// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms.Design;

namespace System.Windows.Forms;

/// <summary>
///  A non selectable ToolStrip item
/// </summary>
[ToolStripItemDesignerAvailability(ToolStripItemDesignerAvailability.ToolStrip)]
public partial class ToolStripLabel : ToolStripItem
{
    private LinkBehavior _linkBehavior = LinkBehavior.SystemDefault;
    private bool _isLink;
    private bool _linkVisited;

    private Color _linkColor = Color.Empty;
    private Color _activeLinkColor = Color.Empty;
    private Color _visitedLinkColor = Color.Empty;
    private Font? _hoverLinkFont;
    private Font? _linkFont;
    private Cursor? _lastCursor;

    /// <summary>
    ///  A non selectable ToolStrip item
    /// </summary>
    public ToolStripLabel()
    {
    }

    public ToolStripLabel(string? text)
        : base(text, image: null, onClick: null)
    {
    }

    public ToolStripLabel(Image? image)
        : base(text: null, image, onClick: null)
    {
    }

    public ToolStripLabel(string? text, Image? image)
        : base(text, image, onClick: null)
    {
    }

    public ToolStripLabel(string? text, Image? image, bool isLink)
        : this(text, image, isLink, onClick: null)
    {
    }

    public ToolStripLabel(string? text, Image? image, bool isLink, EventHandler? onClick)
        : this(text, image, isLink, onClick, name: null)
    {
    }

    public ToolStripLabel(string? text, Image? image, bool isLink, EventHandler? onClick, string? name)
        : base(text, image, onClick, name)
    {
        IsLink = isLink;
    }

    public override bool CanSelect
    {
        get { return (IsLink || DesignMode); }
    }

    [DefaultValue(false)]
    [SRCategory(nameof(SR.CatBehavior))]
    [SRDescription(nameof(SR.ToolStripLabelIsLinkDescr))]
    public bool IsLink
    {
        get
        {
            return _isLink;
        }
        set
        {
            if (_isLink != value)
            {
                _isLink = value;
                Invalidate();
            }
        }
    }

    [SRCategory(nameof(SR.CatAppearance))]
    [SRDescription(nameof(SR.ToolStripLabelActiveLinkColorDescr))]
    public Color ActiveLinkColor
    {
        get
        {
            if (_activeLinkColor.IsEmpty)
            {
                return IEActiveLinkColor;
            }
            else
            {
                return _activeLinkColor;
            }
        }
        set
        {
            if (_activeLinkColor != value)
            {
                _activeLinkColor = value;
                Invalidate();
            }
        }
    }

    private static Color IELinkColor
    {
        get
        {
            return LinkUtilities.IELinkColor;
        }
    }

    private static Color IEActiveLinkColor
    {
        get
        {
            return LinkUtilities.IEActiveLinkColor;
        }
    }

    private static Color IEVisitedLinkColor
    {
        get
        {
            return LinkUtilities.IEVisitedLinkColor;
        }
    }

    [DefaultValue(LinkBehavior.SystemDefault)]
    [SRCategory(nameof(SR.CatBehavior))]
    [SRDescription(nameof(SR.ToolStripLabelLinkBehaviorDescr))]
    public LinkBehavior LinkBehavior
    {
        get
        {
            return _linkBehavior;
        }
        set
        {
            // valid values are 0x0 to 0x3
            SourceGenerated.EnumValidator.Validate(value);
            if (_linkBehavior != value)
            {
                _linkBehavior = value;
                InvalidateLinkFonts();
                Invalidate();
            }
        }
    }

    [SRCategory(nameof(SR.CatAppearance))]
    [SRDescription(nameof(SR.ToolStripLabelLinkColorDescr))]
    public Color LinkColor
    {
        get
        {
            if (_linkColor.IsEmpty)
            {
                return IELinkColor;
            }
            else
            {
                return _linkColor;
            }
        }
        set
        {
            if (_linkColor != value)
            {
                _linkColor = value;
                Invalidate();
            }
        }
    }

    [DefaultValue(false)]
    [SRCategory(nameof(SR.CatAppearance))]
    [SRDescription(nameof(SR.ToolStripLabelLinkVisitedDescr))]
    public bool LinkVisited
    {
        get
        {
            return _linkVisited;
        }
        set
        {
            if (_linkVisited != value)
            {
                _linkVisited = value;
                Invalidate();
            }
        }
    }

    [SRCategory(nameof(SR.CatAppearance))]
    [SRDescription(nameof(SR.ToolStripLabelVisitedLinkColorDescr))]
    public Color VisitedLinkColor
    {
        get
        {
            if (_visitedLinkColor.IsEmpty)
            {
                return IEVisitedLinkColor;
            }
            else
            {
                return _visitedLinkColor;
            }
        }
        set
        {
            if (_visitedLinkColor != value)
            {
                _visitedLinkColor = value;
                Invalidate();
            }
        }
    }

