//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="ExpSyntaxAnalyzer"
// 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 Microsoft.CodeAnalysis.CSharp.Syntax;

using StgSharp.Threading;

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO.Pipes;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using ExpKeyword = StgSharp.Script.Express.ExpressCompile.Keyword;

namespace StgSharp.Script.Express
{
    public partial class ExpSyntaxAnalyzer : ISyntaxAnalyzer
    {

        private const int EndLine = 1;
        private const int TokenGenerated = 0;
        private const int TokenTypeNotMatch = -1;

        private CompileStack<ExpSyntaxNode, IExpElementSource> _cache;
        private ExpSchema _context;
        private ExpSyntaxNode _lastStatement;
        private IExpElementSource _local;

        public ExpSyntaxAnalyzer()
        {
            _cache = new CompileStack<ExpSyntaxNode, IExpElementSource>();
        }

        public ExpSyntaxAnalyzer(ExpSchema context, IExpElementSource local)
        {
            _cache = new CompileStack<ExpSyntaxNode, IExpElementSource>();
            ArgumentNullException.ThrowIfNull(context);
            if (context is not ExpSchema_Builtin)
            {
                _context = context;
            } else
            {
                throw new InvalidCastException("Not a valid Schema type");
            }
            _local = local;
        }

        /**/
        public void AppendToken(Token expToken)
        {
            switch ((ExpCompileStateCode)TryEnterBranch(expToken).Usage)
            {
                case ExpCompileStateCode.IfBranch:
                    AppendToken_IfBranch(expToken);
                    break;
                case ExpCompileStateCode.CaseBranch:
                    AppendToken_CaseOf(expToken);
                    break;
                case ExpCompileStateCode.RepeatLoop:
                    AppendToken_RepeatLoop(expToken);
                    break;
                default:
                    AppendToken_Common(expToken);
                    break;
            }
        }

        public ExpSyntaxNode GetNextOperandCache()
        {
            if (_cache.PopOperand(out Token t, out ExpSyntaxNode? n))
            {
                return n;
            } else
            {
                // process some rare case here
            }

            throw new NotImplementedException();
        }

        /// <summary>
        ///   Append a token to top of cache. This method will automatically convert token to node
        ///   if meets separators or operators.
        /// </summary>
        private void AppendToken_Common(Token expToken)
        {
            switch (expToken.Flag)
            {
                case TokenFlag.Symbol_Unary or TokenFlag.Symbol_Binary:
                    TryAppendSymbol(expToken);
                    break;
                case TokenFlag.Number or TokenFlag.String:
                    ExpElementInstance node = ExpElementInstance.CreateLiteral(expToken);
                    _cache.PushOperand(node);
                    break;
                case TokenFlag.Separator_Left:
                    TryAppendPrefixSeparator(expToken);
                    break;
                case TokenFlag.Separator_Right:
                    TryAppendPrefixSeparatorEnd(expToken);
                    break;
                case TokenFlag.Separator_Middle:
                    TryAppendMiddleSeparator(expToken);
                    break;
                case TokenFlag.Index_Left:
                    TryAppendIndexLeft(expToken);
                    break;
                case TokenFlag.Index_Right:
                    TryAppendIndexRight(expToken);
                    break;
                case TokenFlag.Member:
                    TryAppendMember(expToken);
                    break;
                default:
                    break;
            }
        }

        private CompileDepthMark TryEnterBranch(Token t)
        {
            if (t.Flag == TokenFlag.String) {
                return _cache.CurrentDepthMark;
            }
            switch (t.Value)
            {
                case ExpKeyword.Case:
                    return _cache.IncreaseDepth((int)ExpCompileStateCode.CaseBranch);
                case ExpKeyword.If:
                    return _cache.IncreaseDepth((int)ExpCompileStateCode.IfBranch);
                case ExpKeyword.Repeat:
                    return _cache.IncreaseDepth((int)ExpCompileStateCode.RepeatLoop);
                default:
                    return _cache.CurrentDepthMark;
            }
        }

        /**/

        public enum ExpCompileStateCode
        {

            Common,
            ForLoop,
            RepeatLoop,
            UntilLoop,
            IfBranch,
            CaseBranch,
            CollectionIndex,

        }

    }
}