/*
    SuperCollider real time audio synthesis system
    Copyright (c) 2002 James McCartney. All rights reserved.
    Copyright (c) 2009 Marije Baalman
    Copyright (c) 2008 Scott Wilson
    Copyright (c) 2012 Tim Blechmann
    http://www.audiosynth.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 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 "SC_SyncCondition.h"
#include "SC_PlugIn.h"

#include <sndfile.h>

#include <atomic>
#include <new>
#include <functional>
#include <SC_Lock.h>

#include <boost/lockfree/queue.hpp>
#include <boost/lockfree/spsc_queue.hpp>

static InterfaceTable* ft;

enum { diskinIdle, diskinStartingEmpty, diskinStartingFull, diskinNormal, diskinLastBuffer, diskinEndSilence };

enum { diskoutIdle, diskoutNormal };


struct DiskIn : public Unit {
    float m_fbufnum;
    SndBuf* m_buf;
    uint32 m_framepos;
};

struct DiskOut : public Unit {
    float m_fbufnum;
    SndBuf* m_buf;
    uint32 m_framepos;
    uint32 m_framewritten;
};

struct VDiskIn : public Unit {
    float m_fbufnum, m_pchRatio, m_rBufSize;
    double m_framePos, m_bufPos;
    uint32 m_count;
    SndBuf* m_buf;
    uint32 m_iFramePos, m_iBufPos;
};

//////////////////////////////////////////////////////////////////////////////////////////////////

extern "C" {

void DiskIn_next(DiskIn* unit, int inNumSamples);
void DiskIn_Ctor(DiskIn* unit);

void DiskOut_next(DiskOut* unit, int inNumSamples);
void DiskOut_Ctor(DiskOut* unit);
void DiskOut_Dtor(DiskOut* unit);

void VDiskIn_next(VDiskIn* unit, int inNumSamples);
void VDiskIn_first(VDiskIn* unit, int inNumSamples);
void VDiskIn_next_rate1(VDiskIn* unit, int inNumSamples);
void VDiskIn_Ctor(VDiskIn* unit);
}

//////////////////////////////////////////////////////////////////////////////////////////////////


enum {
    kDiskCmd_Read,
    kDiskCmd_Write,
    kDiskCmd_ReadLoop,
};

namespace {

struct DiskIOMsg {
    World* mWorld;
    int16 mCommand;
    int16 mChannels;
    int32 mBufNum;
    int32 mPos;
    int32 mFrames;

    void Perform();
};

void DiskIOMsg::Perform() {
    NRTLock(mWorld);

    SndBuf* buf = World_GetNRTBuf(mWorld, mBufNum);
    if (mPos > buf->frames || mPos + mFrames > buf->frames || buf->channels != mChannels)
        goto leave;

    sf_count_t count;
    switch (mCommand) {
    case kDiskCmd_Read:
        count = buf->sndfile ? sf_readf_float(GETSNDFILE(buf), buf->data + mPos * buf->channels, mFrames) : 0;
        if (count < mFrames) {
            memset(buf->data + (mPos + count) * buf->channels, 0, (mFrames - count) * buf->channels * sizeof(float));
            World_GetBuf(mWorld, mBufNum)->mask = mPos + count;
            // NOTE: Possible race condition above: The disk IO thread may write to the rt SndBuf
            // while the stage3 of the sequenced commands copies the non-rt SndBuf struct to the rt buf.
            // This only happens if the buffer is modified via an osc command.
            // We can't use the non-rt SndBuf above since buf->mask won't be reflected to the rt buf.
        }
        break;
    case kDiskCmd_ReadLoop:
        if (!buf->sndfile) {
            memset(buf->data + mPos * buf->channels, 0, mFrames * buf->channels * sizeof(float));
            goto leave;
        }
        count = sf_readf_float(GETSNDFILE(buf), buf->data + mPos * buf->channels, mFrames);
        while (mFrames -= count) {
            sf_seek(GETSNDFILE(buf), 0, SEEK_SET);
            count = sf_readf_float(GETSNDFILE(buf), buf->data + (mPos + count) * buf->channels, mFrames);
        }
        break;
    case kDiskCmd_Write:
        // printf("kDiskCmd_Write %d %p\n", mBufNum, buf->sndfile);
        if (!buf->sndfile)
            goto leave;
        count = sf_writef_float(GETSNDFILE(buf), buf->data + mPos * buf->channels, mFrames);
        break;
    }

