/*
 * This file is part of libsidplayfp, a SID player engine.
 *
 * Copyright 2011-2019 Leandro Nini <drfiemost@users.sourceforge.net>
 * Copyright 2007-2010 Antti Lankila
 * Copyright 2001 Simon White
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include "resid-emu.h"

#include <cstdio>
#include <cstring>
#include <cmath>
#include <sstream>
#include <string>

#include "resid/siddefs.h"
#include "resid/spline.h"

namespace libsidplayfp
{

const char* ReSID::getCredits()
{
    static std::string credits;

    if (credits.empty())
    {
        // Setup credits
        std::ostringstream ss;
        ss << "ReSID V" << VERSION << " Engine:\n";
        ss << "\t(C) 1999-2002 Simon White\n";
        ss << "MOS6581 (SID) Emulation (ReSID V" << resid_version_string << "):\n";
        ss << "\t(C) 1999-2010 Dag Lem\n";
        credits = ss.str();
    }

    return credits.c_str();
}

ReSID::ReSID(sidbuilder *builder) :
    sidemu(builder),
    m_sid(*(new reSID::SID)),
    m_voiceMask(0x07)
{
    reset(0);
}

ReSID::~ReSID()
{
    delete &m_sid;
    delete[] m_buffer;
}

void ReSID::bias(double dac_bias)
{
    m_sid.adjust_filter_bias(dac_bias);
}

// Standard component options
void ReSID::reset(uint8_t volume)
{
    m_accessClk = 0;
    m_sid.reset();
    m_sid.write(0x18, volume);
}

uint8_t ReSID::read(uint_least8_t addr)
{
    clock();
    return m_sid.read(addr);
}

void ReSID::write(uint_least8_t addr, uint8_t data)
{
    clock();
    m_sid.write(addr, data);
}

void ReSID::clock()
{
    reSID::cycle_count cycles = eventScheduler->getTime(EVENT_CLOCK_PHI1) - m_accessClk;
    m_accessClk += cycles;
    m_bufferpos += m_sid.clock(cycles, (short *) m_buffer + m_bufferpos, m_buffersize - m_bufferpos, 1);
    // Adjust in case not all cycles have been consumed
    m_accessClk -= cycles;
}

void ReSID::filter(bool enable)
{
    m_sid.enable_filter(enable);
}

void ReSID::sampling(float systemclock, float freq,
        SidConfig::sampling_method_t method, bool fast)
{
    reSID::sampling_method sampleMethod;
    switch (method)
    {
    case SidConfig::INTERPOLATE:
        sampleMethod = fast ? reSID::SAMPLE_FAST : reSID::SAMPLE_INTERPOLATE;
        break;
    case SidConfig::RESAMPLE_INTERPOLATE:
        sampleMethod = fast ? reSID::SAMPLE_RESAMPLE_FASTMEM : reSID::SAMPLE_RESAMPLE;
        break;
    default:
        m_status = false;
        m_error = ERR_INVALID_SAMPLING;
        return;
    }

    if (! m_sid.set_sampling_parameters(systemclock, sampleMethod, freq))
    {
        m_status = false;
        m_error = ERR_UNSUPPORTED_FREQ;
        return;
    }

    if (m_buffer)
        delete[] m_buffer;

    // 20ms buffer
    m_buffersize = std::ceil((freq / 1000.f) * 20.f);
    m_buffer = new short[m_buffersize];
    m_status = true;
}

// Set the emulated SID model
void ReSID::model(SidConfig::sid_model_t model, bool digiboost)
{
    reSID::chip_model chipModel;
    short sample = 0;
    m_voiceMask &= 0x07;
    switch (model)
    {
        case SidConfig::MOS6581:
            chipModel = reSID::MOS6581;
            break;
        case SidConfig::MOS8580:
            chipModel = reSID::MOS8580;
            if (digiboost)
            {
                m_voiceMask |= 0x08;
                sample = -32768;
            }
            break;
        default:
            m_status = false;
            m_error = ERR_INVALID_CHIP;
            return;
    }

    m_sid.set_chip_model(chipModel);
    m_sid.set_voice_mask(m_voiceMask);
    m_sid.input(sample);
    m_status = true;
}

}
