using System;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using Microsoft.Win32;

namespace Common
{
    class FormDimensions
    {
        public Form Form;
        public string RegSubKey;
        public FormWindowState DefaultFormWindowState = FormWindowState.Normal;

        [DllImport("user32.dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        static extern bool GetWindowPlacement(IntPtr hWnd, ref WINDOWPLACEMENT lpwndpl);

        public FormDimensions()
        {
            RegSubKey = "Forms";
        }

        private struct WINDOWPLACEMENT
        {
            public int length;
            public int flags;
            public int showCmd;
            public System.Drawing.Point ptMinPosition;
            public System.Drawing.Point ptMaxPosition;
            public System.Drawing.Rectangle rcNormalPosition;
        }

        const UInt32 SW_HIDE = 0;
        const UInt32 SW_SHOWNORMAL = 1;
        const UInt32 SW_NORMAL = 1;
        const UInt32 SW_SHOWMINIMIZED = 2;
        const UInt32 SW_SHOWMAXIMIZED = 3;
        const UInt32 SW_MAXIMIZE = 3;
        const UInt32 SW_SHOWNOACTIVATE = 4;
        const UInt32 SW_SHOW = 5;
        const UInt32 SW_MINIMIZE = 6;
        const UInt32 SW_SHOWMINNOACTIVE = 7;
        const UInt32 SW_SHOWNA = 8;
        const UInt32 SW_RESTORE = 9;

        private WINDOWPLACEMENT GetPlacement(Form form)
        {
            WINDOWPLACEMENT placement = new WINDOWPLACEMENT();
            placement.length = Marshal.SizeOf(placement);
            GetWindowPlacement(form.Handle, ref placement);
            return placement;
        }

        private bool IsVisibleOnAnyScreen(Rectangle rect)
        {
            int minVisible = 50;
            foreach (Screen screen in Screen.AllScreens)
            {
                Rectangle visibleArea = screen.WorkingArea;
                visibleArea.Intersect(rect);
                if ((visibleArea.Width > minVisible) && (visibleArea.Height > minVisible) && (rect.Top >= 0))
                {
                    return true;
                }
            }
            return false;
        }

        public void Load(Form form, Form parentForm = null)
        {
            this.Form = form;
            RegistryKey regKey = Application.UserAppDataRegistry.OpenSubKey(RegSubKey + "\\" + form.Name);
            if (regKey == null) regKey = Application.UserAppDataRegistry.CreateSubKey(RegSubKey + "\\" + form.Name);

            string name = "";
            if (parentForm != null) name = parentForm.Name;