leave:
    NRTUnlock(mWorld);
}

struct DiskIOThread {
    SC_SyncCondition mDiskFifoHasData;

#ifdef SUPERNOVA
    boost::lockfree::queue<DiskIOMsg, boost::lockfree::capacity<256>> mDiskFifo;
#else
    boost::lockfree::spsc_queue<DiskIOMsg, boost::lockfree::capacity<256>> mDiskFifo;
#endif

    std::atomic<bool> mRunning;
    SC_Thread mThread;

    DiskIOThread(): mRunning(false) {}

    ~DiskIOThread() {
        if (mRunning) {
            mRunning.store(false);
            mDiskFifoHasData.Signal();
            mThread.join();
        }
    }

    void launchThread() {
        using namespace std;
        mRunning.store(true);

        mThread = thread(bind(&DiskIOThread::ioThreadFunc, this));
    }

    bool Write(DiskIOMsg& data) {
        bool pushSucceeded = mDiskFifo.push(data);
        if (pushSucceeded)
            mDiskFifoHasData.Signal();
        return pushSucceeded;
    }

    void ioThreadFunc() {
        while (mRunning.load()) {
            mDiskFifoHasData.WaitEach();

            DiskIOMsg msg;
            bool popSucceeded = mDiskFifo.pop(msg);

            if (popSucceeded)
                msg.Perform();
        }
    }
};

DiskIOThread* gDiskIO;

}

//////////////////////////////////////////////////////////////////////////////////////////////////

#define SETUP_OUT(offset)                                                                                              \
    if (unit->mNumOutputs != bufChannels) {                                                                            \
        ClearUnitOutputs(unit, inNumSamples);                                                                          \
        return;                                                                                                        \
    }                                                                                                                  \
    float* const* const out = &OUT(offset);

#define SETUP_IN(offset)                                                                                               \
    if (unit->mNumInputs - (uint32)offset != bufChannels) {                                                            \
        ClearUnitOutputs(unit, inNumSamples);                                                                          \
        return;                                                                                                        \
    }                                                                                                                  \
    const float* const* const in = &IN(offset);

void DiskIn_Ctor(DiskIn* unit) {
    unit->m_fbufnum = -1.f;
    unit->m_buf = unit->mWorld->mSndBufs;
    unit->m_framepos = 0;
    SETCALC(DiskIn_next);
    ClearUnitOutputs(unit, 1);
}

void DiskIn_next(DiskIn* unit, int inNumSamples) {
    GET_BUF_SHARED
    if (!bufData || ((bufFrames & ((unit->mWorld->mBufLength << 1) - 1)) != 0)) {
        unit->m_framepos = 0;
        ClearUnitOutputs(unit, inNumSamples);
        return;
    }
    SETUP_OUT(0)

    if (unit->m_framepos >= bufFrames) {
        unit->m_framepos = 0;
    }

    bufData += unit->m_framepos * bufChannels;

