/***********************************************************************

 * Software License Agreement (BSD License)

 *

 * Copyright 2008-2009  Marius Muja (mariusm@cs.ubc.ca). All rights reserved.

 * Copyright 2008-2009  David G. Lowe (lowe@cs.ubc.ca). All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE NNIndexGOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 *************************************************************************/

#ifndef OPENCV_FLANN_SAVING_H_

#define OPENCV_FLANN_SAVING_H_

//! @cond IGNORED

#include <cstring>

#include <vector>

#include "general.h"

#include "nn_index.h"

#ifdef FLANN_SIGNATURE_

#undef FLANN_SIGNATURE_

#endif

#define FLANN_SIGNATURE_ "FLANN_INDEX"

namespace cvflann

{

template <typename T>

struct Datatype {};

template<>

struct Datatype<char> { static flann_datatype_t type() { return FLANN_INT8; } };

template<>

struct Datatype<short> { static flann_datatype_t type() { return FLANN_INT16; } };

template<>

struct Datatype<int> { static flann_datatype_t type() { return FLANN_INT32; } };

template<>

struct Datatype<unsigned char> { static flann_datatype_t type() { return FLANN_UINT8; } };

template<>

struct Datatype<unsigned short> { static flann_datatype_t type() { return FLANN_UINT16; } };

template<>

struct Datatype<unsigned int> { static flann_datatype_t type() { return FLANN_UINT32; } };

template<>

struct Datatype<float> { static flann_datatype_t type() { return FLANN_FLOAT32; } };

template<>

struct Datatype<double> { static flann_datatype_t type() { return FLANN_FLOAT64; } };

/**

 * Structure representing the index header.

 */

struct IndexHeader

{

    char signature[16];

    char version[16];

    flann_datatype_t data_type;

    flann_algorithm_t index_type;

    size_t rows;

    size_t cols;

};

/**

 * Saves index header to stream

 *

 * @param stream - Stream to save to

 * @param index - The index to save

 */

template<typename Distance>

void save_header(FILE* stream, const NNIndex<Distance>& index)

{

    IndexHeader header;

    memset(header.signature, 0, sizeof(header.signature));

    strcpy(header.signature, FLANN_SIGNATURE_);

    memset(header.version, 0, sizeof(header.version));

    strcpy(header.version, FLANN_VERSION_);

    header.data_type = Datatype<typename Distance::ElementType>::type();

    header.index_type = index.getType();

    header.rows = index.size();

    header.cols = index.veclen();

    std::fwrite(&header, sizeof(header),1,stream);

}

/**

 *

 * @param stream - Stream to load from

 * @return Index header

 */

inline IndexHeader load_header(FILE* stream)

{

    IndexHeader header;

    size_t read_size = fread(&header,sizeof(header),1,stream);

    if (read_size!=(size_t)1) {

        FLANN_THROW(cv::Error::StsError, "Invalid index file, cannot read");

    }

    if (strcmp(header.signature,FLANN_SIGNATURE_)!=0) {

        FLANN_THROW(cv::Error::StsError, "Invalid index file, wrong signature");

    }

    return header;

}

template<typename T>

void save_value(FILE* stream, const T& value, size_t count = 1)

{

    fwrite(&value, sizeof(value),count, stream);

}

template<typename T>

void save_value(FILE* stream, const cvflann::Matrix<T>& value)

{

    fwrite(&value, sizeof(value),1, stream);

    fwrite(value.data, sizeof(T),value.rows*value.cols, stream);

}

template<typename T>

void save_value(FILE* stream, const std::vector<T>& value)

{

    size_t size = value.size();

    fwrite(&size, sizeof(size_t), 1, stream);

    fwrite(&value[0], sizeof(T), size, stream);

}

template<typename T>

void load_value(FILE* stream, T& value, size_t count = 1)

{

    size_t read_cnt = fread(&value, sizeof(value), count, stream);

    if (read_cnt != count) {

        FLANN_THROW(cv::Error::StsParseError, "Cannot read from file");

    }

}

template<typename T>

void load_value(FILE* stream, cvflann::Matrix<T>& value)

{

    size_t read_cnt = fread(&value, sizeof(value), 1, stream);

    if (read_cnt != 1) {

        FLANN_THROW(cv::Error::StsParseError, "Cannot read from file");

    }

    value.data = new T[value.rows*value.cols];

    read_cnt = fread(value.data, sizeof(T), value.rows*value.cols, stream);

    if (read_cnt != (size_t)(value.rows*value.cols)) {

        FLANN_THROW(cv::Error::StsParseError, "Cannot read from file");

    }

}

template<typename T>

void load_value(FILE* stream, std::vector<T>& value)

{

    size_t size;

    size_t read_cnt = fread(&size, sizeof(size_t), 1, stream);

    if (read_cnt!=1) {

        FLANN_THROW(cv::Error::StsError, "Cannot read from file");

    }

    value.resize(size);

    read_cnt = fread(&value[0], sizeof(T), size, stream);

    if (read_cnt != size) {

        FLANN_THROW(cv::Error::StsError, "Cannot read from file");

    }

}

}

//! @endcond

#endif /* OPENCV_FLANN_SAVING_H_ */