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

Copyright (c) Microsoft Corporation. All rights reserved.
This code is licensed under the Visual Studio SDK license terms.
THIS CODE IS PROVIDED *AS IS* WITHOUT WARRANTY OF
ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY
IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR
PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.

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

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Runtime.InteropServices;
using Microsoft.VisualStudio;
using Microsoft.VisualStudio.Shell.Interop;
using IServiceProvider = System.IServiceProvider;

namespace Microsoft.VisualStudio.Project
{
	[CLSCompliant(false)]
	public class SolutionListenerForProjectReferenceUpdate : SolutionListener
	{

		#region ctor
		public SolutionListenerForProjectReferenceUpdate(IServiceProvider serviceProvider)
			: base(serviceProvider)
		{
		}
		#endregion

		#region overridden methods
		/// <summary>
		/// Delete this project from the references of projects of this type, if it is found.
		/// </summary>
		/// <param name="hierarchy"></param>
		/// <param name="removed"></param>
		/// <returns></returns>
		public override int OnBeforeCloseProject(IVsHierarchy hierarchy, int removed)
		{
			if(removed != 0)
			{
				List<ProjectReferenceNode> projectReferences = this.GetProjectReferencesContainingThisProject(hierarchy);

				foreach(ProjectReferenceNode projectReference in projectReferences)
				{
					projectReference.Remove(false);
					// Set back the remove state on the project refererence. The reason why we are doing this is that the OnBeforeUnloadProject immedaitely calls
					// OnBeforeCloseProject, thus we would be deleting references when we should not. Unload should not remove references.
					projectReference.CanRemoveReference = true;
				}
			}

			return VSConstants.S_OK;
		}


		/// <summary>
		/// Needs to update the dangling reference on projects that contain this hierarchy as project reference.
		/// </summary>
		/// <param name="stubHierarchy"></param>
		/// <param name="realHierarchy"></param>
		/// <returns></returns>
		public override int OnAfterLoadProject(IVsHierarchy stubHierarchy, IVsHierarchy realHierarchy)
		{
			List<ProjectReferenceNode> projectReferences = this.GetProjectReferencesContainingThisProject(realHierarchy);

			// Refersh the project reference node. That should trigger the drawing of the normal project reference icon.
			foreach(ProjectReferenceNode projectReference in projectReferences)
			{
				projectReference.CanRemoveReference = true;

				projectReference.OnInvalidateItems(projectReference.Parent);
			}

			return VSConstants.S_OK;
		}


		public override int OnAfterRenameProject(IVsHierarchy hierarchy)
		{
			if(hierarchy == null)
			{
				return VSConstants.E_INVALIDARG;
			}

			try
			{
				List<ProjectReferenceNode> projectReferences = this.GetProjectReferencesContainingThisProject(hierarchy);

				// Collect data that is needed to initialize the new project reference node.
				string projectRef;
				ErrorHandler.ThrowOnFailure(this.Solution.GetProjrefOfProject(hierarchy, out projectRef));

				object nameAsObject;
				ErrorHandler.ThrowOnFailure(hierarchy.GetProperty(VSConstants.VSITEMID_ROOT, (int)__VSHPROPID.VSHPROPID_Name, out nameAsObject));
				string projectName = (string)nameAsObject;

				string projectPath = String.Empty;

				IVsProject3 project = hierarchy as IVsProject3;

				if(project != null)
				{
					ErrorHandler.ThrowOnFailure(project.GetMkDocument(VSConstants.VSITEMID_ROOT, out projectPath));
					projectPath = Path.GetDirectoryName(projectPath);
				}

				// Remove and re add the node.
				foreach(ProjectReferenceNode projectReference in projectReferences)
				{
					ProjectNode projectMgr = projectReference.ProjectMgr;
					IReferenceContainer refContainer = projectMgr.GetReferenceContainer();
					projectReference.Remove(false);

