//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="StepModel"
// 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.PipeLine;
using StgSharp.Script.Express;

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices.Marshalling;
using System.Text;
using System.Xml.Linq;

namespace StgSharp.Model.Step
{
    public class StepModel
    {

        private Dictionary<int, StepEntityBase> _nodes
            = new Dictionary<int, StepEntityBase>();

        private PipelineScheduler _builder;

        private PipelineScheduler _initScheduler = new PipelineScheduler();
        private StepInfo _header;

        internal StepModel(StepInfo header)
        {
            _header = header;
            _builder = new PipelineScheduler();
        }

        public StepEntityBase? this[int id]
        {
            get
            {
                if (id == 0) {
                    return null;
                }
                if (_nodes.TryGetValue(id, out StepEntityBase? node))
                {
                    if (node is StepUnsupportedEntity) {
                        throw new StepEntityUnsupportedException();
                    }
                    return node;
                }
                node = new StepUninitializedEntity(this, id);
                _nodes.Add(id, node);
                return node;
            }
            private set { _nodes[id] = value!; }
        }

        internal StepEntityBase? this[ExpSyntaxNode node]
        {
            get
            {
                if (node is not StepEntityInstanceNode instance) {
                    throw new InvalidCastException();
                }
                return this[instance.Id];
            }
            set
            {
                if (node is not StepEntityInstanceNode instance) {
                    throw new InvalidCastException();
                }
                this[instance.Id] = value;
            }
        }

        public void BindValue(ExpSyntaxNode node, Action<StepEntityBase> action) { }

        public StepUninitializedEntity FromInitSequence(StepEntityDefineSequence sequence)
        {
            int id = (sequence.Expression.Left as StepEntityInstanceNode)!.Id;
            PipelineNode node;
            if (_nodes.TryGetValue(id, out StepEntityBase? e) && e is StepUninitializedEntity u)
            {
                u.FromSequence(sequence);
                node = _initScheduler.GetNode(u.Label);
            } else
            {
                u = new StepUninitializedEntity(this, id);
                u.FromSequenceUnsafe(sequence);
                _nodes.Add(id, u);
                node = _initScheduler.Create(u.Label, u);
            }

            PipelineNodeInPort port = node.GetInputPort(StepUninitializedEntity.InName);
            if (sequence.Dependencies.Count() == 0)
            {
                _initScheduler.LinkToInput(port);
            } else
            {
                foreach (int i in sequence.Dependencies)
                {
                    PipelineNode dNode;
                    StepEntityLabel label = new StepEntityLabel(i);
                    if (_nodes.TryGetValue(i, out e))
                    {
                        dNode = _initScheduler.GetNode(label);
                    } else
                    {
                        u = new StepUninitializedEntity(this, i);
                        _nodes.Add(i, u);
                        dNode = _initScheduler.Create(u.Label, u);
                    }
                    port.Connect(dNode.GetOutputPort(StepUninitializedEntity.OutName));
                }
            }
            return u;
        }

        public void InitEntity()
        {
            if (_initScheduler is null) {
                return;
            }
            _initScheduler.ArrangeNodes();
            PipeLineRunner.Run(_initScheduler);
            _initScheduler = null!;
        }

        public void ReplaceEntity(StepUninitializedEntity uninitialized, StepEntityBase accurateEntity)
        {
            ArgumentNullException.ThrowIfNull(uninitialized);
            if (uninitialized.Context != this || accurateEntity.Context != this) {
                throw new InvalidOperationException();
            }
            if (uninitialized.Id != accurateEntity.Id) {
                throw new InvalidOperationException();
            }
            _nodes[uninitialized.Id] = accurateEntity;
        }

        public string[] ShowStructure(int depth)
        {
            _initScheduler.ArrangeNodes();
            IEnumerable<PipelineNode> nodes = PipelineMarshal.GetNodeSortedEnumeration(
                _initScheduler);
            int count = 0;
            List<string> info = [ @$"Step model root", ];
            foreach (PipelineNode node in nodes)
            {
                count++;
                StepUninitializedEntity uncertain = (node.NodeOperation as StepUninitializedEntity)!;
                string[] strings = uncertain.GetEntityDescription(depth - 1);
                if (count < nodes.Count())
                {
                    info.Add($"  ├-{strings[0]}");
                    for (int i = 1; i < strings.Length; i++) {
                        info.Add($"  | {strings[i]}");
                    }
                } else
                {
                    info.Add($"  └-{strings[0]}");
                    for (int i = 1; i < strings.Length; i++) {
                        info.Add($"    {strings[i]}");
                    }
                }
            }
            return info.ToArray();
        }

    }
}