using System;
using System.Drawing;
using System.Web.Mvc;
using ThinkGeo.MapSuite.Core;
using ThinkGeo.MapSuite.MvcEdition;

namespace DisplayASimpleMap.Controllers
{
    public class DisplayASimpleMapController : Controller
    {
        public ActionResult DisplayASimpleMap()
        {
            Map map = new Map("Map1",
                 new System.Web.UI.WebControls.Unit(1600, System.Web.UI.WebControls.UnitType.Pixel),
                 new System.Web.UI.WebControls.Unit(1600, System.Web.UI.WebControls.UnitType.Pixel));

            map.MapBackground = new BackgroundLayer(new GeoSolidBrush(GeoColor.FromHtml("#E5E3DF")));
            map.MapUnit = GeographyUnit.Meter;
            RectangleShape extent = GetSnappedCurrentExtent(new RectangleShape(-14639183.0384644, 7524757.1810634, -7399085.82811318, 2358849.98232628), map);

            map.CurrentExtent = extent;

            GoogleMapsLayer gl = new GoogleMapsLayer();
            gl.TileMode = GoogleMapsTileMode.SingleTile;

            LayerOverlay lo = new LayerOverlay();
            lo.TileType = TileType.SingleTile;
            lo.Layers.Add(gl);

            lo.IsBaseOverlay = true;

            map.CustomOverlays.Add(lo);

            Bitmap bitmap = map.GetBitmap(1600, 1600);

            return View(map);
        }

        private RectangleShape GetSnappedCurrentExtent(RectangleShape value, Map map)
        {
            RectangleShape snappedShape = null;

            PointF currentCenter;
            PointShape centerPoint = value.GetCenterPoint();
            currentCenter = new PointF((float)centerPoint.X, (float)centerPoint.Y);
            int zoomLevelIndex = GetSnappedZoomLevelIndex(value, map);

            snappedShape = GetRectangle(new PointShape(currentCenter.X, currentCenter.Y), map.ZoomLevelSet.GetZoomLevels()[zoomLevelIndex].Scale);

            return snappedShape;
        }

        private int GetSnappedZoomLevelIndex(RectangleShape targetExtent, Map map)
        {
            double screenWidth = 1600;
            double screenHeight = 1600;

            double resolution = Math.Max(targetExtent.Width / screenWidth, targetExtent.Height / screenHeight);
            double scale = resolution * (39.3701 * 96);

            PointShape center = targetExtent.GetCenterPoint();

            int zoomLevel = -1;

            foreach (ZoomLevel item in map.ZoomLevelSet.GetZoomLevels())
            {
                if (item.Scale >= scale || Math.Abs(item.Scale - scale) < 0.1)
                {
                    zoomLevel++;
                }
                else
                {
                    break;
                }
            }

            return zoomLevel == -1 ? 0 : zoomLevel;
        }

        private RectangleShape GetRectangle(PointShape center, double scale)
        {
            double resolution = scale / (39.3701 * 96);
            double left = center.X - resolution * 1600 * 0.5;
            double top = center.Y + resolution * 1600 * 0.5;
            double right = center.X + resolution * 1600 * 0.5;
            double bottom = center.Y - resolution * 1600 * 0.5;
            return new RectangleShape(left, top, right, bottom);
        }
    }
}