    // buffer must be allocated as a multiple of 2*blocksize.
    if (bufChannels > 2) {
        for (int j = 0; j < inNumSamples; ++j) {
            for (uint32 i = 0; i < bufChannels; ++i)
                out[i][j] = *bufData++;
        }
    } else if (bufChannels == 2) {
        float* out0 = out[0];
        float* out1 = out[1];
        for (int j = 0; j < inNumSamples; ++j) {
            out0[j] = *bufData++;
            out1[j] = *bufData++;
        }
    } else {
        float* out0 = out[0];
        for (int j = 0; j < inNumSamples; ++j) {
            out0[j] = *bufData++;
        }
    }
    if (unit->m_buf->mask1 >= 0 && unit->m_framepos >= unit->m_buf->mask1)
        unit->mDone = true;
    unit->m_framepos += inNumSamples;
    uint32 bufFrames2 = bufFrames >> 1;
    if (unit->m_framepos == bufFrames) {
        unit->m_framepos = 0;
        goto sendMessage;
    } else if (unit->m_framepos == bufFrames2) {
    sendMessage:
        if (unit->m_buf->mask >= 0)
            unit->m_buf->mask1 = unit->m_buf->mask;
        if (unit->mWorld->mRealTime) {
            // send a message to read
            DiskIOMsg msg;
            msg.mWorld = unit->mWorld;
            msg.mCommand = (int)ZIN0(1) ? kDiskCmd_ReadLoop : kDiskCmd_Read;
            msg.mBufNum = (int)fbufnum;
            msg.mPos = bufFrames2 - unit->m_framepos;
            msg.mFrames = bufFrames2;
            msg.mChannels = bufChannels;
            gDiskIO->Write(msg);
        } else {
            SndBuf* bufr = World_GetNRTBuf(unit->mWorld, (int)fbufnum);
            uint32 mPos = bufFrames2 - unit->m_framepos;
            if (mPos > (uint32)bufr->frames || mPos + bufFrames2 > (uint32)bufr->frames
                || (uint32)bufr->channels != bufChannels)
                return;
            sf_count_t count;

            if ((int)ZIN0(1)) { // loop
                if (!bufr->sndfile)
                    memset(bufr->data + mPos * bufr->channels, 0, bufFrames2 * bufr->channels * sizeof(float));
                count = sf_readf_float(GETSNDFILE(bufr), bufr->data + mPos * bufr->channels, bufFrames2);
                while (bufFrames2 -= count) {
                    sf_seek(GETSNDFILE(bufr), 0, SEEK_SET);
                    count = sf_readf_float(GETSNDFILE(bufr), bufr->data + (mPos + count) * bufr->channels, bufFrames2);
                }
            } else { // non-loop
                count = bufr->sndfile ? sf_readf_float(GETSNDFILE(bufr), bufr->data + mPos * bufr->channels, bufFrames2)
                                      : 0;
                if (count < bufFrames2) {
                    memset(bufr->data + (mPos + count) * bufr->channels, 0,
                           (bufFrames2 - count) * bufr->channels * sizeof(float));
                    unit->m_buf->mask = mPos + count;
                }
            }
        }
    }
}

////////////////////////////////////////////////////////////////////////////////////////////////////////

void DiskOut_Ctor(DiskOut* unit) {
    unit->m_fbufnum = -1.f;
    unit->m_buf = unit->mWorld->mSndBufs;
    unit->m_framepos = 0;
    unit->m_framewritten = 0;
    SETCALC(DiskOut_next);
    ClearUnitOutputs(unit, 1);
}


void DiskOut_next(DiskOut* unit, int inNumSamples) {
    GET_BUF

    if (!bufData || ((bufFrames & ((unit->mWorld->mBufLength << 1) - 1)) != 0)) {
        unit->m_framepos = 0;
        //		unit->m_framewritten = 0;
        return;
    }
    SETUP_IN(1)

    float* out = OUT(0);
    uint32 framew = unit->m_framewritten;

