/*******************************************************************************
 * You may amend and distribute as you like, but don't remove this header!
 *
 * EPPlus provides server-side generation of Excel 2007/2010 spreadsheets.
 * See http://www.codeplex.com/EPPlus for details.
 *
 * Copyright (C) 2011  Jan Källman
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.

 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
 * See the GNU Lesser General Public License for more details.
 *
 * The GNU Lesser General Public License can be viewed at http://www.opensource.org/licenses/lgpl-license.php
 * If you unfamiliar with this license or have questions about it, here is an http://www.gnu.org/licenses/gpl-faq.html
 *
 * All code and executables are provided "as is" with no warranty either express or implied. 
 * The author accepts no liability for any damage or loss of business that this product may cause.
 *
 * Code change notes:
 * 
 * Author							Change						Date
 * ******************************************************************************
 * Jan Källman		    Initial Release		        2009-10-01
 * Jan Källman		    License changed GPL-->LGPL 2011-12-27
 *******************************************************************************/
using System;
using System.Xml;
using System.Collections.Generic;
using draw=System.Drawing;
using OfficeOpenXml.Style;
using OfficeOpenXml.Style.XmlAccess;
using OfficeOpenXml.Style.Dxf;
using OfficeOpenXml.ConditionalFormatting;
namespace OfficeOpenXml
{
	/// <summary>
	/// Containts all shared cell styles for a workbook
	/// </summary>
    public sealed class ExcelStyles : XmlHelper
    {
        const string NumberFormatsPath = "d:styleSheet/d:numFmts";
        const string FontsPath = "d:styleSheet/d:fonts";
        const string FillsPath = "d:styleSheet/d:fills";
        const string BordersPath = "d:styleSheet/d:borders";
        const string CellStyleXfsPath = "d:styleSheet/d:cellStyleXfs";
        const string CellXfsPath = "d:styleSheet/d:cellXfs";
        const string CellStylesPath = "d:styleSheet/d:cellStyles";
        const string dxfsPath = "d:styleSheet/d:dxfs";

        //internal Dictionary<int, ExcelXfs> Styles = new Dictionary<int, ExcelXfs>();
        XmlDocument _styleXml;
        ExcelWorkbook _wb;
        XmlNamespaceManager _nameSpaceManager;
        internal int _nextDfxNumFmtID = 164;
        internal ExcelStyles(XmlNamespaceManager NameSpaceManager, XmlDocument xml, ExcelWorkbook wb) :
            base(NameSpaceManager, xml)
        {       
            _styleXml=xml;
            _wb = wb;
            _nameSpaceManager = NameSpaceManager;
            SchemaNodeOrder = new string[] { "numFmts", "fonts", "fills", "borders", "cellStyleXfs", "cellXfs", "cellStyles", "dxfs" };
            LoadFromDocument();
        }
        /// <summary>
        /// Loads the style XML to memory
        /// </summary>
        private void LoadFromDocument()
        {
            //NumberFormats
            ExcelNumberFormatXml.AddBuildIn(NameSpaceManager, NumberFormats);
            XmlNode numNode = _styleXml.SelectSingleNode(NumberFormatsPath, _nameSpaceManager);
            if (numNode != null)
            {
                foreach (XmlNode n in numNode)
                {
                    ExcelNumberFormatXml nf = new ExcelNumberFormatXml(_nameSpaceManager, n);
                    NumberFormats.Add(nf.Id, nf);
                    if (nf.NumFmtId >= NumberFormats.NextId) NumberFormats.NextId=nf.NumFmtId+1;
                }
            }

            //Fonts
            XmlNode fontNode = _styleXml.SelectSingleNode(FontsPath, _nameSpaceManager);
            foreach (XmlNode n in fontNode)
            {
                ExcelFontXml f = new ExcelFontXml(_nameSpaceManager, n);
                Fonts.Add(f.Id, f);
            }

