// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using Windows.Win32.System.Com;
using Windows.Win32.System.Variant;
using Windows.Win32.UI.Accessibility;
 
namespace System.Windows.Forms;
 
internal unsafe class LabelEditAccessibleObject : AccessibleObject
{
    private readonly WeakReference<LabelEditNativeWindow> _labelEdit;
    private readonly LabelEditUiaTextProvider _textProvider;
    private int[]? _runtimeId;
 
    public LabelEditAccessibleObject(Control owningControl, LabelEditNativeWindow labelEdit)
    {
        ArgumentNullException.ThrowIfNull(owningControl);
 
        _labelEdit = new(labelEdit);
        UseStdAccessibleObjects(labelEdit.Handle);
        _textProvider = new(owningControl, labelEdit, this);
    }
 
    internal override IRawElementProviderFragment.Interface? FragmentNavigate(NavigateDirection direction)
        => direction switch
        {
            NavigateDirection.NavigateDirection_Parent => Parent,
            _ => base.FragmentNavigate(direction)
        };
 
    internal override VARIANT GetPropertyValue(UIA_PROPERTY_ID propertyID)
        => propertyID switch
        {
            UIA_PROPERTY_ID.UIA_ProcessIdPropertyId => (VARIANT)Environment.ProcessId,
            UIA_PROPERTY_ID.UIA_ControlTypePropertyId => (VARIANT)(int)UIA_CONTROLTYPE_ID.UIA_EditControlTypeId,
            UIA_PROPERTY_ID.UIA_AccessKeyPropertyId => (VARIANT)string.Empty,
            UIA_PROPERTY_ID.UIA_HasKeyboardFocusPropertyId => VARIANT.True,
            UIA_PROPERTY_ID.UIA_IsKeyboardFocusablePropertyId => (VARIANT)State.HasFlag(AccessibleStates.Focusable),
            UIA_PROPERTY_ID.UIA_IsContentElementPropertyId => VARIANT.True,
            UIA_PROPERTY_ID.UIA_NativeWindowHandlePropertyId => UIAHelper.WindowHandleToVariant(_labelEdit.TryGetTarget(out var target) ? target.HWND : HWND.Null),
            _ => base.GetPropertyValue(propertyID),
        };
 
    internal override IRawElementProviderSimple* HostRawElementProvider
    {
        get
        {
            if (_labelEdit.TryGetTarget(out var target))
            {
                PInvoke.UiaHostProviderFromHwnd(target.HWND, out IRawElementProviderSimple* provider);
                return provider;
            }
 
            return null;
        }
    }
 
    internal override bool IsPatternSupported(UIA_PATTERN_ID patternId) => patternId switch
    {
        UIA_PATTERN_ID.UIA_TextPatternId => true,
        UIA_PATTERN_ID.UIA_TextPattern2Id => true,
        UIA_PATTERN_ID.UIA_ValuePatternId => true,
        UIA_PATTERN_ID.UIA_LegacyIAccessiblePatternId => true,
        _ => base.IsPatternSupported(patternId),
    };
 
    public override string? Name => _labelEdit.TryGetTarget(out var target)
        ? PInvoke.GetWindowText(target)
        : null;
 
    private protected override bool IsInternal => true;
 
    internal override bool CanGetNameInternal => false;
 
    internal override int[] RuntimeId => _runtimeId ??=
    [
        RuntimeIDFirstItem,
        _labelEdit.TryGetTarget(out var target) ? (int)target.HWND : (int)HWND.Null
    ];
 
    internal override ITextRangeProvider* DocumentRangeInternal
        => _textProvider.DocumentRange;
 
    internal override HRESULT GetTextSelection(SAFEARRAY** pRetVal)
        => _textProvider.GetSelection(pRetVal);
 
    internal override HRESULT GetTextVisibleRanges(SAFEARRAY** pRetVal)
        => _textProvider.GetVisibleRanges(pRetVal);
 
    internal override HRESULT GetTextRangeFromChild(IRawElementProviderSimple* childElement, ITextRangeProvider** pRetVal)
        => _textProvider.RangeFromChild(childElement, pRetVal);
 
    internal override HRESULT GetTextRangeFromPoint(UiaPoint screenLocation, ITextRangeProvider** pRetVal)
        => _textProvider.RangeFromPoint(screenLocation, pRetVal);
 
    internal override SupportedTextSelection SupportedTextSelectionInternal
        => _textProvider.SupportedTextSelection;
 
    internal override HRESULT GetTextCaretRange(BOOL* isActive, ITextRangeProvider** pRetVal)
        => _textProvider.GetCaretRange(isActive, pRetVal);
 
    internal override HRESULT GetRangeFromAnnotation(IRawElementProviderSimple* annotationElement, ITextRangeProvider** pRetVal)
        => _textProvider.RangeFromAnnotation(annotationElement, pRetVal);
}