// route_sim.c++ by Brett Tjaden

#include "route_sim.h"

void run_route_sim();
int test_path(string src, string dest);

int main(int argc,char **argv)
{
  int status = -1;
  if (argc > 2)       // Error: too many arguments
    {
      cout << "Usage: " << argv[0] << " [conf_file]" << endl;
      exit(-1);
    }
  else if (argc == 1) // read conf_file from standard input
    status=yyparse();
  else                // read conf_file from file
    {
      FILE *yyin;
      yyin=freopen(argv[1],"r",stdin);
      if (yyin != NULL)
	status=yyparse(); // call the parser
      else
	{
	  cout << "Error opening input file: " << argv[1] << endl;
	  exit(-1);
	}
    }
  if (status == 0)   // Everything worked! Data structures should be full.
    run_route_sim(); // so go run the simulation
  else
    cout << "Error parsing input file." << endl;
  exit(status);
}

void print_conf()
{
  cout << "Here is the configuration of the internet:" << endl;
  for (vector<struct host>::iterator i=hosts.begin(); i != hosts.end(); i++)
    {
      cout << "\t" << (*i).name << ":" << endl;
      for (vector<struct interface>::iterator j=(*i).interfaces.begin(); j != (*i).interfaces.end(); j++)
	cout << "\t\t" << (*j).name << "\t" << (*j).ip_address << "\t" << (*j).netmask << endl;
    }
}

void print_routing_tables()
{
  cout << "Here are the routing tables:" << endl;
  for (vector<struct routing_table>::iterator i=tables.begin(); i != tables.end(); i++)
    {
      cout << "\t" << (*i).hostname << ":" << endl;
      for (vector<struct table_entry>::iterator j=(*i).table.begin(); j != (*i).table.end(); j++)
	cout << "\t\t" << (*j).target << "\t" << (*j).netmask << "\t" << (*j).next_hop << endl;
    }
}

void print_tests()
{
  cout << "Here are the tests to be run:" << endl;
  for (vector<struct test>::iterator i=tests.begin(); i != tests.end(); i++)
    cout << "\t" << (*i).src << " -> " << (*i).dest << endl;
  cout << endl;
}

void run_tests()
{
  // For each path to be tested, call the test_path routine.
  // Report any of the tested paths that failed (due to a bad routing entry).
  for (vector<struct test>::iterator i=tests.begin(); i != tests.end(); i++)
    {
      int result=FAIL;
      result=test_path((*i).src,(*i).dest);
      if (result==FAIL)
	cout << "FAILED: " << (*i).src << " -> " << (*i).dest << endl;
    }
}

void run_route_sim()
{
  // These routines are provided to give you an example of how you can
  // access all the information stored in the various data structures.
  // 
  // print_conf();
  // print_routing_tables();
  // print_tests();
  run_tests();
}

int test_path(string src, string dest)
{
  // This routine (and probably several supporting routines) is yours to
  // write. You will do yourself a big favor if you develop and test 
  // functionality in incremental stages and include lots of diagnostic
  // code so that you can follow the simulation (especially when things go
  // wrong). Here is an outline of how you can code this routine:
  //
  // let current_host = src and end_host = dest
  // while (current_host is not the same as end_host) {
  //   Use current_host's routing table to make a routing decision (next_hop)
  //   Check that the routing decision if valid (i.e. current_host and
  //                      next_hop's interface are on the same subnet)
  //   If not valid return FAIL
  //   else current_host = next_hop
  // }
  // return SUCCESS

  // That's the end of the pseudocode. Right now this routine is just a stub
  // that always returns FAIL.
  return(FAIL);
}