using System;

using System.Collections.Generic;

using System.Globalization;

using GeoAPI;

using GeoAPI.Features;

using GeoAPI.Geometries;

using GeoAPI.SpatialReference;

using GeoAPI.Utilities;

namespace SharpMap.SpatialReference

{

/// <summary>

/// Reprojector proxy class used and accessed within SharpMap

/// </summary>

public class Reprojector : IReprojector

{

/// <summary>

/// The <see cref="IReprojector"/> implementation used internally

/// </summary>

private readonly IReprojectorCore _instance;

private readonly ThreadSafeStore<ISpatialReference, IGeometryFactory> _factories =

new ThreadSafeStore<ISpatialReference, IGeometryFactory>(CreateGeometryFactory);

private IGeometryFactory GetFactory(ISpatialReference spatialReference)

{

return _factories.Get(spatialReference);

}

private static volatile int _newId = 1000000;

private static IGeometryFactory CreateGeometryFactory(ISpatialReference spatialReference)

{

var split = spatialReference.Oid.Split(new[] { ':' });

int srid;

if (split.Length < 2)

{

srid = ++_newId;

}

else

{

if (!(Int32.TryParse(split[1], NumberStyles.Integer, NumberFormatInfo.InvariantInfo, out srid)))

srid = ++_newId;

}

return GeometryServiceProvider.Instance.CreateGeometryFactory(srid);

}

/// <summary>

/// Creates an instance of this class, assigning a <see cref="NoopReprojector"/>

/// </summary>

public Reprojector()

:this(new NoopReprojector())

{}

/// <summary>

/// Creates an instance of this class, that uses <paramref name="instance"/> <see cref="IReprojector"/> internally.

/// </summary>

/// <param name="instance"></param>

public Reprojector(IReprojectorCore instance)

{

_instance = instance;

}

public Coordinate Reproject(Coordinate point, ISpatialReference from, ISpatialReference to)

{

return _instance.Reproject(point, from, to);

}

public Envelope Reproject(Envelope envelope, ISpatialReference @from, ISpatialReference to)

{

return _instance.Reproject(envelope, from, to);

}

public ICoordinateSequence Reproject(ICoordinateSequence sequence, ISpatialReference @from, ISpatialReference to)

{

return _instance.Reproject(sequence, from, to);

}

public ISpatialReferenceFactory Factory { get { return _instance.Factory; } }

public IGeometry Reproject(IGeometry geometry, ISpatialReference @from, ISpatialReference to)

{

var factory = GetFactory(to);

switch (geometry.OgcGeometryType)

{

case OgcGeometryType.Point:

return ReprojectPoint(factory, (IPoint)geometry, @from, to);

case OgcGeometryType.LineString:

return ReprojectLineString(factory, (ILineString)geometry, @from, to);

case OgcGeometryType.Polygon:

return ReprojectPolygon(factory, (IPolygon)geometry, @from, to);

default:

var lst = new List<IGeometry>(geometry.NumGeometries);

for (var i = 0; i < geometry.NumGeometries; i++)

{

lst.Add(Reproject(geometry.GetGeometryN(i), from, to));

}

return factory.BuildGeometry(lst);

}

}

private IPoint ReprojectPoint(IGeometryFactory factory, IPoint point, ISpatialReference @from,

ISpatialReference to)

{

return factory.CreatePoint(Reproject(point.CoordinateSequence, from, to));

}

private ILineString ReprojectLineString(IGeometryFactory factory, ILineString line, ISpatialReference @from,

ISpatialReference to, bool lineString = true)

{

return lineString

? factory.CreateLineString(Reproject(line.CoordinateSequence, from, to))

: factory.CreateLinearRing(Reproject(line.CoordinateSequence, from, to));

}

private IPolygon ReprojectPolygon(IGeometryFactory factory, IPolygon polygon, ISpatialReference @from,

ISpatialReference to)

{

var exterior = (ILinearRing)ReprojectLineString(factory, polygon.ExteriorRing, from, to, false);

var interior = new ILinearRing[polygon.NumInteriorRings];

for (var i = 0; i < polygon.NumInteriorRings; i++)

{

interior[i] = (ILinearRing)ReprojectLineString(factory, polygon.GetInteriorRingN(i), from, to, false);

}

return factory.CreatePolygon(exterior, interior);

}

public IFeature Reproject(IFeature feature, ISpatialReference @from, ISpatialReference to)

{

feature.Geometry = Reproject(feature.Geometry, @from, to);

return feature;

}

public IEnumerable<IFeature> Reproject(IEnumerable<IFeature> features, ISpatialReference @from, ISpatialReference to)

{

foreach (var feature in features)

{

yield return Reproject(feature, @from, @to);

}

}

}

}