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

using System.Runtime.InteropServices;

namespace System.Speech.Internal.SapiInterop
{
    internal class SapiGrammar : IDisposable
    {
        #region Constructors

        internal SapiGrammar(ISpRecoGrammar sapiGrammar, SapiProxy thread)
        {
            _sapiGrammar = sapiGrammar;
            _sapiProxy = thread;
        }

        public void Dispose()
        {
            if (!_disposed)
            {
                Marshal.ReleaseComObject(_sapiGrammar);
                GC.SuppressFinalize(this);
                _disposed = true;
            }
        }

        #endregion

        #region Internal Methods

        internal void SetGrammarState(SPGRAMMARSTATE state)
        {
            _sapiProxy.Invoke2(delegate { _sapiGrammar.SetGrammarState(state); });
        }

        internal void SetWordSequenceData(string text, SPTEXTSELECTIONINFO info)
        {
            SPTEXTSELECTIONINFO selectionInfo = info;
            _sapiProxy.Invoke2(delegate { _sapiGrammar.SetWordSequenceData(text, (uint)text.Length, ref selectionInfo); });
        }

        internal void LoadCmdFromMemory(IntPtr grammar, SPLOADOPTIONS options)
        {
            _sapiProxy.Invoke2(delegate { _sapiGrammar.LoadCmdFromMemory(grammar, options); });
        }

        internal void LoadDictation(string? pszTopicName, SPLOADOPTIONS options)
        {
            _sapiProxy.Invoke2(delegate { _sapiGrammar.LoadDictation(pszTopicName, options); });
        }

        internal SAPIErrorCodes SetDictationState(SPRULESTATE state)
        {
            return (SAPIErrorCodes)_sapiProxy.Invoke(delegate { return _sapiGrammar.SetDictationState(state); })!;
        }

        internal SAPIErrorCodes SetRuleState(string? name, SPRULESTATE state)
        {
            return (SAPIErrorCodes)_sapiProxy.Invoke(delegate { return _sapiGrammar.SetRuleState(name, IntPtr.Zero, state); })!;
        }

        /*
         * The Set of methods are only available with SAPI 5.3. There is no need then to use the SAPI proxy to switch
         * the call to an MTA thread.
         *
         */
        internal void SetGrammarLoader(ISpGrammarResourceLoader resourceLoader)
        {
            SpRecoGrammar2.SetGrammarLoader(resourceLoader);
        }

        internal void LoadCmdFromMemory2(IntPtr grammar, SPLOADOPTIONS options, string? sharingUri, string? baseUri)
        {
            SpRecoGrammar2.LoadCmdFromMemory2(grammar, options, sharingUri, baseUri);
        }

        internal void SetRulePriority(string? name, uint id, int priority)
        {
            SpRecoGrammar2.SetRulePriority(name, id, priority);
        }
        internal void SetRuleWeight(string? name, uint id, float weight)
        {
            SpRecoGrammar2.SetRuleWeight(name, id, weight);
        }
        internal void SetDictationWeight(float weight)
        {
            SpRecoGrammar2.SetDictationWeight(weight);
        }

        #endregion

        #region Internal Properties

        internal ISpRecoGrammar2 SpRecoGrammar2 =>
            _sapiGrammar2 ??= (ISpRecoGrammar2)_sapiGrammar;

        #endregion

        #region Private Methods

        private ISpRecoGrammar2? _sapiGrammar2;
        private ISpRecoGrammar _sapiGrammar;
        private SapiProxy _sapiProxy;
        private bool _disposed;

        #endregion
    }
}