#include <cmath>
#include <cstdlib>
#include <iostream>
#include <sstream>
#include <hpc/aux/hsvcolor.h>
#include <hpc/matvec/gematrix.h>
#include <hpc/matvec/matrix2pixbuf.h>
#include "jacobi.hpp"

char* cmdname;
void usage() {
   std::cerr << "Usage: " << cmdname << " eps n" << std::endl;
   exit(1);
}

template<typename T>
bool next_arg(int& argc, char**& argv, T& val) {
   if (argc == 0) return false;
   std::istringstream arg(*argv++); --argc;
   return !!(arg >> val);
}

int main(int argc, char** argv) {
   double eps;
   unsigned int n;

   cmdname = *argv++; --argc;
   if (!next_arg(argc, argv, eps) || eps <= 0) usage();
   if (!next_arg(argc, argv, n) || n == 0) usage();
   if (argc > 0) usage();

   const double E_POWER_MINUS_PI = pow(M_E, -M_PI);

   using T = double;
   using namespace hpc::matvec;
   GeMatrix<T> A(n+2, n+2, StorageOrder::RowMajor);
   jacobi([=](T x, T y) -> T {
	 if (y == 0) {
	    return sin(M_PI * x);
	 } else if (y == 1) {
	    return sin(M_PI * x) * E_POWER_MINUS_PI;
	 } else {
	    return 0;
	 }
      }, A, eps);

   using namespace hpc::aux;
   auto pixbuf = create_pixbuf(A, [](double val) -> HSVColor<double> {
      return HSVColor<double>((1-val) * 240, 1, 1);
   }, 8);
   gdk_pixbuf_save(pixbuf, "jacobi.jpg", "jpeg", nullptr,
      "quality", "100", nullptr);
}