            bool prevVisibleState = form.Visible;
            form.Visible = false;
            Rectangle windowPosition = form.DesktopBounds;
            Rectangle restoreBounds = form.RestoreBounds;
            if (parentForm != null)
            {
                // Set default form position centered to parent form
                Point currentParentFormCenter = parentForm.DesktopBounds.Center();
                windowPosition.X = currentParentFormCenter.X - windowPosition.Width / 2;
                windowPosition.Y = currentParentFormCenter.Y - windowPosition.Height / 2;
                restoreBounds.X = currentParentFormCenter.X - restoreBounds.Width / 2;
                restoreBounds.Y = currentParentFormCenter.Y - restoreBounds.Height / 2;
            }
            windowPosition = new Rectangle(
                (int)regKey.GetValue("DesktopBoundsLeft" + name, windowPosition.Left),
                (int)regKey.GetValue("DesktopBoundsTop" + name, windowPosition.Top),
                (int)regKey.GetValue("DesktopBoundsWidth" + name, windowPosition.Width),
                (int)regKey.GetValue("DesktopBoundsHeight" + name, windowPosition.Height));
            restoreBounds = new Rectangle(
                (int)regKey.GetValue("RestoreBoundsLeft" + name, restoreBounds.Left),
                (int)regKey.GetValue("RestoreBoundsTop" + name, restoreBounds.Top),
                (int)regKey.GetValue("RestoreBoundsWidth" + name, restoreBounds.Width),
                (int)regKey.GetValue("RestoreBoundsHeight" + name, restoreBounds.Height));
            FormWindowState windowState = (FormWindowState)regKey.GetValue("State" + name, (int)DefaultFormWindowState);
            if (parentForm != null)
            {
                Rectangle parentBounds = new Rectangle(
                    (int)regKey.GetValue("ParentBoundsLeft" + name, parentForm.DesktopBounds.Left),
                    (int)regKey.GetValue("ParentBoundsTop" + name, parentForm.DesktopBounds.Top),
                    (int)regKey.GetValue("ParentBoundsWidth" + name, parentForm.DesktopBounds.Width),
                    (int)regKey.GetValue("ParentBoundsHeight" + name, parentForm.DesktopBounds.Height));
                Point currentParentFormCenter = parentForm.DesktopBounds.Center();
                Point previousParentFormCenter = parentBounds.Center();
                Point parentShift = Point.Subtract(currentParentFormCenter, new Size(previousParentFormCenter));
                windowPosition.Offset(parentShift);
            }
            switch (windowState)
            {
                case FormWindowState.Normal:
                    form.WindowState = FormWindowState.Normal;
                    if ((windowPosition != Rectangle.Empty) && IsVisibleOnAnyScreen(windowPosition))
                    {
                        form.DesktopBounds = windowPosition;
                    }
                    form.WindowState = windowState;
                    break;
                case FormWindowState.Minimized:
                    form.WindowState = FormWindowState.Normal;
                    if ((windowPosition != Rectangle.Empty) && IsVisibleOnAnyScreen(restoreBounds))
                    {
                        form.DesktopBounds = restoreBounds;
                    }
                    break;
                case FormWindowState.Maximized:
                    form.WindowState = FormWindowState.Normal;
                    if ((windowPosition != Rectangle.Empty) && IsVisibleOnAnyScreen(restoreBounds))
                    {
                        form.DesktopBounds = restoreBounds;
                    }
                    form.WindowState = FormWindowState.Maximized;
                    break;
                default:
                    break;
            }
            form.Visible = prevVisibleState;
            LoadControl(form);
        }

        public void Save(Form form, Form parentForm = null)
        {
            this.Form = form;
            RegistryKey regKey = Application.UserAppDataRegistry.OpenSubKey(RegSubKey + "\\" + form.Name, true);
            if (regKey == null) regKey = Application.UserAppDataRegistry.CreateSubKey(RegSubKey + "\\" + form.Name);

            string name = "";
            if (parentForm != null) name = parentForm.Name;

            WINDOWPLACEMENT placement = GetPlacement(form);
            const int WPF_RESTORETOMAXIMIZED = 0x2;

            if ((form.WindowState == FormWindowState.Minimized) &&
                ((placement.flags | WPF_RESTORETOMAXIMIZED) != WPF_RESTORETOMAXIMIZED))
            {
                regKey.SetValue("State" + name, (int)FormWindowState.Minimized);
            }
            else
            {
                regKey.SetValue("State" + name, (int)form.WindowState);
            }
            regKey.SetValue("DesktopBoundsLeft" + name, form.DesktopBounds.Left);
            regKey.SetValue("DesktopBoundsTop" + name, form.DesktopBounds.Top);
            regKey.SetValue("DesktopBoundsWidth" + name, form.DesktopBounds.Width);
            regKey.SetValue("DesktopBoundsHeight" + name, form.DesktopBounds.Height);
            regKey.SetValue("RestoreBoundsLeft" + name, form.RestoreBounds.Left);
            regKey.SetValue("RestoreBoundsTop" + name, form.RestoreBounds.Top);
            regKey.SetValue("RestoreBoundsWidth" + name, form.RestoreBounds.Width);
            regKey.SetValue("RestoreBoundsHeight" + name, form.RestoreBounds.Height);
            if (parentForm != null)
            {
                regKey.SetValue("ParentBoundsLeft" + name, parentForm.DesktopBounds.Left);
                regKey.SetValue("ParentBoundsTop" + name, parentForm.DesktopBounds.Top);
                regKey.SetValue("ParentBoundsWidth" + name, parentForm.DesktopBounds.Width);
                regKey.SetValue("ParentBoundsHeight" + name, parentForm.DesktopBounds.Height);
            }
            SaveControl(form);
        }

