/* ****************************************************************************
 *
 * Copyright (c) Microsoft Corporation. 
 *
 * This source code is subject to terms and conditions of the Apache License, Version 2.0. A 
 * copy of the license can be found in the License.html file at the root of this distribution. If 
 * you cannot locate the Apache License, Version 2.0, please send an email to 
 * vspython@microsoft.com. By using this source code in any fashion, you are agreeing to be bound 
 * by the terms of the Apache License, Version 2.0.
 *
 * You must not remove this notice, or any other, from this software.
 *
 * ***************************************************************************/

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.Runtime.InteropServices;
using Microsoft.VisualStudio;
using Microsoft.VisualStudio.OLE.Interop;
using Microsoft.VisualStudio.Shell;
//#define ConfigTrace
using Microsoft.VisualStudio.Shell.Interop;
using MSBuildConstruction = Microsoft.Build.Construction;
using MSBuildExecution = Microsoft.Build.Execution;

namespace Microsoft.VisualStudio.Project
{
    [ComVisible(true)]
    public abstract class Config :
        IVsCfg,
        IVsProjectCfg,
        IVsProjectCfg2,
        IVsProjectFlavorCfg,
        IVsDebuggableProjectCfg,
        ISpecifyPropertyPages,
        IVsSpecifyProjectDesignerPages,
        IVsCfgBrowseObject
    {
        public const string Debug = "Debug";
        public const string AnyCPU = "AnyCPU";

        internal string configName;
        private string platformName;
        private ProjectNode project;
        private MSBuildExecution.ProjectInstance currentConfig;
        private IVsProjectFlavorCfg flavoredCfg;
        private List<OutputGroup> outputGroups;
        private BuildableProjectConfig buildableCfg;

        #region properties
        public ProjectNode ProjectMgr
        {
            get
            {
                return this.project;
            }
        }

        public virtual string ConfigName
        {
            get { return configName; }
        }

        public virtual string PlatformName
        {
            get { return platformName; }
        }

        protected IList<OutputGroup> OutputGroups
        {
            get
            {
                if (null == this.outputGroups)
                {
                    // Initialize output groups
                    this.outputGroups = new List<OutputGroup>();

                    // Get the list of group names from the project.
                    // The main reason we get it from the project is to make it easier for someone to modify
                    // it by simply overriding that method and providing the correct MSBuild target(s).
                    IList<KeyValuePair<string, string>> groupNames = project.GetOutputGroupNames();

                    if (groupNames != null)
                    {
                        // Populate the output array
                        foreach (KeyValuePair<string, string> group in groupNames)
                        {
                            OutputGroup outputGroup = CreateOutputGroup(project, group);
                            this.outputGroups.Add(outputGroup);
                        }
                    }

                }
                return this.outputGroups;
            }
        }

        #endregion

        #region ctors
        public Config(ProjectNode project, string configuration, string platform)
        {
            this.project = project;
            this.configName = configuration;
            this.platformName = platform;

            var flavoredCfgProvider = ProjectMgr.GetOuterInterface<IVsProjectFlavorCfgProvider>();
            VsUtilities.ArgumentNotNull("flavoredCfgProvider", flavoredCfgProvider);
            ErrorHandler.ThrowOnFailure(flavoredCfgProvider.CreateProjectFlavorCfg(this, out flavoredCfg));
            VsUtilities.ArgumentNotNull("flavoredCfg", flavoredCfg);

            // if the flavored object support XML fragment, initialize it
            IPersistXMLFragment persistXML = flavoredCfg as IPersistXMLFragment;
            if (null != persistXML)
            {
                this.project.LoadXmlFragment(persistXML, ConfigName, PlatformName);
            }
        }
        #endregion

