#region  --------------- Copyright Dresser Wayne Pignone -------------
/*
 * $Log: /Wrk/Support/ForecourtControl/Wrk/ForecourtControl/AllowedFuelGrades.cs $
 * 
 * 2     07-01-05 8:58 roger.månsson
 * Moved out fuelgrade out of range exception to separate file. Created an
 * interface for COM.
 */
#endregion

namespace Wayne.ForecourtControl
{
    /// <summary>
    /// A collection representing the allowed fuel grades that should be used within the authrorize parameters.
    /// </summary>
    public sealed class AllowedFuelGrades : Wayne.ForecourtControl.IAllowedFuelGrades
    {
        #region Fields

        bool[] allowedFuelGrades = new bool[Defines.MaxFuelGradeCount];

        #endregion 

        #region Construction

        /// <summary>
        /// Internal constructor prohibits creation of this class outside the assembly.
        /// </summary>
        internal AllowedFuelGrades()
        {
        }

        #endregion 

        #region Indexer

        /// <summary>
        /// Indexer returning if the fuel grade is allowed.
        /// </summary>
        /// <param name="index">Fuel grade</param>
        /// <returns>True if the fuel grade is allowed, False if it is disallowed.</returns>
        /// <exception cref="FuelGradeOutOfRangeException">Thrown if the fuel grade is out of range.</exception>
        public bool this[int index]
        {
            get
            {
                EvaluateIndex(index);
                return allowedFuelGrades[index];
            }
            set
            {
                EvaluateIndex(index);
                allowedFuelGrades[index] = value;
            }
        }

        #endregion 

        #region Methods

        private void EvaluateIndex(int index)
        {
            if ((index < 0) || (index >= allowedFuelGrades.Length))
                throw new FuelGradeOutOfRangeException(index.ToString(System.Globalization.CultureInfo.InvariantCulture) + " is out of range for fuel grades");
        }

        #endregion 

        #region Properties

        /// <summary>
        /// Indicates the number of fuel grades.
        /// </summary>
        public int Count
        {
            get
            {
                return allowedFuelGrades.Length;
            }
        }

        #endregion 
    }
}