// Copyright (C) Stichting Deltares 2016. All rights reserved.
//
// This file is part of Ringtoets.
//
// Ringtoets is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
// All names, logos, and references to "Deltares" are registered trademarks of
// Stichting Deltares and remain full property of Stichting Deltares at all times.
// All rights reserved.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using Core.Common.Base;
using Core.Components.DotSpatial.Layer;
using Core.Components.DotSpatial.MapFunctions;
using Core.Components.Gis.Data;
using Core.Components.Gis.Forms;
using DotSpatial.Controls;
using DotSpatial.Data;
using DotSpatial.Topology;

namespace Core.Components.DotSpatial.Forms
{
    /// <summary>
    /// This class describes a map view with configured projection and function mode.
    /// </summary>
    public sealed class MapControl : Control, IMapControl
    {
        private readonly Cursor defaultCursor = Cursors.Default;
        private readonly RecursiveObserver<MapDataCollection, MapDataCollection> mapDataCollectionObserver;
        private readonly IList<DrawnMapData> drawnMapDataList = new List<DrawnMapData>();

        private Map map;
        private MapFunctionPan mapFunctionPan;
        private MapFunctionSelectionZoom mapFunctionSelectionZoom;
        private MouseCoordinatesMapExtension mouseCoordinatesMapExtension;
        private MapDataCollection data;

        /// <summary>
        /// Creates a new instance of <see cref="MapControl"/>.
        /// </summary>
        public MapControl()
        {
            InitializeMapView();
            TogglePanning();

            mapDataCollectionObserver = new RecursiveObserver<MapDataCollection, MapDataCollection>(HandleMapDataCollectionChange, mdc => mdc.Collection);
        }

        public bool IsPanningEnabled { get; private set; }

        public bool IsRectangleZoomingEnabled { get; private set; }

        public bool IsMouseCoordinatesVisible { get; private set; }

        public MapDataCollection Data
        {
            get
            {
                return data;
            }
            set
            {
                if (data != null)
                {
                    ClearMapData();
                }

                data = value;

                mapDataCollectionObserver.Observable = data;

                if (data != null)
                {
                    DrawInitialMapData();
                }
            }
        }

        public void ZoomToAllVisibleLayers()
        {
            ZoomToAllVisibleLayers(Data);
        }

        public void ZoomToAllVisibleLayers(MapData layerData)
        {
            IEnvelope envelope = CreateEnvelopeForAllVisibleLayers(layerData);
            if (!envelope.IsNull)
            {
                Extent extent = envelope.ToExtent();
                AddPadding(extent);
                map.ViewExtents = extent;
            }
        }

        public void TogglePanning()
        {
            ResetDefaultInteraction();

            IsPanningEnabled = true;

            map.FunctionMode = FunctionMode.Pan;
        }

        public void ToggleRectangleZooming()
        {
            ResetDefaultInteraction();

            IsRectangleZoomingEnabled = true;

            map.ActivateMapFunction(mapFunctionSelectionZoom);
        }

        public void ToggleMouseCoordinatesVisibility()
        {
            if (!IsMouseCoordinatesVisible)
            {
                mouseCoordinatesMapExtension.Activate();
                IsMouseCoordinatesVisible = true;
            }
            else
            {
                mouseCoordinatesMapExtension.Deactivate();
                IsMouseCoordinatesVisible = false;
            }
        }

        protected override void Dispose(bool disposing)
        {
            map.Dispose();
            mouseCoordinatesMapExtension.Dispose();
            mapDataCollectionObserver.Dispose();

            base.Dispose(disposing);
        }

        private static void AddPadding(Extent extent)
        {
            var padding = Math.Min(extent.Height, extent.Width) * 0.05;
            if (Math.Max(extent.Height, extent.Width) + padding <= double.MaxValue)
            {
                extent.ExpandBy(padding);
            }
        }

        /// <summary>
        /// Defines the area taken up by the visible map-data based on the provided map-data.
        /// </summary>
        /// <param name="mapData">The data to determine the visible extent for.</param>
        /// <returns>The area definition.</returns>
        /// <exception cref="ArgumentException">Thrown when <paramref name="mapData"/> is
        /// not part of the drawn map features.</exception>
        private IEnvelope CreateEnvelopeForAllVisibleLayers(MapData mapData)
        {
            var collection = mapData as MapDataCollection;
            if (collection != null)
            {
                return CreateEnvelopeForAllVisibleLayers(collection);
            }

