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

namespace Wayne.Lib.StateEngine
{
    /// <summary>
    /// An attribute that can be applied to state classes, that is used to 
    /// document the state.
    /// </summary>
    [AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = true)]
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1036:OverrideMethodsOnComparableTypes")]
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1019:DefineAccessorsForAttributeArguments")]
    public sealed class StateDescriptionAttribute : Attribute, IComparable
    {
        #region Fields

        private StateDescriptionType descriptionType;
        private string description;

        #endregion

        #region Construction

        /// <summary>
        /// Creates a Summary state engine description for the class.
        /// </summary>
        /// <param name="description">Description.</param>
        public StateDescriptionAttribute(string description)
            : this(StateDescriptionType.Summary, description)
        {
        }

        /// <summary>
        /// Creates a state engine description for the class.
        /// </summary>
        /// <param name="descriptionType">Category for the description.</param>
        /// <param name="description">Description.</param>
        public StateDescriptionAttribute(StateDescriptionType descriptionType, string description)
        {
            this.descriptionType = descriptionType;
            this.description = description;
        }

        /// <summary>
        /// Creates a state engine description for the class.
        /// </summary>
        /// <param name="descriptionType">Category for the description.</param>
        /// <param name="type">Type that stands for the description.</param>
        public StateDescriptionAttribute(StateDescriptionType descriptionType, Type type)
        {
            if (type == null)
                throw new ArgumentNullException("type");
            this.descriptionType = descriptionType;
            this.description = type.FullName;
        }

        #endregion

        #region Properties

        /// <summary>
        /// The category of the description.
        /// </summary>
        public StateDescriptionType DescriptionType
        {
            get { return descriptionType; }
        }

        /// <summary>
        /// Description.
        /// </summary>
        public string Description
        {
            get { return description; }
        }

        #endregion

        #region IComparable Members

        /// <summary>
        /// Compares this attribute with another one.
        /// </summary>
        /// <param name="obj"></param>
        /// <returns></returns>
        public int CompareTo(object obj)
        {
            StateDescriptionAttribute compareStateDescriptionAttribute = obj as StateDescriptionAttribute;
            if (compareStateDescriptionAttribute != null)
                return DescriptionType.CompareTo(compareStateDescriptionAttribute.DescriptionType);
            return 0;
        }

        #endregion
    }
}