﻿// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

#nullable disable

using System.Collections.Specialized;
using System.ComponentModel;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms.Layout;
using static Interop;

namespace System.Windows.Forms
{
    [SRDescription(nameof(SR.DescriptionStatusStrip))]
    public class StatusStrip : ToolStrip
    {
        private const AnchorStyles AllAnchor = AnchorStyles.Left | AnchorStyles.Right | AnchorStyles.Bottom | AnchorStyles.Top;
        private const AnchorStyles HorizontalAnchor = AnchorStyles.Left | AnchorStyles.Right;
        private const AnchorStyles VerticalAnchor = AnchorStyles.Top | AnchorStyles.Bottom;

        private BitVector32 state;

        private static readonly int stateSizingGrip = BitVector32.CreateMask();
        private static readonly int stateCalledSpringTableLayout = BitVector32.CreateMask(stateSizingGrip);

        private const int gripWidth = 12;
        private RightToLeftLayoutGrip rtlLayoutGrip;
        private Orientation lastOrientation = Orientation.Horizontal;

        public StatusStrip()
        {
            SuspendLayout();
            CanOverflow = false;
            LayoutStyle = ToolStripLayoutStyle.Table;
            RenderMode = ToolStripRenderMode.System;
            GripStyle = ToolStripGripStyle.Hidden;

            SetStyle(ControlStyles.ResizeRedraw, true);
            Stretch = true;
            state[stateSizingGrip] = true;
            ResumeLayout(true);
        }

        [DefaultValue(false)]
        [SRDescription(nameof(SR.ToolStripCanOverflowDescr))]
        [SRCategory(nameof(SR.CatLayout))]
        [Browsable(false)]
        public new bool CanOverflow
        {
            get => base.CanOverflow;
            set => base.CanOverflow = value;
        }

        protected override bool DefaultShowItemToolTips
        {
            get
            {
                return false;
            }
        }

        protected override Size DefaultSize
        {
            get
            {
                return new Size(200, 22);
            }
        }

        protected override Padding DefaultPadding
        {
            get
            {
                if (Orientation == Orientation.Horizontal)
                {
                    if (RightToLeft == RightToLeft.No)
                    {
                        return new Padding(1, 0, 14, 0);
                    }
                    else
                    {
                        return new Padding(14, 0, 1, 0);
                    }
                }
                else
                {
                    // vertical
                    // the difference in symmetry here is that the grip does not actually rotate, it remains the same height it
                    // was before, so the DisplayRectangle needs to shrink up by its height.
                    return new Padding(1, 3, 1, DefaultSize.Height);
                }
            }
        }

        protected override DockStyle DefaultDock
        {
            get
            {
                return DockStyle.Bottom;
            }
        }

        [DefaultValue(DockStyle.Bottom)]
        public override DockStyle Dock
        {
            get => base.Dock;
            set => base.Dock = value;
        }

        [DefaultValue(ToolStripGripStyle.Hidden)]
        public new ToolStripGripStyle GripStyle
        {
            get => base.GripStyle;
            set => base.GripStyle = value;
        }

        [DefaultValue(ToolStripLayoutStyle.Table)]
        public new ToolStripLayoutStyle LayoutStyle
        {
            get => base.LayoutStyle;
            set => base.LayoutStyle = value;
        }

        // we do some custom stuff with padding to accomodate size grip.
        // changing this is not supported at DT
        [Browsable(false)]
        public new Padding Padding
        {
            get => base.Padding;
            set => base.Padding = value;
        }

        [Browsable(false)]
        public new event EventHandler PaddingChanged
        {
            add => base.PaddingChanged += value;
            remove => base.PaddingChanged -= value;
        }

        private Control RTLGrip
        {
            get
            {
                if (rtlLayoutGrip is null)
                {
                    rtlLayoutGrip = new RightToLeftLayoutGrip();
                }
                return rtlLayoutGrip;
            }
        }

        [DefaultValue(false)]
        [SRDescription(nameof(SR.ToolStripShowItemToolTipsDescr))]
        [SRCategory(nameof(SR.CatBehavior))]
        public new bool ShowItemToolTips
        {
            get => base.ShowItemToolTips;
            set => base.ShowItemToolTips = value;
        }

        // return whether we should paint the sizing grip.
        private bool ShowSizingGrip
        {
            get
            {
                if (SizingGrip && IsHandleCreated)
                {
                    if (DesignMode)
                    {
                        return true;  // we dont care about the state of VS.
                    }

