using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

namespace InABox.Core
{
    // Equivalent to DataColumn

    [Serializable]
    public class CoreColumn
    {
        public CoreColumn()
        {
            DataType = typeof(object);
        }
        public CoreColumn(string columnName) : this(typeof(object), columnName) { }

        public CoreColumn(Type dataType, string columnName)
        {
            DataType = dataType;
            ColumnName = columnName;
        }

        public Type DataType { get; set; }

        public string ColumnName { get; set; }

        public override string ToString()
        {
            return string.Format("{0} ({1})", ColumnName, DataType.EntityName().Split('.').Last());
        }

    }

    [Serializable]
    public class CoreRow : ICoreRow
    {
        #region Fields

        [NonSerialized]
        private static Dictionary<int, string> _accessedcolumns = new Dictionary<int, string>();

        [NonSerialized]
        private Dictionary<string, int> _columnindexes = new Dictionary<string, int>();

        #endregion

        #region Properties

        [DoNotSerialize]
        [field: NonSerialized]
        public CoreTable Table { get; private set; }
        public List<object?> Values { get; private set; }

        [DoNotSerialize]
        public int Index => Table.Rows.IndexOf(this);

        #endregion

        protected internal CoreRow(CoreTable owner)
        {
            Table = owner;
            Values = new List<object?>();
        }

        public static CoreRow[] None
        {
            get { return new CoreRow[] { }; }
        }

        //private DynamicObject rowObject;

        public Dictionary<string, object> ToDictionary(string[] exclude)
        {
            var result = new Dictionary<string, object>();
            foreach (var column in Table.Columns.Where(x => !exclude.Contains(x.ColumnName)))
                result[column.ColumnName] = this[column.ColumnName];
            return result;
        }

        [DoNotSerialize]
        public object? this[string columnName]
        {
            get =>
                //return this.RowObject.GetValue<object>(columnName);
                Get<object>(columnName);
            set =>
                //this.RowObject.SetValue(columnName, value);
                Set(columnName, value);
        }

        public BaseObject ToObject(Type t)
        {
            var entity = (Activator.CreateInstance(t) as BaseObject)!;
            entity.SetObserving(false);

            if (!Table.Setters.TryGetValue("", out var setters))
            {
                setters = new List<Action<object, object>?>();
                Table.Setters[""] = setters;
            }
            
            var bFirst = !setters.Any();

            for (var i = 0; i < Table.Columns.Count; i++)
            {
                var column = Table.Columns[i].ColumnName;
                var value = this[column];
                try
                {
                    if (bFirst)
                    {
                        var prop = DatabaseSchema.Property(t, column);
                        setters.Add(prop?.Setter());
                    }

                    var setter = setters[i];
                    if (setter != null && value != null)
                        setter.Invoke(entity, value);
                    else
                        CoreUtils.SetPropertyValue(entity, column, value);
                }
                catch (Exception e)
                {
                    Logger.Send(LogType.Error, "", string.Format("*** Unknown Error: {0}\n{1}", e.Message, e.StackTrace));
                }
            }

            entity.CommitChanges();
            entity.SetObserving(true);
            return entity;
        }

        public T ToObject<T>() where T : BaseObject, new()
        {
            return (ToObject(typeof(T)) as T)!;
        }

        public T Get<T>(int col, bool usedefault = true)
        {
            if (col < 0 || col >= Values.Count)
            {
                if (usedefault)
                    return CoreUtils.GetDefault<T>();
                throw new Exception(string.Format("Column [{0}] does not exist!", col));
            }

            return Values[col] != null ? (T)CoreUtils.ChangeType(Values[col], typeof(T)) : CoreUtils.GetDefault<T>();

        }
        
        public T Get<T>(string columnname, bool usedefault = true)
        {
            var col = GetColumn(columnname);

            if (col < 0 || col >= Values.Count)
            {
                if (usedefault)
                    return CoreUtils.GetDefault<T>();
                throw new Exception(string.Format("Column [{0}] does not exist!", columnname));
            }

            return Values[col] != null ? (T)CoreUtils.ChangeType(Values[col], typeof(T)) : CoreUtils.GetDefault<T>();
        }

        public TType Get<TSource, TType>(Expression<Func<TSource, TType>> expression, bool usedefault = true)
        {
            var colname = GetColName(expression);
            //String colname = CoreUtils.GetFullPropertyName(expression, ".");
            return Get<TType>(colname, usedefault);
        }

        public void Set<TSource, TType>(Expression<Func<TSource, TType>> expression, TType value)
        {
            var colname = GetColName(expression);
            //String colname = CoreUtils.GetFullPropertyName(expression, ".");
            Set(colname, value);
        }

        public void Set<T>(int col, T value)
        {
            while (Values.Count <= col)
                Values.Add(Table.Columns[Values.Count].DataType.GetDefault());

