using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows;

namespace DTS.Common.Classes
{
    public static class WindowsAPIHelpers
    {
        /// <summary>
        /// POINT aka POINTAPI
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct POINT
        {
            /// <summary>
            /// x coordinate of point.
            /// </summary>
            public int x;
            /// <summary>
            /// y coordinate of point.
            /// </summary>
            public int y;

            /// <summary>
            /// Construct a point of coordinates (x,y).
            /// </summary>
            public POINT(int x, int y)
            {
                this.x = x;
                this.y = y;
            }
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct MINMAXINFO
        {
            public POINT ptReserved;
            public POINT ptMaxSize;
            public POINT ptMaxPosition;
            public POINT ptMinTrackSize;
            public POINT ptMaxTrackSize;
        };


        /// <summary>
        /// </summary>
        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        public class MONITORINFO
        {
            /// <summary>
            /// </summary>            
            public int cbSize = Marshal.SizeOf(typeof(MONITORINFO));

            /// <summary>
            /// </summary>            
            public RECT rcMonitor = new RECT();

            /// <summary>
            /// </summary>            
            public RECT rcWork = new RECT();

            /// <summary>
            /// </summary>            
            public int dwFlags = 0;
        }


        /// <summary> Win32 </summary>
        [StructLayout(LayoutKind.Sequential, Pack = 0)]
        public struct RECT
        {
            /// <summary> Win32 </summary>
            public int left;
            /// <summary> Win32 </summary>
            public int top;
            /// <summary> Win32 </summary>
            public int right;
            /// <summary> Win32 </summary>
            public int bottom;

            /// <summary> Win32 </summary>
            public static readonly RECT Empty = new RECT();

            /// <summary> Win32 </summary>
            public int Width => Math.Abs(right - left);

            /// <summary> Win32 </summary>
            public int Height => bottom - top;

            /// <summary> Win32 </summary>
            public RECT(int left, int top, int right, int bottom)
            {
                this.left = left;
                this.top = top;
                this.right = right;
                this.bottom = bottom;
            }


            /// <summary> Win32 </summary>
            public RECT(RECT rcSrc)
            {
                left = rcSrc.left;
                top = rcSrc.top;
                right = rcSrc.right;
                bottom = rcSrc.bottom;
            }

            /// <summary> Win32 </summary>
            public bool IsEmpty => left >= right || top >= bottom;

            /// <summary> Return a user friendly representation of this struct </summary>
            public override string ToString()
            {
                if (this == Empty) { return "RECT {Empty}"; }
                return "RECT { left : " + left + " / top : " + top + " / right : " + right + " / bottom : " + bottom + " }";
            }

            /// <summary> Determine if 2 RECT are equal (deep compare) </summary>
            public override bool Equals(object obj)
            {
                if (!(obj is Rect)) { return false; }
                return (this == (RECT)obj);
            }

            /// <summary>Return the HashCode for this struct (not garanteed to be unique)</summary>
            public override int GetHashCode()
            {
                return left.GetHashCode() + top.GetHashCode() + right.GetHashCode() + bottom.GetHashCode();
            }


            /// <summary> Determine if 2 RECT are equal (deep compare)</summary>
            public static bool operator ==(RECT rect1, RECT rect2)
            {
                return (rect1.left == rect2.left && rect1.top == rect2.top && rect1.right == rect2.right && rect1.bottom == rect2.bottom);
            }

            /// <summary> Determine if 2 RECT are different(deep compare)</summary>
            public static bool operator !=(RECT rect1, RECT rect2)
            {
                return !(rect1 == rect2);
            }


        }

        public enum WM
        {
            WINDOWMAX = 0x0024,
            WINDOWPOSCHANGING = 0x0046,
        }

        public enum SWP
        {
            NOMOVE = 0x0002,
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct WINDOWPOS
        {
            public IntPtr hwnd;
            public IntPtr hwndInsertAfter;
            public int x;
            public int y;
            public int cx;
            public int cy;
            public int flags;
        }
        public static void GetMinMaxInfo(IntPtr hwnd, IntPtr lParam)
        {

            var mmi = (MINMAXINFO)Marshal.PtrToStructure(lParam, typeof(MINMAXINFO));

            // Adjust the maximized size and position to fit the work area of the correct monitor
            const int monitorDefaulttonearest = 0x00000002;
            var monitor = MonitorFromWindow(hwnd, monitorDefaulttonearest);

            if (monitor != IntPtr.Zero)
            {

                var monitorInfo = new MONITORINFO();
                GetMonitorInfo(monitor, monitorInfo);
                var rcWorkArea = monitorInfo.rcWork;
                var rcMonitorArea = monitorInfo.rcMonitor;
                mmi.ptMaxPosition.x = Math.Abs(rcWorkArea.left - rcMonitorArea.left);
                mmi.ptMaxPosition.y = Math.Abs(rcWorkArea.top - rcMonitorArea.top);
                mmi.ptMaxSize.x = Math.Abs(rcWorkArea.right - rcWorkArea.left);
                mmi.ptMaxSize.y = Math.Abs(rcWorkArea.bottom - rcWorkArea.top);
            }

            Marshal.StructureToPtr(mmi, lParam, true);
        }

        [DllImport("user32")]
        public static extern bool GetMonitorInfo(IntPtr hMonitor, MONITORINFO lpmi);

        /// <summary>
        /// 
        /// </summary>
        [DllImport("User32")]
        public static extern IntPtr MonitorFromWindow(IntPtr handle, int flags);

    }
}