            //Fills
            XmlNode fillNode = _styleXml.SelectSingleNode(FillsPath, _nameSpaceManager);
            foreach (XmlNode n in fillNode)
            {
                ExcelFillXml f;
                if (n.FirstChild != null && n.FirstChild.LocalName == "gradientFill")
                {
                    f = new ExcelGradientFillXml(_nameSpaceManager, n);
                }
                else
                {
                    f = new ExcelFillXml(_nameSpaceManager, n);
                }
                Fills.Add(f.Id, f);
            }

            //Borders
            XmlNode borderNode = _styleXml.SelectSingleNode(BordersPath, _nameSpaceManager);
            foreach (XmlNode n in borderNode)
            {
                ExcelBorderXml b = new ExcelBorderXml(_nameSpaceManager, n);
                Borders.Add(b.Id, b);
            }

            //cellStyleXfs
            XmlNode styleXfsNode = _styleXml.SelectSingleNode(CellStyleXfsPath, _nameSpaceManager);
            if (styleXfsNode != null)
            {
                foreach (XmlNode n in styleXfsNode)
                {
                    ExcelXfs item = new ExcelXfs(_nameSpaceManager, n, this);
                    CellStyleXfs.Add(item.Id, item);
                }
            }

            XmlNode styleNode = _styleXml.SelectSingleNode(CellXfsPath, _nameSpaceManager);
            for (int i = 0; i < styleNode.ChildNodes.Count; i++)
            {
                XmlNode n = styleNode.ChildNodes[i];
                ExcelXfs item = new ExcelXfs(_nameSpaceManager, n, this);
                CellXfs.Add(item.Id, item);
            }

            //cellStyle
            XmlNode namedStyleNode = _styleXml.SelectSingleNode(CellStylesPath, _nameSpaceManager);
            if (namedStyleNode != null)
            {
                foreach (XmlNode n in namedStyleNode)
                {
                    ExcelNamedStyleXml item = new ExcelNamedStyleXml(_nameSpaceManager, n, this);
                    NamedStyles.Add(item.Name, item);
                }
            }

            //dxfsPath
            XmlNode dxfsNode = _styleXml.SelectSingleNode(dxfsPath, _nameSpaceManager);
            if (dxfsNode != null)
            {
                foreach (XmlNode x in dxfsNode)
                {
                    ExcelDxfStyleConditionalFormatting item = new ExcelDxfStyleConditionalFormatting(_nameSpaceManager, x, this);
                    Dxfs.Add(item.Id, item);
                }
            }
        }
        internal ExcelStyle GetStyleObject(int Id,int PositionID, string Address)
        {
            if (Id < 0) Id = 0;
            return new ExcelStyle(this, PropertyChange, PositionID, Address, Id);
        }
        /// <summary>
        /// Handels changes of properties on the style objects
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        /// <returns></returns>
        internal int PropertyChange(StyleBase sender, Style.StyleChangeEventArgs e)
        {
            var address = new ExcelAddressBase(e.Address);
            var ws = _wb.Worksheets[e.PositionID];
            Dictionary<int, int> styleCashe = new Dictionary<int, int>();
            //Set single address
            SetStyleAddress(sender, e, address, ws, ref styleCashe);
            if (address.Addresses != null)
            {
                //Handle multiaddresses
                foreach (var innerAddress in address.Addresses)
                {
                    SetStyleAddress(sender, e, innerAddress, ws, ref styleCashe);
                }
            }
            return 0;
        }

        private void SetStyleAddress(StyleBase sender, Style.StyleChangeEventArgs e, ExcelAddressBase address, ExcelWorksheet ws, ref Dictionary<int, int> styleCashe)
        {
            if (address.Start.Column == 0 || address.Start.Row == 0)
            {
                throw (new Exception("error address"));
            }
            //Columns
            else if (address.Start.Row == 1 && address.End.Row == ExcelPackage.MaxRows)
            {
                ExcelColumn column;
                //Get the startcolumn
                ulong colID = ExcelColumn.GetColumnID(ws.SheetID, address.Start.Column);
                if (!ws._columns.ContainsKey(colID))
                {
                    column=ws.Column(address.Start.Column);
                }
                else
                {
                    column = ws._columns[colID] as ExcelColumn;
                }