            Values[col] = value;
        }
        
        public void Set<T>(string columnname, T value)
        {
            var col = GetColumn(columnname);
            if (col < 0)
                throw new Exception("Column not found: " + columnname);

            while (Values.Count <= col)
                Values.Add(Table.Columns[Values.Count].DataType.GetDefault());

            Values[col] = value;

            //this.RowObject.SetValue(columnname, value);
        }

        public void LoadValues(IEnumerable<object?> values)
        {
            Values = values.ToList();
        }

        public T ToObject<TSource, TLink, T>(Expression<Func<TSource, TLink>> property)
            where TLink : IEntityLink<T>
            where T : BaseObject, new()
        {
            var entity = new T();
            entity.SetObserving(false);

            var prefix = CoreUtils.GetFullPropertyName(property, ".");
            if (!Table.Setters.TryGetValue(prefix, out var setters))
            {
                setters = new List<Action<object, object>?>();
                Table.Setters[prefix] = setters;
            }
            var bFirst = !setters.Any();

            var cols = Table.Columns.Where(x => x.ColumnName.StartsWith(prefix + ".")).ToArray();

            for (var i = 0; i < cols.Length; i++)
            {
                var column = cols[i].ColumnName;

                var prop = column.Substring((prefix + ".").Length);
                var value = this[column];
                try
                {
                    if (bFirst)
                    {
                        var p2 = DatabaseSchema.Property(typeof(T), prop);
                        setters.Add(p2?.Setter());
                    }

                    var setter = setters[i];
                    if (setter != null && value != null)
                        setter.Invoke(entity, value);
                    else
                        CoreUtils.SetPropertyValue(entity, prop, value);
                }
                catch (Exception e)
                {
                    Logger.Send(LogType.Error, "", string.Format("*** Unknown Error: {0}\n{1}", e.Message, e.StackTrace));
                }
            }

            entity.CommitChanges();
            entity.SetObserving(true);
            return entity;
        }

        private string GetColName<TSource, TType>(Expression<Func<TSource, TType>> expression)
        {
            //int hash = expression.GetHashCode();
            //if (_accessedcolumns.ContainsKey(hash))
            //    return _accessedcolumns[hash];
            var colname = CoreUtils.GetFullPropertyName(expression, ".");
            //_accessedcolumns[hash] = colname;
            return colname;
        }

        private int GetColumn(string columnname)
        {
            if (_columnindexes.ContainsKey(columnname))
                return _columnindexes[columnname];

            for (var i = 0; i < Table.Columns.Count; i++)
                if (Table.Columns[i].ColumnName.Equals(columnname))
                {
                    _columnindexes[columnname] = i;
                    return i;
                }

            _columnindexes[columnname] = -1;
            return -1;
        }

    }

    public class CoreFieldMap<T1, T2>
    {
        private List<CoreFieldMapPair<T1, T2>> _fields = new List<CoreFieldMapPair<T1, T2>>();

        public CoreFieldMapPair<T1, T2>[] Fields => _fields.ToArray();
        
        public CoreFieldMap<T1, T2> Add(Expression<Func<T1, object>> from, Expression<Func<T2, object>> to)
        {
            _fields.Add(new CoreFieldMapPair<T1, T2>(from, to));
            return this;
        }
    }
    
    public class CoreFieldMapPair<T1, T2>
    {
            
        public Expression<Func<T1, object>> From { get; private set; }
        public Expression<Func<T2, object>> To { get; private set; }
            
        public CoreFieldMapPair(Expression<Func<T1, object>> from, Expression<Func<T2, object>> to)
        {
            From = from;
            To = to;
        }
    }

    [Serializable]
    public class CoreTable : ICoreTable, ISerializeBinary //: IEnumerable, INotifyCollectionChanged
    {

        #region Fields

        private List<CoreRow>? rows;
        private List<CoreColumn> columns = new List<CoreColumn>();

