/*
 * Copyright (c) 2023 Codefoco (codefoco@codefoco.com)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

using System;
using System.ComponentModel;

namespace Tizen.NUI.Physics2D.Chipmunk
{
    /// <summary>
    ///  Contains information about a contact point. <see cref="PointA"/> and <see cref="PointB"/>
    ///  are the contact positions on the surface of each shape. <see cref="Distance"/> is the
    ///  penetration distance of the two, which is a negative value. This value is calculated as
    ///  dot(point2 - point1), normal) and is ignored when you set the
    ///  <see cref="Arbiter.ContactPointSet"/>.
    /// </summary>
    [EditorBrowsable(EditorBrowsableState.Never)]
    public sealed class ContactPoint : IEquatable<ContactPoint>
    {
#pragma warning disable IDE0032
        private readonly Vect pointA;
        private readonly Vect pointB;
        private readonly double distance;
#pragma warning restore IDE0032

        /// <summary>
        /// Point A in the contact point.
        /// </summary>
        [EditorBrowsable(EditorBrowsableState.Never)]
        public Vect PointA => pointA;

        /// <summary>
        ///  Point B in the contact point.
        /// </summary>
        [EditorBrowsable(EditorBrowsableState.Never)]
        public Vect PointB => pointB;

        /// <summary>
        /// The penetration distance of the two shapes (as a negative value). This value is
        /// calculated as  dot(point2 - point1), normal) and is ignored when you set the
        /// <see cref="Arbiter.ContactPointSet"/>.
        /// </summary>
        [EditorBrowsable(EditorBrowsableState.Never)]
        public double Distance => distance;

        private ContactPoint(Vect pointA, Vect pointB, double distance)
        {
            this.pointA = pointA;
            this.pointB = pointB;
            this.distance = distance;
        }

        /// <summary>
        /// Returns true if neither <see cref="ContactPoint"/> is null and the points are within
        /// <see cref="float.Epsilon"/> distance of each other.
        /// </summary>
        [EditorBrowsable(EditorBrowsableState.Never)]
        public bool Equals(ContactPoint other)
        {
            if (ReferenceEquals(other, null))
            {
                return false;
            }

            return other.pointA.Equals(pointA)
                && other.pointB.Equals(pointB)
                && Math.Abs(other.distance - distance) < float.Epsilon;
        }


        /// <summary>
        /// Check if this <see cref="ContactPoint"/> is equal to an object.
        /// </summary>
        [EditorBrowsable(EditorBrowsableState.Never)]
        public override bool Equals(object obj)
        {
            var other = obj as ContactPoint;

            if (other == null)
            {
                return false;
            }

            return Equals(other);
        }

        /// <summary>
        /// Get the <see cref="ContactPoint"/> hash set.
        /// </summary>
        [EditorBrowsable(EditorBrowsableState.Never)]
        public override int GetHashCode()
        {
            unchecked
            {
                var hashCode = -1285340573;

                hashCode = hashCode * -1521134295 + pointA.GetHashCode();
                hashCode = hashCode * -1521134295 + pointB.GetHashCode();
                hashCode = hashCode * -1521134295 + distance.GetHashCode();

                return hashCode;
            }
        }

        /// <summary>
        /// Returns a string in the format of "a: {pointA}, b: {pointB}, distance: {distance}".
        /// </summary>
        [EditorBrowsable(EditorBrowsableState.Never)]
        public override string ToString()
        {
            return $"a: {pointA}, b: {pointB}, distance: {distance}";
        }

        /// <summary>
        /// Returns true if both <see cref="ContactPoint"/>s are the same object or the dimensions
        /// are within <see cref="float.Epsilon"/> distance of each other.
        /// </summary>
        [EditorBrowsable(EditorBrowsableState.Never)]
        public static bool operator ==(ContactPoint left, ContactPoint right)
        {
            if (ReferenceEquals(left, null))
            {
                return ReferenceEquals(right, null);
            }

            return left.Equals(right);
        }

        /// <summary>
        /// Returns false if both <see cref="ContactPoint"/>s are the same object or the dimensions
        /// are within <see cref="float.Epsilon"/> distance of each other.
        /// </summary>
        [EditorBrowsable(EditorBrowsableState.Never)]
        public static bool operator !=(ContactPoint left, ContactPoint right)
        {
            return !(left == right);
        }

        internal static ContactPoint Empty => new ContactPoint(Vect.Zero, Vect.Zero, 0.0);

        internal static ContactPoint FromCollidePoint(cpContactPoint contactPoint)
        {
            return new ContactPoint(
                contactPoint.pointA,
                contactPoint.pointB,
                contactPoint.distance);
        }

        internal cpContactPoint ToContactPoint()
        {
            return new cpContactPoint
            {
                pointA = pointA,
                pointB = pointB,
                distance = distance
            };
        }
    }
}