        #region methods

        public virtual OutputGroup CreateOutputGroup(ProjectNode project, KeyValuePair<string, string> group)
        {
            OutputGroup outputGroup = new OutputGroup(group.Key, group.Value, project, this);
            return outputGroup;
        }
        public void PrepareBuild(uint vsopts, bool clean)
        {
            project.PrepareBuild(vsopts, this.ConfigName, this.PlatformName, clean);
        }

        public virtual string GetConfigurationProperty(string propertyName, bool resetCache)
        {
            MSBuildExecution.ProjectPropertyInstance property = GetMsBuildProperty(propertyName, resetCache);
            if (property == null)
                return null;

            return property.EvaluatedValue;
        }

        public virtual void SetConfigurationProperty(string propertyName, string propertyValue)
        {
            if (!this.project.QueryEditProjectFile(false))
            {
                throw Marshal.GetExceptionForHR(VSConstants.OLE_E_PROMPTSAVECANCELLED);
            }

            string condition = String.Format(CultureInfo.InvariantCulture, ConfigProvider.configString, this.ConfigName);

            SetPropertyUnderCondition(propertyName, propertyValue, condition);

            // property cache will need to be updated
            this.currentConfig = null;

            this.project.SetProjectFileDirty(true);

            return;
        }

        /// <summary>
        /// Emulates the behavior of SetProperty(name, value, condition) on the old MSBuild object model.
        /// This finds a property group with the specified condition (or creates one if necessary) then sets the property in there.
        /// </summary>
        private void SetPropertyUnderCondition(string propertyName, string propertyValue, string condition)
        {
            string conditionTrimmed = (condition == null) ? String.Empty : condition.Trim();

            if (conditionTrimmed.Length == 0)
            {
                this.project.BuildProject.SetProperty(propertyName, propertyValue);
                return;
            }

            // New OM doesn't have a convenient equivalent for setting a property with a particular property group condition. 
            // So do it ourselves.
            MSBuildConstruction.ProjectPropertyGroupElement newGroup = null;

            foreach (MSBuildConstruction.ProjectPropertyGroupElement group in this.project.BuildProject.Xml.PropertyGroups)
            {
                if (String.Equals(group.Condition.Trim(), conditionTrimmed, StringComparison.OrdinalIgnoreCase))
                {
                    newGroup = group;
                    break;
                }
            }

            if (newGroup == null)
            {
                newGroup = this.project.BuildProject.Xml.AddPropertyGroup(); // Adds after last existing PG, else at start of project
                newGroup.Condition = condition;
            }

            foreach (MSBuildConstruction.ProjectPropertyElement property in newGroup.PropertiesReversed) // If there's dupes, pick the last one so we win
            {
                if (String.Equals(property.Name, propertyName, StringComparison.OrdinalIgnoreCase) && property.Condition.Length == 0)
                {
                    property.Value = propertyValue;
                    return;
                }
            }

            newGroup.AddProperty(propertyName, propertyValue);
        }

        /// <summary>
        /// If flavored, and if the flavor config can be dirty, ask it if it is dirty
        /// </summary>
        /// <param name="storageType">Project file or user file</param>
        /// <returns>0 = not dirty</returns>
        public int IsFlavorDirty(_PersistStorageType storageType)
        {
            int isDirty = 0;
            if (this.flavoredCfg != null && this.flavoredCfg is IPersistXMLFragment)
            {
                ErrorHandler.ThrowOnFailure(((IPersistXMLFragment)this.flavoredCfg).IsFragmentDirty((uint)storageType, out isDirty));
            }
            return isDirty;
        }

        /// <summary>
        /// If flavored, ask the flavor if it wants to provide an XML fragment
        /// </summary>
        /// <param name="flavor">Guid of the flavor</param>
        /// <param name="storageType">Project file or user file</param>
        /// <param name="fragment">Fragment that the flavor wants to save</param>
        /// <returns>HRESULT</returns>
        public int GetXmlFragment(Guid flavor, _PersistStorageType storageType, out string fragment)
        {
            fragment = null;
            int hr = VSConstants.S_OK;
            if (this.flavoredCfg != null && this.flavoredCfg is IPersistXMLFragment)
            {
                Guid flavorGuid = flavor;
                hr = ((IPersistXMLFragment)this.flavoredCfg).Save(ref flavorGuid, (uint)storageType, out fragment, 1);
            }
            return hr;
        }
        #endregion

