/*-*- compile-command: "/usr/bin/gcc -c -o mainEK.gp.o -O3 -Wall -fno-strict-aliasing -fomit-frame-pointer -fPIC -I\"/usr/local/include\" mainEK.gp.c && /usr/bin/gcc -o mainEK.gp.so -bundle -undefined dynamic_lookup -O3 -Wall -fno-strict-aliasing -fomit-frame-pointer -fPIC mainEK.gp.o "; -*-*/
#include <pari/pari.h>
/*
GP;install("my_init_mainEK","v","init_mainEK","./mainEK.gp.so");
GP;install("my_mainEK","vD0,G,","mainEK","./mainEK.gp.so");
*/
void my_init_mainEK(void);
void my_mainEK(GEN my_q);
/*End of prototype*/

void
my_init_mainEK(void)	  /* void */
{
  pari_sp ltop = avma;
  avma = ltop;
  return;
}

/*
Copyright (C) 2019 Alessandro Languasco
*/

/****************   	A. LANGUASCO  		******************** 
************* COMPUTATION OF THE EULER KRONECKER CONSTANTS MOD q(PRIME) *******/


/*****************   Precomputations for the external C program   ****************/
/* \p needed to decide the precision  default (format, f)  for the floating point  */

void
my_mainEK(GEN my_q)	  /* void */
{
  pari_sp ltop = avma;
  GEN my_g = gen_0, my_g1 = gen_0, my_minutes = gen_0, my_millisec = gen_0, my_seconds = gen_0, my_elaptimeprecomp = gen_0, my_prootfile = gen_0, my_f = pol_x(fetch_user_var("f"));
  default0("format", GENtostr_unquoted(my_f));
  /* print numbers with floating point notation (not E notation) */
  
  if ((gequal0(gisprime(my_q, 0))) || gequalgs(my_q, 2))
  {
    pari_printf("****** error: q has to be an odd prime ******\n");
    avma = ltop;
    return;
  }
  /* initialization */ 
  
  my_prootfile = stoi(gp_fileopen("./primroot.res", "w"));
  gp_filewrite(gtos(my_prootfile), GENtostr_unquoted(my_q));
  gettime();
  pari_printf("Computing the primitive root for q = %Ps and saving on file\n", my_q);
  my_g1 = znprimroot(my_q);
  my_g = lift(my_g1);
  my_elaptimeprecomp = stoi(gettime());
  gp_filewrite(gtos(my_prootfile), GENtostr_unquoted(my_g));
  gp_fileclose(gtos(my_prootfile));
  /* print computation time */
  my_seconds = gmodgs(gfloor(gdivgs(my_elaptimeprecomp, 1000)), 60);
  my_minutes = gfloor(gdivgs(my_elaptimeprecomp, 60000));
  my_millisec = gsub(gsub(my_elaptimeprecomp, gmulgs(my_minutes, 60000)), gmulgs(my_seconds, 1000));
  /*print(elaptimeprecomp);  */
  pari_printf("Primitive root generation time: %Ps min, %Ps sec, %Ps millisec\n", my_minutes, my_seconds, my_millisec);
  pari_printf("******************************************\n");
  pari_printf("Now you can call the precomputation programs\n");
  pari_printf("******************************************\n");
  avma = ltop;
  return;
}