        public void LoadControl(Control control)
        {
            if (control is ListView)
            {
                RegistryKey regKey = Application.UserAppDataRegistry.OpenSubKey(RegSubKey + "\\" + Form.Name + "\\" + control.Name, true);
                if (regKey == null) regKey = Application.UserAppDataRegistry.CreateSubKey(RegSubKey + "\\" + Form.Name + "\\" + control.Name);

                for (int I = 0; I < (control as ListView).Columns.Count; I++)
                {
                    if (regKey.GetValue("ColWidth" + I.ToString()) != null)
                          (control as ListView).Columns[I].Width = (int) regKey.GetValue("ColWidth" + I.ToString());
                }
            } else
            if (control is DataGridView)
            {
                RegistryKey regKey = Application.UserAppDataRegistry.OpenSubKey(RegSubKey + "\\" + Form.Name + "\\" + control.Name, true);
                if (regKey == null) regKey = Application.UserAppDataRegistry.CreateSubKey(RegSubKey + "\\" + Form.Name + "\\" + control.Name);

                for (int I = 0; I < (control as DataGridView).Columns.Count; I++)
                {
                    if (regKey.GetValue("ColWidth" + I.ToString()) != null)
                        (control as DataGridView).Columns[I].Width = (int)regKey.GetValue("ColWidth" + I.ToString());
                }
            }
            if (control is SplitContainer)
            {
                RegistryKey regKey = Application.UserAppDataRegistry.OpenSubKey(RegSubKey + "\\" + Form.Name + "\\" + control.Name, true);
                if (regKey == null) regKey = Application.UserAppDataRegistry.CreateSubKey(RegSubKey + "\\" + Form.Name + "\\" + control.Name);

                if (regKey.GetValue("SplitterDistance") != null)
                    (control as SplitContainer).SplitterDistance = (int)regKey.GetValue("SplitterDistance");
            }

            foreach (Control child in control.Controls)
            {
                LoadControl(child);
            }
        }

        public void SaveControl(Control control)
        {
            if (control is ListView)
            {
                RegistryKey regKey = Application.UserAppDataRegistry.OpenSubKey(RegSubKey + "\\" + Form.Name + "\\" + control.Name, true);
                if (regKey == null) regKey = Application.UserAppDataRegistry.CreateSubKey(RegSubKey + "\\" + Form.Name + "\\" + control.Name);

                for (int I = 0; I < (control as ListView).Columns.Count; I++)
                {
                    regKey.SetValue("ColWidth" + I.ToString(), (control as ListView).Columns[I].Width);
                }
            } else
            if (control is DataGridView)
            {
                RegistryKey regKey = Application.UserAppDataRegistry.OpenSubKey(RegSubKey + "\\" + Form.Name + "\\" + control.Name, true);
                if (regKey == null) regKey = Application.UserAppDataRegistry.CreateSubKey(RegSubKey + "\\" + Form.Name + "\\" + control.Name);

                for (int I = 0; I < (control as DataGridView).Columns.Count; I++)
                {
                    regKey.SetValue("ColWidth" + I.ToString(), (control as DataGridView).Columns[I].Width);
                }
            }
            if (control is SplitContainer)
            {
                RegistryKey regKey = Application.UserAppDataRegistry.OpenSubKey(RegSubKey + "\\" + Form.Name + "\\" + control.Name, true);
                if (regKey == null) regKey = Application.UserAppDataRegistry.CreateSubKey(RegSubKey + "\\" + Form.Name + "\\" + control.Name);

                regKey.SetValue("SplitterDistance", (control as SplitContainer).SplitterDistance);
            }

            foreach (Control child in control.Controls)
            {
                SaveControl(child);
            }
        }
    }

    public static class RectangleExt
    {
        public static Point Center(this Rectangle rect)
        {
            return new Point(rect.Left + rect.Width / 2,
                             rect.Top + rect.Height / 2);
        }
    }
}