#include <cmath>
#include <cstdlib>
#include <iostream>
#include <sstream>
#include "jacobi.hpp"
#include "matrix.hpp"

char* cmdname;
void usage() {
   std::cerr << "Usage: " << cmdname << " eps n nofthreads" << 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;
   unsigned int nofthreads;

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

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

   Jacobi<double> jacobi([=](double x, double y) -> double {
	 if (y == 0) {
	    return sin(M_PI * x);
	 } else if (y == 1) {
	    return sin(M_PI * x) * E_POWER_MINUS_PI;
	 } else {
	    return 0;
	 }
      }, n, eps, nofthreads);
   std::cout << n+2 << std::endl << jacobi.get_result();
}