        #region IVsSpecifyPropertyPages

        /// <summary>
        /// Retrieves the configuration dependent property pages.
        /// </summary>
        /// <param name="pages">The pages to return.</param>
        public virtual void GetPages(CAUUID[] pages)
        {
            // We do not check whether the supportsProjectDesigner is set to true on the ProjectNode.
            // We rely that the caller knows what to call on us.
            VsUtilities.ArgumentNotNull("pages", pages);


            if (pages.Length == 0)
            {
                throw new ArgumentException(SR.GetString(SR.InvalidParameter, CultureInfo.CurrentUICulture), "pages");
            }

            // Retrive the list of guids from hierarchy properties.
            // Because a flavor could modify that list we must make sure we are calling the outer most implementation of IVsHierarchy
            string guidsList = String.Empty;
            IVsHierarchy hierarchy = project.GetOuterInterface<IVsHierarchy>();
            object variant = null;
            ErrorHandler.ThrowOnFailure(hierarchy.GetProperty(VSConstants.VSITEMID_ROOT, (int)__VSHPROPID2.VSHPROPID_PropertyPagesCLSIDList, out variant), new int[] { VSConstants.DISP_E_MEMBERNOTFOUND, VSConstants.E_NOTIMPL });
            guidsList = (string)variant;

            Guid[] guids = VsUtilities.GuidsArrayFromSemicolonDelimitedStringOfGuids(guidsList);
            if (guids == null || guids.Length == 0)
            {
                pages[0] = new CAUUID();
                pages[0].cElems = 0;
            }
            else
            {
                pages[0] = PackageUtilities.CreateCAUUIDFromGuidArray(guids);
            }
        }
        #endregion

        #region IVsSpecifyProjectDesignerPages
        /// <summary>
        /// Implementation of the IVsSpecifyProjectDesignerPages. It will retun the pages that are configuration dependent.
        /// </summary>
        /// <param name="pages">The pages to return.</param>
        /// <returns>VSConstants.S_OK</returns>		
        public virtual int GetProjectDesignerPages(CAUUID[] pages)
        {
            // We do not check whether the supportsProjectDesigner is set to true on the ProjectNode.
            // We rely that the caller knows what to call on us.
            VsUtilities.ArgumentNotNull("pages", pages);


            if (pages.Length == 0)
            {
                throw new ArgumentException(SR.GetString(SR.InvalidParameter, CultureInfo.CurrentUICulture), "pages");
            }

            // Retrive the list of guids from hierarchy properties.
            // Because a flavor could modify that list we must make sure we are calling the outer most implementation of IVsHierarchy
            string guidsList = String.Empty;
            IVsHierarchy hierarchy = project.GetOuterInterface<IVsHierarchy>();
            object variant = null;
            ErrorHandler.ThrowOnFailure(hierarchy.GetProperty(VSConstants.VSITEMID_ROOT, (int)__VSHPROPID2.VSHPROPID_CfgPropertyPagesCLSIDList, out variant), new int[] { VSConstants.DISP_E_MEMBERNOTFOUND, VSConstants.E_NOTIMPL });
            guidsList = (string)variant;

            Guid[] guids = VsUtilities.GuidsArrayFromSemicolonDelimitedStringOfGuids(guidsList);
            if (guids == null || guids.Length == 0)
            {
                pages[0] = new CAUUID();
                pages[0].cElems = 0;
            }
            else
            {
                pages[0] = PackageUtilities.CreateCAUUIDFromGuidArray(guids);
            }

            return VSConstants.S_OK;
        }
        #endregion

        #region IVsCfg methods
        /// <summary>
        /// The display name is a two part item
        /// first part is the config name, 2nd part is the platform name
        /// </summary>
        public virtual int get_DisplayName(out string name)
        {
            name = DisplayName;
            return VSConstants.S_OK;
        }

        private string DisplayName
        {
            get
            {
                return this.ConfigName + "|" + this.PlatformName;
            }
        }

        public virtual int get_IsDebugOnly(out int fDebug)
        {
            fDebug = 0;
            if (this.ConfigName == "Debug")
            {
                fDebug = 1;
            }
            return VSConstants.S_OK;
        }
        public virtual int get_IsReleaseOnly(out int fRelease)
        {
            fRelease = 0;
            if (this.ConfigName == "Release")
            {
                fRelease = 1;
            }
            return VSConstants.S_OK;
        }
        #endregion