            DrawnMapData drawnMapData = drawnMapDataList.FirstOrDefault(dmd => dmd.FeatureBasedMapData.Equals(mapData));
            if (drawnMapData == null)
            {
                throw new ArgumentException($@"Can only zoom to {typeof(MapData).Name} that is part of this {typeof(MapControl).Name}s drawn {nameof(mapData)}.",
                                            nameof(mapData));
            }

            IEnvelope envelope = new Envelope();
            if (LayerHasVisibleExtent(drawnMapData.FeatureBasedMapDataLayer))
            {
                envelope.ExpandToInclude(drawnMapData.FeatureBasedMapDataLayer.Extent.ToEnvelope());
            }
            return envelope;
        }

        /// <summary>
        /// Defines the area taken up by the visible map-data based on the provided map-data.
        /// </summary>
        /// <param name="mapData">The data to determine the visible extent for.</param>
        /// <returns>The area definition.</returns>
        /// <exception cref="ArgumentException">Thrown when <paramref name="mapData"/> or
        /// any of its children is not part of the drawn map features.</exception>
        private IEnvelope CreateEnvelopeForAllVisibleLayers(MapDataCollection mapData)
        {
            IEnvelope envelope = new Envelope();
            foreach (MapData childMapData in mapData.Collection)
            {
                envelope.ExpandToInclude(CreateEnvelopeForAllVisibleLayers(childMapData));
            }
            return envelope;
        }

        private static bool LayerHasVisibleExtent(IMapLayer layer)
        {
            return layer.IsVisible && !layer.Extent.IsEmpty();
        }

        private void ResetDefaultInteraction()
        {
            IsPanningEnabled = false;
            IsRectangleZoomingEnabled = false;

            map.FunctionMode = FunctionMode.None;
        }

        private void InitializeMapView()
        {
            map = new DotSpatialMap
            {
                ProjectionModeDefine = ActionMode.Never,
                Dock = DockStyle.Fill,
                ZoomOutFartherThanMaxExtent = true
            };

            // Configure the map pan function
            mapFunctionPan = map.MapFunctions.OfType<MapFunctionPan>().First();
            mapFunctionPan.FunctionActivated += MapFunctionActivateFunction;
            mapFunctionPan.MouseDown += MapFunctionPanOnMouseDown;
            mapFunctionPan.MouseUp += MapFunctionOnMouseUp;

            // Add and configure the map selection zoom function
            mapFunctionSelectionZoom = new MapFunctionSelectionZoom(map);
            map.MapFunctions.Add(mapFunctionSelectionZoom);
            mapFunctionSelectionZoom.FunctionActivated += MapFunctionActivateFunction;
            mapFunctionSelectionZoom.MouseDown += MapFunctionSelectionZoomOnMouseDown;
            mapFunctionSelectionZoom.MouseUp += MapFunctionOnMouseUp;

            mouseCoordinatesMapExtension = new MouseCoordinatesMapExtension(map);
            ToggleMouseCoordinatesVisibility();

            Controls.Add(map);
        }

        private void DrawInitialMapData()
        {
            foreach (FeatureBasedMapData featureBasedMapData in Data.GetFeatureBasedMapDataRecursively())
            {
                DrawMapData(featureBasedMapData);
            }
        }

        private void ClearMapData()
        {
            foreach (DrawnMapData drawnMapData in drawnMapDataList)
            {
                drawnMapData.Observer.Dispose();
            }

            drawnMapDataList.Clear();

            map.ClearLayers();
        }

        private void HandleMapDataCollectionChange()
        {
            var mapDataThatShouldBeDrawn = Data.GetFeatureBasedMapDataRecursively().ToList();
            var drawnMapDataLookup = drawnMapDataList.ToDictionary(dmd => dmd.FeatureBasedMapData, dmd => dmd);

            DrawMissingMapDataOnCollectionChange(mapDataThatShouldBeDrawn, drawnMapDataLookup);
            RemoveRedundantMapDataOnCollectionChange(mapDataThatShouldBeDrawn, drawnMapDataLookup);

            drawnMapDataLookup = drawnMapDataList.ToDictionary(dmd => dmd.FeatureBasedMapData, dmd => dmd);

