/*   `Deep Thought', a softcore CPU implemented on a FPGA

    Copyright (C) 2010 Markus Hofstaetter <markus.manrow@gmx.at>
    Copyright (C) 2010 Martin Perner <e0725782@student.tuwien.ac.at>
    Copyright (C) 2010 Stefan Rebernig <stefan.rebernig@gmail.com>
    Copyright (C) 2010 Manfred Schwarz <e0725898@student.tuwien.ac.at>
    Copyright (C) 2010 Bernhard Urban <lewurm@gmail.com>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>. */

#include "ccpu.hpp"

/*		CDat m_pc, m_pc_next;
		CMem m_regfile, m_ram;
*/

//void registerExtension() {};

const char* expression = "(;.*)|(r0)|(rX)|(r1[0-5])|(r[1-5])|(r[6-9])|(0x[a-fA-F0-9]+)|([-]?\\d+)";
const char* format = "(?1$&)"
					//Return-Register: violett
					"(?2\033[0m\033[35m$&\033[0m\\3:)"
					// Callee-saved Register: rot
					"(?4\033[0m\033[31m$&\033[0m\\3:)"
					//Argument-Register: gruen
					"(?5\033[0m\033[32m$&\033[0m\\3:)"
					// Temporary Register: gelb
					"(?6\033[0m\033[33m$&\033[0m\\3:)"
					// Zahlenwerte: tuerkis
					"(?7\033[0m\033[36m$&\033[0m\\3:)"
					"(?8\033[0m\033[36m$&\033[0m\\3:)";


string CCpu::colorifyInstr(string instr)
{
	boost::regex e;
	e.assign(expression);
	return boost::regex_replace(instr, e, format, boost::match_default | boost::format_all);
}

void CCpu::registerExtension(Iext* ext)
{
	m_exts.push_back(ext);
}

void CCpu::applyToExtensions(const vector<string>& in)
{
	for(auto iter = m_exts.begin(); iter != m_exts.end(); ++iter) {
		(*iter)->parseInput(in);
	}
}

void CCpu::breakNext()
{
	m_breakNext = true;
}

bool CCpu::shouldBreak()
{
	return m_breakNext;
}

void CCpu::tick()
{
	// signal extensions
	// Todo

	m_pc = m_pc_next;
	m_pc_next += 4;
	Iinstr* instr = this->getProg(m_pc);

	if(instr == NULL) {
		throw string("Out of Instructions!");
	}

	for(auto iter = m_exts.begin(); iter != m_exts.end(); ++iter) {
		(*iter)->applyTick();
	}

	if(this->conditionMet(instr->getCondition())) {
		cout << color(green,black) << "Executing: " << color(white,black) << colorifyInstr(instr->toString()) << " (0x" << std::hex << m_pc << std::dec << ")" << endl;
		instr->execInstr();
		this->incPerfBy(instr->getClockCount());
	}
	else {
		cout << color(red,black) << "Didn't Execute " << color(white,black) << colorifyInstr(instr->toString()) << "; condition wasn't met" << endl;
		this->incPerf();
	}

}

bool CCpu::conditionMet(short cond)
{
	switch(cond) {
		case NOT_EQUAL:
			return !this->m_Z;
			break;
		case EQUAL:
			return this->m_Z;
			break;
		case NOT_OVERFLOW:
			return !this->m_O;
			break;
		case OVER_FLOW:
			return this->m_O;
			break;
		case NOT_CARRY:
			return !this->m_C;
			break;
		case CARRY:
			return this->m_C;
			break;
		case NOT_SIGNED:
			return !this->m_S;
			break;
		case SIGNED:
			return this->m_S;
			break;
		case ABOVE:
			return (!this->m_C && !this->m_Z);
			break;
		case BELOW_EQ:
			return (this->m_C || this->m_Z);
			break;
		case GREATER_EQ:
			return (this->m_S == this->m_O);
			break;
		case LESS:
			return (this->m_S != this->m_O);
			break;
		case GREATER:
			return (!this->m_Z && (this->m_S == this->m_O));
			break;
		case LESS_EQ:
			return (!this->m_Z || (this->m_S != this->m_O));
			break;
		case ALWAYS:
			return true;
			break;
		case NEVER:
			return false;
			break;
		default:
			cerr << "What did you do? more than 16 values in 5 bits?!" << endl;
			return false;
	}