        #endregion

        #region Properties

        public string TableName { get; set; }

        public IList<CoreColumn> Columns { get => columns; }
        public IList<CoreRow> Rows
        {
            get
            {
                rows ??= new List<CoreRow>();
                //this.rows.CollectionChanged += OnRowsCollectionChanged;
                return rows;
            }
        }

        [field: NonSerialized]
        public Dictionary<string, IList<Action<object, object>?>> Setters { get; } = new Dictionary<string, IList<Action<object, object>?>>();

        #endregion

        public CoreTable() : base()
        {
            TableName = "";
        }

        public CoreTable(Type type) : this()
        {
            LoadColumns(type);
        }
        
        public void AddColumn<T>(Expression<Func<T, object>> column)
        {
            Columns.Add(
                new CoreColumn()
                {
                    ColumnName = CoreUtils.GetFullPropertyName(column, "."),
                    DataType = column.ReturnType
                }
            );
        }
        
        public CoreRow NewRow(bool populate = false)
        {
            var result = new CoreRow(this);
            if (populate)
                foreach (var column in Columns)
                    result[column.ColumnName] = column.DataType.GetDefault();
            return result;
        }

        /*
        private void OnRowsCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            switch (e.Action)
            {
                case NotifyCollectionChangedAction.Add:
                    this.InternalView.Insert(e.NewStartingIndex, ((DataRow)e.NewItems[0]).RowObject);
                    break;
                case NotifyCollectionChangedAction.Remove:
                    this.InternalView.RemoveAt(e.OldStartingIndex);
                    break;
                case NotifyCollectionChangedAction.Replace:
                    this.InternalView.Remove(((DataRow)e.OldItems[0]).RowObject);
                    this.InternalView.Insert(e.NewStartingIndex, ((DataRow)e.NewItems[0]).RowObject);
                    break;
                case NotifyCollectionChangedAction.Reset:
                default:
                    this.InternalView.Clear();
                    this.Rows.Select(r => r.RowObject).ToList().ForEach(o => this.InternalView.Add(o));
                    break;
            }
        }
        
        private IList InternalView
        {
            get
            {
                if (this.internalView == null)
                {
                    this.CreateInternalView();
                }

                return this.internalView;
            }
        }

        private void CreateInternalView()
        {
            this.internalView = (IList)Activator.CreateInstance(typeof(ObservableCollection<>).MakeGenericType(this.ElementType));
            ((INotifyCollectionChanged)internalView).CollectionChanged += (s, e) => { this.OnCollectionChanged(e); };
        }

        internal Type ElementType
        {
            get
            {
                if (this.elementType == null)
                {
                    this.InitializeElementType();
                }

                return this.elementType;
            }
        }

        private void InitializeElementType()
        {
            this.Seal();
            this.elementType = DynamicObjectBuilder.GetDynamicObjectBuilderType(this.Columns);
        }

        private void Seal()
        {
            this.columns = new ReadOnlyCollection<DataColumn>(this.Columns);
        }

        public IEnumerator GetEnumerator()
        {
            return this.InternalView.GetEnumerator();
        }

        public IList ToList()
        {
            return this.InternalView;
        }

        protected virtual void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
        {
            var handler = this.CollectionChanged;
            if (handler != null)
            {
                handler(this, e);
            }
        }
        */

        public void LoadColumns(Type T)
        {
            var iprops = DatabaseSchema.Properties(T);
            foreach (var iprop in iprops)
                Columns.Add(new CoreColumn { ColumnName = iprop.Name, DataType = iprop.PropertyType });
        }
        
        public void LoadColumns(IColumns columns)
        {
            foreach (var col in columns.GetColumns())
                Columns.Add(new CoreColumn { ColumnName = col.Property, DataType = col.Type });
        }
        
        public void LoadColumns(IEnumerable<CoreColumn> columns)
        {
            Columns.Clear();
            foreach (var col in columns)
                Columns.Add(new CoreColumn() { ColumnName = col.ColumnName, DataType = col.DataType }); 
        }

        public void LoadRows(IEnumerable<object> objects)
        {
            foreach (var obj in objects)
            {
                var row = NewRow();
                LoadRow(row, obj);
                Rows.Add(row);
            }
        }

        public void LoadRows(CoreRow[] rows)
        {
            foreach (var row in rows)
            {
                var newrow = NewRow();
                LoadRow(newrow, row);
                Rows.Add(newrow);
            }
        }

