/*
  ==============================================================================

    This file contains the basic framework code for a JUCE plugin processor.

  ==============================================================================
*/

#include "PluginProcessor.h"
#include "PluginEditor.h"

//==============================================================================
DelayPluginAudioProcessor::DelayPluginAudioProcessor()
#ifndef JucePlugin_PreferredChannelConfigurations
     : AudioProcessor (BusesProperties()
                     #if ! JucePlugin_IsMidiEffect
                      #if ! JucePlugin_IsSynth
                       .withInput  ("Input",  juce::AudioChannelSet::stereo(), true)
                      #endif
                       .withOutput ("Output", juce::AudioChannelSet::stereo(), true)
                     #endif
                       ), lowPassFilter(juce::dsp::IIR::Coefficients<float>::makeLowPass(44100, 15000.0, 1.0))
#endif
{
    for (int i = 0; i < 2; i++)
        fDelayTime[i] = 1000.0;
}

DelayPluginAudioProcessor::~DelayPluginAudioProcessor()
{
}

//==============================================================================
const juce::String DelayPluginAudioProcessor::getName() const
{
    return JucePlugin_Name;
}

bool DelayPluginAudioProcessor::acceptsMidi() const
{
   #if JucePlugin_WantsMidiInput
    return true;
   #else
    return false;
   #endif
}

bool DelayPluginAudioProcessor::producesMidi() const
{
   #if JucePlugin_ProducesMidiOutput
    return true;
   #else
    return false;
   #endif
}

bool DelayPluginAudioProcessor::isMidiEffect() const
{
   #if JucePlugin_IsMidiEffect
    return true;
   #else
    return false;
   #endif
}

double DelayPluginAudioProcessor::getTailLengthSeconds() const
{
    return 0.0;
}

int DelayPluginAudioProcessor::getNumPrograms()
{
    return 1;   // NB: some hosts don't cope very well if you tell them there are 0 programs,
                // so this should be at least 1, even if you're not really implementing programs.
}

int DelayPluginAudioProcessor::getCurrentProgram()
{
    return 0;
}

void DelayPluginAudioProcessor::setCurrentProgram (int index)
{
}

const juce::String DelayPluginAudioProcessor::getProgramName (int index)
{
    return {};
}

void DelayPluginAudioProcessor::changeProgramName (int index, const juce::String& newName)
{
}

//==============================================================================
void DelayPluginAudioProcessor::prepareToPlay (double sampleRate, int samplesPerBlock)
{
    const int iNumInputChannels = getTotalNumInputChannels();
    const int iDelayBufferSize = 2 * sampleRate;
    
    iSampleRate = sampleRate;
    
    delayBuffer.setSize(iNumInputChannels, iDelayBufferSize);
    
    // Filter
    juce::dsp::ProcessSpec spec;
    spec.sampleRate = sampleRate;
    spec.maximumBlockSize = samplesPerBlock;
    spec.numChannels = getTotalNumOutputChannels();
    
    lowPassFilter.prepare(spec);
    lowPassFilter.reset();
}

void DelayPluginAudioProcessor::releaseResources()
{
    // When playback stops, you can use this as an opportunity to free up any
    // spare memory, etc.
}

#ifndef JucePlugin_PreferredChannelConfigurations
bool DelayPluginAudioProcessor::isBusesLayoutSupported (const BusesLayout& layouts) const
{
  #if JucePlugin_IsMidiEffect
    juce::ignoreUnused (layouts);
    return true;
  #else
    // This is the place where you check if the layout is supported.
    // In this template code we only support mono or stereo.
    // Some plugin hosts, such as certain GarageBand versions, will only
    // load plugins that support stereo bus layouts.
    if (layouts.getMainOutputChannelSet() != juce::AudioChannelSet::mono()
     && layouts.getMainOutputChannelSet() != juce::AudioChannelSet::stereo())
        return false;

    // This checks if the input layout matches the output layout
   #if ! JucePlugin_IsSynth
    if (layouts.getMainOutputChannelSet() != layouts.getMainInputChannelSet())
        return false;
   #endif

    return true;
  #endif
}
#endif

void DelayPluginAudioProcessor::updateFilter(float cutoff, float res)
{
    *lowPassFilter.state = *juce::dsp::IIR::Coefficients<float>::makeLowPass(getSampleRate(), cutoff, res);
}

void DelayPluginAudioProcessor::processBlock (juce::AudioBuffer<float>& buffer, juce::MidiBuffer& midiMessages)
{
    juce::ScopedNoDenormals noDenormals;
    auto totalNumInputChannels  = getTotalNumInputChannels();
    auto totalNumOutputChannels = getTotalNumOutputChannels();

    for (auto i = totalNumInputChannels; i < totalNumOutputChannels; ++i)
    {
        buffer.clear (i, 0, buffer.getNumSamples());
    }
    
    filterBuffer.makeCopyOf(buffer);
    
    const int iBufferLength = buffer.getNumSamples();
    const int iDelayBufferLength = delayBuffer.getNumSamples();
    
    for (int channel = 0; channel < totalNumInputChannels; ++channel)
    {
        const float* fBufferData = buffer.getReadPointer(channel);
        const float* fDelayBufferData = delayBuffer.getReadPointer(channel);
        float* fDryBuffer = filterBuffer.getWritePointer(channel);
        
