#include <math.h> // for floor
#include <float.h> // for FLT_MAX

#include <stdio.h>
#include "ofxsImageEffect.h"
#include "ofxsMultiThread.h"

#include "../include/ofxsProcessing.H"
#include "../include/ofxsImageBlender.H"

  namespace OFX {
  extern ImageEffectHostDescription gHostDescription;
  }
////////////////////////////////////////////////////////////////////////////////
/** @brief The plugin that does our work */
class RetimerPlugin : public OFX::ImageEffect {
protected :
    // do not need to delete these, the ImageEffect is managing them for us
    OFX::Clip *dstClip_;            /**< @brief Mandated output clips */
    OFX::Clip *srcClip_;            /**< @brief Mandated input clips */

    OFX::DoubleParam  *sourceTime_; /**< @brief mandated parameter, only used in the retimer context. */
    OFX::DoubleParam  *speed_;      /**< @brief only used in the filter context. */
    OFX::DoubleParam  *duration_;   /**< @brief how long the output should be as a proportion of input. General context only  */

public :
    /** @brief ctor */
    RetimerPlugin(OfxImageEffectHandle handle)
      : ImageEffect(handle)
      , dstClip_(0)
      , srcClip_(0)
      , sourceTime_(0)
      , speed_(0)
      , duration_(0)
    {
        dstClip_ = fetchClip(kOfxImageEffectOutputClipName);
        srcClip_ = fetchClip(kOfxImageEffectSimpleSourceClipName);

        // What parameters we instantiate depend on the context
        if(getContext() == OFX::eContextRetimer)
            // fetch the mandated parameter which the host uses to pass us the frame to retime to
            sourceTime_   = fetchDoubleParam(kOfxImageEffectRetimerParamName);
        else // context == OFX::eContextFilter || context == OFX::eContextGeneral
            // filter context means we are in charge of how to retime, and our example is using a speed curve to do that
            speed_   = fetchDoubleParam("Speed");

        // fetch duration param for general context
        if(getContext() == OFX::eContextGeneral)
            duration_ = fetchDoubleParam("Duration");
    }

    /* Override the render */
    virtual void render(const OFX::RenderArguments &args);

    /** Override the get frames needed action */
    virtual void getFramesNeeded(const OFX::FramesNeededArguments &args, OFX::FramesNeededSetter &frames);

    /* override the time domain action, only for the general context */
    virtual bool getTimeDomain(OfxRangeD &range);
    
    /* set up and run a processor */
    void
    setupAndProcess(OFX::ImageBlenderBase &, const OFX::RenderArguments &args);
};


////////////////////////////////////////////////////////////////////////////////
/** @brief render for the filter */

////////////////////////////////////////////////////////////////////////////////
// basic plugin render function, just a skelington to instantiate templates from

// make sure components are sane
static void
checkComponents(const OFX::Image &src,
                OFX::BitDepthEnum dstBitDepth,
                OFX::PixelComponentEnum dstComponents)
{
    OFX::BitDepthEnum      srcBitDepth     = src.getPixelDepth();
    OFX::PixelComponentEnum srcComponents  = src.getPixelComponents();
        
    // see if they have the same depths and bytes and all
    if(srcBitDepth != dstBitDepth || srcComponents != dstComponents)
        throw int(1); // HACK!! need to throw an sensible exception here!        
}

static void framesNeeded(double sourceTime, OFX::FieldEnum fieldToRender, double *fromTimep, double *toTimep, double *blendp)
{
    // figure the two images we are blending between
    double fromTime, toTime;
    double blend;

    if (fieldToRender == OFX::eFieldNone) {
        // unfielded, easy peasy
        fromTime = floor(sourceTime);
        toTime = fromTime + 1;
        blend = sourceTime - fromTime;
    }
    else {
        // Fielded clips, pook. We are rendering field doubled images,
        // and so need to blend between fields, not frames.
        double frac = sourceTime - floor(sourceTime);
        if(frac < 0.5) {
            // need to go between the first and second fields of this frame
            fromTime = floor(sourceTime); // this will get the first field
            toTime   = fromTime + 0.5;    // this will get the second field of the same frame
            blend    = frac * 2.0;        // and the blend is between those two
        }
        else { // frac > 0.5
            fromTime = floor(sourceTime) + 0.5; // this will get the second field of this frame
            toTime   = floor(sourceTime) + 1.0; // this will get the first field of the next frame
            blend    = (frac - 0.5) * 2.0;
        }
    }
    *fromTimep = fromTime;
    *toTimep = toTime;
    *blendp = blend;
}

/* set up and run a processor */
void
RetimerPlugin::setupAndProcess(OFX::ImageBlenderBase &processor, const OFX::RenderArguments &args)
{
    // get a dst image
    std::unique_ptr<OFX::Image>  dst(dstClip_->fetchImage(args.time));
    OFX::BitDepthEnum          dstBitDepth    = dst->getPixelDepth();
    OFX::PixelComponentEnum    dstComponents  = dst->getPixelComponents();
  