        public void LoadFrom<T1, T2>(CoreTable table, CoreFieldMap<T1, T2> mappings, Action<CoreRow>? customization = null)
        {
            foreach (var row in table.Rows)
            {
                var newrow = NewRow();
                foreach (var map in mappings.Fields)
                    newrow.Set(map.To, row.Get(map.From));
                customization?.Invoke(newrow);
                Rows.Add(newrow);
            }
        }

        public void LoadRow(CoreRow row, object obj)
        {
            foreach (var col in Columns)
                try
                {
                    //var prop = DataModel.Property(obj.GetType(), col.ColumnName);
                    //if (prop is CustomProperty)
                    //    prop is CustomProperty ? item.UserProperties[key] : CoreUtils.GetPropertyValue(item, key);
                    var fieldvalue = CoreUtils.GetPropertyValue(obj, col.ColumnName);
                    row[col.ColumnName] = fieldvalue;
                }
                catch (Exception e)
                {
                    Logger.Send(LogType.Error, "", string.Format("*** Unknown Error: {0}\n{1}", e.Message, e.StackTrace));
                }
        }

        public void LoadRow(CoreRow row, CoreRow from)
        {
            foreach (var col in Columns)
                try
                {
                    if (from.Table.Columns.Any(x => x.ColumnName.Equals(col.ColumnName)))
                        row[col.ColumnName] = from[col.ColumnName];
                }
                catch (Exception e)
                {
                    Logger.Send(LogType.Error, "", string.Format("*** Unknown Error: {0}\n{1}", e.Message, e.StackTrace));
                }
        }

        public void Filter(Func<CoreRow, bool> predicate)
        {
            for (var i = Rows.Count - 1; i > -1; i--)
            {
                var row = Rows[i];
                var predresult = predicate.Invoke(row);
                if (!predresult)
                    Rows.Remove(row);
            }
        }

        public IDictionary ToDictionary(string keycol, string displaycol, string sortcol = "")
        {
            var kc = Columns.FirstOrDefault(x => x.ColumnName.Equals(keycol));
            var dc = Columns.FirstOrDefault(x => x.ColumnName.Equals(displaycol));
            var dt = typeof(Dictionary<,>).MakeGenericType(kc.DataType, dc.DataType);
            var id = (Activator.CreateInstance(dt) as IDictionary)!;
            var sorted = string.IsNullOrWhiteSpace(sortcol) ? Rows : Rows.OrderBy(x => x.Get<object>(sortcol)).ToList();
            foreach (var row in sorted)
                id[row[keycol]] = row[displaycol];
            return id;
        }

        public Dictionary<TKey, TValue> ToDictionary<T, TKey, TValue>(Expression<Func<T, TKey>> key, Expression<Func<T, TValue>> value,
            Expression<Func<T, object>>? sort = null)
        {
            var result = new Dictionary<TKey, TValue>();
            var sorted = sort == null ? Rows : Rows.OrderBy(x => x.Get(sort)).ToList();
            foreach (var row in Rows)
                result[row.Get(key)] = row.Get(value);
            return result;
        }

        public Dictionary<TKey, string> ToDictionary<T, TKey>(Expression<Func<T, TKey>> key, Expression<Func<T, object>>[] values,
            Expression<Func<T, object>>? sort = null)
        {
            var result = new Dictionary<TKey, string>();
            var sorted = sort == null ? Rows : Rows.OrderBy(x => x.Get(sort)).ToList();
            foreach (var row in Rows)
            {
                var display = new List<object>();
                foreach (var value in values)
                    display.Add(row.Get(value));
                result[row.Get(key)] = string.Join(" : ", display);
            }

            return result;
        }

        public Dictionary<TKey, TValue> ToDictionary<T, TKey, TValue>(Expression<Func<T, TKey>> key, Func<CoreRow, TValue> value,
            Expression<Func<T, object>>? sort = null)
        {
            var result = new Dictionary<TKey, TValue>();
            var sorted = sort == null ? Rows : Rows.OrderBy(x => x.Get(sort)).ToList();
            foreach (var row in Rows)
                result[row.Get(key)] = value(row);
            return result;
        }

        public void LoadDictionary<T, TKey, TValue>(Dictionary<TKey, TValue> dictionary, Expression<Func<T, TKey>> key,
            Expression<Func<T, TValue>> value)
        {
            foreach (var row in Rows) dictionary[row.Get(key)] = row.Get(value);
        }

        public DataTable ToDataTable(string name = "", IColumns? additionalColumns = null)
        {
            var result = new DataTable(name);
            foreach (var column in Columns)
                result.Columns.Add(column.ColumnName.Replace('.', '_'), column.DataType);
            if(additionalColumns != null)
            {
                foreach (var (column, type) in additionalColumns.AsDictionary())
                    result.Columns.Add(column.Replace('.', '_'), type);
            }