        // Copy data from audio buffer to delay buffer
        fillDelayBuffer(channel, iBufferLength, iDelayBufferLength, fBufferData, fDelayBufferData);
        
        // Add delay buffer audio into filtered buffer
        getFromDelayBuffer(filterBuffer, channel, iBufferLength, iDelayBufferLength, fBufferData, fDelayBufferData);
        
        feedbackDelay(channel, iBufferLength, iDelayBufferLength, fDryBuffer);
        
    }
    // Move through delay buffer the length of the audio buffer
    iWritePosition += iBufferLength;
    iWritePosition %= iDelayBufferLength;
    
    juce::dsp::AudioBlock<float> block (filterBuffer);
    lowPassFilter.process(juce::dsp::ProcessContextReplacing<float> (block));
    
    // Sum filterBuffer into buffer
    for (int channel = 0; channel < totalNumInputChannels; ++channel)
    {
        buffer.addFromWithRamp(channel, 0, filterBuffer.getWritePointer(channel), filterBuffer.getNumSamples(), 0.5, 0.5);
    }
    
 
}

void DelayPluginAudioProcessor::fillDelayBuffer(int channel, const int iBufferLength, const int iDelayBufferLength, const float* fBufferData, const float* fDelayBufferData)
{
    // Is delayBuffer big enough to fit buffer in from write position
    if (iDelayBufferLength > iBufferLength + iWritePosition)
        delayBuffer.copyFromWithRamp(channel, iWritePosition, fBufferData, iBufferLength, 0.8, 0.8);
    //
    else
    {
        // Calculate remaining samples to be implemented
        const int iBufferRemaining = iDelayBufferLength - iWritePosition;
        delayBuffer.copyFromWithRamp(channel, iWritePosition, fBufferData, iBufferLength, 0.8, 0.8); // Fill delay til end
        // Fill delay from start to remaining samples left
        delayBuffer.copyFromWithRamp(channel, 0, fBufferData, iBufferLength - iBufferRemaining, 0.8, 0.8);
    }
}

void DelayPluginAudioProcessor::getFromDelayBuffer(juce::AudioBuffer<float>& buffer, int channel, const int iBufferLength, const int iDelayBufferLength, const float* fBufferData, const float* fDelayBufferData)
{
    // Calculate read position from delay buffer based on delay time
    const int iReadPosition = static_cast<int>(iDelayBufferLength + iWritePosition - (iSampleRate * fDelayTime[channel] / 1000))  % iDelayBufferLength;
    
    if (iDelayBufferLength > iBufferLength + iReadPosition )
        buffer.addFromWithRamp(channel, 0, fDelayBufferData + iReadPosition, iBufferLength, fFeedbackGain, fFeedbackGain);
    else
    {
        const int iBufferRemaining = iDelayBufferLength - iReadPosition;
        buffer.addFromWithRamp(channel, 0, fDelayBufferData + iReadPosition, iBufferRemaining, fFeedbackGain, fFeedbackGain);
        buffer.addFromWithRamp(channel, iBufferRemaining, fDelayBufferData + iReadPosition, iBufferLength - iBufferRemaining, fFeedbackGain, fFeedbackGain);
    }
}

void DelayPluginAudioProcessor::feedbackDelay(int channel, const int iBufferLength, const int iDelayBufferLength, float* fDryBuffer)
{
    
    if (iDelayBufferLength > iBufferLength + iWritePosition)
        delayBuffer.addFromWithRamp(channel, iWritePosition, fDryBuffer, iBufferLength, fFeedbackGain, fFeedbackGain);
    else
    {
        const int iBufferRemaining = iDelayBufferLength - iWritePosition;
        delayBuffer.addFromWithRamp(channel, iBufferRemaining, fDryBuffer, iBufferRemaining, fFeedbackGain, fFeedbackGain);
        delayBuffer.addFromWithRamp(channel, 0, fDryBuffer, iBufferLength - iBufferRemaining, fFeedbackGain, fFeedbackGain);
    }
}

//==============================================================================
bool DelayPluginAudioProcessor::hasEditor() const
{
    return true; // (change this to false if you choose to not supply an editor)
}

juce::AudioProcessorEditor* DelayPluginAudioProcessor::createEditor()
{
    return new DelayPluginAudioProcessorEditor (*this);
}

//==============================================================================
void DelayPluginAudioProcessor::getStateInformation (juce::MemoryBlock& destData)
{
    // You should use this method to store your parameters in the memory block.
    // You could do that either as raw data, or use the XML or ValueTree classes
    // as intermediaries to make it easy to save and load complex data.
}

void DelayPluginAudioProcessor::setStateInformation (const void* data, int sizeInBytes)
{
    // You should use this method to restore your parameters from this memory block,
    // whose contents will have been created by the getStateInformation() call.
}

//==============================================================================
// This creates new instances of the plugin..
juce::AudioProcessor* JUCE_CALLTYPE createPluginFilter()
{
    return new DelayPluginAudioProcessor();
}