/// Copyright (c) Microsoft Corporation.  All rights reserved.

using System;
using System.Diagnostics;
using Microsoft.VisualStudio;
using Microsoft.VisualStudio.Shell.Interop;

namespace Microsoft.VisualStudio.Project
{
	/// <summary>
	/// Used by a project to query the environment for permission to add, remove, or rename a file or directory in a solution
	/// </summary>
	internal class TrackDocumentsHelper
	{
		#region fields
		private ProjectNode projectMgr;
		#endregion

		#region properties

		#endregion

		#region ctors
		internal TrackDocumentsHelper(ProjectNode project)
		{
			this.projectMgr = project;
		}
		#endregion

		#region helper methods
		/// <summary>
		/// Gets the IVsTrackProjectDocuments2 object by asking the service provider for it.
		/// </summary>
		/// <returns>the IVsTrackProjectDocuments2 object</returns>
		private IVsTrackProjectDocuments2 GetIVsTrackProjectDocuments2()
		{
			Debug.Assert(this.projectMgr != null && !this.projectMgr.IsClosed && this.projectMgr.Site != null);

			IVsTrackProjectDocuments2 documentTracker = this.projectMgr.Site.GetService(typeof(SVsTrackProjectDocuments)) as IVsTrackProjectDocuments2;
			if(documentTracker == null)
			{
				throw new InvalidOperationException();
			}

			return documentTracker;
		}

		/// <summary>
		/// Asks the environment for permission to add files.
		/// </summary>
		/// <param name="files">The files to add.</param>
		/// <param name="flags">The VSQUERYADDFILEFLAGS flags associated to the files added</param>
		/// <returns>true if the file can be added, false if not.</returns>
		internal bool CanAddItems(string[] files, VSQUERYADDFILEFLAGS[] flags)
		{
			// If we are silent then we assume that the file can be added, since we do not want to trigger this event.
			if((this.projectMgr.EventTriggeringFlag & ProjectNode.EventTriggering.DoNotTriggerTrackerEvents) != 0)
			{
				return true;
			}

			if(files == null || files.Length == 0)
			{
				return false;
			}

			int len = files.Length;
			VSQUERYADDFILERESULTS[] summary = new VSQUERYADDFILERESULTS[1];
			ErrorHandler.ThrowOnFailure(this.GetIVsTrackProjectDocuments2().OnQueryAddFiles(this.projectMgr, len, files, flags, summary, null));
			if(summary[0] == VSQUERYADDFILERESULTS.VSQUERYADDFILERESULTS_AddNotOK)
			{
				return false;
			}

			return true;
		}

		/// <summary>
		/// Notify the environment about a file just added
		/// </summary>
		internal void OnItemAdded(string file, VSADDFILEFLAGS flag)
		{
			if((this.projectMgr.EventTriggeringFlag & ProjectNode.EventTriggering.DoNotTriggerTrackerEvents) == 0)
			{
				ErrorHandler.ThrowOnFailure(this.GetIVsTrackProjectDocuments2().OnAfterAddFilesEx(this.projectMgr, 1, new string[1] { file }, new VSADDFILEFLAGS[1] { flag }));
			}
		}

		/// <summary>
		///  Asks the environment for permission to remove files.
		/// </summary>
		/// <param name="files">an array of files to remove</param>
		/// <param name="flags">The VSQUERYREMOVEFILEFLAGS associated to the files to be removed.</param>
		/// <returns>true if the files can be removed, false if not.</returns>
		internal bool CanRemoveItems(string[] files, VSQUERYREMOVEFILEFLAGS[] flags)
		{
			// If we are silent then we assume that the file can be removed, since we do not want to trigger this event.
			if((this.projectMgr.EventTriggeringFlag & ProjectNode.EventTriggering.DoNotTriggerTrackerEvents) != 0)
			{
				return true;
			}

			if(files == null || files.Length == 0)
			{
				return false;
			}
			int length = files.Length;

			VSQUERYREMOVEFILERESULTS[] summary = new VSQUERYREMOVEFILERESULTS[1];

			ErrorHandler.ThrowOnFailure(this.GetIVsTrackProjectDocuments2().OnQueryRemoveFiles(this.projectMgr, length, files, flags, summary, null));
			if(summary[0] == VSQUERYREMOVEFILERESULTS.VSQUERYREMOVEFILERESULTS_RemoveNotOK)
			{
				return false;
			}

			return true;
		}

		/// <summary>
		/// Notify the environment about a file just removed
		/// </summary>
		internal void OnItemRemoved(string file, VSREMOVEFILEFLAGS flag)
		{
			if((this.projectMgr.EventTriggeringFlag & ProjectNode.EventTriggering.DoNotTriggerTrackerEvents) == 0)
			{
				ErrorHandler.ThrowOnFailure(this.GetIVsTrackProjectDocuments2().OnAfterRemoveFiles(this.projectMgr, 1, new string[1] { file }, new VSREMOVEFILEFLAGS[1] { flag }));
			}
		}

		/// <summary>
		///  Asks the environment for permission to rename files.
		/// </summary>
		/// <param name="oldFileName">Path to the file to be renamed.</param>
		/// <param name="newFileName">Path to the new file.</param>
		/// <param name="flag">The VSRENAMEFILEFLAGS associated with the file to be renamed.</param>
		/// <returns>true if the file can be renamed. Otherwise false.</returns>
		internal bool CanRenameItem(string oldFileName, string newFileName, VSRENAMEFILEFLAGS flag)
		{
			// If we are silent then we assume that the file can be renamed, since we do not want to trigger this event.
			if((this.projectMgr.EventTriggeringFlag & ProjectNode.EventTriggering.DoNotTriggerTrackerEvents) != 0)
			{
				return true;
			}

			int iCanContinue = 0;
			ErrorHandler.ThrowOnFailure(this.GetIVsTrackProjectDocuments2().OnQueryRenameFile(this.projectMgr, oldFileName, newFileName, flag, out iCanContinue));
			return (iCanContinue != 0);
		}

		/// <summary>
		/// Get's called to tell the env that a file was renamed
		/// </summary>
		/// 
		internal void OnItemRenamed(string strOldName, string strNewName, VSRENAMEFILEFLAGS flag)
		{
			if((this.projectMgr.EventTriggeringFlag & ProjectNode.EventTriggering.DoNotTriggerTrackerEvents) == 0)
			{
				ErrorHandler.ThrowOnFailure(this.GetIVsTrackProjectDocuments2().OnAfterRenameFile(this.projectMgr, strOldName, strNewName, flag));
			}
		}
		#endregion
	}
}