            //result.Columns["ID"].Unique = true;
            //result.PrimaryKey = new DataColumn[] { result.Columns["ID"] };

            foreach (var row in Rows)
            {
                //result.Rows.Add(row.Values.ToArray());
                var newrow = result.NewRow();
                newrow.ItemArray = row.Values.ToArray();
                result.Rows.Add(newrow);
            }

            return result;
        }

        public IEnumerable<BaseObject> ToObjects(Type T)
            => Rows.Select(x => x.ToObject(T));
        public IEnumerable<T> ToObjects<T>() where T : BaseObject, new()
            => Rows.Select(x => x.ToObject<T>());
        public List<T> ToList<T>() where T : BaseObject, new()
            => ToObjects<T>().ToList();

        public void CopyTo(DataTable table)
        {
            var columns = new List<string>();
            foreach (var column in Columns)
                columns.Add(column.ColumnName.Replace('.', '_'));

            foreach (var row in Rows)
            {
                var newrow = table.NewRow();
                for (var i = 0; i < columns.Count; i++)
                    newrow[columns[i]] = row.Values[i];
                table.Rows.Add(newrow);
            }
        }

        public void CopyTo(CoreTable table)
        {
            var columns = new List<string>();
            //foreach (var column in Columns)
            //    columns.Add(column.ColumnName.Replace('.', '_'));

            foreach (var row in Rows)
            {
                var newrow = table.NewRow();
                foreach (var column in Columns)
                    if (table.Columns.Any(x => x.ColumnName.Equals(column.ColumnName)))
                        newrow[column.ColumnName] = row[column.ColumnName];
                //for (int i = 0; i < columns.Count; i++)
                //    newrow.Set(columns[i], row.Values[i]);
                table.Rows.Add(newrow);
            }
        }

        public IEnumerable<TValue> ExtractValues<TSource, TValue>(Expression<Func<TSource, TValue>> column, bool distinct = true)
        {
            var result = Rows.Select(r => r.Get(column));
            if (distinct)
                result = result.Distinct();
            return result;
        }

        public IEnumerable<TValue> ExtractValues<TValue>(string column, bool distinct = true)
        {
            var result = Rows.Select(r => r.Get<TValue>(column));
            if (distinct)
                result = result.Distinct();
            return result;
        }



        public CoreTable LoadRow(object obj)
        {
            var row = NewRow();
            LoadRow(row, obj);
            Rows.Add(row);
            return this;
        }

        public Dictionary<TKey, string> IntoDictionary<T, TKey>(Dictionary<TKey, string> result, Expression<Func<T, TKey>> key,
            params Expression<Func<T, object>>[] values)
        {
            foreach (var row in Rows)
            {
                var display = new List<object>();
                foreach (var value in values)
                    display.Add(row.Get(value));
                result[row.Get(key)] = string.Join(" : ", display);
            }

            return result;
        }

        public Dictionary<TKey, TValue> IntoDictionary<T, TKey, TValue>(Dictionary<TKey, TValue> result, Expression<Func<T, TKey>> key,
            Func<CoreRow, TValue> value)
        {
            foreach (var row in Rows)
                result[row.Get(key)] = value(row);
            return result;
        }

        public IMutableLookup<TKey, TValue> ToLookup<T, TKey, TValue>(Expression<Func<T, TKey>> key, Expression<Func<T, TValue>> value,
            Expression<Func<T, object>>? sort = null)
        {
            IMutableLookup<TKey, TValue> result = new MutableLookup<TKey, TValue>(
                Rows.ToLookup(
                    r => r.Get(key),
                    r => r.Get(value)
                )
            );
            return result;
        }

        public IMutableLookup<TKey, TValue> ToLookup<T, TKey, TValue>(Expression<Func<T, TKey>> key, Func<CoreRow, TValue> value,
            Expression<Func<T, object>>? sort = null)
        {
            IMutableLookup<TKey, TValue> result = new MutableLookup<TKey, TValue>(
                Rows.ToLookup(
                    r => r.Get(key),
                    r => value(r)
                )
            );
            return result;
        }

