using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using Biff8Excel.Interfaces;

namespace Biff8Excel.Records
{
    [StructLayoutAttribute(LayoutKind.Sequential, CharSet = CharSet.Auto, Pack = 1)]
    struct RecordDBCell
    {
        public ushort opcode;
        public ushort length;
        public uint RowOffset;
    }

    public class DBCell : IRecords  
    {

        RecordDBCell dbcell;
        int m_NumberOfCellOffsets;
        const int STRUCT_DBCELL_LENGTH = 8;             // ushort 2 + ushort 2 + uint 4 = 8
        int[] m_CellOffset;
        //List<int> m_CellOffset;

        public DBCell()
        {
            dbcell.opcode = 0xD7;
        }

        public ushort Id
        {
            get {return dbcell.opcode ;}
        }

        public ushort RecordSize
        {
            get { return (ushort)(STRUCT_DBCELL_LENGTH + (m_NumberOfCellOffsets * 4)); }
        }

        public int[] CellOffsets
        //public List<int> CellOffsets
        {
            internal set 
            {
                m_NumberOfCellOffsets = value.Length;
                //m_NumberOfCellOffsets = value.Count;
                m_CellOffset = value;
            }
            get { return m_CellOffset; }
        }

        public uint RowOffset
        {
            set {dbcell.RowOffset = value;}
            get { return dbcell.RowOffset; }
        }

        #region IRecords 成员

        public byte[] GetByte()
        {

            if (m_CellOffset == null)
                throw new Biff8ExcelException("先设定CellOffsets");

            byte[] tmp, r;

            int ln = STRUCT_DBCELL_LENGTH + (2 * m_NumberOfCellOffsets);
            r = new byte[ln];
            dbcell.length = (ushort)(ln - 4);
            tmp = Globals.GetStructToBytes(dbcell);
            tmp.CopyTo(r, 0);
            int pos = 8;
            //for (int i = 0; i < m_CellOffset.Length; i++, pos += 2)
            for (int i = 0; i < m_CellOffset.Length ; i++, pos += 2)
            {
                tmp = BitConverter.GetBytes(m_CellOffset[i]);
                Array.Copy(tmp, 0, r, pos, 2);
                //BitConverter.GetBytes( m_CellOffset[i]).CopyTo( r,pos);
            }

            return r;
        }

        #endregion
    }
}