    // figure the frame we should be retiming from
    double sourceTime;
    
    if(getContext() == OFX::eContextRetimer) {
        // the host is specifying it, so fetch it from the kOfxImageEffectRetimerParamName pseudo-param
        sourceTime = sourceTime_->getValueAtTime(args.time);
    }
    else {
        // we have our own param, which is a speed, so we integrate it to get the time we want
        sourceTime = speed_->integrate(0, args.time);
    }

    // figure the two images we are blending between
    double fromTime, toTime;
    double blend;
    framesNeeded(sourceTime, args.fieldToRender, &fromTime, &toTime, &blend);

    // fetch the two source images
    std::unique_ptr<OFX::Image> fromImg(srcClip_->fetchImage(fromTime));
    std::unique_ptr<OFX::Image> toImg(srcClip_->fetchImage(toTime));

    // make sure bit depths are sane
    if(fromImg.get()) checkComponents(*fromImg, dstBitDepth, dstComponents);
    if(toImg.get()) checkComponents(*toImg, dstBitDepth, dstComponents);

    // set the images
    processor.setDstImg(dst.get());
    processor.setFromImg(fromImg.get());
    processor.setToImg(toImg.get());

    // set the render window
    processor.setRenderWindow(args.renderWindow);

    // set the blend between
    processor.setBlend((float)blend);

    // Call the base class process member, this will call the derived templated process code
    processor.process();
}

void
RetimerPlugin::getFramesNeeded(const OFX::FramesNeededArguments &args,
                OFX::FramesNeededSetter &frames)
{
    // figure the two images we are blending between
    double fromTime, toTime;
    double blend;
    // whatever the rendered field is, the frames are the same
    framesNeeded(args.time, OFX::eFieldNone, &fromTime, &toTime, &blend);
    OfxRangeD range;
    range.min = fromTime;
    range.max = toTime;
    frames.setFramesNeeded(*srcClip_, range);
}

/* override the time domain action, only for the general context */
bool 
RetimerPlugin::getTimeDomain(OfxRangeD &range)
{
    // this should only be called in the general context, ever!
    if(getContext() == OFX::eContextGeneral) {
        // If we are a general context, we can changed the duration of the effect, so have a param to do that
        // We need a separate param as it is impossible to derive this from a speed param and the input clip
        // duration (the speed may be animating or wired to an expression).
        double duration = duration_->getValue(); //don't animate
        
        // how many frames on the input clip
        OfxRangeD srcRange = srcClip_->getFrameRange();
        
        range.min = 0;
        range.max = srcRange.max * duration;
        return true;
    }

    return false;
}

// the overridden render function
void
RetimerPlugin::render(const OFX::RenderArguments &args)
{
    // instantiate the render code based on the pixel depth of the dst clip
    OFX::BitDepthEnum       dstBitDepth    = dstClip_->getPixelDepth();
    OFX::PixelComponentEnum dstComponents  = dstClip_->getPixelComponents();

    // do the rendering
    if(dstComponents == OFX::ePixelComponentRGBA) {
        switch(dstBitDepth) {
        case OFX::eBitDepthUByte : {      
            OFX::ImageBlender<unsigned char, 4> fred(*this);
            setupAndProcess(fred, args);
        }
        break;

        case OFX::eBitDepthUShort : {
            OFX::ImageBlender<unsigned short, 4> fred(*this);
            setupAndProcess(fred, args);
        }                          
        break;

        case OFX::eBitDepthFloat : {
            OFX::ImageBlender<float, 4> fred(*this);
            setupAndProcess(fred, args);
        }
        break;
        default :
            OFX::throwSuiteStatusException(kOfxStatErrUnsupported);
        }
    }
    else {
        switch(dstBitDepth) {
        case OFX::eBitDepthUByte : {
            OFX::ImageBlender<unsigned char, 1> fred(*this);
            setupAndProcess(fred, args);
        }
        break;

        case OFX::eBitDepthUShort : {
            OFX::ImageBlender<unsigned short, 1> fred(*this);
            setupAndProcess(fred, args);
        }                          
        break;

        case OFX::eBitDepthFloat : {
            OFX::ImageBlender<float, 1> fred(*this);
            setupAndProcess(fred, args);
        }                          
        break;
        default :
            OFX::throwSuiteStatusException(kOfxStatErrUnsupported);
        }
    } // switch
}

using namespace OFX;
mDeclarePluginFactory(RetimerExamplePluginFactory, ;, {});

namespace OFX
{
  namespace Plugin
  {
    void getPluginIDs(OFX::PluginFactoryArray &ids)
    {
      static RetimerExamplePluginFactory p("net.sf.openfx.retimer", 1, 0);
      ids.push_back(&p);
    }
  };
};

void RetimerExamplePluginFactory::load()
{
  // we can't be used on hosts that don't perfrom temporal clip access
  if(!gHostDescription.temporalClipAccess) {
    throw OFX::Exception::HostInadequate("Need random temporal image access to work");
  }
}

