using System.ComponentModel;
using System.Reflection;

/// <summary>
/// Contains an enumerated constant value and a friendly description of that value, if one exists.
/// </summary>
/// <typeparam name="T">
/// The enumerated type of the value.
/// </typeparam>
public class EnumDescriptor<T>
{
    /// <summary>
    /// The friendly description of the value.
    /// </summary>
    private string _description;
    /// <summary>
    /// The enumerated constant value.
    /// </summary>
    private T _value;

    /// <summary>
    /// Gets the friendly description of the value.
    /// </summary>
    /// <value>
    /// A <b>String</b> containing the value's Description attribute value if one exists; otherwise, the value name.
    /// </value>
    public string Description
    {
        get
        {
            return this._description;
        }
        set
        {
            this._description = value;
        }
    }

    /// <summary>
    /// Gets the enumerated constant value.
    /// </summary>
    /// <value>
    /// An enumerated constant of the <b>EnumDescriptor's</b> generic parameter type.
    /// </value>
    public T Value
    {
        get
        {
            return this._value;
        }
        set
        {
            this._value = value;
        }
    }

    /// <summary>
    /// Creates a new instance of the <b>EnumDescriptor</b> class.
    /// </summary>
    /// <param name="value">
    /// The value to provide a description for.
    /// </param>
    public EnumDescriptor(T value)
    {
        this._value = value;

        // Get the Description attribute.
        FieldInfo field = value.GetType().GetField(value.ToString());
        DescriptionAttribute[] attributes = (DescriptionAttribute[])field.GetCustomAttributes(typeof(DescriptionAttribute),
                                                                                              false);

        // Use the Description attribte if one exists, otherwise use the value itself as the description.
        this._description = attributes.Length == 0 ? value.ToString()
                                                   : attributes[0].Description;
    }

    /// <summary>
    /// Overridden.  Creates a string representation of the object.
    /// </summary>
    /// <returns>
    /// The friendly description of the value.
    /// </returns>
    public override string ToString()
    {
        return this._description;
    }
}