                    IntPtr rootHwnd = User32.GetAncestor(this, User32.GA.ROOT);
                    if (rootHwnd != IntPtr.Zero)
                    {
                        return !User32.IsZoomed(rootHwnd).IsTrue();
                    }
                }

                return false;
            }
        }

        [SRCategory(nameof(SR.CatAppearance))]
        [DefaultValue(true)]
        [SRDescription(nameof(SR.StatusStripSizingGripDescr))]
        public bool SizingGrip
        {
            get
            {
                return state[stateSizingGrip];
            }
            set
            {
                if (value != state[stateSizingGrip])
                {
                    state[stateSizingGrip] = value;
                    EnsureRightToLeftGrip();
                    Invalidate(true);
                }
            }
        }

        [Browsable(false)]
        public Rectangle SizeGripBounds
        {
            get
            {
                if (SizingGrip)
                {
                    Size statusStripSize = Size;
                    // we cant necessarily make this the height of the status strip, as
                    // the orientation could change.
                    int gripHeight = Math.Min(DefaultSize.Height, statusStripSize.Height);

                    if (RightToLeft == RightToLeft.Yes)
                    {
                        return new Rectangle(0, statusStripSize.Height - gripHeight, gripWidth, gripHeight);
                    }
                    else
                    {
                        return new Rectangle(statusStripSize.Width - gripWidth, statusStripSize.Height - gripHeight, gripWidth, gripHeight);
                    }
                }
                return Rectangle.Empty;
            }
        }

        [DefaultValue(true)]
        [SRCategory(nameof(SR.CatLayout))]
        [SRDescription(nameof(SR.ToolStripStretchDescr))]
        public new bool Stretch
        {
            get => base.Stretch;
            set => base.Stretch = value;
        }

        private TableLayoutSettings TableLayoutSettings
        {
            get { return LayoutSettings as TableLayoutSettings; }
        }

        protected override AccessibleObject CreateAccessibilityInstance()
        {
            return new StatusStripAccessibleObject(this);
        }

        protected internal override ToolStripItem CreateDefaultItem(string text, Image image, EventHandler onClick)
        {
            return new ToolStripStatusLabel(text, image, onClick);
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                if (rtlLayoutGrip != null)
                {
                    rtlLayoutGrip.Dispose();
                    rtlLayoutGrip = null;
                }
            }
            base.Dispose(disposing);
        }

        // in RTL, we parent a transparent control over the grip to support mirroring.
        private void EnsureRightToLeftGrip()
        {
            if (SizingGrip && RightToLeft == RightToLeft.Yes)
            {
                RTLGrip.Bounds = SizeGripBounds;
                if (!Controls.Contains(RTLGrip))
                {
                    if (Controls is ReadOnlyControlCollection controlCollection)
                    {
                        controlCollection.AddInternal(RTLGrip);
                    }
                }
            }
            else if (rtlLayoutGrip != null)
            {
                if (Controls.Contains(rtlLayoutGrip))
                {
                    if (Controls is ReadOnlyControlCollection controlCollection)
                    {
                        controlCollection.RemoveInternal(rtlLayoutGrip);
                    }
                    rtlLayoutGrip.Dispose();
                    rtlLayoutGrip = null;
                }
            }
        }

        internal override Size GetPreferredSizeCore(Size proposedSize)
        {
            if (LayoutStyle == ToolStripLayoutStyle.Table)
            {
                if (proposedSize.Width == 1)
                {
                    proposedSize.Width = int.MaxValue;
                }
                if (proposedSize.Height == 1)
                {
                    proposedSize.Height = int.MaxValue;
                }
                if (Orientation == Orientation.Horizontal)
                {
                    return GetPreferredSizeHorizontal(this, proposedSize) + Padding.Size;
                }
                else
                {
                    return GetPreferredSizeVertical(this, proposedSize) + Padding.Size;
                }
            }
            return base.GetPreferredSizeCore(proposedSize);
        }

        protected override void OnPaintBackground(PaintEventArgs e)
        {
            base.OnPaintBackground(e);

            if (ShowSizingGrip)
            {
                Renderer.DrawStatusStripSizingGrip(new ToolStripRenderEventArgs(e.Graphics, this));
            }
        }

        protected override void OnLayout(LayoutEventArgs levent)
        {
            state[stateCalledSpringTableLayout] = false;
            bool inDisplayedItemCollecton = false;
            ToolStripItem item = levent.AffectedComponent as ToolStripItem;
            int itemCount = DisplayedItems.Count;
            if (item != null)
            {
                inDisplayedItemCollecton = DisplayedItems.Contains(item);
            }

            if (LayoutStyle == ToolStripLayoutStyle.Table)
            {
                OnSpringTableLayoutCore();
            }
            base.OnLayout(levent);

            if (itemCount != DisplayedItems.Count || (item != null && (inDisplayedItemCollecton != DisplayedItems.Contains(item))))
            {
                // calling OnLayout has changed the displayed items collection
                // the SpringTableLayoutCore requires the count of displayed items to
                // be accurate.
                // - so we need to perform layout again.
                if (LayoutStyle == ToolStripLayoutStyle.Table)
                {
                    OnSpringTableLayoutCore();
                    base.OnLayout(levent);
                }
            }