                var index = ws._columns.IndexOf(colID);
                while(column.ColumnMin <= address.End.Column)
                {
                    if (column.ColumnMax > address.End.Column)
                    {
                        var newCol = ws.CopyColumn(column, address.End.Column + 1, column.ColumnMax);
                        column.ColumnMax = address.End.Column;
                    }

                    if (styleCashe.ContainsKey(column.StyleID))
                    {
                        column.StyleID = styleCashe[column.StyleID];
                    }
                    else
                    {
                        ExcelXfs st = CellXfs[column.StyleID];
                        int newId = st.GetNewID(CellXfs, sender, e.StyleClass, e.StyleProperty, e.Value);
                        styleCashe.Add(column.StyleID, newId);
                        column.StyleID = newId;
                    }

                    index++;
                    if (index >= ws._columns.Count)
                    {
                        break;
                    }
                    else
                    {
                        column = (ws._columns[index] as ExcelColumn);
                    }
                }

                if (column._columnMax < address.End.Column)
                {
                    var newCol = ws.Column(column._columnMax + 1) as ExcelColumn;
                    newCol._columnMax = address.End.Column;

                    if (styleCashe.ContainsKey(newCol.StyleID))
                    {
                        newCol.StyleID = styleCashe[newCol.StyleID];
                    }
                    else
                    {
                        ExcelXfs st = CellXfs[column.StyleID];
                        int newId = st.GetNewID(CellXfs, sender, e.StyleClass, e.StyleProperty, e.Value);
                        styleCashe.Add(newCol.StyleID, newId);
                        newCol.StyleID = newId;
                    }
                    
                    //column._columnMax = address.End.Column;
                }

                //Set for individual cells in the spann. We loop all cells here since the cells are sorted with columns first.
                foreach (ExcelCell cell in ws._cells)
                {
                    if (cell.Column >= address.Start.Column &&
                       cell.Column <= address.End.Column)
                    {
                        if (styleCashe.ContainsKey(cell.StyleID))
                        {
                            cell.StyleID = styleCashe[cell.StyleID];
                        }
                        else
                        {
                            ExcelXfs st = CellXfs[cell.StyleID];
                            int newId = st.GetNewID(CellXfs, sender, e.StyleClass, e.StyleProperty, e.Value);
                            styleCashe.Add(cell.StyleID, newId);
                            cell.StyleID = newId;
                        }
                    }

                }
            }
            //Rows
            else if(address.Start.Column==1 && address.End.Column==ExcelPackage.MaxColumns)
            {
                for (int rowNum = address.Start.Row; rowNum <= address.End.Row; rowNum++)
                {
                    ExcelRow row = ws.Row(rowNum);
                    if (row.StyleID == 0 && ws._columns.Count > 0)
                    {
                        //TODO: We should loop all columns here and change each cell. But for now we take style of column A.
                        foreach (ExcelColumn column in ws._columns)
                        {
                            row.StyleID = column.StyleID;
                            break;  //Get the first one and break. 
                        }

                    }
                    if (styleCashe.ContainsKey(row.StyleID))
                    {
                        row.StyleID = styleCashe[row.StyleID];
                    }
                    else
                    {
                        ExcelXfs st = CellXfs[row.StyleID];
                        int newId = st.GetNewID(CellXfs, sender, e.StyleClass, e.StyleProperty, e.Value);
                        styleCashe.Add(row.StyleID, newId);
                        row.StyleID = newId;
                    }
                }

