/*
 * DISTRHO Kars Plugin, based on karplong by Chris Cannam.
 * Copyright (C) 2015 Filipe Coelho <falktx@falktx.com>
 *
 * Permission to use, copy, modify, and/or distribute this software for any purpose with
 * or without fee is hereby granted, provided that the above copyright notice and this
 * permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
 * TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "DistrhoPluginKars.hpp"

START_NAMESPACE_DISTRHO

// -----------------------------------------------------------------------

DistrhoPluginKars::DistrhoPluginKars()
    : Plugin(paramCount, 0, 0), // 0 programs, 0 states
      fSustain(false),
      fSampleRate(getSampleRate()),
      fBlockStart(0)
{
    for (int i=kMaxNotes; --i >= 0;)
    {
        fNotes[i].index = i;
        fNotes[i].setSampleRate(fSampleRate);
    }
}

// -----------------------------------------------------------------------
// Init

void DistrhoPluginKars::initParameter(uint32_t index, Parameter& parameter)
{
    if (index != 0)
        return;

    parameter.hints      = kParameterIsAutomable|kParameterIsBoolean;
    parameter.name       = "Sustain";
    parameter.symbol     = "sustain";
    parameter.ranges.def = 0.0f;
    parameter.ranges.min = 0.0f;
    parameter.ranges.max = 1.0f;
}

// -----------------------------------------------------------------------
// Internal data

float DistrhoPluginKars::getParameterValue(uint32_t index) const
{
    if (index != 0)
        return 0.0f;

    return fSustain ? 1.0f : 0.0f;
}

void DistrhoPluginKars::setParameterValue(uint32_t index, float value)
{
    if (index != 0)
        return;

    fSustain = value > 0.5f;
}

// -----------------------------------------------------------------------
// Process

void DistrhoPluginKars::activate()
{
    fBlockStart = 0;

    for (int i=kMaxNotes; --i >= 0;)
    {
        fNotes[i].on  = kNoteNull;
        fNotes[i].off = kNoteNull;
        fNotes[i].velocity = 0;
    }
}

void DistrhoPluginKars::run(const float**, float** outputs, uint32_t frames, const MidiEvent* midiEvents, uint32_t midiEventCount)
{
    uint8_t note, velo;
    float* out = outputs[0];

    for (uint32_t count, pos=0, curEventIndex=0; pos<frames;)
    {
        for (;curEventIndex < midiEventCount && pos >= midiEvents[curEventIndex].frame; ++curEventIndex)
        {
            if (midiEvents[curEventIndex].size > MidiEvent::kDataSize)
                continue;

            const uint8_t*  data = midiEvents[curEventIndex].data;
            const uint8_t status = data[0] & 0xF0;

            switch (status)
            {
            case 0x90:
                note = data[1];
                velo = data[2];
                DISTRHO_SAFE_ASSERT_BREAK(note < 128); // kMaxNotes
                if (velo > 0)
                {
                    fNotes[note].on  = fBlockStart + midiEvents[curEventIndex].frame;
                    fNotes[note].off = kNoteNull;
                    fNotes[note].velocity = velo;
                    break;
                }
                // nobreak
            case 0x80:
                note = data[1];
                DISTRHO_SAFE_ASSERT_BREAK(note < 128); // kMaxNotes
                fNotes[note].off = fBlockStart + midiEvents[curEventIndex].frame;
                break;
            }
        }

        if (curEventIndex < midiEventCount && midiEvents[curEventIndex].frame < frames)
            count = midiEvents[curEventIndex].frame - pos;
        else
            count = frames - pos;

        std::memset(out+pos, 0, sizeof(float)*count);
        //for (uint32_t i=0; i<count; ++i)
        //    out[pos + i] = 0.0f;

        for (int i=kMaxNotes; --i >= 0;)
        {
            if (fNotes[i].on != kNoteNull)
                addSamples(out, i, pos, count);
        }

        pos += count;
    }

    fBlockStart += frames;
}

void DistrhoPluginKars::addSamples(float* out, int voice, uint32_t offset, uint32_t count)
{
    const uint32_t start = fBlockStart + offset;

    Note& note(fNotes[voice]);

    if (start < note.on)
        return;

    if (start == note.on)
    {
        for (int i=note.sizei; --i >= 0;)
            note.wavetable[i] = (float(rand()) / float(RAND_MAX)) * 2.0f - 1.0f;
    }

    const float vgain = float(note.velocity) / 127.0f;

    bool decay;
    float gain, sample;
    uint32_t index, size;

    for (uint32_t i=0, s=start-note.on; i<count; ++i, ++s)
    {
        gain = vgain;

        if ((! fSustain) && note.off != kNoteNull && note.off < i+start)
        {
            // reuse index and size to save some performance.
            // actual values are release and dist
            index = 1 + uint32_t(0.01 * fSampleRate); // release, not index
            size   = i + start - note.off;            // dist, not size

            if (size > index)
            {
                note.on = kNoteNull;
                break;
            }

            gain = gain * float(index - size) / float(index);
        }

        size  = uint32_t(note.sizei);
        decay = s > size;
        index = s % size;

        sample = note.wavetable[index];

        if (decay)
        {
            if (index == 0)
                sample += note.wavetable[size-1];
            else
                sample += note.wavetable[index-1];

            note.wavetable[index] = sample/2;
        }

        out[offset+i] += gain * sample;
    }
}

// -----------------------------------------------------------------------

Plugin* createPlugin()
{
    return new DistrhoPluginKars();
}

// -----------------------------------------------------------------------

END_NAMESPACE_DISTRHO