//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//     file="StepReader.ToModel.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 StgSharp.Script;
using StgSharp.Script.Express;

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace StgSharp.Model.Step
{
    public partial class StepReader
    {

        private volatile int _version = 0;
        private StepDataTokenReader tokenReader;

        private StepExpSyntaxAnalyzer analyzer;

        private StepModel Model { get; set; }

        private Task<StepModel> ReadToModelTask { get; set; }

        public StepModel ReadToModel()
        {
            if( Model is not null ) {
                return Model;
            }
            if( _version != 0 ) {
                throw new InvalidOperationException(
                    "A ReadToModel method has been called and is running now, use Async version instead" );
            }
            Interlocked.Increment( ref _version );
            GetInfo();
            tokenReader = new StepDataTokenReader( DataTransmitter );
            analyzer = new StepExpSyntaxAnalyzer();
            ConcurrentQueue<StepEntityDefineSequence> initStatements = analyzer.StepEntityInitStatements;
            Task secTask = Task.Run( ReadDataSection );
            Task anTask = Task.Run( ReadStepToken );
            Model = new StepModel( _info );
            while( initStatements.TryDequeue( out StepEntityDefineSequence? statement ) ||
                   !anTask.IsCompleted )
            {
                if( statement is null )
                {
                    Thread.Sleep( 0 );
                    continue;
                }
                StepUninitializedEntity entity = Model.FromInitSequence( statement );
            }
            Task.WaitAll( secTask, anTask );
            return Model;
        }

        public async Task<StepModel> ReadToModelAsync()
        {
            if( ReadToModelTask is null ) {
                ReadToModelTask = Task.Run( ReadToModel );
            }
            return await ReadToModelTask;
        }

        public StepModel ReadToModelSingleThread()
        {
            if( Model is not null ) {
                return Model;
            }
            if( _version != 0 ) {
                throw new InvalidOperationException(
                    "A ReadToModel method has been called and is running now, use Async version instead" );
            }
            Interlocked.Increment( ref _version );
            GetInfo();
            tokenReader = new StepDataTokenReader( DataTransmitter );
            analyzer = new StepExpSyntaxAnalyzer();
            ConcurrentQueue<StepEntityDefineSequence> initStatements = analyzer.StepEntityInitStatements;
            ReadDataSection();
            ReadStepToken();
            Model = new StepModel( _info );
            while( initStatements.TryDequeue( out StepEntityDefineSequence? statement ) )
            {
                if( statement is null )
                {
                    Thread.Sleep( 0 );
                    continue;
                }
                StepUninitializedEntity entity = Model.FromInitSequence( statement );
            }
            return Model;
        }

        private void ReadStepToken()
        {
            while( !tokenReader.IsEmpty )
            {
                Token t = tokenReader.ReadToken();
                analyzer.AppendToken( t );
            }
        }

    }
}