    /// <summary>
    ///  Invalidates the current set of fonts we use when painting
    ///  links. The fonts will be recreated when needed.
    /// </summary>
    private void InvalidateLinkFonts()
    {
        _linkFont?.Dispose();

        if (_hoverLinkFont is not null && _hoverLinkFont != _linkFont)
        {
            _hoverLinkFont.Dispose();
        }

        _linkFont = null;
        _hoverLinkFont = null;
    }

    protected override void OnFontChanged(EventArgs e)
    {
        InvalidateLinkFonts();
        base.OnFontChanged(e);
    }

    protected override void OnMouseEnter(EventArgs e)
    {
        if (IsLink)
        {
            ToolStrip? parent = Parent;
            if (parent is not null)
            {
                _lastCursor = parent.Cursor;
                parent.Cursor = Cursors.Hand;
            }
        }

        base.OnMouseEnter(e);
    }

    protected override void OnMouseLeave(EventArgs e)
    {
        if (IsLink)
        {
            ToolStrip? parent = Parent;
            parent?.Cursor = _lastCursor;
        }

        base.OnMouseLeave(e);
    }

    private void ResetActiveLinkColor()
    {
        ActiveLinkColor = IEActiveLinkColor;
    }

    private void ResetLinkColor()
    {
        LinkColor = IELinkColor;
    }

    private void ResetVisitedLinkColor()
    {
        VisitedLinkColor = IEVisitedLinkColor;
    }

    [EditorBrowsable(EditorBrowsableState.Never)]
    private bool ShouldSerializeActiveLinkColor()
    {
        return !_activeLinkColor.IsEmpty;
    }

    [EditorBrowsable(EditorBrowsableState.Never)]
    private bool ShouldSerializeLinkColor()
    {
        return !_linkColor.IsEmpty;
    }

    [EditorBrowsable(EditorBrowsableState.Never)]
    private bool ShouldSerializeVisitedLinkColor()
    {
        return !_visitedLinkColor.IsEmpty;
    }

    /// <summary>
    ///  Creates an instance of the object that defines how image and text
    ///  gets laid out in the ToolStripItem
    /// </summary>
    private protected override ToolStripItemInternalLayout CreateInternalLayout()
    {
        return new ToolStripLabelLayout(this);
    }

    [EditorBrowsable(EditorBrowsableState.Advanced)]
    protected override AccessibleObject CreateAccessibilityInstance()
    {
        return new ToolStripLabelAccessibleObject(this);
    }

    /// <summary>
    ///  Inheriting classes should override this method to handle this event.
    /// </summary>
    protected override void OnPaint(PaintEventArgs e)
    {
        if (Owner is not null)
        {
            ToolStripRenderer renderer = Renderer!;

            renderer.DrawLabelBackground(new ToolStripItemRenderEventArgs(e.Graphics, this));

            if ((DisplayStyle & ToolStripItemDisplayStyle.Image) == ToolStripItemDisplayStyle.Image)
            {
                renderer.DrawItemImage(new ToolStripItemImageRenderEventArgs(e.Graphics, this, InternalLayout.ImageRectangle));
            }

            PaintText(e.Graphics);
        }
    }

    internal void PaintText(Graphics g)
    {
        ToolStripRenderer renderer = Renderer!;

        if ((DisplayStyle & ToolStripItemDisplayStyle.Text) == ToolStripItemDisplayStyle.Text)
        {
            Font font = Font;
            Color textColor = ForeColor;
            if (IsLink)
            {
                LinkUtilities.EnsureLinkFonts(font, LinkBehavior, ref _linkFont, ref _hoverLinkFont);

                if (Pressed)
                {
                    font = _hoverLinkFont;
                    textColor = ActiveLinkColor;
                }
                else if (Selected)
                {
                    font = _hoverLinkFont;
                    textColor = (LinkVisited) ? VisitedLinkColor : LinkColor;
                }
                else
                {
                    font = _linkFont;
                    textColor = (LinkVisited) ? VisitedLinkColor : LinkColor;
                }
            }

            Rectangle textRect = InternalLayout.TextRectangle;
            renderer.DrawItemText(new ToolStripItemTextRenderEventArgs(g, this, Text, textRect, textColor, font, InternalLayout.TextFormat));
        }
    }

    protected internal override bool ProcessMnemonic(char charCode)
    {
        // checking IsMnemonic is not necessary - toolstrip does this for us.
        if (ParentInternal is not null)
        {
            if (!CanSelect)
            {
                ParentInternal.SetFocusUnsafe();
                ParentInternal.SelectNextToolStripItem(this, forward: true);
            }
            else
            {
                FireEvent(ToolStripItemEventType.Click);
            }

            return true;
        }

        return false;
    }
}
