// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
#nullable disable
 
using System.Collections;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Drawing.Design;
 
namespace System.Windows.Forms.Design;
 
/// <summary>
///  Class for sharing code for launching the ToolStripItemsCollectionEditor from a verb.
///  This class implements the IWindowsFormsEditorService and ITypeDescriptorContext to display the dialog.
/// </summary>
internal class CollectionEditVerbManager : IWindowsFormsEditorService, ITypeDescriptorContext
{
    private readonly ComponentDesigner _designer;
    private IComponentChangeService _componentChangeService;
    private readonly PropertyDescriptor _targetProperty;
    private readonly DesignerVerb _editItemsVerb;
 
    /// <summary>
    ///  Create one of these things...
    /// </summary>
    internal CollectionEditVerbManager(string text, ComponentDesigner designer, PropertyDescriptor prop, bool addToDesignerVerbs)
    {
        Debug.Assert(designer is not null, "Can't have a CollectionEditVerbManager without an associated designer");
        _designer = designer;
        _targetProperty = prop;
        if (prop is null)
        {
            prop = TypeDescriptor.GetDefaultProperty(designer.Component);
            if (prop is not null && typeof(ICollection).IsAssignableFrom(prop.PropertyType))
            {
                _targetProperty = prop;
            }
        }
 
        Debug.Assert(_targetProperty is not null, "Need PropertyDescriptor for ICollection property to associate collection editor with.");
        text ??= SR.ToolStripItemCollectionEditorVerb;
 
        _editItemsVerb = new DesignerVerb(text, new EventHandler(OnEditItems));
 
        if (addToDesignerVerbs)
        {
            _designer.Verbs.Add(_editItemsVerb);
        }
    }
 
    /// <summary>
    ///  Our caching property for the IComponentChangeService
    /// </summary>
    private IComponentChangeService ChangeService
    {
        get
        {
            _componentChangeService ??= this.GetService<IComponentChangeService>();
 
            return _componentChangeService;
        }
    }
 
    /// <summary>
    ///  Self-explanitory interface impl.
    /// </summary>
    IContainer ITypeDescriptorContext.Container
    {
        get
        {
            if (_designer.Component.Site is not null)
            {
                return _designer.Component.Site.Container;
            }
 
            return null;
        }
    }
 
    public DesignerVerb EditItemsVerb
    {
        get => _editItemsVerb;
    }
 
    /// <summary>
    ///  Self-explanitory interface impl.
    /// </summary>
    void ITypeDescriptorContext.OnComponentChanged() => ChangeService.OnComponentChanged(_designer.Component, _targetProperty);
 
    /// <summary>
    ///  Self-explanitory interface impl.
    /// </summary>
    bool ITypeDescriptorContext.OnComponentChanging()
    {
        try
        {
            ChangeService.OnComponentChanging(_designer.Component, _targetProperty);
        }
        catch (CheckoutException checkoutException)
        {
            if (checkoutException == CheckoutException.Canceled)
            {
                return false;
            }
 
            throw;
        }
 
        return true;
    }
 
    /// <summary>
    ///  Self-explanitory interface impl.
    /// </summary>
    object ITypeDescriptorContext.Instance
    {
        get => _designer.Component;
    }
 
    /// <summary>
    ///  Self-explanitory interface impl.
    /// </summary>
    PropertyDescriptor ITypeDescriptorContext.PropertyDescriptor
    {
        get => _targetProperty;
    }
 
    /// <summary>
    ///  Self-explanitory interface impl.
    /// </summary>
    object IServiceProvider.GetService(Type serviceType)
    {
        if (serviceType == typeof(ITypeDescriptorContext) || serviceType == typeof(IWindowsFormsEditorService))
        {
            return this;
        }
 
        if (_designer.Component.Site is not null)
        {
            return _designer.Component.Site.GetService(serviceType);
        }
 
        return null;
    }
 
    /// <summary>
    ///  Self-explanitory interface impl.
    /// </summary>
    void IWindowsFormsEditorService.CloseDropDown()
    {
        // we'll never be called to do this.
        Debug.Fail("NOTIMPL");
        return;
    }
 
    /// <summary>
    ///  Self-explanitory interface impl.
    /// </summary>
    void IWindowsFormsEditorService.DropDownControl(Control control)
    {
        Debug.Fail("NOTIMPL");
        return;
    }
 
    /// <summary>
    ///  Self-explanitory interface impl.
    /// </summary>
    DialogResult IWindowsFormsEditorService.ShowDialog(Form dialog)
    {
        IUIService uiSvc = (IUIService)((IServiceProvider)this).GetService(typeof(IUIService));
        if (uiSvc is not null)
        {
            return uiSvc.ShowDialog(dialog);
        }
        else
        {
            return dialog.ShowDialog(_designer.Component as IWin32Window);
        }
    }
 
    /// <summary>
    ///  When the verb is invoked, use all the stuff above to show the dialog, etc.
    /// </summary>
    private void OnEditItems(object sender, EventArgs e)
    {
        DesignerActionUIService actionUIService = (DesignerActionUIService)((IServiceProvider)this).GetService(typeof(DesignerActionUIService));
        actionUIService?.HideUI(_designer.Component);
 
        object propertyValue = _targetProperty.GetValue(_designer.Component);
        if (propertyValue is null)
        {
            return;
        }
 
        CollectionEditor itemsEditor = TypeDescriptor.GetEditor(propertyValue, typeof(UITypeEditor)) as CollectionEditor;
        Debug.Assert(itemsEditor is not null, $"Didn't get a collection editor for type '{_targetProperty.PropertyType.FullName}'");
        itemsEditor?.EditValue(this, this, propertyValue);
    }
}