    //	printf("Start frames %i %i\n", unit->m_framewritten, framew );

    if (unit->m_framepos >= bufFrames)
        unit->m_framepos = 0;

    bufData += unit->m_framepos * bufChannels;

    if (bufChannels > 2) {
        for (int j = 0; j < inNumSamples; ++j) {
            for (uint32 i = 0; i < bufChannels; ++i)
                *bufData++ = in[i][j];

            out[j] = framew++;
        }
    } else if (bufChannels == 2) {
        const float* in0 = in[0];
        const float* in1 = in[1];
        for (int j = 0; j < inNumSamples; ++j) {
            *bufData++ = in0[j];
            *bufData++ = in1[j];
            out[j] = framew++;
        }
    } else {
        const float* in0 = in[0];
        for (int j = 0; j < inNumSamples; ++j) {
            *bufData++ = in0[j];
            out[j] = framew++;
        }
    }

    unit->m_framepos += inNumSamples;
    //	unit->m_framewritten += inNumSamples;
    unit->m_framewritten = framew;

    //	printf("frames %i %i\n", unit->m_framewritten, framew );

    uint32 bufFrames2 = bufFrames >> 1;
    if (unit->m_framepos == bufFrames) {
        unit->m_framepos = 0;
        goto sendMessage;
    } else if (unit->m_framepos == bufFrames2) {
    sendMessage:
        // send a message to write
        DiskIOMsg msg;
        msg.mWorld = unit->mWorld;
        msg.mCommand = kDiskCmd_Write;
        msg.mBufNum = (int)fbufnum;
        msg.mPos = bufFrames2 - unit->m_framepos;
        msg.mFrames = bufFrames2;
        msg.mChannels = bufChannels;
        // printf("sendMessage %d  %d %d %d\n", msg.mBufNum, msg.mPos, msg.mFrames, msg.mChannels);
        gDiskIO->Write(msg);
    }
}

void DiskOut_Dtor(DiskOut* unit) {
    GET_BUF

    uint32 framepos = unit->m_framepos;
    uint32 bufFrames2 = bufFrames >> 1;
    // check that we didn't just write
    if (framepos != 0 && framepos != bufFrames2) {
        // if not write the last chunk of samples
        uint32 writeStart;
        if (framepos > bufFrames2) {
            writeStart = bufFrames2;
        } else {
            writeStart = 0;
        }
        DiskIOMsg msg;
        msg.mWorld = unit->mWorld;
        msg.mCommand = kDiskCmd_Write;
        msg.mBufNum = (int)fbufnum;
        msg.mPos = writeStart;
        msg.mFrames = framepos - writeStart;
        msg.mChannels = bufChannels;
        // printf("sendMessage %d  %d %d %d\n", msg.mBufNum, msg.mPos, msg.mFrames, msg.mChannels);
        gDiskIO->Write(msg);
    }
}


void VDiskIn_Ctor(VDiskIn* unit) {
    unit->m_fbufnum = -1.f;
    unit->m_buf = unit->mWorld->mSndBufs;
    unit->m_framePos = 0.;
    unit->m_bufPos = 0.;
    unit->m_pchRatio = sc_max(IN0(1), 0.f);
    unit->m_count = 0;
    unit->m_iFramePos = 0;
    unit->m_iBufPos = 0;

    if (INRATE(1) == calc_ScalarRate && (unit->m_pchRatio == 1))
        SETCALC(VDiskIn_next_rate1);
    else
        SETCALC(VDiskIn_first);

    ClearUnitOutputs(unit, 1);
}

static void VDiskIn_request_buffer(VDiskIn* unit, float fbufnum, uint32 bufFrames2, uint32 bufChannels, double bufPos) {
    if (unit->m_buf->mask >= 0)
        unit->m_buf->mask1 = unit->m_buf->mask;
    unit->m_count++;
    if (unit->mWorld->mRealTime) {
        DiskIOMsg msg;
        msg.mWorld = unit->mWorld;
        msg.mCommand = (int)ZIN0(2) ? kDiskCmd_ReadLoop : kDiskCmd_Read;
        msg.mBufNum = (int)fbufnum;
        uint32 thisPos;
        if ((uint32)bufPos >= bufFrames2)
            thisPos = 0;
        else
            thisPos = bufFrames2;
        msg.mPos = thisPos;
        msg.mFrames = bufFrames2;
        msg.mChannels = bufChannels;
        gDiskIO->Write(msg);

