#include <iostream>
#include <cstdlib>
using namespace std;
#include <getopt.h>

// ----------------------------------------------
// description of possible arguments
// that can be used in
// - short format : -m 1 
// - or long format : --method=1
// ----------------------------------------------
static struct option long_options[] = {
	{"method",  required_argument, 0, 'm'},
	{"alpha",   required_argument, 0, 'a'},
	{"message", required_argument, 0, 's'},
	{"verbose", no_argument,       0, 'v'},
	{0,0,0,0}
	
};

// ----------------------------------------------
// Definition of a structure that will gather the
// parameters of the program
// ----------------------------------------------
typedef struct {
	int method;
	float alpha;
	char *message;
	bool verbose;
} Parameters;

Parameters params;

// ----------------------------------------------
// main function
// ----------------------------------------------
int main(int argc, char *argv[]) {

	params.verbose = false;
	
	if (argc <= 3) {
		cerr << "the program needs at least 3 arguments" << endl;
		cerr << argv[0] << " method alpha message" << endl; 
		exit(EXIT_FAILURE);
	}
	
	cout << "program's name = " << argv[0] << endl;
	for (int i=1; i<argc; ++i) {
		cout << "argument " << i << " = " << argv[i] << endl;
	}
	
	int option_index;
	while (true) {
		option_index = 0;
		// the format m: means that the 'm' option needs one argument
		// the option 'v' does not need argument so it is listed as 'v' 
        int c = getopt_long(argc, argv, "m:a:s:v", long_options, &option_index);
        if (c == -1) break;

		switch(c) {
			case 'm':
				params.method = atoi(optarg); 
				break;
			case 'a':
				params.alpha = atof(optarg);
				break;
			case 's':
				params.message = optarg;	
				break;
			case 'v':
				params.verbose = true;
				break;	
		}
	}
	
	if (params.verbose) {
		cout << "method = " << params.method << endl;
		cout << "alpha = " << params.alpha << endl;
		cout << "message = " << params.message << endl;
	}
	
	return EXIT_SUCCESS;	
}