                //Get Start Cell
                ulong rowID = ExcelRow.GetRowID(ws.SheetID, address.Start.Row);
                int index = ws._cells.IndexOf(rowID);

                index = ~index;
                while (index < ws._cells.Count)
                {                        
                    var cell = ws._cells[index] as ExcelCell;
                    if(cell.Row > address.End.Row)
                    {
                        break;
                    }
                    if (styleCashe.ContainsKey(cell.StyleID))
                    {
                        cell.StyleID = styleCashe[cell.StyleID];
                    }
                    else
                    {
                        ExcelXfs st = CellXfs[cell.StyleID];
                        int newId = st.GetNewID(CellXfs, sender, e.StyleClass, e.StyleProperty, e.Value);
                        styleCashe.Add(cell.StyleID, newId);
                        cell.StyleID = newId;
                    }
                    index++;
                }
            }
            else             //Cellrange
            {
                for (int col = address.Start.Column; col <= address.End.Column; col++)
                {
                    for (int row = address.Start.Row; row <= address.End.Row; row++)
                    {
                        ExcelCell cell = ws.Cell(row, col);
                        if (styleCashe.ContainsKey(cell.StyleID))
                        {
                            cell.StyleID = styleCashe[cell.StyleID];
                        }
                        else
                        {
                            ExcelXfs st = CellXfs[cell.StyleID];
                            int newId = st.GetNewID(CellXfs, sender, e.StyleClass, e.StyleProperty, e.Value);
                            styleCashe.Add(cell.StyleID, newId);
                            cell.StyleID = newId;
                        }
                    }
                }            
            }
        }
        /// <summary>
        /// Handles property changes on Named styles.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        /// <returns></returns>
        internal int NamedStylePropertyChange(StyleBase sender, Style.StyleChangeEventArgs e)
        {

            int index = NamedStyles.FindIndexByID(e.Address);
            if (index >= 0)
            {
                int newId = CellStyleXfs[NamedStyles[index].StyleXfId].GetNewID(CellStyleXfs, sender, e.StyleClass, e.StyleProperty, e.Value);
                int prevIx=NamedStyles[index].StyleXfId;
                NamedStyles[index].StyleXfId = newId;
                NamedStyles[index].Style.Index = newId;

                NamedStyles[index].XfId = int.MinValue;
                foreach (var style in CellXfs)
                {
                    if (style.XfId == prevIx)
                    {
                        style.XfId = newId;
                    }
                }
            }
            return 0;
        }
        public ExcelStyleCollection<ExcelNumberFormatXml> NumberFormats = new ExcelStyleCollection<ExcelNumberFormatXml>();
        public ExcelStyleCollection<ExcelFontXml> Fonts = new ExcelStyleCollection<ExcelFontXml>();
        public ExcelStyleCollection<ExcelFillXml> Fills = new ExcelStyleCollection<ExcelFillXml>();
        public ExcelStyleCollection<ExcelBorderXml> Borders = new ExcelStyleCollection<ExcelBorderXml>();
        public ExcelStyleCollection<ExcelXfs> CellStyleXfs = new ExcelStyleCollection<ExcelXfs>();
        public ExcelStyleCollection<ExcelXfs> CellXfs = new ExcelStyleCollection<ExcelXfs>();
        public ExcelStyleCollection<ExcelNamedStyleXml> NamedStyles = new ExcelStyleCollection<ExcelNamedStyleXml>();
        public ExcelStyleCollection<ExcelDxfStyleConditionalFormatting> Dxfs = new ExcelStyleCollection<ExcelDxfStyleConditionalFormatting>();
        
        internal string Id
        {
            get { return ""; }
        }

        public ExcelNamedStyleXml CreateNamedStyle(string name)
        {
            return CreateNamedStyle(name, null);
        }
        public ExcelNamedStyleXml CreateNamedStyle(string name, ExcelStyle Template)
        {
            if (_wb.Styles.NamedStyles.ExistsKey(name))
            {
                throw new Exception(string.Format("Key {0} already exists in collection", name));
            }

