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

 * Project:  PROJ

 * Purpose:  Functionality related to TIN based transformations

 * Author:   Even Rouault, <even.rouault at spatialys.com>

 *

 ******************************************************************************

 * Copyright (c) 2020, Even Rouault, <even.rouault at spatialys.com>

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and associated documentation files (the "Software"),

 * to deal in the Software without restriction, including without limitation

 * the rights to use, copy, modify, merge, publish, distribute, sublicense,

 * and/or sell copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included

 * in all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

 * DEALINGS IN THE SOFTWARE.

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

#ifndef TINSHIFT_HPP

#define TINSHIFT_HPP

#ifdef PROJ_COMPILATION

#include "proj/internal/include_nlohmann_json.hpp"

#else

#include "nlohmann/json.hpp"

#endif

#include <algorithm>

#include <cmath>

#include <exception>

#include <functional>

#include <limits>

#include <memory>

#include <string>

#include <vector>

#include "quadtree.hpp"

#ifndef TINSHIFT_NAMESPACE

#define TINSHIFT_NAMESPACE TINShift

#endif

#include "tinshift_exceptions.hpp"

namespace TINSHIFT_NAMESPACE {

enum FallbackStrategy {

    FALLBACK_NONE,

    FALLBACK_NEAREST_SIDE,

    FALLBACK_NEAREST_CENTROID,

};

using json = nlohmann::json;

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

/** Content of a TINShift file. */

class TINShiftFile {

  public:

    /** Parse the provided serialized JSON content and return an object.

     *

     * @throws ParsingException in case of error.

     */

    static std::unique_ptr<TINShiftFile> parse(const std::string &text);

    /** Get file type. Should always be "triangulation_file" */

    const std::string &fileType() const { return mFileType; }

    /** Get the version of the format. At time of writing, only "1.0" is known

     */

    const std::string &formatVersion() const { return mFormatVersion; }

    /** Get brief descriptive name of the deformation model. */

    const std::string &name() const { return mName; }

    /** Get a string identifying the version of the deformation model.

     * The format for specifying version is defined by the agency

     * responsible for the deformation model. */

    const std::string &version() const { return mVersion; }

    /** Get a string identifying the license of the file.

     * e.g "Create Commons Attribution 4.0 International" */

    const std::string &license() const { return mLicense; }

    /** Get a text description of the model. Intended to be longer than name()

     */

    const std::string &description() const { return mDescription; }

    /** Get a text description of the model. Intended to be longer than name()

     */

    const std::string &publicationDate() const { return mPublicationDate; }

    const enum FallbackStrategy &fallbackStrategy() const {

        return mFallbackStrategy;

    }

    /** Basic information on the agency responsible for the model. */

    struct Authority {

        std::string name{};

        std::string url{};

        std::string address{};

        std::string email{};

    };

    /** Get basic information on the agency responsible for the model. */

    const Authority &authority() const { return mAuthority; }

    /** Hyperlink related to the model. */

    struct Link {

        /** URL holding the information */

        std::string href{};

        /** Relationship to the dataset. e.g. "about", "source", "license",

         * "metadata" */

        std::string rel{};

        /** Mime type */

        std::string type{};

        /** Description of the link */

        std::string title{};

    };

    /** Get links to related information. */

    const std::vector<Link> links() const { return mLinks; }

    /** Get a string identifying the CRS of source coordinates in the

     * vertices. Typically "EPSG:XXXX". If the transformation is for vertical

     * component, this should be the code for a compound CRS (can be

     * EPSG:XXXX+YYYY where XXXX is the code of the horizontal CRS and YYYY

     * the code of the vertical CRS).

     * For example, for the KKJ->ETRS89 transformation, this is EPSG:2393

     * ("KKJ / Finland Uniform Coordinate System").

     * The input coordinates are assumed to

     * be passed in the "normalized for visualisation" / "GIS friendly" order,

     * that is longitude, latitude for geographic coordinates and

     * easting, northing for projected coordinates.

     * This may be empty for unspecified CRS.

