/*!
 * \file CyclopsFeature.h
 * \date 2019/11/12
 *
 * \author Lin, Chi
 * Contact: lin.chi@hzleaper.com
 *
 *
 * \note
*/

#ifndef __CyclopsFeature_h_
#define __CyclopsFeature_h_

#include "CyclopsParam.h"
#include "CyclopsEnums.h"
#include "CyclopsGrid.h"

/*! \brief External properties that would affect feature's computation.
It's stored inside sample instance's user data */
enum CyclopsFeatureExtProp
{
	CFExtPropStart = 9000,
	
	/*! Used by SizeFeature, instead of image/bounding rect size of sample instance, 2 float */
	CFExtPropSize,
	/*! Used by PPFeature, instead of max-value normalization, 1 double */
	CFExtPropNormValue,

	CFExtPropEnd = 10000,
};

class SampleInstance;

/*! \brief Base class for feature extractor */
class CyclopsFeature
{
public:
	/*! Parameter configurations */
	CyclopsParams mParams;
	/*! Default auto-tune search grid */
	CyclopsGrids mDefaultGrids;

	virtual ~CyclopsFeature() {}
	typedef std::shared_ptr<CyclopsFeature> Ptr;

	/*! Feature's type */
	FeatureType getType() const { return mType; }

	/*! Enable or disable this feature */
	void setEnabled(bool val = true) { mDisable = !val; }

	/*! Check if this feature is enabled or not */
	bool isEnabled() const { return !mDisable; }

	/*! Change weight of this feature */
	void setWeight(double w) { mWeight = w; mParams.setDirtyBit(true); }

	/*! Get weight of this feature */
	double getWeight() const { return mWeight; }

	/*! Serialized to file or in-memory string */
	void serialize(FileStorage& fs) const {
		mParams.serialize(fs);
		fs << "name" << mName;
		fs << "disable" << mDisable;
		fs << "weight" << mWeight;
		fs << "feature" << "{:";
		serializeFeature(fs);
		fs << "}";
	}

	/*! Deserialize from file or in-memory string */
	void deserialize(const FileNode& node) {
		mParams.deserialize(node);
		node["name"] >> mName;
		node["disable"] >> mDisable;
		node["weight"] >> mWeight;
		deserializeFeature(node["feature"]);
	}

	/*! @overload */
	Mat compute(const SampleInstance* pinst) {
		Mat f;
		compute(pinst, f);
		return f;
	}

	/*! Compute feature vector for provided image
	* @param pinst pointer to sample instance for computation
	* @param f output feature vector
	* @return size of feature vector, 0 for fail
	*/
	int compute(const SampleInstance* pinst, Mat& f) {
		if (mDisable) return 0;
		syncParam();
		int ret = doCompute(pinst, f);
		if (!f.empty() && mWeight != 1) f *= mWeight;
		return ret;
	}

	/*! Get size of feature vector for given normalized image size */
	int getSize(const Size& sampleSize) {
		if (mDisable) return 0;
		syncParam();
		return doGetSize(sampleSize);
	}

	/*! Set parameter configuration for definition to real implementation */
	void syncParam() {
		if (mParams.isDirty()) {
			doSyncParam();
			mParams.setDirtyBit(false);
		}
	}

	/*! Backup parameters */
	virtual void backupAll() { mParams.backupAll(); }
	/*! Restore parameter from last backup */
	virtual void restoreAll() { mParams.restoreAll(); }

	/*! Whether any parameter is modified */
	virtual bool isDirty() { return mParams.isDirty(); }

	/*! Do training of given samples */
	virtual bool train(const std::vector<const SampleInstance*>& trainSamples) { return true; }
	/*! Whether we need to re-train this feature */
	virtual bool needTrain() { return false; }
	/*! Whether we need to fix some bad parameter configuration
	* @param sampleSize uniformed sample size
	* @param doFix true if we should also do the real fix
	* @return true if fix is needed
	*/
	virtual bool needFix(const Size& sampleSize, bool doFix) {
		return !mParams.isValid(sampleSize, doFix).empty();
	}