            ExcelNamedStyleXml style;
            style = new ExcelNamedStyleXml(NameSpaceManager, this);
            int xfIdCopy, positionID;
            ExcelStyles styles;
            if (Template == null)
            {
//                style.Style = new ExcelStyle(this, NamedStylePropertyChange, -1, name, 0);
                xfIdCopy = 0;
                positionID = -1;
                styles = this;
            }
            else
            {
                if (Template.PositionID < 0 && Template.Styles==this)
                {
                    xfIdCopy = Template.Index;
                    positionID=Template.PositionID;
                    styles = this;
                    //style.Style = new ExcelStyle(this, NamedStylePropertyChange, Template.PositionID, name, Template.Index);
                    //style.StyleXfId = Template.Index;
                }
                else
                {
                    xfIdCopy = Template.XfId;
                    positionID = -1;
                    styles = Template.Styles;
                }
            }
            //Clone namedstyle
            int styleXfId = CloneStyle(styles, xfIdCopy, true);
            //Close cells style
            CellStyleXfs[styleXfId].XfId = CellStyleXfs.Count-1;
            int xfid = CloneStyle(styles, xfIdCopy, false, true); //Always add a new style (We create a new named style here)
            CellXfs[xfid].XfId = styleXfId;
            style.Style = new ExcelStyle(this, NamedStylePropertyChange, positionID, name, styleXfId);
            style.StyleXfId = styleXfId;
            
            style.Name = name;
            int ix =_wb.Styles.NamedStyles.Add(style.Name, style);
            style.Style.SetIndex(ix);
            //style.Style.XfId = ix;
            return style;
        }
        public void UpdateXml()
        {
            RemoveUnusedStyles();

            //NumberFormat
            XmlNode nfNode=_styleXml.SelectSingleNode(NumberFormatsPath, _nameSpaceManager);
            if (nfNode == null)
            {
                CreateNode(NumberFormatsPath, true);
                nfNode = _styleXml.SelectSingleNode(NumberFormatsPath, _nameSpaceManager);
            }
            else
            {
                nfNode.RemoveAll();                
            }

            int count = 0;
            int normalIx = NamedStyles.FindIndexByID("Normal");
            if (NamedStyles.Count > 0 && normalIx>=0 && NamedStyles[normalIx].Style.Numberformat.NumFmtID >= 164)
            {
                ExcelNumberFormatXml nf = NumberFormats[NumberFormats.FindIndexByID(NamedStyles[normalIx].Style.Numberformat.Id)];
                nfNode.AppendChild(nf.CreateXmlNode(_styleXml.CreateElement("numFmt", ExcelPackage.schemaMain)));
                nf.newID = count++;
            }
            foreach (ExcelNumberFormatXml nf in NumberFormats)
            {
                if(!nf.BuildIn /*&& nf.newID<0*/) //Buildin formats are not updated.
                {
                    nfNode.AppendChild(nf.CreateXmlNode(_styleXml.CreateElement("numFmt", ExcelPackage.schemaMain)));
                    nf.newID = count;
                    count++;
                }
            }
            (nfNode as XmlElement).SetAttribute("count", count.ToString());

            //Font
            count=0;
            XmlNode fntNode = _styleXml.SelectSingleNode(FontsPath, _nameSpaceManager);
            fntNode.RemoveAll();

            //Normal should be first in the collection
            if (NamedStyles.Count > 0 && normalIx >= 0 && NamedStyles[normalIx].Style.Font.Index > 0)
            {
                ExcelFontXml fnt = Fonts[NamedStyles[normalIx].Style.Font.Index];
                fntNode.AppendChild(fnt.CreateXmlNode(_styleXml.CreateElement("font", ExcelPackage.schemaMain)));
                fnt.newID = count++;
            }

            foreach (ExcelFontXml fnt in Fonts)
            {
                if (fnt.useCnt > 0/* && fnt.newID<0*/)
                {
                    fntNode.AppendChild(fnt.CreateXmlNode(_styleXml.CreateElement("font", ExcelPackage.schemaMain)));
                    fnt.newID = count;
                    count++;
                }
            }
            (fntNode as XmlElement).SetAttribute("count", count.ToString());


