using System;
using System.Collections.Generic;
using System.Text;

namespace Biff8Excel.Excel
{
    public class ExternSheet : Interfaces.IExternSheet, IDisposable
    {
        Biff8Excel.Records.ExternSheet m_extern;
        ushort numRefs;
        Records.StructExternSheet[] marrRefs;
        ExcelWorkbook mWorkbook;

        internal byte[] WriteRecord()
        {
            m_extern.ExternSheets = marrRefs;
            return m_extern.GetByte();
        }

        public ExcelWorkbook Workbook
        {
            set { mWorkbook = value; }
        }

        public ExternSheet()
        {
            m_extern = new Biff8Excel.Records.ExternSheet();
        }

        #region IDisposable ³ΙΤ±

        public void Dispose()
        {
            marrRefs = null;
            m_extern = null;
            mWorkbook = null;
        }

        #endregion


        #region IExternSheet ³ΙΤ±

        public void SheetNameToIndex(string sSheetName, ref ushort iSheetIndex)
        {
            iSheetIndex = mWorkbook.SheetIndexFromName(sSheetName);
        }

        public ushort AddEntry(string fromSheet)
        {
            return AddEntry(fromSheet, "");
        }

        public ushort AddEntry(string fromSheet, string toSheet)
        {
            ushort iFrom;
            ushort iTo;

            iFrom = mWorkbook.SheetIndexFromName(fromSheet);

            if (toSheet.Length == 0)
            {
                toSheet = fromSheet;
                iTo = iFrom;
            }
            else
            {
                iTo = mWorkbook.SheetIndexFromName(toSheet);
            }
            if (numRefs == 0)
                //marrRefs = TArray<Records.tExternSheet>.Preserve(marrRefs, 1);
                Array.Resize<Records.StructExternSheet>(ref marrRefs, 1);
            else
                //marrRefs = TArray<Records.tExternSheet>.Preserve(marrRefs, numRefs);
                Array.Resize<Records.StructExternSheet>(ref marrRefs, numRefs);


            // see if it already exists in the array
            for (ushort i = 0; i < numRefs; i++)
            {
                if (marrRefs[i].tFirstSheet == iFrom && marrRefs[i].tLastSheet == iTo)
                    return i;
            }

            // add a new entry
            marrRefs[numRefs].tIndex = 0;
            marrRefs[numRefs].tFirstSheet = iFrom;
            marrRefs[numRefs].tLastSheet = iTo;

            numRefs++;
            return (ushort)(numRefs-1);
        }
        #endregion
    }
}