using System.Collections.ObjectModel;
using System.Collections.Generic;
using GisSharpBlog.NetTopologySuite.Index.Strtree;
using GisSharpBlog.NetTopologySuite.Geometries;
using System.Collections;
using ThinkGeo.MapSuite.Core;

    public class IndexedInMemoryFeatureLayer : FeatureLayer
    {
        public IndexedInMemoryFeatureLayer(IEnumerable featureSourceColumns)
        {
            // Create our new improved feature source and set it.
            this.FeatureSource = new IndexedInMemoryFeatureSource(featureSourceColumns);
        }

        // Don't mind this code, just some plumbing.
        public Collection Columns
        {
            get
            {
                if (!FeatureSource.IsOpen)
                {
                    FeatureSource.Open();
                }
                Collection columns = ((InMemoryFeatureSource)FeatureSource).GetColumns();

                return columns;
            }
        }

        // Don't mind this code, just some plumbing.
        protected override void OpenCore()
        {
            base.OpenCore();

            if (FeatureSource.Projection != null && !FeatureSource.Projection.IsOpen)
            {
                FeatureSource.Projection.Open();
            }
        }

        // just say this layer supports getting a bounding box.
        // No longer supported
        public override bool HasBoundingBox
        {
            get
            {
                return false;
            }
        }
    }

    public class IndexedInMemoryFeatureSource : InMemoryFeatureSource
    {        
        STRtree rTree = new STRtree();

        public IndexedInMemoryFeatureSource(IEnumerable featureSourceColumns)
            : base(featureSourceColumns)
        {
        }

        protected override TransactionResult CommitTransactionCore(TransactionBuffer transactions)
        {
            // Here we are going to cache our own bounding boxes and then 
            // call the default logic to process the transactions

            // We only handle adds at this point
            //TODO: Thow an exception if they try and do a delete or an edit
            //TODO: Or add support for edits and ads
            
            // Handle the new features
            foreach (KeyValuePair<string, Feature> addTransaction in transactions.AddBuffer)
            {
                RectangleShape rectangle = ((Feature)addTransaction.Value).GetBoundingBox();
                Envelope envelope = new Envelope(rectangle.UpperLeftPoint.X, rectangle.LowerRightPoint.X, rectangle.UpperLeftPoint.Y, rectangle.LowerRightPoint.Y);
                rTree.Insert(envelope, addTransaction.Key);
            }
            rTree.Build();

            return base.CommitTransactionCore(transactions);
        }

        protected override Collection GetFeaturesForDrawingCore(RectangleShape boundingBox, double screenWidth, double screenHeight, IEnumerable<string> returningColumnNames)
        {
            return GetFeaturesBasedOnCachedBoundingBoxes(boundingBox);
        }

        protected override Collection GetFeaturesInsideBoundingBoxCore(RectangleShape boundingBox, IEnumerable<string> returningColumnNames)
        {
            return GetFeaturesBasedOnCachedBoundingBoxes(boundingBox);
        }

        private Collection GetFeaturesBasedOnCachedBoundingBoxes(RectangleShape extent)
        {            
            Envelope envelope = new Envelope(extent.UpperLeftPoint.X, extent.LowerRightPoint.X, extent.UpperLeftPoint.Y, extent.LowerRightPoint.Y);
            ArrayList RecordIds = (ArrayList)rTree.Query(envelope);

            Collection features = new Collection();
            foreach (string key in RecordIds)
            {
                features.Add((Feature)InternalFeatures[key]);
            }

            return features;
        }

        //TODO: Add support for this
        //No longer supported
        //protected override RectangleShape GetBoundingBoxCore()
        //{
        //    // Here we just optimize the get bounding box since this will
        //    // be faster than re-calculating them.
        //    Collection canidates = new Collection();
        //    foreach (string key in boundingBoxes.Keys)
        //    {
        //        canidates.Add((RectangleShape)boundingBoxes[key]);
        //    }
        //    return ExtentHelper.GetBoundingBoxOfItems(canidates);
        //}
    }