            //Fills
            count = 0;
            XmlNode fillsNode = _styleXml.SelectSingleNode(FillsPath, _nameSpaceManager);
            fillsNode.RemoveAll();
            Fills[0].useCnt = 1;    //Must exist (none);  
            Fills[1].useCnt = 1;    //Must exist (gray125);
            foreach (ExcelFillXml fill in Fills)
            {
                if (fill.useCnt > 0)
                {
                    fillsNode.AppendChild(fill.CreateXmlNode(_styleXml.CreateElement("fill", ExcelPackage.schemaMain)));
                    fill.newID = count;
                    count++;
                }
            }

            (fillsNode as XmlElement).SetAttribute("count", count.ToString());

            //Borders
            count = 0;
            XmlNode bordersNode = _styleXml.SelectSingleNode(BordersPath, _nameSpaceManager);
            bordersNode.RemoveAll();
            Borders[0].useCnt = 1;    //Must exist blank;
            foreach (ExcelBorderXml border in Borders)
            {
                if (border.useCnt > 0)
                {
                    bordersNode.AppendChild(border.CreateXmlNode(_styleXml.CreateElement("border", ExcelPackage.schemaMain)));
                    border.newID = count;
                    count++;
                }
            }
            (bordersNode as XmlElement).SetAttribute("count", count.ToString());

            XmlNode styleXfsNode = _styleXml.SelectSingleNode(CellStyleXfsPath, _nameSpaceManager);
            if (styleXfsNode == null && NamedStyles.Count > 0)
            {
                CreateNode(CellStyleXfsPath);
                styleXfsNode = _styleXml.SelectSingleNode(CellStyleXfsPath, _nameSpaceManager);
            }
            if (NamedStyles.Count > 0)
            {
                styleXfsNode.RemoveAll();
            }
            //NamedStyles
            count = normalIx > -1 ? 1 : 0;  //If we have a normal style, we make sure it's added first.

            XmlNode cellStyleNode = _styleXml.SelectSingleNode(CellStylesPath, _nameSpaceManager);
            if(cellStyleNode!=null)
            {
                cellStyleNode.RemoveAll();
            }
            XmlNode cellXfsNode = _styleXml.SelectSingleNode(CellXfsPath, _nameSpaceManager);
            cellXfsNode.RemoveAll();

            if (NamedStyles.Count > 0 && normalIx >= 0)
            {
                NamedStyles[normalIx].newID = 0;
                AddNamedStyle(0, styleXfsNode, cellXfsNode, NamedStyles[normalIx]);
            }
            foreach (ExcelNamedStyleXml style in NamedStyles)
            {
                if (style.Name.ToLower() != "normal")
                {
                    style.newID = count;
                    AddNamedStyle(count++, styleXfsNode, cellXfsNode, style);
                }
                else
                {
                    style.newID = 0;
                }
                cellStyleNode.AppendChild(style.CreateXmlNode(_styleXml.CreateElement("cellStyle", ExcelPackage.schemaMain)));
            }
            if (cellStyleNode!=null) (cellStyleNode as XmlElement).SetAttribute("count", count.ToString());
            if (styleXfsNode != null) (styleXfsNode as XmlElement).SetAttribute("count", count.ToString());

            //CellStyle
            int xfix = 0;
            foreach (ExcelXfs xf in CellXfs)
            {
                if (xf.useCnt > 0 && !(normalIx == xfix))
                {
                    cellXfsNode.AppendChild(xf.CreateXmlNode(_styleXml.CreateElement("xf", ExcelPackage.schemaMain)));
                    xf.newID = count;
                    count++;
                }
                xfix++;
            }
            (cellXfsNode as XmlElement).SetAttribute("count", count.ToString());