            EnsureRightToLeftGrip();
        }

        internal override bool SupportsUiaProviders => true;

        protected override void SetDisplayedItems()
        {
            if (state[stateCalledSpringTableLayout])
            {
                bool rightToLeft = ((Orientation == Orientation.Horizontal) && (RightToLeft == RightToLeft.Yes));

                // shove all items that dont fit one pixel outside the displayed region
                Rectangle displayRect = DisplayRectangle;
                Point noMansLand = displayRect.Location;
                noMansLand.X += ClientSize.Width + 1;
                noMansLand.Y += ClientSize.Height + 1;
                bool overflow = false;
                Rectangle lastItemBounds = Rectangle.Empty;

                ToolStripItem lastItem = null;
                for (int i = 0; i < Items.Count; i++)
                {
                    ToolStripItem item = Items[i];

                    // using spring layout we can get into a situation where there's extra items which arent
                    // visible.
                    if (overflow || ((IArrangedElement)item).ParticipatesInLayout)
                    {
                        if (overflow || (SizingGrip && item.Bounds.IntersectsWith(SizeGripBounds)))
                        {
                            // if the item collides with the size grip, set the location to nomansland.
                            SetItemLocation(item, noMansLand);
                            item.SetPlacement(ToolStripItemPlacement.None);
                        }
                    }
                    else if (lastItem != null && (lastItemBounds.IntersectsWith(item.Bounds)))
                    {
                        // if it overlaps the previous element, set the location to nomansland.
                        SetItemLocation(item, noMansLand);
                        item.SetPlacement(ToolStripItemPlacement.None);
                    }
                    else if (item.Bounds.Width == 1)
                    {
                        if (item is ToolStripStatusLabel panel && panel.Spring)
                        {
                            // once we get down to one pixel, there can always be a one pixel
                            // distribution problem with the TLP - there's usually a spare one around.
                            // so set this off to nomansland as well.
                            SetItemLocation(item, noMansLand);
                            item.SetPlacement(ToolStripItemPlacement.None);
                        }
                    }

                    if (item.Bounds.Location != noMansLand)
                    {
                        // set the next item to inspect for collisions
                        lastItem = item;
                        lastItemBounds = lastItem.Bounds;
                    }
                    else
                    {
                        // we cant fit an item, everything else after it should not be displayed
                        if (((IArrangedElement)item).ParticipatesInLayout)
                        {
                            overflow = true;
                        }
                    }
                }
            }
            base.SetDisplayedItems();
        }

        internal override void ResetRenderMode()
        {
            RenderMode = ToolStripRenderMode.System;
        }
        internal override bool ShouldSerializeRenderMode()
        {
            // We should NEVER serialize custom.
            return (RenderMode != ToolStripRenderMode.System && RenderMode != ToolStripRenderMode.Custom);
        }

        /// <summary>
        ///  Override this function if you want to do custom table layouts for the
        ///  StatusStrip.  The default layoutstyle is tablelayout, and we need to play
        ///  with the row/column styles
        /// </summary>
        protected virtual void OnSpringTableLayoutCore()
        {
            if (LayoutStyle == ToolStripLayoutStyle.Table)
            {
                state[stateCalledSpringTableLayout] = true;

                SuspendLayout();

                if (lastOrientation != Orientation)
                {
                    TableLayoutSettings settings = TableLayoutSettings;
                    settings.RowCount = 0;
                    settings.ColumnCount = 0;
                    settings.ColumnStyles.Clear();
                    settings.RowStyles.Clear();
                }
                lastOrientation = Orientation;

                if (Orientation == Orientation.Horizontal)
                {
                    //
                    // Horizontal layout
                    //
                    TableLayoutSettings.GrowStyle = TableLayoutPanelGrowStyle.AddColumns;

                    int originalColumnCount = TableLayoutSettings.ColumnStyles.Count;

