// Copyright (C) Stichting Deltares 2025. 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.Collections.Generic;

namespace Deltares.DamEngine.Data.Geometry;

/// <summary>
/// Helper class for Line objects
/// </summary>
public static class LineHelper
{
    /// <summary>
    /// Determine intersection between two lines (strict interpolation)
    /// </summary>
    /// <param name="line1"></param>
    /// <param name="line2"></param>
    /// <param name="intersectPoint"></param>
    /// <returns></returns>
    public static bool DetermineStrictIntersectionPoint(Line line1, Line line2, ref Point2D intersectPoint)
    {
        var point1 = new Point2D(line1.BeginPoint.X, line1.BeginPoint.Z);
        var point2 = new Point2D(line1.EndPoint.X, line1.EndPoint.Z);
        var point3 = new Point2D(line2.BeginPoint.X, line2.BeginPoint.Z);
        var point4 = new Point2D(line2.EndPoint.X, line2.EndPoint.Z);

        Point2D ip;
        LineIntersection res = Routines2D.DetermineIf2DLinesIntersectStrickly(point1, point2, point3,
                                                                              point4, out ip);
        if (ip != null)
        {
            intersectPoint.X = ip.X;
            intersectPoint.Z = ip.Z;
        }

        return res == LineIntersection.Intersects;
    }

    public static Point2D DetermineIntersectionPointWithExtrapolation(Point2D p1, Point2D p2, Point2D p3, Point2D p4)
    {
        Point2D intersectPoint = null;
        Routines2D.DetermineIf2DLinesIntersectWithExtrapolation(p1, p2, p3, p4, out intersectPoint);
        return intersectPoint;
    }

    /// <summary>
    /// Deletes the duplicated points.
    /// </summary>
    /// <param name="points">List of points</param>
    /// <param name="tolerance">The tolerance.</param>
    public static void RemoveDuplicatedPoints(IList<Point2D> points, double tolerance)
    {
        // First build a list of indices of points that have to be removed (from end of list to start)
        var indicesToDelete = new List<int>();
        for (int pointIndex = points.Count - 1; pointIndex > 0; pointIndex--)
        {
            int nextPointIndex = pointIndex - 1;
            if (points[pointIndex].LocationEquals(points[pointIndex - 1], tolerance))
            {
                indicesToDelete.Add(nextPointIndex);
            }
        }

        // Remove duplicated points beginning from the end
        foreach (int index in indicesToDelete)
        {
            points.RemoveAt(index);
        }
    }
}