using System.Collections;

namespace RhSolutions.ExcelTable;

public class ExcelColumns : IEnumerable<ExcelColumn>
{
    public Range Range { get; }
    public ExcelTable ParentTable { get; }
    public int Length
    {
        get => Range.Columns.Count;
    }

    public ExcelColumns(Range range, ExcelTable parentTable)
    {
        Range = range;
        ParentTable = parentTable;
    }

    public ExcelColumn this[int index]
    {
        get
        {
            if (index < 0 || index + 1 > Range.Columns.Count)
            {
                throw new IndexOutOfRangeException();
            }

            return new ExcelColumn(Range.Columns[index + 1], ParentTable);
        }
    }

    public IEnumerator<ExcelColumn> GetEnumerator()
    {
        return new ExcelColumnsEnumerator(Range, ParentTable);
    }

    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
}