        #region Serialize Binary

        private static void WriteValue(BinaryWriter writer, Type type, object? value)
        {
            value ??= CoreUtils.GetDefault(type);
            if (type == typeof(byte[]) && value is byte[] bArray)
            {
                writer.Write(bArray.Length);
                writer.Write(bArray);
            }
            else if (type == typeof(byte[]) && value is null)
            {
                writer.Write(0);
            }
            else if (type.IsArray && value is Array array)
            {
                var elementType = type.GetElementType();
                writer.Write(array.Length);
                foreach (var val1 in array)
                {
                    WriteValue(writer, elementType, val1);
                }
            }
            else if (type.IsArray && value is null)
            {
                writer.Write(0);
            }
            else if (type.IsEnum && value is Enum e)
            {
                var underlyingType = type.GetEnumUnderlyingType();
                WriteValue(writer, underlyingType, Convert.ChangeType(e, underlyingType));
            }
            else if (type == typeof(bool) && value is bool b)
            {
                writer.Write(b);
            }
            else if (type == typeof(string) && value is string str)
            {
                writer.Write(str);
            }
            else if (type == typeof(string) && value is null)
            {
                writer.Write("");
            }
            else if (type == typeof(Guid) && value is Guid guid)
            {
                writer.Write(guid.ToByteArray());
            }
            else if (type == typeof(byte) && value is byte i8)
            {
                writer.Write(i8);
            }
            else if (type == typeof(Int16) && value is Int16 i16)
            {
                writer.Write(i16);
            }
            else if (type == typeof(Int32) && value is Int32 i32)
            {
                writer.Write(i32);
            }
            else if (type == typeof(Int64) && value is Int64 i64)
            {
                writer.Write(i64);
            }
            else if (type == typeof(float) && value is float f32)
            {
                writer.Write(f32);
            }
            else if (type == typeof(double) && value is double f64)
            {
                writer.Write(f64);
            }
            else if (type == typeof(DateTime) && value is DateTime date)
            {
                writer.Write(date.Ticks);
            }
            else if (type == typeof(TimeSpan) && value is TimeSpan time)
            {
                writer.Write(time.Ticks);
            }
            else if (type == typeof(LoggablePropertyAttribute))
            {
                writer.Write((value as LoggablePropertyAttribute)?.Format ?? "");
            }
            else if (typeof(IPackable).IsAssignableFrom(type) && value is IPackable pack)
            {
                pack.Pack(writer);
            }
            else
            {
                throw new Exception($"Invalid type; Target DataType is {type} and value DataType is {value?.GetType().ToString() ?? "null"}");
            }
        }

        public void WriteBinary(BinaryWriter writer, bool includeColumns)
        {
            writer.Write(TableName);

            if (includeColumns)
            {
                foreach (var column in Columns)
                {
                    writer.Write(true);
                    writer.Write(column.ColumnName);
                    writer.Write(column.DataType.EntityName());
                }
                writer.Write(false);
            }

            writer.Write(Rows.Count);
            foreach (var row in Rows)
            {
                foreach (var col in Columns)
                {
                    var val = row[col.ColumnName];
                    WriteValue(writer, col.DataType, val);
                }
            }
        }

        public void SerializeBinary(BinaryWriter writer) => WriteBinary(writer, true);

        private static object? ReadValue(BinaryReader reader, Type type)
        {
            if (type == typeof(byte[]))
            {
                var length = reader.ReadInt32();
                return reader.ReadBytes(length);
            }
            else if (type.IsArray)
            {
                var length = reader.ReadInt32();
                var elementType = type.GetElementType();

                var array = Array.CreateInstance(elementType, length);
                for (int i = 0; i < array.Length; ++i)
                {
                    array.SetValue(ReadValue(reader, elementType), i);
                }
                return array;
            }
            else if (type.IsEnum)
            {
                var val = ReadValue(reader, type.GetEnumUnderlyingType());
                return Enum.ToObject(type, val);
            }
            else if (type == typeof(bool))
            {
                return reader.ReadBoolean();
            }
            else if (type == typeof(string))
            {
                return reader.ReadString();
            }
            else if (type == typeof(Guid))
            {
                return new Guid(reader.ReadBytes(16));
            }
            else if (type == typeof(byte))
            {
                return reader.ReadByte();
            }
            else if (type == typeof(Int16))
            {
                return reader.ReadInt16();
            }
            else if (type == typeof(Int32))
            {
                return reader.ReadInt32();
            }
            else if (type == typeof(Int64))
            {
                return reader.ReadInt64();
            }
            else if (type == typeof(float))
            {
                return reader.ReadSingle();
            }
            else if (type == typeof(double))
            {
                return reader.ReadDouble();
            }
            else if (type == typeof(DateTime))
            {
                return new DateTime(reader.ReadInt64());
            }
            else if (type == typeof(TimeSpan))
            {
                return new TimeSpan(reader.ReadInt64());
            }
            else if (type == typeof(LoggablePropertyAttribute))
            {
                String format = reader.ReadString();
                return String.IsNullOrWhiteSpace(format)
                    ? null
                    : new LoggablePropertyAttribute() { Format = format };
            }
            else if (typeof(IPackable).IsAssignableFrom(type))
            {
                var packable = (Activator.CreateInstance(type) as IPackable)!;
                packable.Unpack(reader);
                return packable;
            }
            else
            {
                throw new Exception($"Invalid type; Target DataType is {type}");
            }
        }