                    // iterate through the elements which are going to be displayed.
                    for (int i = 0; i < DisplayedItems.Count; i++)
                    {
                        if (i >= originalColumnCount)
                        {
                            // add if it's necessary.
                            TableLayoutSettings.ColumnStyles.Add(new ColumnStyle());
                        }

                        // determine if we "spring" or "autosize" the column
                        bool spring = (DisplayedItems[i] is ToolStripStatusLabel panel && panel.Spring);
                        DisplayedItems[i].Anchor = (spring) ? AllAnchor : VerticalAnchor;

                        // spring is achieved by using 100% as the column style
                        ColumnStyle colStyle = TableLayoutSettings.ColumnStyles[i];
                        colStyle.Width = 100; // this width is ignored in AutoSize.
                        colStyle.SizeType = (spring) ? SizeType.Percent : SizeType.AutoSize;
                    }

                    if (TableLayoutSettings.RowStyles.Count > 1 || TableLayoutSettings.RowStyles.Count == 0)
                    {
                        TableLayoutSettings.RowStyles.Clear();
                        TableLayoutSettings.RowStyles.Add(new RowStyle());
                    }
                    TableLayoutSettings.RowCount = 1;

                    TableLayoutSettings.RowStyles[0].SizeType = SizeType.Absolute;
                    TableLayoutSettings.RowStyles[0].Height = Math.Max(0, DisplayRectangle.Height);
                    TableLayoutSettings.ColumnCount = DisplayedItems.Count + 1; // add an extra cell so it fills the remaining space

                    // dont remove the extra column styles, just set them back to autosize.
                    for (int i = DisplayedItems.Count; i < TableLayoutSettings.ColumnStyles.Count; i++)
                    {
                        TableLayoutSettings.ColumnStyles[i].SizeType = SizeType.AutoSize;
                    }
                }
                else
                {
                    //
                    // Vertical layout
                    //

                    TableLayoutSettings.GrowStyle = TableLayoutPanelGrowStyle.AddRows;

                    int originalRowCount = TableLayoutSettings.RowStyles.Count;

                    // iterate through the elements which are going to be displayed.
                    for (int i = 0; i < DisplayedItems.Count; i++)
                    {
                        if (i >= originalRowCount)
                        {
                            // add if it's necessary.
                            TableLayoutSettings.RowStyles.Add(new RowStyle());
                        }

                        // determine if we "spring" or "autosize" the row
                        bool spring = (DisplayedItems[i] is ToolStripStatusLabel panel && panel.Spring);
                        DisplayedItems[i].Anchor = (spring) ? AllAnchor : HorizontalAnchor;

                        // spring is achieved by using 100% as the row style
                        RowStyle rowStyle = TableLayoutSettings.RowStyles[i];
                        rowStyle.Height = 100; // this width is ignored in AutoSize.
                        rowStyle.SizeType = (spring) ? SizeType.Percent : SizeType.AutoSize;
                    }
                    TableLayoutSettings.ColumnCount = 1;

                    if (TableLayoutSettings.ColumnStyles.Count > 1 || TableLayoutSettings.ColumnStyles.Count == 0)
                    {
                        TableLayoutSettings.ColumnStyles.Clear();
                        TableLayoutSettings.ColumnStyles.Add(new ColumnStyle());
                    }

                    TableLayoutSettings.ColumnCount = 1;
                    TableLayoutSettings.ColumnStyles[0].SizeType = SizeType.Absolute;
                    TableLayoutSettings.ColumnStyles[0].Width = Math.Max(0, DisplayRectangle.Width);

                    TableLayoutSettings.RowCount = DisplayedItems.Count + 1; // add an extra cell so it fills the remaining space

                    // dont remove the extra column styles, just set them back to autosize.
                    for (int i = DisplayedItems.Count; i < TableLayoutSettings.RowStyles.Count; i++)
                    {
                        TableLayoutSettings.RowStyles[i].SizeType = SizeType.AutoSize;
                    }
                }

                ResumeLayout(false);
            }
        }

        protected override void WndProc(ref Message m)
        {
            if ((m.Msg == (int)User32.WM.NCHITTEST) && SizingGrip)
            {
                // if we're within the grip bounds tell windows
                // that we're the bottom right of the window.
                Rectangle sizeGripBounds = SizeGripBounds;
                int x = PARAM.LOWORD(m.LParam);
                int y = PARAM.HIWORD(m.LParam);

                if (sizeGripBounds.Contains(PointToClient(new Point(x, y))))
                {
                    IntPtr rootHwnd = User32.GetAncestor(this, User32.GA.ROOT);