					VSCOMPONENTSELECTORDATA selectorData = new VSCOMPONENTSELECTORDATA();
					selectorData.type = VSCOMPONENTTYPE.VSCOMPONENTTYPE_Project;
					selectorData.bstrTitle = projectName;
					selectorData.bstrFile = projectPath;
					selectorData.bstrProjRef = projectRef;
					refContainer.AddReferenceFromSelectorData(selectorData);
				}
			}
			catch(COMException e)
			{
				return e.ErrorCode;
			}

			return VSConstants.S_OK;
		}


		public override int OnBeforeUnloadProject(IVsHierarchy realHierarchy, IVsHierarchy stubHierarchy)
		{
			List<ProjectReferenceNode> projectReferences = this.GetProjectReferencesContainingThisProject(realHierarchy);

			// Refresh the project reference node. That should trigger the drawing of the dangling project reference icon.
			foreach(ProjectReferenceNode projectReference in projectReferences)
			{
				projectReference.IsNodeValid = true;
				projectReference.OnInvalidateItems(projectReference.Parent);
				projectReference.CanRemoveReference = false;
				projectReference.IsNodeValid = false;
				projectReference.ReferencedProjectObject = null;
			}

			return VSConstants.S_OK;

		}

		#endregion

		#region helper methods
		private List<ProjectReferenceNode> GetProjectReferencesContainingThisProject(IVsHierarchy inputHierarchy)
		{
			List<ProjectReferenceNode> projectReferences = new List<ProjectReferenceNode>();
			if(this.Solution == null || inputHierarchy == null)
			{
				return projectReferences;
			}

			uint flags = (uint)(__VSENUMPROJFLAGS.EPF_ALLPROJECTS | __VSENUMPROJFLAGS.EPF_LOADEDINSOLUTION);
			Guid enumOnlyThisType = Guid.Empty;
			IEnumHierarchies enumHierarchies = null;

			ErrorHandler.ThrowOnFailure(this.Solution.GetProjectEnum(flags, ref enumOnlyThisType, out enumHierarchies));
			Debug.Assert(enumHierarchies != null, "Could not get list of hierarchies in solution");

			IVsHierarchy[] hierarchies = new IVsHierarchy[1];
			uint fetched;
			int returnValue = VSConstants.S_OK;
			do
			{
				returnValue = enumHierarchies.Next(1, hierarchies, out fetched);
				Debug.Assert(fetched <= 1, "We asked one project to be fetched VSCore gave more than one. We cannot handle that");
				if(returnValue == VSConstants.S_OK && fetched == 1)
				{
					IVsHierarchy hierarchy = hierarchies[0];
					Debug.Assert(hierarchy != null, "Could not retrieve a hierarchy");
					IReferenceContainerProvider provider = hierarchy as IReferenceContainerProvider;
					if(provider != null)
					{
						IReferenceContainer referenceContainer = provider.GetReferenceContainer();

						Debug.Assert(referenceContainer != null, "Could not found the References virtual node");
						ProjectReferenceNode projectReferenceNode = GetProjectReferenceOnNodeForHierarchy(referenceContainer.EnumReferences(), inputHierarchy);
						if(projectReferenceNode != null)
						{
							projectReferences.Add(projectReferenceNode);
						}
					}
				}
			} while(returnValue == VSConstants.S_OK && fetched == 1);

			return projectReferences;
		}

		private static ProjectReferenceNode GetProjectReferenceOnNodeForHierarchy(IList<ReferenceNode> references, IVsHierarchy inputHierarchy)
		{
			if(references == null)
			{
				return null;
			}

			Guid projectGuid;
			ErrorHandler.ThrowOnFailure(inputHierarchy.GetGuidProperty(VSConstants.VSITEMID_ROOT, (int)__VSHPROPID.VSHPROPID_ProjectIDGuid, out projectGuid));

			string canonicalName;
			ErrorHandler.ThrowOnFailure(inputHierarchy.GetCanonicalName(VSConstants.VSITEMID_ROOT, out canonicalName));
			foreach(ReferenceNode refNode in references)
			{
				ProjectReferenceNode projRefNode = refNode as ProjectReferenceNode;
				if(projRefNode != null)
				{
					if(projRefNode.ReferencedProjectGuid == projectGuid)
					{
						return projRefNode;
					}

					// Try with canonical names, if the project that is removed is an unloaded project than the above criteria will not pass.
					if(!String.IsNullOrEmpty(projRefNode.Url) && NativeMethods.IsSamePath(projRefNode.Url, canonicalName))
					{
						return projRefNode;
					}
				}
			}

			return null;

		}
		#endregion
	}
}