalues will be computed most accurately when ABSTOL is\n*          set to twice the underflow threshold 2*SLAMCH('S'), not zero.\n*          If this routine returns with INFO>0, indicating that some\n*          eigenvectors did not converge, try setting ABSTOL to\n*          2*SLAMCH('S').\n*\n*  M       (output) INTEGER\n*          The total number of eigenvalues found.  0 <= M <= N.\n*          If RANGE = 'A', M = N, and if RANGE = 'I', M = IU-IL+1.\n*\n*  W       (output) REAL array, dimension (N)\n*          If INFO = 0, the eigenvalues in ascending order.\n*\n*  Z       (output) REAL array, dimension (LDZ, N)\n*          If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of\n*          eigenvectors, with the i-th column of Z holding the\n*          eigenvector associated with W(i).  The eigenvectors are\n*          normalized so Z**T*B*Z = I.\n*          If JOBZ = 'N', then Z is not referenced.\n*\n*  LDZ     (input) INTEGER\n*          The leading dimension of the array Z.  LDZ >= 1, and if\n*          JOBZ = 'V', LDZ >= max(1,N).\n*\n*  WORK    (workspace/output) REAL array, dimension (7N)\n*\n*  IWORK   (workspace/output) INTEGER array, dimension (5N)\n*\n*  IFAIL   (output) INTEGER array, dimension (M)\n*          If JOBZ = 'V', then if INFO = 0, the first M elements of\n*          IFAIL are zero.  If INFO > 0, then IFAIL contains the\n*          indices of the eigenvalues that failed to converge.\n*          If JOBZ = 'N', then IFAIL is not referenced.\n*\n*  INFO    (output) INTEGER\n*          = 0 : successful exit\n*          < 0 : if INFO = -i, the i-th argument had an illegal value\n*          <= N: if INFO = i, then i eigenvectors failed to converge.\n*                  Their indices are stored in IFAIL.\n*          > N : SPBSTF returned an error code; i.e.,\n*                if INFO = N + i, for 1 <= i <= N, then the leading\n*                minor of order i of B is not positive definite.\n*                The factorization of B could not be completed and\n*                no eigenvalues or eigenvectors were computed.\n*\n\n*  Further Details\n*  ===============\n*\n*  Based on contributions by\n*     Mark Fahey, Department of Mathematics, Univ. of Kentucky, USA\n*\n*  =====================================================================\n*\n\n");
      return Qnil;
    }
    if (rb_hash_aref(rblapack_options, sUsage) == Qtrue) {
      printf("%s\n", "USAGE:\n  q, m, w, z, work, iwork, ifail, info, ab, bb = NumRu::Lapack.ssbgvx( jobz, range, uplo, ka, kb, ab, bb, vl, vu, il, iu, abstol, [:usage => usage, :help => help])\n");
      return Qnil;
    } 
  } else
    rblapack_options = Qnil;
  if (argc != 12 && argc != 12)
    rb_raise(rb_eArgError,"wrong number of arguments (%d for 12)", argc);
  rblapack_jobz = argv[0];
  rblapack_range = argv[1];
  rblapack_uplo = argv[2];
  rblapack_ka = argv[3];
  rblapack_kb = argv[4];
  rblapack_ab = argv[5];
  rblapack_bb = argv[6];
  rblapack_vl = argv[7];
  rblapack_vu = argv[8];
  rblapack_il = argv[9];
  rblapack_iu = argv[10];
  rblapack_abstol = argv[11];
  if (argc == 12) {
  } else if (rblapack_options != Qnil) {
  } else {
  }

