#include <ctype.h>
#include <stdlib.h>

#include <iostream>
#include <stdexcept>
#include <string>

#include "replacement.h"
#include "readtest.h"
#include "lru.h"
#include "fifo.h"
#include "nru.h"
//#include "clock.h"
//#include "aging.h"

using std::string;

class Args {
public:
	Args(int argc, char **argv): m_argc(argc), m_argv(argv),
				     m_lastexists("argument") {
		m_name = *m_argv++;
		--m_argc;
	}

	char *program_name() { return m_name; }

	// If there are no more arguments, print a message using msg, and
	// exit.  Otherwise, return *this.
	Args & exists(string msg = "argument")
	{
		if(m_argc <= 0) {
			std::cout << msg << " missing" << std::endl;
			exit(1);
		}
		m_lastexists = msg;
		return *this;
	}

	// Get the next argument, with given default value if absent.
	char *next(char *dflt = NULL) {
		if(m_argc <= 0) return dflt;
		char *ret = *m_argv++;
		--m_argc;
		return ret;
	}

	// Get the next argument as an integer value with the indicated
	// default, and the indicated msg.  If the message is blank, use 
	// the previous one from exists(), if any.
	int nexti(int dflt = 0, string msg = "") {
		if(m_argc <= 0) return dflt;
		char *ret = next();
		if(!isdigit(*ret)) {
			if(msg == "") msg = m_lastexists;
			if(msg == "") msg = "numeric argument";
			std::cout << msg << " is not numeric: " << ret
				  << std::endl;
			exit(1);
		}
		m_lastexists = "";
		return atoi(ret);
	}
	int nexti(string msg) {
		return nexti(0, msg);
	}

private:
	char *m_name;		// Program name.
	int m_argc;		// Number of remaining args.
	char **m_argv;		// Remaining args.
	string m_lastexists;	// Keep the string from exists() as default
				// message for required arguments.
};

int main(int argc, char **argv)
{
	Args args(argc, argv);

	// Get the basic stuff from the command line: 
	char *tracefile = args.exists("file name").next();
	string algname = args.exists("algorithm").next();
	int nframe = args.exists("frame count").nexti();
	int pagebits = args.nexti(12);

	// Create the algorithm object.
	ReplacementAlg *alg;
	if(algname == "readtest") 
		alg = new ReadTest;
	else if(algname == "lru") 
		alg = new LRUReplacementAlg(nframe, pagebits);
	else if(algname == "nru") 
		alg = new NRUReplacementAlg(nframe, pagebits,
					    args.nexti(100));
	else if(algname == "fifo") 
		alg = new FIFOReplacementAlg(nframe, pagebits);
//	else if(algname == "clock") 
//		alg = new ClockReplacementAlg(nframe, pagebits);
//	else if(algname == "aging") 
//		alg = new AgingReplacementAlg(nframe, pagebits,
//					      args.nexti(500));
	else {
		std::cerr << "Unknown or unimplemented replacement algorithm "
			  << algname << std::endl;
		exit(2);
	}

	try {
		alg->read(tracefile);
	} catch(std::exception &e) {
		std::cerr << "Failed: " << e.what() << std::endl;
	}

	alg->print_stats(std::cout);
}