        public void ReadBinary(BinaryReader reader, IList<CoreColumn>? columns)
        {
            TableName = reader.ReadString();

            Columns.Clear();
            if (columns is null)
            {
                while (reader.ReadBoolean())
                {
                    var columnName = reader.ReadString();
                    var dataType = CoreUtils.GetEntity(reader.ReadString());
                    Columns.Add(new CoreColumn(dataType, columnName));
                }
            }
            else
            {
                foreach (var column in columns)
                {
                    Columns.Add(column);
                }
            }

            Rows.Clear();
            var nRows = reader.ReadInt32();
            for (int i = 0; i < nRows; ++i)
            {
                var row = NewRow();
                foreach (var column in Columns)
                {
                    var value = ReadValue(reader, column.DataType);
                    row.Values.Add(value);
                }
                Rows.Add(row);
            }
        }

        public void DeserializeBinary(BinaryReader reader) => ReadBinary(reader, null);

        #endregion
    }

    public class CoreTableAdapter<T> : IEnumerable<T> where T : BaseObject, new()
    {
        private List<T>? _objects;

        private readonly CoreTable _table;

        public CoreTableAdapter(CoreTable table)
        {
            _table = table;
        }

        private List<T> Objects
        {
            get => _objects ??= _table.Rows.Select(row => row.ToObject<T>()).ToList();
        }

        public T this[int index] => Objects[index];


        public IEnumerator<T> GetEnumerator()
        {
            return GetObjects();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetObjects();
        }

        private IEnumerator<T> GetObjects()
        {
            return Objects.GetEnumerator();
        }
    }

    public class DataTableJsonConverter : JsonConverter
    {
        public override void WriteJson(JsonWriter writer, object? value, JsonSerializer serializer)
        {
            if(!(value is CoreTable table))
            {
                writer.WriteNull();
                return;
            }

            writer.WriteStartObject();
            writer.WritePropertyName("Columns");
            var cols = new Dictionary<string, string>();
            foreach (var column in table.Columns)
                cols[column.ColumnName] = column.DataType.EntityName();
            serializer.Serialize(writer, cols);
            //writer.WriteEndObject();

            //writer.WriteStartObject();
            writer.WritePropertyName("Rows");
            writer.WriteStartArray();
            var size = 0;
            foreach (var row in table.Rows)
                //Console.WriteLine("- Serializing Row #"+row.Index.ToString());
                try
                {
                    writer.WriteStartArray();
                    foreach (var col in table.Columns)
                    {
                        var val = row[col.ColumnName];
                        if (val != null) size += val.ToString().Length;
                        //Console.WriteLine(String.Format("Serializing Row #{0} Column [{1}] Length={2}", row.Index.ToString(), col.ColumnName, val.ToString().Length));
                        if (col.DataType.IsArray && val != null)
                        {
                            writer.WriteStartArray();
                            foreach (var val1 in (Array)val)
                                writer.WriteValue(val1);
                            writer.WriteEndArray();
                        }
                        else if (col.DataType.GetInterfaces().Contains(typeof(IPackableList)))
                        {
                            writer.WriteStartArray();
                            foreach (var val1 in (IList)val)
                                writer.WriteValue(val1);
                            writer.WriteEndArray();
                        }
                        else
                        {
                            writer.WriteValue(val ?? CoreUtils.GetDefault(col.DataType));
                        }
                    }

                    writer.WriteEndArray();
                    //Console.WriteLine(String.Format("[{0:D8}] Serializing Row #{1}", size, row.Index.ToString()));
                }
                catch (Exception e)
                {
                    Logger.Send(LogType.Error, "", string.Format("*** Unknown Error: {0}\n{1}", e.Message, e.StackTrace));
                }