            //Set dxf styling for conditional Formatting
            XmlNode dxfsNode = _styleXml.SelectSingleNode(dxfsPath, _nameSpaceManager);
            foreach (var ws in _wb.Worksheets)
            {
                foreach (var cf in ws.ConditionalFormatting)
                {
                    if (cf.Style.HasValue)
                    {
                        int ix = Dxfs.FindIndexByID(cf.Style.Id);
                        if (ix < 0)
                        {
                            ((ExcelConditionalFormattingRule)cf).DxfId = Dxfs.Count;
                            Dxfs.Add(cf.Style.Id, cf.Style);
                            var elem = ((XmlDocument)TopNode).CreateElement("d", "dxf", ExcelPackage.schemaMain);
                            cf.Style.CreateNodes(new XmlHelperInstance(NameSpaceManager, elem), "");
                            dxfsNode.AppendChild(elem);
                        }
                        else
                        {
                            ((ExcelConditionalFormattingRule)cf).DxfId = ix;
                        }
                    }
                }
            }
        }

        private void AddNamedStyle(int id, XmlNode styleXfsNode,XmlNode cellXfsNode, ExcelNamedStyleXml style)
        {
            var styleXfs = CellStyleXfs[style.StyleXfId];
            styleXfsNode.AppendChild(styleXfs.CreateXmlNode(_styleXml.CreateElement("xf", ExcelPackage.schemaMain), true));
            styleXfs.newID = id;
            styleXfs.XfId = style.StyleXfId;

            var ix = CellXfs.FindIndexByID(styleXfs.Id);
            if (ix < 0)
            {
                cellXfsNode.AppendChild(styleXfs.CreateXmlNode(_styleXml.CreateElement("xf", ExcelPackage.schemaMain)));
            }
            else
            {
                if (id < 0) CellXfs[ix].XfId = id;
                cellXfsNode.AppendChild(CellXfs[ix].CreateXmlNode(_styleXml.CreateElement("xf", ExcelPackage.schemaMain)));
                CellXfs[ix].useCnt = 0;
                CellXfs[ix].newID = id;

            }

            if (style.XfId >= 0)
                style.XfId = CellXfs[style.XfId].newID;
            else
                style.XfId = 0;
        }

        private void RemoveUnusedStyles()
        {
            CellXfs[0].useCnt = 1; //First item is allways used.
            foreach (ExcelWorksheet sheet in _wb.Worksheets)
            {
                foreach (ExcelCell cell in sheet._cells) //sheet._cells.Values
                {
                    CellXfs[cell.GetCellStyleID()].useCnt++;
                }
                foreach(ExcelRow row in sheet._rows)
                {
                    CellXfs[row.StyleID].useCnt++;
                }
                foreach (ExcelColumn col in sheet._columns)
                {
                    if(col.StyleID>=0) CellXfs[col.StyleID].useCnt++;
                }
            }
            foreach (ExcelNamedStyleXml ns in NamedStyles)
            {
                CellStyleXfs[ns.StyleXfId].useCnt++;
            }

            foreach (ExcelXfs xf in CellXfs)
            {
                if (xf.useCnt > 0)
                {
                    if (xf.FontId >= 0) Fonts[xf.FontId].useCnt++;
                    if (xf.FillId >= 0) Fills[xf.FillId].useCnt++;
                    if (xf.BorderId >= 0) Borders[xf.BorderId].useCnt++;
                }
            }
            foreach (ExcelXfs xf in CellStyleXfs)
            {
                if (xf.useCnt > 0)
                {
                    if (xf.FontId >= 0) Fonts[xf.FontId].useCnt++;
                    if (xf.FillId >= 0) Fills[xf.FillId].useCnt++;
                    if (xf.BorderId >= 0) Borders[xf.BorderId].useCnt++;                    
                }
            }
        }
        internal int GetStyleIdFromName(string Name)
        {
            int i = NamedStyles.FindIndexByID(Name);
            if (i >= 0)
            {
                int id = NamedStyles[i].XfId;
                if (id < 0)
                {
                    int styleXfId=NamedStyles[i].StyleXfId;
                    ExcelXfs newStyle = CellStyleXfs[styleXfId].Copy();
                    newStyle.XfId = styleXfId;
                    id = CellXfs.FindIndexByID(newStyle.Id);
                    if (id < 0)
                    {
                        id = CellXfs.Add(newStyle.Id, newStyle);
                    }
                    NamedStyles[i].XfId=id;
                }
                return id;
            }
            else
            {
                return 0;
                //throw(new Exception("Named style does not exist"));        	         
            }
        }
   #region XmlHelpFunctions
        private int GetXmlNodeInt(XmlNode node)
        {
            int i;
            if (int.TryParse(GetXmlNode(node), out i))
            {
                return i;
            }
            else
            {
                return 0;
            }
        }
        private string GetXmlNode(XmlNode node)
        {
            if (node == null)
            {
                return "";
            }
            if (node.Value != null)
            {
                return node.Value;
            }
            else
            {
                return "";
            }
        }