        #region IVsProjectCfg methods
        public virtual int EnumOutputs(out IVsEnumOutputs eo)
        {
            eo = null;
            return VSConstants.E_NOTIMPL;
        }

        public virtual int get_BuildableProjectCfg(out IVsBuildableProjectCfg pb)
        {
            if (buildableCfg == null) {
                buildableCfg = new BuildableProjectConfig(this);
            }
            pb = buildableCfg;
            return VSConstants.E_NOTIMPL;
        }

        public virtual int get_CanonicalName(out string name)
        {
            name = ConfigName;
            return VSConstants.S_OK;
        }

        public virtual int get_IsPackaged(out int pkgd)
        {
            pkgd = 0;
            return VSConstants.S_OK;
        }

        public virtual int get_IsSpecifyingOutputSupported(out int f)
        {
            f = 1;
            return VSConstants.S_OK;
        }

        public virtual int get_Platform(out Guid platform)
        {
            platform = Guid.Empty;
            return VSConstants.E_NOTIMPL;
        }

        public virtual int get_ProjectCfgProvider(out IVsProjectCfgProvider p)
        {
            p = null;
            IVsCfgProvider cfgProvider = null;
            this.project.GetCfgProvider(out cfgProvider);
            if (cfgProvider != null)
            {
                p = cfgProvider as IVsProjectCfgProvider;
            }

            return (null == p) ? VSConstants.E_NOTIMPL : VSConstants.S_OK;
        }

        public virtual int get_RootURL(out string root)
        {
            root = null;
            return VSConstants.S_OK;
        }

        public virtual int get_TargetCodePage(out uint target)
        {
            target = (uint)System.Text.Encoding.Default.CodePage;
            return VSConstants.S_OK;
        }

        public virtual int get_UpdateSequenceNumber(ULARGE_INTEGER[] li)
        {
            VsUtilities.ArgumentNotNull("li", li);

            li[0] = new ULARGE_INTEGER();
            li[0].QuadPart = 0;
            return VSConstants.S_OK;
        }

        public virtual int OpenOutput(string name, out IVsOutput output)
        {
            output = null;
            return VSConstants.E_NOTIMPL;
        }
        #endregion

        #region IVsProjectCfg2 Members

        public virtual int OpenOutputGroup(string szCanonicalName, out IVsOutputGroup ppIVsOutputGroup)
        {
            ppIVsOutputGroup = null;
            // Search through our list of groups to find the one they are looking forgroupName
            foreach (OutputGroup group in OutputGroups)
            {
                string groupName;
                group.get_CanonicalName(out groupName);
                if (String.Compare(groupName, szCanonicalName, StringComparison.OrdinalIgnoreCase) == 0)
                {
                    ppIVsOutputGroup = group;
                    break;
                }
            }
            return (ppIVsOutputGroup != null) ? VSConstants.S_OK : VSConstants.E_FAIL;
        }

        public virtual int OutputsRequireAppRoot(out int pfRequiresAppRoot)
        {
            pfRequiresAppRoot = 0;
            return VSConstants.E_NOTIMPL;
        }

        public virtual int get_CfgType(ref Guid iidCfg, out IntPtr ppCfg)
        {
            // Delegate to the flavored configuration (to enable a flavor to take control)
            // Since we can be asked for Configuration we don't support, avoid throwing and return the HRESULT directly
            int hr = flavoredCfg.get_CfgType(ref iidCfg, out ppCfg);

            return hr;
        }

        public virtual int get_IsPrivate(out int pfPrivate)
        {
            pfPrivate = 0;
            return VSConstants.S_OK;
        }

        public virtual int get_OutputGroups(uint celt, IVsOutputGroup[] rgpcfg, uint[] pcActual)
        {
            // Are they only asking for the number of groups?
            if (celt == 0)
            {
                if ((null == pcActual) || (0 == pcActual.Length))
                {
                    throw new ArgumentNullException("pcActual");
                }
                pcActual[0] = (uint)OutputGroups.Count;
                return VSConstants.S_OK;
            }