        if ((int)ZIN0(3)) {
            //	float outval = bufPos + sc_mod((float)(unit->m_count * bufFrames2), (float)buf->fileinfo.frames);
            float outval = bufPos + (float)(unit->m_count * bufFrames2);
            SendNodeReply(&unit->mParent->mNode, (int)ZIN0(3), "/diskin", 1, &outval);
        }
    } else {
        SndBuf* bufr = World_GetNRTBuf(unit->mWorld, (int)fbufnum);
        uint32 mPos;
        if ((uint32)bufPos >= bufFrames2)
            mPos = 0;
        else
            mPos = bufFrames2;
        if (mPos > (uint32)bufr->frames || mPos + bufFrames2 > (uint32)bufr->frames
            || (uint32)bufr->channels != bufChannels)
            return;
        sf_count_t count;

        if ((int)ZIN0(2)) { // loop
            if (!bufr->sndfile)
                memset(bufr->data + mPos * bufr->channels, 0, bufFrames2 * bufr->channels * sizeof(float));
            count = sf_readf_float(GETSNDFILE(bufr), bufr->data + mPos * bufr->channels, bufFrames2);
            while (bufFrames2 -= count) {
                sf_seek(GETSNDFILE(bufr), 0, SEEK_SET);
                count = sf_readf_float(GETSNDFILE(bufr), bufr->data + (mPos + count) * bufr->channels, bufFrames2);
            }
        } else { // non-loop
            count =
                bufr->sndfile ? sf_readf_float(GETSNDFILE(bufr), bufr->data + mPos * bufr->channels, bufFrames2) : 0;
            if (count < bufFrames2) {
                memset(bufr->data + (mPos + count) * bufr->channels, 0,
                       (bufFrames2 - count) * bufr->channels * sizeof(float));
                unit->m_buf->mask = mPos + count;
            }
        }
    }
}

// first time through, the FIRST sample doesn't need the interpolation... the buffer won't be filled 'correctly' for
// interpolation, so use the _first function to make this exception
template <bool First> static inline void VDiskIn_next_(VDiskIn* unit, int inNumSamples) {
    bool test = false;

    GET_BUF_SHARED
    if (!bufData || ((bufFrames & ((unit->mWorld->mBufLength << 1) - 1)) != 0)) {
        unit->m_framePos = 0.;
        unit->m_count = 0;
        ClearUnitOutputs(unit, inNumSamples);
        return;
    }

    SETUP_OUT(0);
    if (First)
        unit->m_rBufSize = 1. / bufFrames;

    double framePos = unit->m_framePos;
    double bufPos = unit->m_bufPos; // where we are in the DiskIn buffer
    float newPchRatio = sc_max(IN0(1), 0.f);
    if ((newPchRatio * inNumSamples * unit->m_rBufSize) >= 0.5) {
        printf("pitch ratio is greater then max allowed (see VDiskIn help)\n");
        ClearUnitOutputs(unit, inNumSamples);
        return;
    }

    float pchRatio = unit->m_pchRatio;
    float pchSlope = CALCSLOPE(newPchRatio, pchRatio);
    uint32 bufFrames2 = bufFrames >> 1;
    double fbufFrames2 = (double)bufFrames2;
    double fbufFrames = (double)bufFrames;

    if (First) {
        for (uint32 i = 0; i < bufChannels; i++)
            out[i][0] = bufData[0 + i];
    }

    const int firstLoopSample = First ? 1 : 0;

