using System;
using System.Runtime.InteropServices;
using UnityEngine;

namespace UnityEngine.XR.ARSubsystems
{
    /// <summary>
    /// Parameters of the Unity <c>Camera</c> that may be necessary/useful to the provider.
    /// </summary>
    [StructLayout(LayoutKind.Sequential)]
    public struct XRCameraParams : IEquatable<XRCameraParams>
    {
        /// <summary>
        /// Distance from the camera to the near plane.
        /// </summary>
        /// <value>
        /// Distance from the camera to the near plane.
        /// </value>
        public float zNear
        {
            get { return m_ZNear; }
            set { m_ZNear = value; }
        }
        float m_ZNear;

        /// <summary>
        /// Distance from the camera to the far plane.
        /// </summary>
        /// <value>
        /// Distance from the camera to the far plane.
        /// </value>
        public float zFar
        {
            get { return m_ZFar; }
            set { m_ZFar = value; }
        }
        float m_ZFar;

        /// <summary>
        /// Width, in pixels, of the screen resolution.
        /// </summary>
        /// <value>
        /// Width, in pixels, of the screen resolution.
        /// </value>
        public float screenWidth
        {
            get { return m_ScreenWidth; }
            set { m_ScreenWidth = value; }
        }
        float m_ScreenWidth;

        /// <summary>
        /// Height, in pixels, of the screen resolution.
        /// </summary>
        /// <value>
        /// Height, in pixels, of the screen resolution.
        /// </value>
        public float screenHeight
        {
            get { return m_ScreenHeight; }
            set { m_ScreenHeight = value; }
        }
        float m_ScreenHeight;

        /// <summary>
        /// The orientation of the screen.
        /// </summary>
        /// <value>
        /// The orientation of the screen.
        /// </value>
        public ScreenOrientation screenOrientation
        {
            get { return m_ScreenOrientation; }
            set { m_ScreenOrientation = value; }
        }
        ScreenOrientation m_ScreenOrientation;

        public bool Equals(XRCameraParams other)
        {
            return (m_ZNear.Equals(other.m_ZNear) && m_ZFar.Equals(other.m_ZFar)
                    && m_ScreenWidth.Equals(other.m_ScreenWidth) && m_ScreenHeight.Equals(other.m_ScreenHeight)
                    && m_ScreenOrientation.Equals(other.m_ScreenOrientation));
        }

        public override bool Equals(System.Object obj)
        {
            return ((obj is XRCameraParams) && Equals((XRCameraParams)obj));
        }

        public static bool operator ==(XRCameraParams lhs, XRCameraParams rhs)
        {
            return lhs.Equals(rhs);
        }

        public static bool operator !=(XRCameraParams lhs, XRCameraParams rhs)
        {
            return !lhs.Equals(rhs);
        }

        public override int GetHashCode()
        {
            int hashCode = 486187739;
            unchecked
            {
                hashCode = (hashCode * 486187739) + m_ZNear.GetHashCode();
                hashCode = (hashCode * 486187739) + m_ZFar.GetHashCode();
                hashCode = (hashCode * 486187739) + m_ScreenWidth.GetHashCode();
                hashCode = (hashCode * 486187739) + m_ScreenHeight.GetHashCode();
                hashCode = (hashCode * 486187739) + ((int)m_ScreenOrientation).GetHashCode();
            }
            return hashCode;
        }

        public override string ToString()
        {
            return string.Format("zNear:{0} zFar:{1} screen:{2}x{3}({4})", m_ZNear.ToString("0.000"),
                                 m_ZFar.ToString("0.000"), m_ScreenWidth.ToString(), m_ScreenHeight.ToString(),
                                 m_ScreenOrientation.ToString());
        }
    }
}