  jobz = StringValueCStr(rblapack_jobz)[0];
  uplo = StringValueCStr(rblapack_uplo)[0];
  kb = NUM2INT(rblapack_kb);
  if (!NA_IsNArray(rblapack_bb))
    rb_raise(rb_eArgError, "bb (7th argument) must be NArray");
  if (NA_RANK(rblapack_bb) != 2)
    rb_raise(rb_eArgError, "rank of bb (7th argument) must be %d", 2);
  ldbb = NA_SHAPE0(rblapack_bb);
  n = NA_SHAPE1(rblapack_bb);
  if (NA_TYPE(rblapack_bb) != NA_SFLOAT)
    rblapack_bb = na_change_type(rblapack_bb, NA_SFLOAT);
  bb = NA_PTR_TYPE(rblapack_bb, real*);
  vu = (real)NUM2DBL(rblapack_vu);
  iu = NUM2INT(rblapack_iu);
  range = StringValueCStr(rblapack_range)[0];
  if (!NA_IsNArray(rblapack_ab))
    rb_raise(rb_eArgError, "ab (6th argument) must be NArray");
  if (NA_RANK(rblapack_ab) != 2)
    rb_raise(rb_eArgError, "rank of ab (6th argument) must be %d", 2);
  ldab = NA_SHAPE0(rblapack_ab);
  if (NA_SHAPE1(rblapack_ab) != n)
    rb_raise(rb_eRuntimeError, "shape 1 of ab must be the same as shape 1 of bb");
  if (NA_TYPE(rblapack_ab) != NA_SFLOAT)
    rblapack_ab = na_change_type(rblapack_ab, NA_SFLOAT);
  ab = NA_PTR_TYPE(rblapack_ab, real*);
  il = NUM2INT(rblapack_il);
  ldz = lsame_(&jobz,"V") ? MAX(1,n) : 1;
  ldq = 1 ? jobz = 'n' : MAX(1,n) ? jobz = 'v' : 0;
  ka = NUM2INT(rblapack_ka);
  abstol = (real)NUM2DBL(rblapack_abstol);
  vl = (real)NUM2DBL(rblapack_vl);
  m = lsame_(&range,"A") ? n : lsame_(&range,"I") ? iu-il+1 : 0;
  {
    na_shape_t shape[2];
    shape[0] = ldq;
    shape[1] = n;
    rblapack_q = na_make_object(NA_SFLOAT, 2, shape, cNArray);
  }
  q = NA_PTR_TYPE(rblapack_q, real*);
  {
    na_shape_t shape[1];
    shape[0] = n;
    rblapack_w = na_make_object(NA_SFLOAT, 1, shape, cNArray);
  }
  w = NA_PTR_TYPE(rblapack_w, real*);
  {
    na_shape_t shape[2];
    shape[0] = ldz;
    shape[1] = n;
    rblapack_z = na_make_object(NA_SFLOAT, 2, shape, cNArray);
  }
  z = NA_PTR_TYPE(rblapack_z, real*);
  {
    na_shape_t shape[1];
    shape[0] = 7*n;
    rblapack_work = na_make_object(NA_SFLOAT, 1, shape, cNArray);
  }
  work = NA_PTR_TYPE(rblapack_work, real*);
  {
    na_shape_t shape[1];
    shape[0] = 5*n;
    rblapack_iwork = na_make_object(NA_LINT, 1, shape, cNArray);
  }
  iwork = NA_PTR_TYPE(rblapack_iwork, integer*);
  {
    na_shape_t shape[1];
    shape[0] = m;
    rblapack_ifail = na_make_object(NA_LINT, 1, shape, cNArray);
  }
  ifail = NA_PTR_TYPE(rblapack_ifail, integer*);
  {
    na_shape_t shape[2];
    shape[0] = ldab;
    shape[1] = n;
    rblapack_ab_out__ = na_make_object(NA_SFLOAT, 2, shape, cNArray);
  }
  ab_out__ = NA_PTR_TYPE(rblapack_ab_out__, real*);
  MEMCPY(ab_out__, ab, real, NA_TOTAL(rblapack_ab));
  rblapack_ab = rblapack_ab_out__;
  ab = ab_out__;
  {
    na_shape_t shape[2];
    shape[0] = ldbb;
    shape[1] = n;
    rblapack_bb_out__ = na_make_object(NA_SFLOAT, 2, shape, cNArray);
  }
  bb_out__ = NA_PTR_TYPE(rblapack_bb_out__, real*);
  MEMCPY(bb_out__, bb, real, NA_TOTAL(rblapack_bb));
  rblapack_bb = rblapack_bb_out__;
  bb = bb_out__;

  ssbgvx_(&jobz, &range, &uplo, &n, &ka, &kb, ab, &ldab, bb, &ldbb, q, &ldq, &vl, &vu, &il, &iu, &abstol, &m, w, z, &ldz, work, iwork, ifail, &info);

  rblapack_m = INT2NUM(m);
  rblapack_info = INT2NUM(info);
  return rb_ary_new3(10, rblapack_q, rblapack_m, rblapack_w, rblapack_z, rblapack_work, rblapack_iwork, rblapack_ifail, rblapack_info, rblapack_ab, rblapack_bb);
}

void
init_lapack_ssbgvx(VALUE mLapack, VALUE sH, VALUE sU, VALUE zero){
  sHelp = sH;
  sUsage = sU;
  rblapack_ZERO = zero;

  rb_define_module_function(mLapack, "ssbgvx", rblapack_ssbgvx, -1);
}
