#include <cstdlib>
#include <sys/time.h>
#include <iostream>
#include <math.h>
#include "Heuristics.h"
using namespace std;


int             param_N;        // use N items                          
double          param_u;        // pick weights between [0,u]  for u<1  
bool            param_useFast;  // if true, use FastPQ
bool            param_verbose;  // if true, print verbose output.      
unsigned long   param_seed;     // seed for random number generator (if desired)


void generateWeights(double* w, int N, double u, long seed = (unsigned)time(NULL)) {
  srandom(seed);
  for (int i = 0; i<N; i++) w[i] = u*((double) random())/(((double) (RAND_MAX))+1.0);
}


void runTrial(int N, double u, bool useFast, bool verbose, long seed) {
  struct timeval  starttime,endtime;
  long diff;

  double* w = new double[N];
  generateWeights(w,N,u,seed);

  if (verbose) { 
    cout << "Original weights:\n  ";
    for (int i = 0; i<N; i++) {
      cout << w[i];
      if (i!=N-1) {
	cout << ", ";
  	if ((i%10)==9) cout << endl << "  ";
      }
    }
    cout << endl << endl;
  }


  double sum = 0.0;
  for (int i = 0; i<N; i++) {
    sum += w[i];
  }
  double round = ceil(sum);

  cout << "The sum of the weights is equal to " << sum <<  " and so\n";
  cout << "  any valid solution will require at least " << ((long) round) << " bins." << endl << endl;

  int numbins = 0;

  gettimeofday(&starttime,NULL);
  numbins = worstFit(w,N,false,useFast,verbose);
  gettimeofday(&endtime,NULL);

  cout << endl << "worstFit claims a solution using " << numbins << " bins." << endl;
  diff = (endtime.tv_sec - starttime.tv_sec)*1000;
  diff += (endtime.tv_usec - starttime.tv_usec)/1000;
  cout << "The time used was " << diff/1000.0 << " seconds." << endl << endl;


  // regenerate original weights (in case corrupted)
  generateWeights(w,N,u,seed);

  gettimeofday(&starttime,NULL);
  numbins = worstFit(w,N,true,useFast,verbose);
  gettimeofday(&endtime,NULL);

  cout << endl << "worstFitDecreasing claims a solution using " << numbins << " bins." << endl;
  diff = (endtime.tv_sec - starttime.tv_sec)*1000;
  diff += (endtime.tv_usec - starttime.tv_usec)/1000;
  cout << "The time used was " << diff/1000.0 << " seconds.\n";

  delete [] w;
}


bool getArguments(int argc, const char* argv[]) {
    bool valid = true;
    char *endptr;

    if (argc<5) {
      cout << "This program requires the following command-line arguments,\n";
      cout << "  - first  argument = N (number of items to pack).\n";
      cout << "  - second argument = u (paramater 0 < u <= 1, gives range for weights).\n";
      cout << "  - third  argument = 0 for slowPQ, 1 for fastPQ.\n";
      cout << "  - fourth argument = 0 for brief output, 1 for verbose output.\n";
      cout << "  - fifth argument (optional) = 'seed' value for random number generator.\n";
      valid = false;
    } else {

      param_N = strtol(argv[1],&endptr,10);
      if (endptr==argv[1] || param_N < 1) {
	cout << "first  argument = N (number of items to pack).\n";
	cout << "  (argument given was '" << argv[1] << "')\n";
	valid = false;
      }

      
      param_u = strtod(argv[2],&endptr);
      if (endptr==argv[2] || param_u <= 0.0 || param_u > 1.0) {
	cout << "second  argument = u  (paramater 0 < u <= 1, gives range for weights).\n";
	cout << "  (argument given was '" << argv[2] << "')\n";
	valid = false;
      }

      param_useFast = (argv[3][0]=='1');
      if (argv[3][0] != '0' && argv[3][0] != '1') {
	cout << "third argument should be '0' for slowPQ or '1' for fastPQ.\n";
	cout << "  (argument given was '" << argv[3] << "')\n";
	valid = false;
      }


      param_verbose = (argv[4][0]=='1');
      if (argv[4][0] != '0' && argv[4][0] != '1') {
	cout << "fourth argument should be '0' for brief output or '1' for verbose output.\n";
	cout << "  (argument given was '" << argv[4] << "')\n";
	valid = false;
      }


      if (valid) {
	if (argc>5) {
	  param_seed = strtoul(argv[5],&endptr,10);
	  if (endptr==argv[5]) {
	    cout << "fifth argument (optional) = 'seed' value for random number generator.\n";
	    cout << "  (argument given was '" << argv[5] << "')\n";
	    valid = false;
	  }
	} else {
	  // use clock as seed
	  param_seed =  (unsigned)time(NULL);
	}
      }
    }


    if (valid) {
      cout << "------------------------------------------\n";
      cout << "Parameters:\n";
      cout << "  N=" << param_N << ", u=" << param_u << ".\n";
      cout << "  PQ: " << (param_useFast ? "fast" : "slow") <<  ".\n";
      cout << "  Verbose output: " << (param_verbose ? "yes" : "no") <<  ".\n";
      cout << "  Random Seed: " << param_seed << ".\n";
      cout << "------------------------------------------\n";
      cout << "\n";
    }


    return(valid);
}




int main(int argc, const char* argv[]) {

  if (getArguments(argc,argv))
    runTrial(param_N,param_u,param_useFast,param_verbose,param_seed);

  return(0);
}