     */

    const std::string &inputCRS() const { return mInputCRS; }

    /** Get a string identifying the CRS of target coordinates in the

     * vertices. Typically "EPSG:XXXX". If the transformation is for vertical

     * component, this should be the code for a compound CRS (can be

     * EPSG:XXXX+YYYY where XXXX is the code of the horizontal CRS and YYYY

     * the code of the vertical CRS).

     * For example, for the KKJ->ETRS89 transformation, this is EPSG:3067

     * ("ETRS89 / TM35FIN(E,N)").

     * The output coordinates will be

     * returned in the "normalized for visualisation" / "GIS friendly" order,

     * that is longitude, latitude for geographic coordinates and

     * easting, northing for projected coordinates.

     * This may be empty for unspecified CRS.

     */

    const std::string &outputCRS() const { return mOutputCRS; }

    /** Return whether horizontal coordinates are transformed. */

    bool transformHorizontalComponent() const {

        return mTransformHorizontalComponent;

    }

    /** Return whether vertical coordinates are transformed. */

    bool transformVerticalComponent() const {

        return mTransformVerticalComponent;

    }

    /** Indices of vertices of a triangle */

    struct VertexIndices {

        /** Index of first vertex */

        unsigned idx1;

        /** Index of second vertex */

        unsigned idx2;

        /** Index of third vertex */

        unsigned idx3;

    };

    /** Return number of elements per vertex of vertices() */

    unsigned verticesColumnCount() const { return mVerticesColumnCount; }

    /** Return description of triangulation vertices.

     * Each vertex is described by verticesColumnCount() consecutive values.

     * They are respectively:

     * - the source X value

     * - the source Y value

     * - (if transformHorizontalComponent() is true) the target X value

     * - (if transformHorizontalComponent() is true) the target Y value

     * - (if transformVerticalComponent() is true) the delta Z value (to go from

     * source to target Z)

     *

     * X is assumed to be a longitude (in degrees) or easting value.

     * Y is assumed to be a latitude (in degrees) or northing value.

     */

    const std::vector<double> &vertices() const { return mVertices; }

    /** Return triangles*/

    const std::vector<VertexIndices> &triangles() const { return mTriangles; }

  private:

    TINShiftFile() = default;

    std::string mFileType{};

    std::string mFormatVersion{};

    std::string mName{};

    std::string mVersion{};

    std::string mLicense{};

    std::string mDescription{};

    std::string mPublicationDate{};

    enum FallbackStrategy mFallbackStrategy {};

    Authority mAuthority{};

    std::vector<Link> mLinks{};

    std::string mInputCRS{};

    std::string mOutputCRS{};

    bool mTransformHorizontalComponent = false;

    bool mTransformVerticalComponent = false;

    unsigned mVerticesColumnCount = 0;

    std::vector<double> mVertices{};

    std::vector<VertexIndices> mTriangles{};

};

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

/** Class to evaluate the transformation of a coordinate */

class Evaluator {

  public:

    /** Constructor. */

    explicit Evaluator(std::unique_ptr<TINShiftFile> &&fileIn);

    /** Get file */

    const TINShiftFile &file() const { return *(mFile.get()); }

    /** Evaluate displacement of a position given by (x,y,z,t) and

     * return it in (x_out,y_out_,z_out).

     */

    bool forward(double x, double y, double z, double &x_out, double &y_out,

                 double &z_out);

    /** Apply inverse transformation. */

    bool inverse(double x, double y, double z, double &x_out, double &y_out,

                 double &z_out);

  private:

    std::unique_ptr<TINShiftFile> mFile;

    // Reused between invocations to save memory allocations

    std::vector<unsigned> mTriangleIndices{};

    std::unique_ptr<NS_PROJ::QuadTree::QuadTree<unsigned>> mQuadTreeForward{};

    std::unique_ptr<NS_PROJ::QuadTree::QuadTree<unsigned>> mQuadTreeInverse{};

};

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

} // namespace TINSHIFT_NAMESPACE

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

#include "tinshift_impl.hpp"

#endif // TINSHIFT_HPP