/** @brief The basic describe function, passed a plugin descriptor */
void RetimerExamplePluginFactory::describe(OFX::ImageEffectDescriptor &desc) 
{
  // basic labels
  desc.setLabels("Retimer", "Retimer", "Retimer");
  desc.setPluginGrouping("OFX Example (Support)");

  // Say we are a transition context
  desc.addSupportedContext(OFX::eContextRetimer);
  desc.addSupportedContext(OFX::eContextFilter);
  desc.addSupportedContext(OFX::eContextGeneral);

  // Add supported pixel depths
  desc.addSupportedBitDepth(eBitDepthUByte);
  desc.addSupportedBitDepth(eBitDepthUShort);
  desc.addSupportedBitDepth(eBitDepthFloat);

  // set a few flags
  desc.setSingleInstance(false);
  desc.setHostFrameThreading(false);
  desc.setSupportsMultiResolution(true);
  desc.setSupportsTiles(true);
  desc.setTemporalClipAccess(true); // say we will be doing random time access on clips
  desc.setRenderTwiceAlways(false);
  desc.setSupportsMultipleClipPARs(false);
}        

/** @brief The describe in context function, passed a plugin descriptor and a context */
void RetimerExamplePluginFactory::describeInContext(OFX::ImageEffectDescriptor &desc, ContextEnum context) 
{
  // we are a transition, so define the sourceTo input clip
  ClipDescriptor *srcClip = desc.defineClip(kOfxImageEffectSimpleSourceClipName);
  srcClip->addSupportedComponent(ePixelComponentRGBA);
  srcClip->addSupportedComponent(ePixelComponentAlpha);
  srcClip->setTemporalClipAccess(true); // say we will be doing random time access on this clip
  srcClip->setSupportsTiles(true);
  srcClip->setFieldExtraction(eFieldExtractDoubled); // which is the default anyway

  // create the mandated output clip
  ClipDescriptor *dstClip = desc.defineClip(kOfxImageEffectOutputClipName);
  dstClip->addSupportedComponent(ePixelComponentRGBA);
  dstClip->addSupportedComponent(ePixelComponentAlpha);
  dstClip->setFieldExtraction(eFieldExtractDoubled); // which is the default anyway
  dstClip->setSupportsTiles(true);

  // what param we have is dependant on the host
  if(context == OFX::eContextRetimer) {
    // Define the mandated kOfxImageEffectRetimerParamName param, note that we don't do anything with this other than.
    // describe it. It is not a true param but how the host indicates to the plug-in which frame
    // it wants you to retime to. It appears on no plug-in side UI, it is purely the host's to manage.
    DoubleParamDescriptor *param = desc.defineDoubleParam(kOfxImageEffectRetimerParamName);
    (void)param;
  }
  else {
    // We are a general or filter context, define a speed param and a page of controls to put that in
    DoubleParamDescriptor *param = desc.defineDoubleParam("Speed");
    param->setLabels("speed", "speed", "speed");
    param->setScriptName("speed");
    param->setHint("How much to changed the speed of the input clip");
    param->setDefault(1);
    param->setRange(-FLT_MAX, FLT_MAX);
    param->setIncrement(0.05);
    param->setDisplayRange(0, 1);
    param->setAnimates(true); // can animate
    param->setDoubleType(eDoubleTypeScale);

    // make a page to put it in
    PageParamDescriptor *page = desc.definePageParam("Controls");

    // add our speed param into it
    page->addChild(*param);

    // If we are a general context, we can change the duration of the effect, so have a param to do that
    // We need a separate param as it is impossible to derive this from a speed param and the input clip
    // duration (the speed may be animating or wired to an expression).
    if(context == OFX::eContextGeneral) {
      // We are a general or filter context, define a speed param and a page of controls to put that in
      DoubleParamDescriptor *param = desc.defineDoubleParam("Duration");
      param->setLabels("duration", "duraction", "duration");
      param->setScriptName("duration");
      param->setHint("How long the output clip should be, as a proportion of the input clip's length.");
      param->setDefault(1);
      param->setRange(0, 10);
      param->setIncrement(0.1);
      param->setDisplayRange(0, 10);
      param->setAnimates(false); // no animation here!
      param->setDoubleType(eDoubleTypeScale);

      // add param to page
      page->addChild(*param);
    }
  }
}

/** @brief The create instance function, the plugin must return an object derived from the \ref OFX::ImageEffect class */
ImageEffect* RetimerExamplePluginFactory::createInstance(OfxImageEffectHandle handle, ContextEnum /*context*/)
{
  return new RetimerPlugin(handle);
}