/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *                                                                         *
 *   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., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#include "Stream.h"

namespace LinuxSampler { namespace gig {

    uint Stream::UnusedStreams = 0;

    /// Returns number of refilled sample points or a value < 0 on error.
    int Stream::ReadAhead(unsigned long SampleCount) {
        if (this->State == state_unused) return -1;
        if (this->State == state_end)    return  0;
        if (!SampleCount)                return  0;
        if (!pRingBuffer->write_space()) return  0;

        long total_readsamples = 0, readsamples = 0;
        long samplestoread = SampleCount / pSample->Channels;
        sample_t* pBuf = pRingBuffer->get_write_ptr();
        bool endofsamplereached;

        // refill the disk stream buffer
        if (this->DoLoop) { // honor looping
            total_readsamples  = pSample->ReadAndLoop(pBuf, samplestoread, &this->PlaybackState);
            endofsamplereached = (this->PlaybackState.position >= pSample->SamplesTotal);
            dmsg(5,("Refilled stream %d with %d (SamplePos: %d)", this->hThis, total_readsamples, this->PlaybackState.position));
        }
        else { // normal forward playback

            pSample->SetPos(this->SampleOffset); // recover old position

            do {
                readsamples        = pSample->Read(&pBuf[total_readsamples * pSample->Channels], samplestoread);
                samplestoread     -= readsamples;
                total_readsamples += readsamples;
            } while (samplestoread && readsamples > 0);

            // we have to store the position within the sample, because other streams might use the same sample
            this->SampleOffset = pSample->GetPos();

            endofsamplereached = (SampleOffset >= pSample->SamplesTotal);
            dmsg(5,("Refilled stream %d with %d (SamplePos: %d)", this->hThis, total_readsamples, this->SampleOffset));
        }

        // we must delay the increment_write_ptr_with_wrap() after the while() loop because we need to
        // ensure that we read exactly SampleCount sample, otherwise the buffer wrapping code will fail
        pRingBuffer->increment_write_ptr_with_wrap(total_readsamples * pSample->Channels);

        // update stream state
        if (endofsamplereached) SetState(state_end);
        else                    SetState(state_active);

        return total_readsamples;
    }

    void Stream::WriteSilence(unsigned long SilenceSampleWords) {
        memset(pRingBuffer->get_write_ptr(), 0, SilenceSampleWords);
        pRingBuffer->increment_write_ptr_with_wrap(SilenceSampleWords);
    }

    Stream::Stream(uint BufferSize, uint BufferWrapElements) {
        this->pExportReference               = NULL;
        this->State                          = state_unused;
        this->hThis                          = 0;
        this->pSample                        = NULL;
        this->SampleOffset                   = 0;
        this->PlaybackState.position         = 0;
        this->PlaybackState.reverse          = false;
        this->pRingBuffer                    = new RingBuffer<sample_t>(BufferSize, BufferWrapElements);
        UnusedStreams++;
    }

    Stream::~Stream() {
        Reset();
        if (pRingBuffer) delete pRingBuffer;
    }

    /// Called by disk thread to activate the disk stream.
    void Stream::Launch(Stream::Handle hStream, reference_t* pExportReference, ::gig::Sample* pSample, unsigned long SampleOffset, bool DoLoop) {
        UnusedStreams--;
        this->pExportReference               = pExportReference;
        this->hThis                          = hStream;
        this->pSample                        = pSample;
        this->SampleOffset                   = SampleOffset;
        this->PlaybackState.position         = SampleOffset;
        this->PlaybackState.reverse          = false;
        this->PlaybackState.loop_cycles_left = pSample->LoopPlayCount;
        this->DoLoop                         = DoLoop;
        SetState(state_active);
    }

}} // namespace LinuxSampler::gig