using System;
using System.Collections.Generic;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using SharpMap.Layers;
using System.Drawing;
using GeoAPI.CoordinateSystems.Transformations;
using ProjNet.CoordinateSystems.Transformations;
using GeoAPI.CoordinateSystems;
using ProjNet.CoordinateSystems;

namespace WinFormSamples
{
 static class LayerTools
 {

 private static ICoordinateTransformation _dhdn2Towgs84;
 private static ICoordinateTransformation _wgs84ToGoogle;
 private static ICoordinateTransformation _googletowgs84;

 /// <summary>
 /// Wgs84 to Google Mercator Coordinate Transformation
 /// </summary>
 public static ICoordinateTransformation Wgs84toGoogleMercator
 {
 get
 {
 if (_wgs84ToGoogle == null)
 {
 CoordinateSystemFactory csFac = new ProjNet.CoordinateSystems.CoordinateSystemFactory();
 CoordinateTransformationFactory ctFac = new CoordinateTransformationFactory();

 IGeographicCoordinateSystem wgs84 = csFac.CreateGeographicCoordinateSystem(
 "WGS 84", AngularUnit.Degrees, HorizontalDatum.WGS84, PrimeMeridian.Greenwich,
 new AxisInfo("north", AxisOrientationEnum.North), new AxisInfo("east", AxisOrientationEnum.East));

 List<ProjectionParameter> parameters = new List<ProjectionParameter>();
 parameters.Add(new ProjectionParameter("semi_major", 6378137.0));
 parameters.Add(new ProjectionParameter("semi_minor", 6378137.0));
 parameters.Add(new ProjectionParameter("latitude_of_origin", 0.0));
 parameters.Add(new ProjectionParameter("central_meridian", 0.0));
 parameters.Add(new ProjectionParameter("scale_factor", 1.0));
 parameters.Add(new ProjectionParameter("false_easting", 0.0));
 parameters.Add(new ProjectionParameter("false_northing", 0.0));
 IProjection projection = csFac.CreateProjection("Google Mercator", "mercator_1sp", parameters);

 IProjectedCoordinateSystem epsg900913 = csFac.CreateProjectedCoordinateSystem(
 "Google Mercator", wgs84, projection, LinearUnit.Metre, new AxisInfo("East", AxisOrientationEnum.East),
 new AxisInfo("North", AxisOrientationEnum.North));

 ((CoordinateSystem)epsg900913).DefaultEnvelope = new [] { -20037508.342789, -20037508.342789, 20037508.342789, 20037508.342789 };

 _wgs84ToGoogle = ctFac.CreateFromCoordinateSystems(wgs84, epsg900913);
 }

 return _wgs84ToGoogle;

 }
 }


 /// <summary>
 /// Wgs84 to Google Mercator Coordinate Transformation
 /// </summary>
 public static ICoordinateTransformation Dhdn2ToWgs84
 {
 get
 {
 if (_dhdn2Towgs84 == null)
 {
 CoordinateSystemFactory csFac = new ProjNet.CoordinateSystems.CoordinateSystemFactory();
 CoordinateTransformationFactory ctFac = new CoordinateTransformationFactory();

 IGeographicCoordinateSystem wgs84 = csFac.CreateGeographicCoordinateSystem(
 "WGS 84", AngularUnit.Degrees, HorizontalDatum.WGS84, PrimeMeridian.Greenwich,
 new AxisInfo("north", AxisOrientationEnum.North), new AxisInfo("east", AxisOrientationEnum.East));

 List<ProjectionParameter> parameters = new List<ProjectionParameter>();
 parameters.Add(new ProjectionParameter("semi_major", 6378137.0));
 parameters.Add(new ProjectionParameter("semi_minor", 6378137.0));
 parameters.Add(new ProjectionParameter("latitude_of_origin", 0.0));
 parameters.Add(new ProjectionParameter("central_meridian", 0.0));
 parameters.Add(new ProjectionParameter("scale_factor", 1.0));
 parameters.Add(new ProjectionParameter("false_easting", 0.0));
 parameters.Add(new ProjectionParameter("false_northing", 0.0));
 IProjection projection = csFac.CreateProjection("Google Mercator", "mercator_1sp", parameters);

 IProjectedCoordinateSystem epsg900913 = csFac.CreateProjectedCoordinateSystem(
 "Google Mercator", wgs84, projection, LinearUnit.Metre, new AxisInfo("East", AxisOrientationEnum.East),
 new AxisInfo("North", AxisOrientationEnum.North));

 _dhdn2Towgs84 = ctFac.CreateFromCoordinateSystems(wgs84, epsg900913);
 }

 return _dhdn2Towgs84;

 }
 }

 public static ICoordinateTransformation GoogleMercatorToWgs84
 {
 get
 {
 if (_dhdn2Towgs84 == null)
 {
 CoordinateSystemFactory csFac = new ProjNet.CoordinateSystems.CoordinateSystemFactory();
 CoordinateTransformationFactory ctFac = new CoordinateTransformationFactory();

 IGeographicCoordinateSystem wgs84 = csFac.CreateGeographicCoordinateSystem(
 "WGS 84", AngularUnit.Degrees, HorizontalDatum.WGS84, PrimeMeridian.Greenwich,
 new AxisInfo("north", AxisOrientationEnum.North), new AxisInfo("east", AxisOrientationEnum.East));