            // Check that the array of output groups is not null
            if ((null == rgpcfg) || (rgpcfg.Length == 0))
            {
                throw new ArgumentNullException("rgpcfg");
            }

            // Fill the array with our output groups
            uint count = 0;
            foreach (OutputGroup group in OutputGroups)
            {
                if (rgpcfg.Length > count && celt > count && group != null)
                {
                    rgpcfg[count] = group;
                    ++count;
                }
            }

            if (pcActual != null && pcActual.Length > 0)
                pcActual[0] = count;

            // If the number asked for does not match the number returned, return S_FALSE
            return (count == celt) ? VSConstants.S_OK : VSConstants.S_FALSE;
        }

        public virtual int get_VirtualRoot(out string pbstrVRoot)
        {
            pbstrVRoot = null;
            return VSConstants.E_NOTIMPL;
        }

        #endregion

        #region IVsDebuggableProjectCfg methods

        /// <summary>
        /// Called by the vs shell to start debugging (managed or unmanaged).
        /// Override this method to support other debug engines.
        /// </summary>
        /// <param name="grfLaunch">A flag that determines the conditions under which to start the debugger. For valid grfLaunch values, see __VSDBGLAUNCHFLAGS</param>
        /// <returns>If the method succeeds, it returns S_OK. If it fails, it returns an error code</returns>
        public abstract int DebugLaunch(uint grfLaunch);

        /// <summary>
        /// Determines whether the debugger can be launched, given the state of the launch flags.
        /// </summary>
        /// <param name="flags">Flags that determine the conditions under which to launch the debugger. 
        /// For valid grfLaunch values, see __VSDBGLAUNCHFLAGS or __VSDBGLAUNCHFLAGS2.</param>
        /// <param name="fCanLaunch">true if the debugger can be launched, otherwise false</param>
        /// <returns>S_OK if the method succeeds, otherwise an error code</returns>
        public virtual int QueryDebugLaunch(uint flags, out int fCanLaunch)
        {
            string assembly = this.project.GetAssemblyName(this.ConfigName, this.PlatformName);
            fCanLaunch = (assembly != null && assembly.ToUpperInvariant().EndsWith(".exe", StringComparison.OrdinalIgnoreCase)) ? 1 : 0;
            if (fCanLaunch == 0)
            {
                string property = GetConfigurationProperty("StartProgram", true);
                fCanLaunch = (property != null && property.Length > 0) ? 1 : 0;
            }
            return VSConstants.S_OK;
        }

        #endregion

        #region IVsCfgBrowseObject

        /// <summary>
        /// Maps back to the configuration corresponding to the browse object. 
        /// </summary>
        /// <param name="cfg">The IVsCfg object represented by the browse object</param>
        /// <returns>If the method succeeds, it returns S_OK. If it fails, it returns an error code. </returns>
        public virtual int GetCfg(out IVsCfg cfg)
        {
            cfg = this;
            return VSConstants.S_OK;
        }

        /// <summary>
        /// Maps back to the hierarchy or project item object corresponding to the browse object.
        /// </summary>
        /// <param name="hier">Reference to the hierarchy object.</param>
        /// <param name="itemid">Reference to the project item.</param>
        /// <returns>If the method succeeds, it returns S_OK. If it fails, it returns an error code. </returns>
        public virtual int GetProjectItem(out IVsHierarchy hier, out uint itemid)
        {
            VsUtilities.CheckNotNull(this.project);
            VsUtilities.CheckNotNull(this.project.NodeProperties);

            return this.project.NodeProperties.GetProjectItem(out hier, out itemid);
        }