                    // if the main window isnt maximized - we should paint a resize grip.
                    // double check that we're at the bottom right hand corner of the window.
                    if (rootHwnd != IntPtr.Zero && !User32.IsZoomed(rootHwnd).IsTrue())
                    {
                        // get the client area of the topmost window.  If we're next to the edge then
                        // the sizing grip is valid.
                        RECT rootHwndClientArea = new RECT();
                        User32.GetClientRect(rootHwnd, ref rootHwndClientArea);

                        // map the size grip FROM statusStrip coords TO the toplevel window coords.
                        Point gripLocation;
                        if (RightToLeft == RightToLeft.Yes)
                        {
                            gripLocation = new Point(SizeGripBounds.Left, SizeGripBounds.Bottom);
                        }
                        else
                        {
                            gripLocation = new Point(SizeGripBounds.Right, SizeGripBounds.Bottom);
                        }
                        User32.MapWindowPoints(new HandleRef(this, Handle), rootHwnd, ref gripLocation, 1);

                        int deltaBottomEdge = Math.Abs(rootHwndClientArea.bottom - gripLocation.Y);
                        int deltaRightEdge = Math.Abs(rootHwndClientArea.right - gripLocation.X);

                        if (RightToLeft != RightToLeft.Yes)
                        {
                            if ((deltaRightEdge + deltaBottomEdge) < 2)
                            {
                                m.Result = (IntPtr)User32.HT.BOTTOMRIGHT;
                                return;
                            }
                        }
                    }
                }
            }
            base.WndProc(ref m);
        }

        // special transparent mirrored window which says it's the bottom left of the form.
        private class RightToLeftLayoutGrip : Control
        {
            public RightToLeftLayoutGrip()
            {
                SetStyle(ControlStyles.SupportsTransparentBackColor, true);
                BackColor = Color.Transparent;
            }
            protected override CreateParams CreateParams
            {
                get
                {
                    CreateParams cp = base.CreateParams;
                    cp.ExStyle |= (int)User32.WS_EX.LAYOUTRTL;
                    return cp;
                }
            }
            protected override void WndProc(ref Message m)
            {
                if (m.Msg == (int)User32.WM.NCHITTEST)
                {
                    int x = PARAM.LOWORD(m.LParam);
                    int y = PARAM.HIWORD(m.LParam);

                    if (ClientRectangle.Contains(PointToClient(new Point(x, y))))
                    {
                        m.Result = (IntPtr)User32.HT.BOTTOMLEFT;
                        return;
                    }
                }
                base.WndProc(ref m);
            }
        }

        internal class StatusStripAccessibleObject : ToolStripAccessibleObject
        {
            public StatusStripAccessibleObject(StatusStrip owner) : base(owner)
            {
            }

            public override AccessibleRole Role
            {
                get
                {
                    AccessibleRole role = Owner.AccessibleRole;
                    if (role != AccessibleRole.Default)
                    {
                        return role;
                    }
                    return AccessibleRole.StatusBar;
                }
            }

            internal override object GetPropertyValue(UiaCore.UIA propertyID)
            {
                if (propertyID == UiaCore.UIA.ControlTypePropertyId)
                {
                    return UiaCore.UIA.StatusBarControlTypeId;
                }

                return base.GetPropertyValue(propertyID);
            }

            internal override UiaCore.IRawElementProviderFragment FragmentNavigate(UiaCore.NavigateDirection direction)
            {
                if (!(Owner is StatusStrip statusStrip) || statusStrip.Items.Count == 0)
                {
                    return null;
                }

                switch (direction)
                {
                    case UiaCore.NavigateDirection.FirstChild:
                        AccessibleObject firstChild = null;
                        for (int i = 0; i < GetChildCount(); i++)
                        {
                            firstChild = GetChild(i);
                            if (firstChild != null && !(firstChild is ControlAccessibleObject))
                            {
                                return firstChild;
                            }
                        }
                        return null;

                    case UiaCore.NavigateDirection.LastChild:
                        AccessibleObject lastChild = null;
                        for (int i = GetChildCount() - 1; i >= 0; i--)
                        {
                            lastChild = GetChild(i);
                            if (lastChild != null && !(lastChild is ControlAccessibleObject))
                            {
                                return lastChild;
                            }
                        }
                        return null;
                }

                return base.FragmentNavigate(direction);
            }

            internal override UiaCore.IRawElementProviderFragment ElementProviderFromPoint(double x, double y)
                => Owner.IsHandleCreated ? HitTest((int)x, (int)y) : null;

            internal override UiaCore.IRawElementProviderFragment GetFocus() => Owner.IsHandleCreated ? GetFocused() : null;
        }
    }
}
