// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
namespace System.Windows.Input
{
    /// <summary>
    ///     The object which input providers use to report input to the input
    ///     manager.
    /// </summary>
    internal class InputProviderSite : IDisposable
    {
        internal InputProviderSite(InputManager inputManager, IInputProvider inputProvider)
        {
            _inputManager = inputManager;
            _inputProvider = inputProvider;
        }
 
        /// <summary>
        ///     Returns the input manager that this site is attached to.
        /// </summary>
        public InputManager InputManager
        {
            get
            {
                return CriticalInputManager;
            }
        }
 
        /// <summary>
        ///     Returns the input manager that this site is attached to.
        /// </summary>
        internal InputManager CriticalInputManager => _inputManager;
 
        /// <summary>
        ///     Unregisters this input provider.
        /// </summary>
        public void Dispose()
        {
            GC.SuppressFinalize(this);
            if (!_isDisposed)
            {
                _isDisposed = true;
 
                if (_inputManager is not null && _inputProvider is not null)
                {
                    _inputManager.UnregisterInputProvider(_inputProvider);
                }
 
                _inputManager = null;
                _inputProvider = null;
            }
        }
 
        /// <summary>
        /// Returns true if the CompositionTarget is disposed.
        /// </summary>
        public bool IsDisposed
        {
            get
            {
                return _isDisposed;
            }
        }
 
        /// <summary>
        ///     Reports input to the input manager.
        /// </summary>
        /// <returns>
        ///     Whether or not any event generated as a consequence of this
        ///     event was handled.
        /// </returns>
        /// <remarks>
        ///  Do we really need this?  Make the "providers" call InputManager.ProcessInput themselves.
        ///  we currently need to map back to providers for other reasons.
        /// </remarks>
        public bool ReportInput(InputReport inputReport)
        {
            if(IsDisposed)
            {
                throw new ObjectDisposedException(SR.InputProviderSiteDisposed);
            }
 
            bool handled = false;
 
            InputReportEventArgs input = new InputReportEventArgs(null, inputReport)
            {
                RoutedEvent = InputManager.PreviewInputReportEvent
            };
 
            if (_inputManager is not null)
            {
                handled = _inputManager.ProcessInput(input);
            }
 
            return handled;
        }
 
        private bool _isDisposed;
        private InputManager _inputManager;
        private IInputProvider _inputProvider;
    }
}