/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2011 Sandro Santilli <strk@kbt.io>
 * Copyright (C) 2005-2006 Refractions Research Inc.
 * Copyright (C) 2001-2002 Vivid Solutions Inc.
 *
 * This is free software; you can redistribute and/or modify it under
 * the terms of the GNU Lesser General Public Licence as published
 * by the Free Software Foundation.
 * See the COPYING file for more information.
 *
 **********************************************************************
 *
 * Last port: linearref/LinearLocation.java r463
 *
 **********************************************************************/

#ifndef GEOS_LINEARREF_LINEARLOCATION_H
#define GEOS_LINEARREF_LINEARLOCATION_H

#include <string>
#include <memory> // for std::unique_ptr

#include <geos/geom/Coordinate.h>
#include <geos/geom/Geometry.h>
#include <geos/geom/LineSegment.h>

namespace geos {
namespace linearref { // geos::linearref


/** \brief
 * Represents a location along a [LineString](@ref geom::LineString)
 * or [MultiLineString](@ref geom::MultiLineString).
 *
 * The referenced geometry is not maintained within this location, but
 * must be provided for operations which require it.
 * Various methods are provided to manipulate the location value and
 * query the geometry it references.
 */
class LinearLocation {
private:
    std::size_t componentIndex;
    std::size_t segmentIndex;
    double segmentFraction;

    /** \brief
     * Ensures the individual values are locally valid.
     *
     * Does **not** ensure that the indexes are valid for
     * a particular linear geometry.
     *
     * @see clamp
     */
    void normalize();

public:
    /** \brief
     * Gets a location which refers to the end of a linear
     * [Geometry](@ref geom::Geometry).
     *
     * @param linear the linear geometry
     * @return a new `LinearLocation`
     */
    static LinearLocation getEndLocation(const geom::Geometry* linear);

    /** \brief
     * Computes the [Coordinate](@ref geom::Coordinate) of a point a given
     * fraction along the line segment `(p0, p1)`.
     *
     * If the fraction is greater than 1.0 the last
     * point of the segment is returned.
     * If the fraction is less than or equal to 0.0 the first point
     * of the segment is returned.
     * The Z ordinate is interpolated from the Z-ordinates of
     * the given points, if they are specified.
     *
     * @param p0 the first point of the line segment
     * @param p1 the last point of the line segment
     * @param frac the length to the desired point
     * @return the Coordinate of the desired point
     */
    static geom::Coordinate pointAlongSegmentByFraction(const geom::Coordinate& p0, const geom::Coordinate& p1,
            double frac);


    /** \brief
     * Creates a location referring to the start of a linear geometry
     */
    LinearLocation(std::size_t segmentIndex = 0, double segmentFraction = 0.0);

    LinearLocation(std::size_t componentIndex, std::size_t segmentIndex, double segmentFraction);

    /** \brief
     * Ensures the indexes are valid for a given linear [Geometry](@ref geom::Geometry).
     *
     * @param linear a linear geometry
     */
    void clamp(const geom::Geometry* linear);

    /** \brief
     * Snaps the value of this location to the nearest vertex on the given linear
     * [Geometry](@ref geom::Geometry), if the vertex is closer than `minDistance`.
     *
     * @param linearGeom a linear geometry
     * @param minDistance the minimum allowable distance to a vertex
     */
    void snapToVertex(const geom::Geometry* linearGeom, double minDistance);

    /** \brief
     * Gets the length of the segment in the given
     * Geometry containing this location.
     *
     * @param linearGeom a linear geometry
     * @return the length of the segment
     */
    double getSegmentLength(const geom::Geometry* linearGeom) const;

    /** \brief
     * Sets the value of this location to
     * refer the end of a linear geometry.
     *
     * @param linear the linear geometry to set
     */
    void setToEnd(const geom::Geometry* linear);

    /** \brief
     * Gets the component index for this location.
     *
     * @return the component index
     */
    std::size_t getComponentIndex() const;

    /** \brief
     * Gets the segment index for this location.
     *
     * @return the segment index
     */
    std::size_t getSegmentIndex() const;

    /** \brief
     * Gets the segment fraction for this location.
     *
     * @return the segment fraction
     */
    double getSegmentFraction() const;

    /** \brief
     * Tests whether this location refers to a vertex.
     *
     * @return true if the location is a vertex
     */
    bool isVertex() const;

    /** \brief
     * Gets the [Coordinate](@ref geom::Coordinate) along the given linear
     * [Geometry](@ref geom::Geometry) which is referenced by this location.
     *
     * @param linearGeom the linear geometry referenced by this location
     * @return the Coordinate at the location
     */
    geom::Coordinate getCoordinate(const geom::Geometry* linearGeom) const;

    /** \brief
     * Gets a [LineSegment](@ref geom::LineSegment) representing the segment of the
     * given linear [Geometry](@ref geom::Geometry) which contains this location.
     *
     * @param linearGeom a linear geometry
     * @return the LineSegment containing the location
     */
    std::unique_ptr<geom::LineSegment> getSegment(const geom::Geometry* linearGeom) const;

    /** \brief
     * Tests whether this location refers to a valid
     * location on the given linear [Geometry](@ref geom::Geometry).
     *
     * @param linearGeom a linear geometry
     * @return true if this location is valid
     */
    bool isValid(const geom::Geometry* linearGeom) const;

    /** \brief
     * Compares this object with the specified object for order.
     *
     * @param  other the LinearLocation with which this Coordinate is being compared
     * @return a negative integer, zero, or a positive integer as this
     *         LinearLocation is less than, equal to, or greater than
     *         the specified LinearLocation
     */
    int compareTo(const LinearLocation& other) const;

    /** \brief
     *  Compares this object with the specified index values for order.
     *
     * @param componentIndex1 a component index
     * @param segmentIndex1 a segment index
     * @param segmentFraction1 a segment fraction
     * @return a negative integer, zero, or a positive integer as this LinearLocation
     *         is less than, equal to, or greater than the specified locationValues
     */
    int compareLocationValues(std::size_t componentIndex1, std::size_t segmentIndex1, double segmentFraction1) const;

    /** \brief
     *  Compares two sets of location values for order.
     *
     * @param componentIndex0 a component index
     * @param segmentIndex0 a segment index
     * @param segmentFraction0 a segment fraction
     * @param componentIndex1 another component index
     * @param segmentIndex1 another segment index
     * @param segmentFraction1 another segment fraction
     * @return a negative integer, zero, or a positive integer
     *         as the first set of location values
     *         is less than, equal to, or greater than the second set of locationValues
     */
    static int compareLocationValues(
        std::size_t componentIndex0, std::size_t segmentIndex0, double segmentFraction0,
        std::size_t componentIndex1, std::size_t segmentIndex1, double segmentFraction1);

    /** \brief
     * Tests whether two locations are on the same
     * segment in the parent [Geometry](@ref geom::Geometry).
     *
     * @param loc a location on the same geometry
     * @return true if the locations are on the same segment of the parent geometry
     */
    bool isOnSameSegment(const LinearLocation& loc) const;

    /**
     * \brief
     * Tests whether this location is an endpoint of
     * the linear component it refers to.
     *
     * @param linearGeom the linear geometry referenced by this location
     * @return true if the location is a component endpoint
     */
    bool isEndpoint(const geom::Geometry& linearGeom) const;

    friend std::ostream& operator<< (std::ostream& out, const LinearLocation& obj);

};


} // namespace geos.linearref
} // namespace geos

#endif
