/*   `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 "../iext.hpp"

class Cuart : public Iext {
	public:
		Cuart() : m_writeAddress(0), m_fetchCount(0), m_readCount(0), m_recRdy(0), m_txRdy(0), m_recVal(0), m_txVal(0) {};
		void applyTick() {};
		void loadData(const int address, CDat value);
		CDat readData(const int);
		void parseInput(const vector<string>& in);
	private:
		int m_writeAddress, m_fetchCount, m_readCount;
		bool m_recRdy, m_txRdy;
		CDat m_recVal, m_txVal;
};


void Cuart::parseInput(const vector<string>& in)
{
	if(in.size() > 1) {
		if((in[1].compare("h") == 0)) {
			cout << "UART:" << endl;
			cout << "\textension uart r 0xXX \t -- to load the module with a value" << endl;
			cout << "\textension uart f \t-- to load a value from the module" << endl;
		}
	}
	if(in.size() < 2) {
		return;
	}
	if(in[1].compare("uart") == 0) {
		if(in[2].compare("r") == 0) {
			if(in.size() < 3) {
				return;
			}
			if(in[3].substr(0,2) == "0x") {
				m_recVal = lexical_cast<uint32_from_hex>(in[3]);
			}
			else {
				m_recVal = lexical_cast<unsigned int>(in[3]);
			}
			cout << "UART: loaded 0x" << std::hex << m_recVal << std::dec << endl;
			m_recRdy = 1;
			m_fetchCount = 0;
			m_readCount = 0;
		}
		else if(in[2].compare("f") == 0) {
			cout << "UART: sended 0x" << std::hex << m_txVal << std::dec << endl;
			m_txRdy = 0;
			m_fetchCount = 0;
			m_readCount = 0;
		}
		else if(in[2].compare("s") == 0) {
			cout << "UART:" << endl;
			cout << "\ttx busy: " << m_txRdy << endl;
			cout << "\trx_newdata: " << m_recRdy << endl;
		}
	}
}

CDat Cuart::readData(const int address)
{
	if(address == 0x2000) {
		//status - r only
/*		cout << "rx: " << m_recRdy << endl;
		cout << "tx: " << m_txRdy << endl;
		CDat helpme = m_recRdy;
		helpme <<= 1;
		helpme |= m_txRdy;
		cout << "rx<<1 | tx: " << helpme << endl;
*/
		if(m_txRdy == 1) {
			m_fetchCount++;
		}
		if(m_recRdy == 0) {
			m_readCount++;
		}

		if(m_fetchCount >= 5) {
			m_fetchCount = 0;
			m_readCount = 0;
			m_txRdy = 0;
			cout << "UART: force fetched 0x" << std::hex << m_txVal << std::dec << endl;
		}
		if(m_readCount >= 5) {
			m_fetchCount = 0;
			m_readCount = 0;
			m_recRdy = 1;
			cout << "UART: force inserted 0x48 ('H')" << endl;
			m_recVal = 'H';
		}
		return (m_recRdy<<1)|(m_txRdy);
	}
	else if(address == 0x2008) {
		//trans - w only
		//data pointer
	}
	else if(address == 0x200c) {
		//recv - r only
		m_recRdy = 0;
		m_fetchCount = 0;
		m_readCount = 0;
		return m_recVal;
	}
	return 0;
}

void Cuart::loadData(const int address, CDat value)
{

	if(address == 0x2000) {
		//status - r only
	}
	else if(address == 0x2008) {
		//trans - w only
		cout << "UART: byte ready to fetch" << endl;
		m_txVal = value;
		m_txRdy = 1;
		m_fetchCount = 0;
		m_readCount = 0;
	}
	else if(address == 0x200c) {
		//recv - r only
	}
}