            ReorderMapDataOnCollectionChange(mapDataThatShouldBeDrawn, drawnMapDataLookup);
        }

        private void DrawMissingMapDataOnCollectionChange(IEnumerable<FeatureBasedMapData> mapDataThatShouldBeDrawn,
                                                          IDictionary<FeatureBasedMapData, DrawnMapData> drawnMapDataLookup)
        {
            foreach (var mapDataToDraw in mapDataThatShouldBeDrawn.Where(mapDataToDraw => !drawnMapDataLookup.ContainsKey(mapDataToDraw)))
            {
                DrawMapData(mapDataToDraw);
            }
        }

        private void RemoveRedundantMapDataOnCollectionChange(IEnumerable<FeatureBasedMapData> mapDataThatShouldBeDrawn,
                                                              IDictionary<FeatureBasedMapData, DrawnMapData> drawnMapDataLookup)
        {
            foreach (var featureBasedMapData in drawnMapDataLookup.Keys.Except(mapDataThatShouldBeDrawn))
            {
                RemoveMapData(drawnMapDataLookup[featureBasedMapData]);
            }
        }

        private void ReorderMapDataOnCollectionChange(IList<FeatureBasedMapData> mapDataThatShouldBeDrawn,
                                                      IDictionary<FeatureBasedMapData, DrawnMapData> drawnMapDataLookup)
        {
            for (var i = 0; i < mapDataThatShouldBeDrawn.Count; i++)
            {
                map.Layers.Move(drawnMapDataLookup[mapDataThatShouldBeDrawn[i]].FeatureBasedMapDataLayer, i);
            }
        }

        private void DrawMapData(FeatureBasedMapData featureBasedMapData)
        {
            var featureBasedMapDataLayer = FeatureBasedMapDataLayerFactory.Create(featureBasedMapData);

            var drawnMapData = new DrawnMapData
            {
                FeatureBasedMapData = featureBasedMapData,
                FeatureBasedMapDataLayer = featureBasedMapDataLayer
            };

            drawnMapData.Observer = new Observer(() => { drawnMapData.FeatureBasedMapDataLayer.Update(); })
            {
                Observable = featureBasedMapData
            };

            drawnMapDataList.Add(drawnMapData);

            map.Layers.Add(featureBasedMapDataLayer);
        }

        private void RemoveMapData(DrawnMapData drawnMapDataToRemove)
        {
            drawnMapDataToRemove.Observer.Dispose();
            drawnMapDataList.Remove(drawnMapDataToRemove);

            map.Layers.Remove(drawnMapDataToRemove.FeatureBasedMapDataLayer);
        }

        private void MapFunctionActivateFunction(object sender, EventArgs e)
        {
            map.Cursor = defaultCursor;
        }

        private void MapFunctionOnMouseUp(object sender, GeoMouseArgs e)
        {
            map.Cursor = defaultCursor;
        }

        private void MapFunctionPanOnMouseDown(object sender, GeoMouseArgs geoMouseArgs)
        {
            map.Cursor = geoMouseArgs.Button != MouseButtons.Right ? Cursors.Hand : defaultCursor;
        }

        private void MapFunctionSelectionZoomOnMouseDown(object sender, GeoMouseArgs geoMouseArgs)
        {
            switch (geoMouseArgs.Button)
            {
                case MouseButtons.Left:
                    map.Cursor = Cursors.SizeNWSE;
                    break;
                default:
                    map.Cursor = map.IsBusy
                                     ? Cursors.SizeNWSE
                                     : defaultCursor;
                    break;
            }
        }

        /// <summary>
        /// Lookup class for administration related to drawn map data layers.
        /// </summary>
        private class DrawnMapData
        {
            /// <summary>
            /// The feature based map data which the drawn <see cref="FeatureBasedMapDataLayer"/> is based upon.
            /// </summary>
            public FeatureBasedMapData FeatureBasedMapData { get; set; }

            /// <summary>
            /// The drawn map data layer.
            /// </summary>
            public IFeatureBasedMapDataLayer FeatureBasedMapDataLayer { get; set; }

            /// <summary>
            /// The observer attached to <see cref="FeatureBasedMapData"/> and responsible for updating <see cref="FeatureBasedMapDataLayer"/>.
            /// </summary>
            public Observer Observer { get; set; }
        }
    }
}