    for (int j = firstLoopSample; j < inNumSamples; ++j) {
        int32 iBufPos = (int32)bufPos;
        double frac = bufPos - (double)iBufPos;
        int table1 = iBufPos * bufChannels;
        int table0 = table1 - bufChannels;
        int table2 = table1 + bufChannels;
        int table3 = table2 + bufChannels;
        while (table1 >= bufSamples)
            table1 -= bufSamples;
        while (table0 < 0)
            table0 += bufSamples;
        while (table2 >= bufSamples)
            table2 -= bufSamples;
        while (table3 >= bufSamples)
            table3 -= bufSamples;
        for (uint32 i = 0; i < bufChannels; i++) {
            float a, b, c, d;
            a = bufData[table0 + i];
            b = bufData[table1 + i];
            c = bufData[table2 + i];
            d = bufData[table3 + i];
            out[i][j] = cubicinterp(frac, a, b, c, d);
        };
        pchRatio += pchSlope;
        framePos += pchRatio;
        const double oldBufPos = bufPos;
        bufPos += pchRatio;

        // the +1 is needed for the cubic interpolation... make SURE the old data isn't needed any more before
        // setting up the new buffer
        if ((oldBufPos < (fbufFrames2 + 1)) && ((bufPos >= (fbufFrames2 + 1)))) {
            test = true;
        }
        if (bufPos >= (fbufFrames + 1)) {
            test = true;
            bufPos -= fbufFrames;
        }
    }
    if (unit->m_buf->mask1 >= 0 && bufPos >= unit->m_buf->mask1)
        unit->mDone = true;
    if (test)
        VDiskIn_request_buffer(unit, fbufnum, bufFrames2, bufChannels, bufPos);

    unit->m_framePos = framePos;
    unit->m_pchRatio = pchRatio;
    unit->m_bufPos = bufPos;

    if (First)
        SETCALC(VDiskIn_next);
}

void VDiskIn_first(VDiskIn* unit, int inNumSamples) { VDiskIn_next_<true>(unit, inNumSamples); }

void VDiskIn_next(VDiskIn* unit, int inNumSamples) { VDiskIn_next_<false>(unit, inNumSamples); }

void VDiskIn_next_rate1(VDiskIn* unit, int inNumSamples) {
    bool test = false;

    GET_BUF_SHARED
    if (!bufData || ((bufFrames & ((unit->mWorld->mBufLength << 1) - 1)) != 0)) {
        unit->m_iFramePos = 0.;
        unit->m_count = 0;
        ClearUnitOutputs(unit, inNumSamples);
        return;
    }

    SETUP_OUT(0)

    uint32 framePos = unit->m_iFramePos;
    uint32 bufPos = unit->m_iBufPos;

    uint32 bufFrames2 = bufFrames >> 1;

    for (int sample = 0; sample < inNumSamples; ++sample) {
        int bufferIndex = bufPos * bufChannels;

        for (uint32 channel = 0; channel < bufChannels; channel++)
            out[channel][sample] = bufData[bufferIndex + channel];

        const uint32 oldBufPos = bufPos;
        bufPos += 1;
        framePos += 1;

        if ((oldBufPos < bufFrames2) && (bufPos >= bufFrames2))
            test = true;

        if (bufPos >= bufFrames) {
            test = true;
            bufPos -= bufFrames;
        }
    }
    if (unit->m_buf->mask1 >= 0 && bufPos >= unit->m_buf->mask1)
        unit->mDone = true;
    if (test)
        VDiskIn_request_buffer(unit, fbufnum, bufFrames2, bufChannels, bufPos);

    unit->m_iFramePos = framePos;
    unit->m_iBufPos = bufPos;
}


////////////////////////////////////////////////////////////////////////////////////////////////////////
C_LINKAGE SC_API_EXPORT void unload(InterfaceTable* inTable) { delete gDiskIO; }

PluginLoad(DiskIO) {
    ft = inTable;
    gDiskIO = new DiskIOThread();
    gDiskIO->launchThread();

    DefineSimpleUnit(DiskIn);
    DefineDtorUnit(DiskOut);
    DefineSimpleUnit(VDiskIn);
}

//////////////////////////////////////////////////////////////////////////////////////////////////