            writer.WriteEndArray();
            writer.WriteEndObject();
        }

        public override object? ReadJson(JsonReader reader, Type objectType, object? existingValue, JsonSerializer serializer)
        {
            if (reader.TokenType == JsonToken.Null)
                return null;

            var result = new CoreTable();
            try
            {
                var json = JObject.Load(reader);
                if (json.TryGetValue("Columns", out var columns))
                {
                    foreach (JProperty column in columns.Children())
                    {
                        var name = column.Name;
                        var type = column.Value.ToObject<string>();
                        result.Columns.Add(new CoreColumn { ColumnName = name, DataType = CoreUtils.GetEntity(type ?? "") });
                    }
                }

                if (json.TryGetValue("Rows", out var rows))
                {
                    foreach (JArray row in rows.Children())
                        if (row.Children().ToArray().Length == result.Columns.Count)
                        {
                            var newrow = result.NewRow();
                            var iCol = 0;
                            foreach (var cell in row.Children())
                            {
                                var column = result.Columns[iCol];
                                try
                                {
                                    if (column.DataType.IsArray)
                                    {
                                        newrow[column.ColumnName] = cell.ToObject(column.DataType);
                                    }
                                    else if (column.DataType.GetInterfaces().Contains(typeof(IPackableList)))
                                    {
                                    }
                                    else
                                    {
                                        newrow[column.ColumnName] = cell.ToObject(column.DataType);
                                    }
                                    //if ((column.DataType == typeof(byte[])) && (value != null))
                                    //    newrow[column.ColumnName] = Convert.FromBase64String(value.ToString());
                                    //else if (cell is JValue)
                                    //    value = ((JValue)cell).Value;
                                    //else if (cell is JObject)
                                    //    value = ((JObject)cell).ToObject(column.DataType);
                                    //else if (cell is JArray)
                                    //    value = ((JArray)cell).ToObject(column.DataType);
                                    //else
                                    //    value = null;
                                }
                                catch (Exception e)
                                {
                                    Logger.Send(LogType.Error, "", string.Format("*** Unknown Error: {0}\n{1}", e.Message, e.StackTrace));
                                }

                                iCol++;
                            }

                            result.Rows.Add(newrow);
                        }
                }
            }
            catch (Exception e)
            {
                Logger.Send(LogType.Error, "", string.Format("*** Unknown Error: {0}\n{1}", e.Message, e.StackTrace));
            }

            return result;

            //String json = reader.Value.ToString();

            //var table = new CoreTable();

            //Dictionary<String, Object> dict = Serialization.Deserialize<Dictionary<String, Object>>(json);

            //Dictionary<String, String> columns = Serialization.Deserialize<Dictionary<String, String>>(dict["Columns"].ToString());
            //List<List<Object>> rows = Serialization.Deserialize<List<List<Object>>>(dict["Rows"].ToString());

            //String[] keys = columns.Keys.ToArray();

            //foreach (String key in keys)
            //    table.Columns.Add(new CoreColumn() { ColumnName = key, DataType = CoreUtils.GetEntity(columns[key]) });


            //foreach (List<Object> row in rows)
            //{
            //    CoreRow newrow = table.NewRow();
            //    for (int i = 0; i < keys.Count(); i++)
            //    {
            //        if (row[i] is JObject)
            //            newrow[keys[i]] = JsonConvert.DeserializeObject(row[i].ToString(), table.Columns[i].DataType);
            //        else if (table.Columns[i].DataType == typeof(byte[]))
            //        {
            //            if (row[i] != null)
            //                newrow.Set(keys[i], Convert.FromBase64String(row[i].ToString()));
            //        }
            //        else
            //        {
            //            try
            //            {
            //                object o = row[i];
            //                if (table.Columns[i].DataType != null)
            //                    o = CoreUtils.ChangeType(o, table.Columns[i].DataType);
            //                newrow.Set(keys[i], o);
            //            }
            //            catch (Exception e)
            //            {

            //            }
            //        }
            //        //newrow[keys[i]] = row[i];
            //    }
            //    table.Rows.Add(newrow);
            //}

            //return table;
        }


        public override bool CanConvert(Type objectType)
        {
            return typeof(CoreTable).GetTypeInfo().IsAssignableFrom(objectType);
        }
    }
}