InMemorySemanticPlane.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Threading.Tasks;
 
namespace Waher.Content.Semantic
{
    public class InMemorySemanticPlane : ISemanticPlane
    {
        private readonly LinkedList<Tuple<ISemanticElement, ISemanticElement, ISemanticTriple>> elements = new LinkedList<Tuple<ISemanticElement, ISemanticElement, ISemanticTriple>>();
        private readonly ISemanticElement reference;
        private SortedDictionary<ISemanticElement, InMemorySemanticLine> yPerX = null;
        private SortedDictionary<ISemanticElement, InMemorySemanticLine> xPerY = null;
 
        public InMemorySemanticPlane(ISemanticElement Reference)
        {
            this.reference = Reference;
        }
 
        public ISemanticElement Reference => this.reference;
 
        public void Add(ISemanticElement X, ISemanticElement Y, ISemanticTriple Triple)
        {
            this.elements.AddLast(new Tuple<ISemanticElement, ISemanticElement, ISemanticTriple>(X, Y, Triple));
            this.xPerY = null;
            this.yPerX = null;
        }
 
        public void Add(IEnumerable<ISemanticTriple> Triples, int XIndex, int YIndex)
        {
            if (!(Triples is null))
            {
                foreach (ISemanticTriple Triple in Triples)
                    this.Add(Triple[XIndex], Triple[YIndex], Triple);
            }
        }
 
        public IEnumerator<ISemanticTriple> GetEnumerator()
        {
            return new TripleEnumerator(this.elements.GetEnumerator());
        }
 
        IEnumerator IEnumerable.GetEnumerator()
        {
            return new TripleEnumerator(this.elements.GetEnumerator());
        }
 
        private class TripleEnumerator : IEnumerator<ISemanticTriple>
        {
            private readonly IEnumerator<Tuple<ISemanticElement, ISemanticElement, ISemanticTriple>> e;
 
            public TripleEnumerator(IEnumerator<Tuple<ISemanticElement, ISemanticElement, ISemanticTriple>> e)
            {
                this.e = e;
            }
 
            public ISemanticTriple Current => this.e.Current.Item3;
            object IEnumerator.Current => this.e.Current.Item3;
            public void Dispose() => this.e.Dispose();
            public bool MoveNext() => this.e.MoveNext();
            public void Reset() => this.e.Reset();
        }
 
        public Task<ISemanticLine> GetTriplesByX(ISemanticElement X)
        {
            this.CheckXOrdered();
 
            if (!this.yPerX.TryGetValue(X, out InMemorySemanticLine Line))
                Line = null;
 
            return Task.FromResult<ISemanticLine>(Line);
        }
 
        public Task<ISemanticLine> GetTriplesByY(ISemanticElement Y)
        {
            this.CheckYOrdered();
 
            if (!this.xPerY.TryGetValue(Y, out InMemorySemanticLine Line))
                Line = null;
 
            return Task.FromResult<ISemanticLine>(Line);
        }
 
        public Task<IEnumerable<ISemanticTriple>> GetTriplesByXAndY(ISemanticElement X, ISemanticElement Y)
        {
            this.CheckXOrdered();
 
            if (!this.yPerX.TryGetValue(X, out InMemorySemanticLine Line))
                return Task.FromResult<IEnumerable<ISemanticTriple>>(null);
 
            return Line.GetTriples(Y);
        }
 
        public Task<IEnumerator<ISemanticElement>> GetXAxisEnumerator()
        {
            this.CheckXOrdered();
 
            return Task.FromResult<IEnumerator<ISemanticElement>>(this.yPerX.Keys.GetEnumerator());
        }
 
        public Task<IEnumerator<ISemanticElement>> GetYAxisEnumerator()
        {
            this.CheckYOrdered();
 
            return Task.FromResult<IEnumerator<ISemanticElement>>(this.xPerY.Keys.GetEnumerator());
        }
 
        private void CheckXOrdered()
        {
            if (this.yPerX is null)
            {
                SortedDictionary<ISemanticElement, InMemorySemanticLine> Ordered =
                    new SortedDictionary<ISemanticElement, InMemorySemanticLine>();
                ISemanticElement LastPoint = null;
                InMemorySemanticLine Last = null;
 
                foreach (Tuple<ISemanticElement, ISemanticElement, ISemanticTriple> P in this.elements)
                {
                    if ((LastPoint is null || !LastPoint.Equals(P.Item1)) &&
                        !Ordered.TryGetValue(P.Item1, out Last))
                    {
                        Last = new InMemorySemanticLine(P.Item1, P.Item2);
                        Ordered[P.Item1] = Last;
                    }
 
                    Last.Add(P.Item2, P.Item3);
                }
 
                this.yPerX = Ordered;
            }
        }
 
        private void CheckYOrdered()
        {
            if (this.xPerY is null)
            {
                SortedDictionary<ISemanticElement, InMemorySemanticLine> Ordered =
                    new SortedDictionary<ISemanticElement, InMemorySemanticLine>();
                ISemanticElement LastPoint = null;
                InMemorySemanticLine Last = null;
 
                foreach (Tuple<ISemanticElement, ISemanticElement, ISemanticTriple> P in this.elements)
                {
                    if ((LastPoint is null || !LastPoint.Equals(P.Item2)) &&
                        !Ordered.TryGetValue(P.Item2, out Last))
                    {
                        Last = new InMemorySemanticLine(P.Item2, P.Item1);
                        Ordered[P.Item2] = Last;
                    }
 
                    Last.Add(P.Item1, P.Item3);
                }
 
                this.xPerY = Ordered;
            }
        }
    }
}