//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//     file="ExpElmentSource.cs"
//     Project: StgSharp
//     AuthorGroup: Nitload Space
//     Copyright (c) Nitload Space. All rights reserved.
//     
//     Permission is hereby granted, free of charge, to any person 
//     obtaining a copy of this software and associated documentation 
//     files (the “Software”), to deal in the Software without restriction, 
//     including without limitation the rights to use, copy, modify, merge,
//     publish, distribute, sublicense, and/or sell copies of the Software, 
//     and to permit persons to whom the Software is furnished to do so, 
//     subject to the following conditions:
//     
//     The above copyright notice and 
//     this permission notice shall be included in all copies 
//     or substantial portions of the Software.
//     
//     THE SOFTWARE IS PROVIDED “AS IS”, 
//     WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
//     INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
//     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
//     IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
//     DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
//     ARISING FROM, OUT OF OR IN CONNECTION WITH 
//     THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//     
//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace StgSharp.Script.Express
{
    public interface IExpElementSource : ITypeSource<IExpElementSource>
    {

        public ExpElementType ElementType { get; }

        IScriptSourceProvider SourceProvider { get; }

        string Name { get; }

        public void Analyse();

        public bool TryGetMember( string name, out ExpNode memberNode );

    }

    public abstract class ExpInstantiableElement : IExpElementSource
    {

        private List<ExpInstantiableElement> _baseList = new List<ExpInstantiableElement>(),
            _derivationList = new List<ExpInstantiableElement>();

        public abstract ExpElementType ElementType { get; }

        public static ExpInstantiableElement Void
        {
            get => ExpVoidElement.Only;
        }

        public abstract IScriptSourceProvider SourceProvider { get; }

        public abstract string Name { get; }

        public abstract void Analyse();

        public abstract ExpNode CreateInstanceNode( Token t );

        public bool IsConvertable( IExpElementSource targetType )
        {
            if( targetType == null ) {
                return false;
            }
            throw new NotImplementedException();
        }

        public static bool IsNullOrVoid( ExpInstantiableElement element )
        {
            return element == null || element == ExpVoidElement.Only;
        }

        public abstract bool TryGetMember( string name, out ExpNode memberNode );

        private sealed class ExpVoidElement : ExpInstantiableElement
        {

            private static readonly ExpVoidElement _only = new ExpVoidElement();

            public override ExpElementType ElementType => ExpElementType.Void;

            public static ExpVoidElement Only => _only;

            public override IScriptSourceProvider SourceProvider => ScriptSourceTransmitter.Empty;

            public override string Name => "void";

            public override void Analyse()
            {
                return;
            }

            public override ExpNode CreateInstanceNode( Token t )
            {
                return ExpNode.Empty;
            }

            public override bool TryGetMember( string name, out ExpNode memberNode )
            {
                memberNode = ExpNode.Empty;
                return false;
            }

        }

    }

    public abstract class ExpImmutableElement : IExpElementSource
    {

        public abstract ExpElementType ElementType { get; }

        public abstract IScriptSourceProvider SourceProvider { get; }

        public abstract string Name { get; }

        public abstract void Analyse();

        public bool IsConvertable( IExpElementSource targetType )
        {
            return false;
        }

        public abstract ExpNode MakeReference( params object[] options );

        public abstract bool TryGetMember( string name, out ExpNode memberNode );

    }
}