// Copyright (C) Stichting Deltares 2019. All rights reserved.
//
// This file is part of the Dam Engine.
//
// The Dam Engine is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero 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;

namespace Deltares.DamEngine.Data.Geometry
{
    /// <summary>
    /// Class for geometry surfaces.
    /// </summary>
    /// <seealso cref="Deltares.DamEngine.Data.Geometry.GeometryObject" />
    [Serializable]
    public class GeometrySurface : GeometryObject
    {
        private readonly List<GeometryLoop> innerLoops = new List<GeometryLoop>();
        private GeometryLoop outerLoop = new GeometryLoop();

        /// <summary>
        /// Empty constructor
        /// </summary>
        public GeometrySurface() { }

        /// <summary>
        /// Initializes a new instance of the <see cref="GeometrySurface"/> class.
        /// </summary>
        /// <param name="loop">The loop.</param>
        public GeometrySurface(GeometryLoop loop)
        {
            outerLoop = loop;
        }

        /// <summary>
        /// The circumference of the surface.
        /// </summary>
        public GeometryLoop OuterLoop
        {
            get
            {
                return outerLoop;
            }
            set
            {
                outerLoop = value;
            }
        }

        /// <summary>
        /// All internal loops encompassed by <see cref="OuterLoop"/>.
        /// </summary>
        public List<GeometryLoop> InnerLoops
        {
            get
            {
                return innerLoops;
            }
        }

        /// <summary>
        /// determine top of geometry surface outerloop as GeometryPointString
        /// </summary>
        /// <returns></returns>
        public GeometryPointString DetermineTopGeometrySurface()
        {
            return DetermineTopCurves();
        }

        /// <summary>
        ///  determine bottom of geometry surface outerloop as GeometryPointString
        /// </summary>
        /// <returns></returns>
        public GeometryPointString DetermineBottomGeometrySurface()
        {
            return DetermineBottomCurves();
        }

        /// <summary>
        /// Gets the geometry bounds.
        /// </summary>
        /// <returns></returns>
        public override GeometryBounds GetGeometryBounds()
        {
            return OuterLoop.GetGeometryBounds();
        }

        /// <summary>
        /// Determine points at the top side of the geometry surface
        /// </summary>
        /// <returns></returns>
        private GeometryPointString DetermineTopCurves()
        {
            //TODO: Lot of similar code to DetermineBottomCurves; Refactoring recommended.
            var minXPoints = OuterLoop.GetPointsAtX(OuterLoop.GetMinX());
            var maxXPoints = OuterLoop.GetPointsAtX(OuterLoop.GetMaxX());

            //verticals at start are omitted
            Point2D startTopPoint = minXPoints.OrderByDescending(p => p.Z).First();

            //verticals at end are omitted
            Point2D endTopPoint = maxXPoints.OrderByDescending(p => p.Z).First();

            var topPoints = new GeometryPointString();

            int currentIndex = OuterLoop.CalcPoints.IndexOf(startTopPoint);

            while (!topPoints.CalcPoints.Contains(endTopPoint))
            {
                topPoints.CalcPoints.Add(OuterLoop.CalcPoints[currentIndex++]);
                if (currentIndex >= OuterLoop.CalcPoints.Count)
                {
                    currentIndex = 0;
                }
            }

            // Replace the points by clones
            for (int i = 0; i < topPoints.CalcPoints.Count; i++)
            {
                topPoints.CalcPoints[i] = new Point2D(topPoints.CalcPoints[i].X, topPoints.CalcPoints[i].Z);
            }

            return topPoints;
        }

        /// <summary>
        /// determine curves at the bottom side of the geometry surface
        /// </summary>
        /// <returns></returns>
        private GeometryPointString DetermineBottomCurves()
        {
            //TODO: Lot of similar code to DetermineTopCurves; Refactoring recommended.
            //create copy, leave original
            var minXPoints = OuterLoop.GetPointsAtX(OuterLoop.GetMinX());
            var maxXPoints = OuterLoop.GetPointsAtX(OuterLoop.GetMaxX());

            //verticals at start are omitted
            var startBottomPoint = minXPoints.OrderBy(p => p.Z).First();

            //verticals at end are omitted
            var endBottomPoint = maxXPoints.OrderBy(p => p.Z).First();

            var bottomPoints = new GeometryPointString();

            int currentIndex = OuterLoop.CalcPoints.IndexOf(endBottomPoint);

            while (!bottomPoints.CalcPoints.Contains(startBottomPoint))
            {
                bottomPoints.CalcPoints.Add(OuterLoop.CalcPoints[currentIndex++]);
                if (currentIndex >= OuterLoop.CalcPoints.Count)
                {
                    currentIndex = 0;
                }
            }

            // Replace the points by clones
            for (int i = 0; i < bottomPoints.CalcPoints.Count; i++)
            {
                bottomPoints.CalcPoints[i] = new Point2D(bottomPoints.CalcPoints[i].X, bottomPoints.CalcPoints[i].Z);
            }

            // As the curves are sorted clockwise, the bottomcurves are always orientated from right to left
            // while this result of this method must be from left to right so reverse the curves
            bottomPoints.CalcPoints.Reverse();
            return bottomPoints;
        }        
    }
}