using System;
using JD.Kernel.StaticHelpers;

namespace JD.TeaBoxAddinSystem.Addins.Description
{
    /// <summary>
    /// An <see cref="ExtensionPoint"/> is a path in the addin tree in which addins can place <see cref="ExtensionNode"/>s.
    /// </summary>
    public sealed class ExtensionPoint : AddinObject, IExtensionTypeSetContainer
    {
        #region Variables

        private readonly string m_path;
        private readonly ExtensionTypeSet m_extensionTypeSet = new ExtensionTypeSet();

        private string m_name = string.Empty;
        private string m_description = string.Empty;

        #endregion

        #region Constructor

        /// <summary>
        /// Constructor.
        /// </summary>
        /// <param name="path"></param>
        public ExtensionPoint(string path)
        {
            Throw.IfEmpty(path, "path");
            m_path = NormalizePath(path);
        }

        #endregion

        #region Properties

        /// <summary>
        /// Whether the extension point is deprecated
        /// </summary>
        public bool IsDeprecated
        {
            get { return !string.IsNullOrEmpty(DeprecationMessage); }
        }

        public string DeprecationMessage
        {
            get;
            set;
        }

        #region Path Separators

        /// <summary>
        /// Main Path Separator.
        /// </summary>
        public static readonly char PathSeparator = System.IO.Path.AltDirectorySeparatorChar;

        /// <summary>
        /// Valid path separators.
        /// </summary>
        private static readonly char[] m_pathSeparators = new char[] { System.IO.Path.AltDirectorySeparatorChar, System.IO.Path.DirectorySeparatorChar };

        /// <summary>
        /// Returns the valid path separators.
        /// </summary>
        /// <returns></returns>
        public static char[] GetPathSeparators()
        {
            return (char[])m_pathSeparators.Clone();
        }

        #endregion

        /// <summary>
        /// Path of this extension point.
        /// </summary>
        public string Path
        {
            get
            {
                return m_path;
            }
        }        

        /// <summary>
        /// The extension type set that is used for this extension point.
        /// </summary>
        public ExtensionTypeSet ExtensionTypeSet
        {
            get
            {
                return m_extensionTypeSet;
            }
        }

        /// <summary>
        /// Optional name of this extension point.
        /// </summary>
        public string Name
        {
            get
            {
                return m_name;
            }
            set
            {
                ThrowIfLoaded();
                m_name = value;
            }
        }

        /// <summary>
        /// Optional description of this extension point.
        /// </summary>
        public string Description
        {
            get
            {
                return m_description;
            }
            set
            {
                ThrowIfLoaded();
                m_description = value;
            }
        }

        #endregion

        #region Methods

        /// <summary>
        /// Overriden.
        /// </summary>
        /// <param name="e"></param>
        internal override void OnModuleChanged(EventArgs e)
        {
            m_extensionTypeSet.Module = Module;

            base.OnModuleChanged(e);
        }

        internal static string NormalizePath(string path)
        {
            path = FileUtility.FormatPath(path);

            if (!string.IsNullOrEmpty(path) && path[0] == PathSeparator)
            {
                path = path.Remove(0, 1);
            }

            return path;
        }

        /// <summary>
        /// Overriden.
        /// </summary>
        /// <returns></returns>
        public override string ToString()
        {
            return $"[ExtensionPoint: Path={Path}{(string.IsNullOrEmpty(Name) ? string.Empty : $", Name={Name}")}]";
        }

        #endregion
    }
}