	/*! Clear trained cache */
	virtual void clear() {}

	/*! Get feature's name */
	const std::string& getName() const {
		return mName;
	}

protected:
	virtual void doSyncParam() {}
	virtual int doCompute(const SampleInstance* pinst, Mat& f) { return 0; }
	virtual int doGetSize(const Size& sampleSize) const { return 0; }
	virtual void serializeFeature(FileStorage& fs) const {}
	virtual void deserializeFeature(const FileNode& node) {}

protected:
	FeatureType mType;
	std::string mName;
	bool mDisable = false;
	double mWeight = 1.;
};

/*! \brief Base class for Bag-of-words feature */
class BOWFeature : public CyclopsFeature
{
public:
	virtual ~BOWFeature() {}
	typedef std::shared_ptr<BOWFeature> Ptr;

	enum Param {
		/*! Count of vocabulary */
		VocCount = 0,
	};

	virtual bool isDirty();
	virtual bool train(const std::vector<const SampleInstance*>& trainSamples);
	virtual bool needTrain() { return true; }
	virtual void clear();

protected:
	explicit BOWFeature();
	virtual int doCompute(const SampleInstance* pinst, Mat& f);
	virtual int doGetSize(const Size& sampleSize) const;
	virtual void serializeFeature(FileStorage& fs) const;
	virtual void deserializeFeature(const FileNode& node);

	virtual int computeRaw(const Mat& img, Mat& f) { return 0; }
	virtual void serializeRaw(FileStorage& fs) const {}
	virtual void deserializeRaw(const FileNode& node) {}

protected:
	cv::Ptr<BOWImgDescriptorExtractor> mExt;
};

/*! \brief Image feature: ORB (oriented BRIEF) */
class ORBFeature : public BOWFeature
{
public:
	virtual ~ORBFeature() {}
	typedef std::shared_ptr<ORBFeature> Ptr;
	/*! Create an ORB feature with default parameters(recommended for 128x128 sample size) */
	static ORBFeature::Ptr create();

	enum Param {
		/*! Size of patch, 4 ~ 256 */
		PatchSize = VocCount + 1,
		/*! Scale factor for pyramid, 1 ~ 2 */
		ScaleFactor,
		/*! Level of pyramid (scale down) */
		DownLevel,
		/* UpLevel, remove scale up level, as there's some bug in image pyramid generation code in opencv.
		add it back some day if they fix the issue https://github.com/opencv/opencv/issues/16197
		*/
		/*! The number of points that produce each element of ORB, 2, 3, or 4 */
		RandomPairCount,
	};
};

/*! \brief Image feature: AKAZE */
class AKAZEFeature : public BOWFeature
{
public:
	~AKAZEFeature() {}
	typedef std::shared_ptr<AKAZEFeature> Ptr;
	/*! Create an AKAZE feature with default parameters(recommended for 128x128 sample size) */
	static AKAZEFeature::Ptr create();

	enum Param {
		/*! Whether this feature is rotation-invariant, true or false */
		RotationInvariant = VocCount + 1,
		/*! Threshold to accept key point, > 0, usualy a small value */
		Threshold,
		/*! Maximum octave evolution */
		Octave,
		/*! Number of sub-levels per scale level (octave) */
		SubLevel,
		/*! Diffusivity type, see DiffusivityType */
		DiffusivityType
	};
	enum DiffusivityType {
		G1 = 0, G2, Weickert, Charbonnier
	};
};

/*! \brief Image feature: HOG */
class HOGFeature : public CyclopsFeature
{
public:
	virtual ~HOGFeature() {}
	typedef std::shared_ptr<HOGFeature> Ptr;
	/*! Create a HOG feature with default parameters(recommended for 128x128 sample size) */
	static HOGFeature::Ptr create();

	enum Param {
		/*! Size of a cell for histogram, 2x2 ~ 128x128, should be 2^x */
		CellSize = 0,
		/*! Bins of histogram, should be factor of 360(or 180 depending on SignedGradient) */
		BinSize,
		/*! Count of cells in a block, block size = cell in block * cell size */
		CellInBlock,
		/*! Count of cells in a block stride, block stride = cell in block stride * cell size */
		CellInBlockStride,
		/*! Count of block in stride, win size = block size + block stride * block stride step */
		BlockStrideStep,
		/*! use signed gradient or not, directions are analyzed in 180 or 360 */
		SignedGradient,
	};
};

