using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Xml;

namespace AIPractice.Shared.Labels
{
    public class RootLabel:LabelObject
    {
        private enum ReadingNode
        {
            /// <summary>
            /// 无意义节点
            /// </summary>
            None,
            /// <summary>
            /// 正在读取描述
            /// </summary>
            Descriptions,
            /// <summary>
            /// 正在读取结论
            /// </summary>
            Conclusions,
            /// <summary>
            /// 正在读取关联关系
            /// </summary>
            LabelAssociations
        }

        /// <summary>
        /// Gets all Descriptions belongs to this root label.
        /// </summary>
        public IReadOnlyList<LabelGroup> Descriptions { get; }

        /// <summary>
        /// Gets all conclusions belongs to this root label.
        /// </summary>
        public IReadOnlyList<LabelGroup> Conclusions { get; }

        /// <summary>
        /// Gets or label associations of this root label.
        /// </summary>
        public IReadOnlyList<LabelAssociation> LabelAssociations { get; }

        /// <summary>
        /// Gets or sets if this root label needs the parts conclusion.
        /// </summary>
        public bool NeedPartsConclusion { get; set; }


        public RootLabel(string id, string title, IEnumerable<LabelGroup> descriptions,
            IEnumerable<LabelGroup> conclusions, IEnumerable<LabelAssociation> labelAssociations) : base(id, title)
        {
            Descriptions = new List<LabelGroup>(descriptions);
            Conclusions = new List<LabelGroup>(conclusions);
            LabelAssociations = new List<LabelAssociation>(labelAssociations);
            foreach(var group in Descriptions)
            {
                group.Root = this;
            }
            foreach (var group in Conclusions)
            {
                group.Root = this;
            }
        }


        /// <summary>
        /// Add one group into the descriptions.
        /// </summary>
        /// <param name="group">The group to be added</param>
        public void AddDescriptionGroup(LabelGroup group)
        {
            var groupList = (List<LabelGroup>)Descriptions;
            if (!groupList.Contains(group))
            {
                groupList.Add(group);
                group.Root = this;
            }
        }

        /// <summary>
        /// Remove the group from the descriptions.
        /// </summary>
        /// <param name="group">The group to be removed.</param>
        public void RemoveDescriptionGroup(LabelGroup group)
        {
            var groupList = (List<LabelGroup>)Descriptions;
            if (groupList.Contains(group))
            {
                groupList.Remove(group);
            }
        }

        /// <summary>
        /// Insert one group into the descriptions on given index.
        /// </summary>
        /// <param name="index">The index to be insert.</param>
        /// <param name="group">The group to be added. and the root label will be assigned to the group.</param>
        public void InsertDescriptionGroup(int index, LabelGroup group)
        {
            var groupList = (List<LabelGroup>)Descriptions;
            if (!groupList.Contains(group))
            {
                groupList.Insert(index,group);
                group.Root = this;
            }
        }


        /// <summary>
        /// Add one group into the Conclusions.
        /// </summary>
        /// <param name="group">The group to be added</param>
        public void AddConclusionGroup(LabelGroup group)
        {
            var groupList = (List<LabelGroup>)Conclusions;
            if (!groupList.Contains(group))
            {
                groupList.Add(group);
                group.Root = this;
            }
        }

        /// <summary>
        /// Remove the group from the Conclusions.
        /// </summary>
        /// <param name="group">The group to be removed.</param>
        public void RemoveConclusionGroup(LabelGroup group)
        {
            var groupList = (List<LabelGroup>)Conclusions;
            if (groupList.Contains(group))
            {
                groupList.Remove(group);
            }
        }

        /// <summary>
        /// Insert one group into the Conclusions on given index.
        /// </summary>
        /// <param name="index">The index to be insert.</param>
        /// <param name="group">The group to be added. and the root label will be assigned to the group.</param>
        public void InsertConclusionGroup(int index, LabelGroup group)
        {
            var groupList = (List<LabelGroup>)Conclusions;
            if (!groupList.Contains(group))
            {
                groupList.Insert(index, group);
                group.Root = this;
            }
        }

        /// <summary>
        /// Add one association into the root.
        /// </summary>
        /// <param name="association">The association to be added</param>
        public void AddLabelAssociation(LabelAssociation association)
        {
            var associationList = (List<LabelAssociation>)LabelAssociations;
            var exists = associationList.FirstOrDefault(x => x.Left.Id == association.Left.Id && x.Right.Id == association.Right.Id);
            if (exists == null)
            {
                associationList.Add(association);
            }
        }

        /// <summary>
        /// Remove the association from the root.
        /// </summary>
        /// <param name="association">The association to be removed.</param>
        public void RemoveLabelAssociation(LabelAssociation association)
        {
            var associationList = (List<LabelAssociation>)LabelAssociations;
            var exists = associationList.FirstOrDefault(x => x.Left.Id == association.Left.Id && x.Right.Id == association.Right.Id);
            if (exists != null)
            {
                associationList.Remove(exists);
            }
        }