 List<ProjectionParameter> parameters = new List<ProjectionParameter>();
 parameters.Add(new ProjectionParameter("semi_major", 6378137.0));
 parameters.Add(new ProjectionParameter("semi_minor", 6378137.0));
 parameters.Add(new ProjectionParameter("latitude_of_origin", 0.0));
 parameters.Add(new ProjectionParameter("central_meridian", 0.0));
 parameters.Add(new ProjectionParameter("scale_factor", 1.0));
 parameters.Add(new ProjectionParameter("false_easting", 0.0));
 parameters.Add(new ProjectionParameter("false_northing", 0.0));
 IProjection projection = csFac.CreateProjection("Google Mercator", "mercator_1sp", parameters);

 IProjectedCoordinateSystem epsg900913 = csFac.CreateProjectedCoordinateSystem(
 "Google Mercator", wgs84, projection, LinearUnit.Metre, new AxisInfo("East", AxisOrientationEnum.East),
 new AxisInfo("North", AxisOrientationEnum.North));

 _googletowgs84 = ctFac.CreateFromCoordinateSystems(epsg900913, wgs84);
 }

 return _googletowgs84;

 }
 }

 public static LabelLayer CreateLabelLayer(VectorLayer originalLayer, string labelColumnName)
 {
 SharpMap.Layers.LabelLayer labelLayer = new SharpMap.Layers.LabelLayer(originalLayer.LayerName + ":Labels");
 labelLayer.DataSource = originalLayer.DataSource;
 labelLayer.LabelColumn = labelColumnName;
 labelLayer.Style.CollisionDetection = true;
 labelLayer.Style.CollisionBuffer = new SizeF(10F, 10F);
 labelLayer.LabelFilter = SharpMap.Rendering.LabelCollisionDetection.ThoroughCollisionDetection;
 labelLayer.Style.Offset = new PointF(0, -5F);
 labelLayer.MultipartGeometryBehaviour = SharpMap.Layers.LabelLayer.MultipartGeometryBehaviourEnum.CommonCenter;
 labelLayer.Style.Font = new Font(FontFamily.GenericSansSerif, 12);
 labelLayer.MaxVisible = originalLayer.MaxVisible;
 labelLayer.MinVisible = originalLayer.MinVisible;
 labelLayer.Style.Halo = new Pen(Color.White, 2);
 labelLayer.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
 labelLayer.CoordinateTransformation = originalLayer.CoordinateTransformation;
 return labelLayer;
 }

 private static readonly Random Rnd = new Random();
 public static Color GetRandomColor()
 {
 return Color.FromArgb(Rnd.Next(0, 127), Rnd.Next(0, 255), Rnd.Next(0,255), Rnd.Next(0,255));
 }

 public static Boolean GetRandomBoolean()
 {
 return Rnd.Next(0, 2) == 1;
 }

 public static Brush GetRandomBrush()
 {
 return new SolidBrush(GetRandomColor());
 }

 public static Pen GetRandomPen()
 {
 return GetRandomPen(1, 4);
 }

 /// <summary>
 /// Generates a random symbol.
 /// </summary>
 /// <returns></returns>
 public static Bitmap GetRandomSymbol()
 {
 var s = Rnd.Next(4, 12);
 var f = new Font("WingDings", 2*s, GraphicsUnit.Pixel);
 var bmp = new Bitmap(2*s + 2, 2*s + 2, PixelFormat.Format32bppArgb);
 using (var g = Graphics.FromImage(bmp))
 {
 g.Clear(Color.Transparent);
 g.DrawString(new string(Convert.ToChar((byte) Rnd.Next(15, 127)), 1), f, GetRandomBrush(), new PointF(s, s) ,
 new StringFormat
 {Alignment = StringAlignment.Center, LineAlignment = StringAlignment.Center});
 }

 return bmp;
 }

 public static SharpMap.Styles.VectorStyle GetRandomVectorStyle()
 {
 return new SharpMap.Styles.VectorStyle
 {
 EnableOutline = GetRandomBoolean(),
 Outline = GetRandomPen(3, 7),
 Line = GetRandomPen(1, 4),
 Fill = GetRandomBrush(),
 Symbol = GetRandomSymbol(),
 //SymbolRotation = Rnd.Next(0, 359),
 };
 }

 private static Pen GetRandomPen(int min, int max)
 {
 var p = new Pen(GetRandomColor(), Rnd.Next(min, max));
 p.LineJoin = LineJoin.MiterClipped;
 p.MiterLimit = 2f;
 return p;
 }

 public static SharpMap.Map GetMapForProviders(IEnumerable<SharpMap.Data.Providers.IProvider> providers)
 {
 var m = new SharpMap.Map();
 foreach (var provider in providers)
 {
 var l = new VectorLayer(provider.ConnectionID, provider)
 {
 Style = GetRandomVectorStyle(),
 IsQueryEnabled = true
 
 };
 if (provider.GetFeatureCount() > 50000)
 m.BackgroundLayer.Add(AsyncLayerProxyLayer.Create(l, new Size(256, 128)));
 else 
 m.Layers.Add(l);

 if (provider.GetFeatureCount() < 50000)
 {
 var ll = new LabelLayer("Label " + provider.ConnectionID);
 ll.DataSource = provider;
 
 provider.Open();
 var f = provider.GetFeature(1);
 provider.Close();

 ll.LabelColumn = f.Table.Columns[0].ColumnName;
 ll.Style.CollisionDetection = false;
 ll.Style.IgnoreLength = true;
 
 m.Layers.Add(ll);
 }
 }
 m.ZoomToExtents();
 return m;
 }
 }
}