/*! \brief Image feature: Pixel-by-pixel */
class PPFeature : public CyclopsFeature
{
public:
	virtual ~PPFeature() {}
	typedef std::shared_ptr<PPFeature> Ptr;
	/*! Create a pixel-by-pixel feature with default parameters(recommended for 128x128 sample size) */
	static PPFeature::Ptr create();

	enum Param {
		/*! Uniformed image size */
		UniSize = 0,
		/*! Pixel value type, see PixelValue */
		PixelValue,
		/*! Projection type , see ProjectionType */
		Projection,
	};

	enum PixelValueType {
		/*! Gray value in 0 ~ 1 */
		GrayValue = 0,
		/*! Normalized gray value with maximum scaling to 0 ~ 1 */
		GrayNormValue,
		/*! Binary value after auto-thresholding, bigger report 1, otherwise report 0.
		    If roi is available, use roi's mask as source.
			If roi is using soft mask, report floating value between 0 ~ 1.
		*/
		BinaryValue,
		/*! Fraction of pixels in the foreground after auto-thresholding, bigger report foreground
			If roi is available, use roi's mask as source
		*/
		FractionValue,
	};

	enum ProjectionType {
		/*! No projection */
		None = 0,
		/*! Horizontal projection, report average of each row */
		Horinzontal,
		/*! Vertical projection, report average of each column */
		Vertical,
		/*! Horizontal and vertical projection, report average of each row and column */
		HorinzontalAndVertical,
	};
};

/*! \brief Image feature: percentage of foreground pixels */
class FGFFeature : public CyclopsFeature
{
public:
	virtual ~FGFFeature() {}
	typedef std::shared_ptr<FGFFeature> Ptr;
	/*! Create a foreground fraction feature with default parameters */
	static FGFFeature::Ptr create();
};

/*! \brief Base class for geometric features based on contours defined in sample's detect roi. Usually no parameter. */
class GeomFeature : public CyclopsFeature
{
public:
	virtual ~GeomFeature() {}
	typedef std::shared_ptr<GeomFeature> Ptr;
protected:
	virtual int doGetSize(const Size& sampleSize) const;
};

/*! \brief Geometric feature: How the sample looks like a circle: contour area / (pi * r ^ 2)\n
For multiple contours, report the smallest value */
class CircularityFeature : public GeomFeature
{
public:
	virtual ~CircularityFeature() {}
	typedef std::shared_ptr<CircularityFeature> Ptr;
	/*! Create a circularity feature with no parameters */
	static CircularityFeature::Ptr create();
};

/*! \brief Geometric feature: How the sample looks like a convex hull: contour area / bounding hull area\n
For multiple contours, report the smallest value */
class ConvexityFeature : public GeomFeature
{
public:
	virtual ~ConvexityFeature() {}
	typedef std::shared_ptr<ConvexityFeature> Ptr;
	/*! Create a convexity feature with no parameters */
	static ConvexityFeature::Ptr create();
};

/*! \brief Geometric feature: difference between the contour and its convex hull: sum(distance of defect)
A convex contour report 0, for multiple contours, report the biggest value */
class ConvDefectsFeature : public GeomFeature
{
public:
	virtual ~ConvDefectsFeature() {}
	typedef std::shared_ptr<ConvDefectsFeature> Ptr;
	/*! Create a convexity defects feature with no parameters */
	static ConvDefectsFeature::Ptr create();
};

/*! \brief Geometric feature: Sin value of orientation of the bonding convex hull of the sample, not rotation-invariant. */
class OrientationFeature : public GeomFeature
{
public:
	virtual ~OrientationFeature() {}
	typedef std::shared_ptr<OrientationFeature> Ptr;
	/*! Create a orientation feature with no parameters */
	static OrientationFeature::Ptr create();
};

