// ****************************************************************

// Copyright 2007, Charlie Poole

// This is free software licensed under the NUnit license. You may

// obtain a copy of the license at http://nunit.org

// ****************************************************************



using System;



namespace NUnit.Util

{

	/// <summary>

	/// Summary description for RecentFilesService.

	/// </summary>

	public class RecentFilesService : RecentFiles, NUnit.Core.IService

	{

		private RecentFilesCollection fileEntries = new RecentFilesCollection();



		private ISettings settings;



		public static readonly int MinSize = 0;



		public static readonly int MaxSize = 24;



		public static readonly int DefaultSize = 5;



		#region Constructor

		public RecentFilesService()

			: this( Services.UserSettings ) { }



		public RecentFilesService( ISettings settings ) 

		{

			this.settings = settings;

		}

		#endregion



		#region Properties

		public int Count

		{

			get { return fileEntries.Count; }

		}



		public int MaxFiles

		{

			get 

			{ 

				int size = settings.GetSetting("Gui.RecentProjects.MaxFiles", -1 );

                if (size < 0)

                {

                    size = settings.GetSetting("RecentProjects.MaxFiles", DefaultSize);

                    if (size != DefaultSize)

                        settings.SaveSetting("Gui.RecentProjects.MaxFiles", size);

                    settings.RemoveSetting("RecentProjects.MaxFiles");

                }

				

				if ( size < MinSize ) size = MinSize;

				if ( size > MaxSize ) size = MaxSize;

				

				return size;

			}

			set 

			{ 

				int oldSize = MaxFiles;

				int newSize = value;

				

				if ( newSize < MinSize ) newSize = MinSize;

				if ( newSize > MaxSize ) newSize = MaxSize;



				settings.SaveSetting( "Gui.RecentProjects.MaxFiles", newSize );

				if ( newSize < oldSize ) SaveEntriesToSettings( this. settings );

			}

		}

		#endregion



		#region Public Methods

		public RecentFilesCollection Entries

		{

			get

			{

				return fileEntries;

			}

		}

		

		public void Remove( string fileName )

		{

			fileEntries.Remove( fileName );

		}



		public void SetMostRecent( string fileName )

		{

			SetMostRecent( new RecentFileEntry( fileName ) );

		}



		public void SetMostRecent( RecentFileEntry entry )

		{

			int index = fileEntries.IndexOf(entry.Path);



			if(index != -1)

				fileEntries.RemoveAt(index);



			fileEntries.Insert( 0, entry );

			if( fileEntries.Count > MaxFiles )

				fileEntries.RemoveAt( MaxFiles );

		}

		#endregion



		#region Helper Methods for saving and restoring the settings

		private void LoadEntriesFromSettings( ISettings settings )

		{

			fileEntries.Clear();



            AddEntriesForPrefix("Gui.RecentProjects");



            // Try legacy entries if nothing was found

            if (fileEntries.Count == 0)

            {

                AddEntriesForPrefix("RecentProjects.V2");

                AddEntriesForPrefix("RecentProjects.V1");

            }



            // Try even older legacy format

            if (fileEntries.Count == 0)

                AddEntriesForPrefix("RecentProjects");

		}



        private void AddEntriesForPrefix(string prefix)

        {

            for (int index = 1; index < MaxFiles; index++)

            {

                if (fileEntries.Count >= MaxFiles) break;



                string fileSpec = settings.GetSetting(GetRecentFileKey(prefix, index)) as string;

                if (fileSpec != null) fileEntries.Add(RecentFileEntry.Parse(fileSpec));

            }

        }



		private void SaveEntriesToSettings( ISettings settings )

		{

			string prefix = "Gui.RecentProjects";



			while( fileEntries.Count > MaxFiles )

				fileEntries.RemoveAt( fileEntries.Count - 1 );



			for( int index = 0; index < MaxSize; index++ ) 

			{

				string keyName = GetRecentFileKey( prefix, index + 1 );

				if ( index < fileEntries.Count )

					settings.SaveSetting( keyName, fileEntries[index].Path );

				else

					settings.RemoveSetting( keyName );

			}



            // Remove legacy entries here

            settings.RemoveGroup("RecentProjects");

		}



		private string GetRecentFileKey( string prefix, int index )

		{

			return string.Format( "{0}.File{1}", prefix, index );

		}

		#endregion



		#region IService Members



		public void UnloadService()

		{

			SaveEntriesToSettings( this.settings );

		}



		public void InitializeService()

		{

			LoadEntriesFromSettings( this.settings );

		}



		#endregion

	}

}