#endregion
        internal int CloneStyle(ExcelStyles style, int styleID)
        {
            return CloneStyle(style, styleID, false, false);
        }
        internal int CloneStyle(ExcelStyles style, int styleID, bool isNamedStyle)
        {
            return CloneStyle(style, styleID, isNamedStyle, false);
        }
        internal int CloneStyle(ExcelStyles style, int styleID, bool isNamedStyle, bool allwaysAdd)
        {
            ExcelXfs xfs;
            if (isNamedStyle)
            {
                xfs = style.CellStyleXfs[styleID];
            }
            else
            {
                xfs = style.CellXfs[styleID];
            }
            ExcelXfs newXfs=xfs.Copy(this);
            //Numberformat
            if (xfs.NumberFormatId > 0)
            {
                string format="";
                foreach (var fmt in style.NumberFormats)
                {
                    if (fmt.NumFmtId == xfs.NumberFormatId)
                    {
                        format=fmt.Format;
                        break;
                    }
                }
                int ix=NumberFormats.FindIndexByID(format);
                if (ix<0)
                {
                    ExcelNumberFormatXml item = new ExcelNumberFormatXml(NameSpaceManager) { Format = format, NumFmtId = NumberFormats.NextId++ };
                    NumberFormats.Add(format, item);
                    ix=item.NumFmtId;
                }
                newXfs.NumberFormatId= ix;
            }

            //Font
            if (xfs.FontId > -1)
            {
                int ix=Fonts.FindIndexByID(xfs.Font.Id);
                if (ix<0)
                {
                    ExcelFontXml item = style.Fonts[xfs.FontId].Copy();
                    ix=Fonts.Add(xfs.Font.Id, item);
                }
                newXfs.FontId=ix;
            }

            //Border
            if (xfs.BorderId > -1)
            {
                int ix = Borders.FindIndexByID(xfs.Border.Id);
                if (ix < 0)
                {
                    ExcelBorderXml item = style.Borders[xfs.BorderId].Copy();
                    ix = Borders.Add(xfs.Border.Id, item);
                }
                newXfs.BorderId = ix;
            }

            //Fill
            if (xfs.FillId > -1)
            {
                int ix = Fills.FindIndexByID(xfs.Fill.Id);
                if (ix < 0)
                {
                    var item = style.Fills[xfs.FillId].Copy();
                    ix = Fills.Add(xfs.Fill.Id, item);
                }
                newXfs.FillId = ix;
            }

            //Named style reference
            if (xfs.XfId > 0)
            {
                var id = style.CellStyleXfs[xfs.XfId].Id;
                var newId = CellStyleXfs.FindIndexByID(id);
                //if (newId < 0)
                //{
                    
                //    newXfs.XfId = CloneStyle(style, xfs.XfId, true);
                //}
                //else
                //{
                    newXfs.XfId = newId;
                //}
            }

            int index;
            if (isNamedStyle)
            {
                index = CellStyleXfs.Add(newXfs.Id, newXfs);
            }
            else
            {
                if (allwaysAdd)
                {
                    index = CellXfs.Add(newXfs.Id, newXfs);
                }
                else
                {
                    index = CellXfs.FindIndexByID(newXfs.Id);
                    if (index < 0)
                    {
                        index = CellXfs.Add(newXfs.Id, newXfs);
                    }
                }
            }
            return index;
        }
    }
}