/*! \brief Geometric feature: Ratio of convex hull's min axes and max axes, whether the sample is long or like a square. */
class InertiaFeature : public GeomFeature
{
public:
	virtual ~InertiaFeature() {}
	typedef std::shared_ptr<InertiaFeature> Ptr;
	/*! Create a inertia feature with no parameters */
	static InertiaFeature::Ptr create();
};

/*! \brief Base class for features count components the sample's contour has. */
class CompCountFeature : public GeomFeature
{
public:
	virtual ~CompCountFeature() {}
	typedef std::shared_ptr<CompCountFeature> Ptr;
	virtual bool train(const std::vector<const SampleInstance*>& trainSamples);
	virtual bool needTrain() { return true; }
protected:
	virtual void serializeFeature(FileStorage& fs) const;
	virtual void deserializeFeature(const FileNode& node);
	float mNormCounts;
};

/*! \brief Geometric feature: How many contours the sample has.\n
Number of connected contour components, aka, count of adding sub-rois in sample's detect roi */
class ContourCountFeature : public CompCountFeature
{
public:
	virtual ~ContourCountFeature() {}
	typedef std::shared_ptr<ContourCountFeature> Ptr;
	/*! Create a contour count feature with no parameters */
	static ContourCountFeature::Ptr create();
};

/*! \brief Geometric feature: How many holes the sample has.\n
Number of holes, aka, count of subtracting sub-rois in sample's detect roi */
class HoleCountFeature : public CompCountFeature
{
public:
	virtual ~HoleCountFeature() {}
	typedef std::shared_ptr<HoleCountFeature> Ptr;
	/*! Create a hole count feature with no parameters */
	static HoleCountFeature::Ptr create();
};

/*! \brief Base class for size features based on sample's original and uniformed image size. Usually no parameter. */
class SizeFeature : public CyclopsFeature
{
public:
	virtual ~SizeFeature() {}
	typedef std::shared_ptr<SizeFeature> Ptr;
protected:
	virtual int doGetSize(const Size& sampleSize) const;
	Size2f getSampleInstSize(const SampleInstance* pinst);
};

/*! \brief Size feature: Aspect ratio of sample image: width / height */
class AspectRatioFeature : public SizeFeature
{
public:
	virtual ~AspectRatioFeature() {}
	typedef std::shared_ptr<AspectRatioFeature> Ptr;
	/*! Create a aspect ratio feature with no parameters */
	static AspectRatioFeature::Ptr create();
};

/*! \brief Base class for features report the abstract size of sample image */
class AbstractSizeFeature : public SizeFeature
{
public:
	virtual ~AbstractSizeFeature() {}
	typedef std::shared_ptr<AbstractSizeFeature> Ptr;
	virtual bool train(const std::vector<const SampleInstance*>& trainSamples);
	virtual bool needTrain() { return true; }
protected:
	virtual void serializeFeature(FileStorage& fs) const;
	virtual void deserializeFeature(const FileNode& node);
	float mNormSize;
};

/*! \brief Size feature: Width of sample image, not scale-invariant */
class WidthFeature : public AbstractSizeFeature
{
public:
	virtual ~WidthFeature() {}
	typedef std::shared_ptr<WidthFeature> Ptr;
	/*! Create a width feature with no parameters */
	static WidthFeature::Ptr create();
};

/*! \brief Size feature: Height of sample image, not scale-invariant */
class HeightFeature : public AbstractSizeFeature
{
public:
	virtual ~HeightFeature() {}
	typedef std::shared_ptr<HeightFeature> Ptr;
	/*! Create a height feature with no parameters */
	static HeightFeature::Ptr create();
};

/*! \brief Size feature: Difference in size between the sample image and uniformed image's sizes:
min(uniformed width / width, uniformed height / height) */
class ZoomFactorFeature : public SizeFeature
{
public:
	virtual ~ZoomFactorFeature() {}
	typedef std::shared_ptr<ZoomFactorFeature> Ptr;
	/*! Create a zoom factor feature with no parameters */
	static ZoomFactorFeature::Ptr create();
};


#endif // CyclopsFeature_h_