//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="_ExpNode"
// 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 CommunityToolkit.HighPerformance.Buffers;

using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;

namespace StgSharp.Script.Express
{
    public abstract class ExpSyntaxNode : ISyntaxNode<ExpSyntaxNode, IExpElementSource>
    {

        protected internal ExpNodeFlag _nodeFlag;
        protected internal Token _source;

        protected ExpSyntaxNode(Token source)
        {
            _source = source;
            Next = this;
            Previous = this;
        }

        public bool IsNumber
        {
            get { return (_nodeFlag | ExpNodeFlag.BuiltinType_Number) != 0; }
        }

        public abstract ExpSyntaxNode Left { get; }

        public static ExpSyntaxNode Empty
        {
            get => ExpEmptyNode._only;
        }

        public ExpSyntaxNode Next { get; set; }

        public abstract ExpSyntaxNode Right { get; }

        public ExpSyntaxNode Previous { get; set; }

        public abstract IExpElementSource EqualityTypeConvert { get; }

        public int Line => _source.Line;

        public int Column => _source.Column;

        public long NodeFlag => (long)_nodeFlag;

        public string CodeConvertTemplate { get; init; }

        public Token Source
        {
            get => _source;
        }

        public void AppendNode(ExpSyntaxNode nextNode)
        {
            Next.Previous = nextNode;
            nextNode.Next = Next;
            Next = nextNode;
            Next.Previous = this;
        }

        public static bool IsNullOrEmpty([AllowNull]ExpSyntaxNode node)
        {
            return  node == ExpEmptyNode._only || node == null;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static ExpSyntaxNode NonOperation(Token source)
        {
            return new ExpEmptyNode(source.Line, source.Column);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static ExpSyntaxNode NonOperation(int line, int column)
        {
            return new ExpEmptyNode(line, column);
        }

        public void PrependNode(ExpSyntaxNode previousNode)
        {
            Previous.Next = previousNode;
            previousNode.Previous = Previous;
            Previous = previousNode;
            previousNode.Next = this;
        }

        public static bool VerifyTypeConvertable(ExpSyntaxNode left, ExpSyntaxNode right)
        {
            IExpElementSource tLeft = left.EqualityTypeConvert,
                tRight = right.EqualityTypeConvert;
            if (tLeft is not ExpInstantiableElement tLeftIns || tRight is not ExpInstantiableElement tRightIns) {
                return false;
            }
            if (ExpInstantiableElement.IsNullOrVoid(tLeftIns) || ExpInstantiableElement.IsNullOrVoid(tLeftIns)) {
                return false;
            }
            return tLeft.IsConvertable(tRight);
        }

        private class ExpEmptyNode : ExpSyntaxNode
        {

            internal static readonly ExpEmptyNode _only = new();

            public ExpEmptyNode() : base(Token.Empty) { }

            public ExpEmptyNode(int line, int column) : base(new Token(string.Empty, line, column, TokenFlag.None)) { }

            public override ExpInstantiableElement EqualityTypeConvert => ExpInstantiableElement.Void;

            public override ExpSyntaxNode Left => _only;

            public override ExpSyntaxNode Right => _only;

        }

    }
}