#include "Memory.h"
#include <fstream>
#include <string>
#include <iostream>
#include <regex>

using std::ifstream;
using std::string;
using std::cout;
using std::cin;
using std::endl;
using std::regex;

int MQ(0),
	AC(0);
bool error(false);
Memory memory;

void execute(int command, int address)
{
	string tmp;
	if (command == 0)
	{
		AC = MQ;
	}
	else if (command == 1)
	{
		tmp = memory.get(address);
		MQ = atoi(tmp.c_str());
	}
	else if (command == 2)
	{
		tmp = memory.get(address);
		AC = atoi(tmp.c_str());
	}
	else if (command == 3)
	{
		tmp = std::to_string(AC);
		memory.set(address, tmp);
	}
	else if (command == 4)
	{
		tmp = memory.get(address);
		AC = -atoi(tmp.c_str());
	}
	else if (command == 5)
	{
		tmp = memory.get(address);
		AC = abs(atoi(tmp.c_str()));
	}
	else if (command == 6)
	{
		tmp = memory.get(address);
		AC = -abs(atoi(tmp.c_str()));
	}
}

bool decode(string data)
{
	int	address;
	string tmp;
	std::match_results<std::string::const_iterator> result;

	regex p1("(L|l)oad MQ");
	regex p2("(L|l)oad MQ,M\\((\\d{1,3})\\)");
	regex p3("(L|l)oad M\\((\\d{1,3})\\)");
	regex p4("(S|s)tor M\\((\\d{1,3})\\)");
	regex p5("(L|l)oad -M\\((\\d{1,3})\\)");
	regex p6("(L|l)oad \\|M\\((\\d{1,3})\\)\\|");
	regex p7("(L|l)oad -\\|M\\((\\d{1,3})\\)\\|");
	regex p8("halt");
	regex p9("begin");
	regex p10("\\.\.*");
	regex p11("([a-zA-Z][a-zA-Z0-9]|\\d+)");
	regex p12("nop");


	if (std::regex_match(data, result, p2))
	{
		cout << endl << 1 << endl;
		tmp = result[2];
		address = atoi(tmp.c_str());
		execute(1, address);
		return false;
	}
	else if (std::regex_match(data, result, p1))
	{
		cout << endl << 0 << endl;
		address = -1;
		execute(0, address);
		return false;
	}
	else if (std::regex_match(data, result, p3))
	{
		cout << endl << 2 << endl;
		tmp = result[2];
		address = atoi(tmp.c_str());
		execute(2, address);
		return false;
	}
	else if (std::regex_match(data, result, p4))
	{
		cout << endl << 3 << endl;
		tmp = result[2];
		address = atoi(tmp.c_str());
		execute(3, address);
		return false;
	}
	else if (std::regex_match(data, result, p5))
	{
		cout << endl << 4 << endl;
		tmp = result[2];
		address = atoi(tmp.c_str());
		execute(4, address);
		return false;
	}
	else if (std::regex_match(data, result, p6))
	{
		cout << endl << 5 << endl;
		tmp = result[2];
		address = atoi(tmp.c_str());
		execute(5, address);
		return false;
	}
	else if (std::regex_match(data, result, p7))
	{
		cout << endl << 6 << endl;
		tmp = result[2];
		address = atoi(tmp.c_str());
		execute(6, address);
		return false;
	}
	else if (std::regex_match(data, result, p8))
	{
		cout << endl << 7 << endl;
		return true;
	}
	else if (std::regex_match(data, result, p9))
	{
		cout << endl << 8 << endl;
		return false;
	}
	else if (std::regex_match(data, result, p10))
	{
		cout << endl << 9 << endl;
		return false;
	}
	else if (std::regex_match(data, result, p11))
	{
		cout << endl << 10 << endl;
		return false;
	}
	else if (std::regex_match(data, result, p12))
	{
		cout << endl << 11 << endl;
		return false;
	}
	else
	{
		cout << "Error: Data could not be processed." << endl;
		error = true;
		return false;
	}
}

int main()
{
	string filename,
		line,
		MBR,
		IR;
	int PC,
		MAR;
	bool halt(false);

	cout << "Input the name of a file of assembly code: ";
	cin >> filename;
	ifstream infile(filename);
	while (infile.fail())
	{
		infile.clear();
		cout << endl << "File was not found.\nInput the name of a file of assembly code: ";
		cin >> filename;
		infile.open(filename);
	}

	cout << endl << "Checking code" << endl;
	regex pattern("([0-9]+)\\s+(\.+)");
	std::match_results<std::string::const_iterator> result;
	int address;
	string linenumber;
	string data;
	getline(infile, line);
	if (std::regex_search(line, result, pattern))
	{
		linenumber = result[1];
		address = atoi(linenumber.c_str());
		data = result[2];
		if (data == "begin")
		{
			PC = address;
		}
	}
	while (!infile.fail())
	{
		memory.set(address, data);
		cout << address << " " << memory.get(address) << endl;
		getline(infile, line);
		if (std::regex_search(line, result, pattern))
		{
			linenumber = result[1];
			address = atoi(linenumber.c_str());
			data = result[2];
			if (data == "begin")
			{
				PC = address;
			}
		}
	}

	cout << endl << "Execution of program" << endl << endl;
	while (!halt)
	{
		MAR = PC;
		MBR = memory.get(MAR);
		IR = MBR;
		cout << "PC = " << PC << " IR = " << IR << endl;
		PC++;
		halt = decode(IR);
		if (error)
		{
			return 0;
		}
		cout << "PC = " << PC << " AC = " << AC << " MQ = " << MQ << endl;
		cout << "_________________________________________________________" << endl;
	}

	cout << endl << "memory" << endl << endl;
	int count = 0;
	while (count < (PC))
	{
		cout << count << " " << memory.get(count) << endl;
		count++;
	}
}