        /// <summary>
        /// Clear all associations.
        /// </summary>
        public void ClearLabelAssociations()
        {
            var associationList = (List<LabelAssociation>)LabelAssociations;
            associationList.Clear();
        }


        public static RootLabel FromXml(string xmlContent)
        {
            using (var ms = new MemoryStream(Encoding.Unicode.GetBytes(xmlContent)))
            {
                using (XmlReader r = XmlReader.Create(ms))
                {
                    r.Read();
                    var readingNode = ReadingNode.None;
                    var id = r.GetAttribute("id");
                    var title = r.GetAttribute("title");
                    var needPartsConclusionStr = r.GetAttribute("needPartsConclusion");
                    bool.TryParse(needPartsConclusionStr, out bool needPartsConclusion);
                    var descriptions = new List<LabelGroup>();
                    var conclusions = new List<LabelGroup>();
                    var labelAssociations = new List<LabelAssociation>();

                    while (r.NodeType == XmlNodeType.Element && 
                           (r.Name == nameof(SingleSelectionLabelGroup) ||
                            r.Name == nameof(MultiSelectionLabelGroup) ||
                            r.Name == nameof(LabelAssociation)) || r.Read())
                    {
                        if (r.NodeType == XmlNodeType.EndElement && r.Name == nameof(RootLabel))
                        {
                            break;
                        }

                        if (r.NodeType == XmlNodeType.Element && r.Name == nameof(Descriptions))
                        {
                            readingNode = ReadingNode.Descriptions;
                        }
                        if (r.NodeType == XmlNodeType.Element && r.Name == nameof(Conclusions))
                        {
                            readingNode = ReadingNode.Conclusions;
                        }
                        if (r.NodeType == XmlNodeType.Element && r.Name == nameof(LabelAssociations))
                        {
                            readingNode = ReadingNode.LabelAssociations;
                        }

                        if (r.NodeType == XmlNodeType.Element && r.Name == nameof(SingleSelectionLabelGroup))
                        {
                            if (readingNode == ReadingNode.Descriptions)
                            {
                                descriptions.Add(SingleSelectionLabelGroup.FromXml(r.ReadOuterXml()));
                            }
                            else if(readingNode == ReadingNode.Conclusions)
                            {
                                conclusions.Add(SingleSelectionLabelGroup.FromXml(r.ReadOuterXml()));
                            }
                        }

                        if (r.NodeType == XmlNodeType.Element && r.Name == nameof(MultiSelectionLabelGroup))
                        {
                            if (readingNode == ReadingNode.Descriptions)
                            {
                                descriptions.Add(MultiSelectionLabelGroup.FromXml(r.ReadOuterXml()));
                            }
                            else if (readingNode == ReadingNode.Conclusions)
                            {
                                conclusions.Add(MultiSelectionLabelGroup.FromXml(r.ReadOuterXml()));
                            }
                        }

                        if (r.NodeType == XmlNodeType.Element && r.Name == nameof(LabelAssociation))
                        {
                            if (readingNode == ReadingNode.LabelAssociations)
                            {
                                labelAssociations.Add(LabelAssociation.FromXml(r.ReadOuterXml()));
                            }
                        }
                    }
                    return new RootLabel(id, title, descriptions,conclusions, labelAssociations)
                    {
                        NeedPartsConclusion = needPartsConclusion,
                    };
                }
            }
        }

        public override string ToXml()
        {
            var sb = new StringBuilder();
            sb.Append($"<{nameof(RootLabel)} id=\"{Id}\" title=\"{Title}\" needPartsConclusion=\"{NeedPartsConclusion}\">");
            sb.Append($"<{nameof(Descriptions)}>");
            if (Descriptions != null)
            {
                foreach (var description in Descriptions)
                {
                    sb.Append(description.ToXml());
                }
            }

            sb.Append($"</{nameof(Descriptions)}>");

            sb.Append($"<{nameof(Conclusions)}>");
            if (Conclusions != null)
            {
                foreach (var conclusion in Conclusions)
                {
                    sb.Append(conclusion.ToXml());
                }
            }

            sb.Append($"</{nameof(Conclusions)}>");

            sb.Append($"<{nameof(LabelAssociations)}>");
            if (LabelAssociations != null)
            {
                foreach (var labelAssociation in LabelAssociations)
                {
                    sb.Append(labelAssociation.ToXml());
                }
            }
            sb.Append($"</{nameof(LabelAssociations)}>");

            sb.Append($"</{nameof(RootLabel)}>");
            return sb.ToString();
        }
    }
}