}

CDat CCpu::getNextPC() const
{
	return m_pc_next;
}

CDat CCpu::getCurPC() const
{
	return m_pc;
}

void CCpu::setNextPC(CDat val)
{
	m_pc_next = val;
}

CDat CCpu::getFlags() const {
	CDat psw = 0;
	psw += (this->m_Z ? 1 : 0);
	psw += (this->m_O ? 2 : 0);
	psw += (this->m_C ? 4 : 0);
	psw += (this->m_S ? 8 : 0);
	return psw;
}

void CCpu::setFlags(CDat psw) {
	this->m_Z = ((psw & 0x1) != 0);
	this->m_O = ((psw & 0x2) != 0);
	this->m_C = ((psw & 0x4) != 0);
	this->m_S = ((psw & 0x8) != 0);
}

void CCpu::updateFlags(CDat val) {
	this->m_Z = (val == 0);
	this->m_S = ((val >> (BIT_LEN-1)) & 0x1);
/*	this->m_C = false;
	this->m_O = false; */
}

void CCpu::updateFlags(CDatd val, CDat a, CDat b) {
	this->m_Z = (val == 0);
	this->m_S = ((val >> (BIT_LEN-1)) & 0x1);
	this->m_C = ((val >> (BIT_LEN)) & 0x1);
	bool a_31 = ((a >> (BIT_LEN-1)) & 0x1);
	bool b_31 = ((b >> (BIT_LEN-1)) & 0x1);
	bool val_31 = ((val >> (BIT_LEN-1)) & 0x1);
	this->m_O = ((a_31 && b_31 && !val_31) || (!a_31 && !b_31 && val_31));
}

void CCpu::updateCarry(bool c)
{
	this->m_C = c;
}

bool CCpu::getCarry()
{
	return this->m_C;
}

void CCpu::updateFlags(bool z, bool o, bool c, bool s)
{
	this->m_Z = z;
	this->m_O = o;
	this->m_C = c;
	this->m_S = s;
}

CDat CCpu::getRegister(const int addr) const
{
	return m_reg.getDirect(addr);
}

void CCpu::setRegister(const int addr, CDat data)
{
	m_reg.setDirect(addr, data);
}

CDat CCpu::getRAM(const int addr) const
{
	if((addr & EXT_MODEL_OFFSET) == 0) {
		return m_ram.get(addr);
	}
	else {
		CDat result = 0;
		for(auto iter = m_exts.begin(); iter != m_exts.end(); ++iter) {
			result = (*iter)->readData(addr);
			if(result != 0) {
				break;
			}
		}
		return result;
	}
}

void CCpu::setRAM(const int addr, CDat data)
{
	if((addr & EXT_MODEL_OFFSET) == 0) {
		m_ram.set(addr, data);
	}
	else {
		for(auto iter = m_exts.begin(); iter != m_exts.end(); ++iter) {
			(*iter)->loadData(addr, data);
		}
	}
}

void CCpu::setProg(int addr, Iinstr* instr)
{
	m_prog.set(addr, instr);
}

Iinstr* CCpu::getProg(const int addr) const
{
	return m_prog.get(addr);
}

int CCpu::getStack() const
{
	return this->m_stack;
}

void CCpu::setStack(const int val)
{
	this->m_stack = val;
}

CDat CCpu::getPerf() const
{
	return this->m_perf;
}

void CCpu::setPerf(CDat val)
{
	this->m_perf = val;
}

void CCpu::incPerf()
{
	this->m_perf++;
}

void CCpu::incPerfBy(short inc)
{
	this->m_perf += inc;
}


CCpu::CCpu(int regs, int ram, int prog) : m_Z(false), m_S(false), m_C(false), m_O(false), m_breakNext(0), m_pc(0), m_pc_next(0), m_perf(0), m_reg(regs), m_ram(ram), m_prog(prog), m_exts(0), m_stack(0)
{
}