        #endregion

        #region helper methods

        private MSBuildExecution.ProjectPropertyInstance GetMsBuildProperty(string propertyName, bool resetCache)
        {
            if (resetCache || this.currentConfig == null)
            {
                // Get properties for current configuration from project file and cache it
                this.project.SetConfiguration(this.ConfigName, this.PlatformName);
                this.project.BuildProject.ReevaluateIfNecessary();
                // Create a snapshot of the evaluated project in its current state
                this.currentConfig = this.project.BuildProject.CreateProjectInstance();

                // Restore configuration
                project.SetCurrentConfiguration();
            }

            if (this.currentConfig == null)
                throw new Exception("Failed to retrieve properties");

            // return property asked for
            return this.currentConfig.GetProperty(propertyName);
        }

        #endregion

        #region IVsProjectFlavorCfg Members
        /// <summary>
        /// This is called to let the flavored config let go
        /// of any reference it may still be holding to the base config
        /// </summary>
        /// <returns></returns>
        int IVsProjectFlavorCfg.Close()
        {
            // This is used to release the reference the flavored config is holding
            // on the base config, but in our scenario these 2 are the same object
            // so we have nothing to do here.
            return VSConstants.S_OK;
        }

        /// <summary>
        /// Actual implementation of get_CfgType.
        /// When not flavored or when the flavor delegate to use
        /// we end up creating the requested config if we support it.
        /// </summary>
        /// <param name="iidCfg">IID representing the type of config object we should create</param>
        /// <param name="ppCfg">Config object that the method created</param>
        /// <returns>HRESULT</returns>
        int IVsProjectFlavorCfg.get_CfgType(ref Guid iidCfg, out IntPtr ppCfg)
        {
            ppCfg = IntPtr.Zero;

            // See if this is an interface we support
            if (iidCfg == typeof(IVsDebuggableProjectCfg).GUID)
            {
                ppCfg = Marshal.GetComInterfaceForObject(this, typeof(IVsDebuggableProjectCfg));
            } else if (iidCfg == typeof(IVsBuildableProjectCfg).GUID) {
                IVsBuildableProjectCfg buildableConfig;
                this.get_BuildableProjectCfg(out buildableConfig);
                ppCfg = Marshal.GetComInterfaceForObject(buildableConfig, typeof(IVsBuildableProjectCfg));
            }

            // If not supported
            if (ppCfg == IntPtr.Zero)
                return VSConstants.E_NOINTERFACE;

            return VSConstants.S_OK;
        }

        #endregion
    }

    [ComVisible(true)]
    [SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Buildable")]
    public class BuildableProjectConfig : IVsBuildableProjectCfg {
        #region fields
        Config config = null;
        EventSinkCollection callbacks = new EventSinkCollection();
        uint vsopts = 0;
        #endregion

        #region ctors
        public BuildableProjectConfig(Config config) {
            this.config = config;
        }
        #endregion

        #region IVsBuildableProjectCfg methods

        public virtual int AdviseBuildStatusCallback(IVsBuildStatusCallback callback, out uint cookie) {
            cookie = callbacks.Add(callback);
            return VSConstants.S_OK;
        }

        public virtual int get_ProjectCfg(out IVsProjectCfg p) {
            p = config;
            return VSConstants.S_OK;
        }

        public virtual int QueryStartBuild(uint options, int[] supported, int[] ready) {
            if (supported != null && supported.Length > 0)
                supported[0] = 1;
            if (ready != null && ready.Length > 0)
                ready[0] = (this.config.ProjectMgr.BuildInProgress) ? 0 : 1;
            return VSConstants.S_OK;
        }

        public virtual int QueryStartClean(uint options, int[] supported, int[] ready) {
            //config.PrepareBuild(false);
            if (supported != null && supported.Length > 0)
                supported[0] = 1;
            if (ready != null && ready.Length > 0)
                ready[0] = (this.config.ProjectMgr.BuildInProgress) ? 0 : 1;
            return VSConstants.S_OK;
    }

        public virtual int QueryStartUpToDateCheck(uint options, int[] supported, int[] ready) {
            //config.PrepareBuild(false);
            if (supported != null && supported.Length > 0)
                supported[0] = 0; // TODO:
            if (ready != null && ready.Length > 0)
                ready[0] = (this.config.ProjectMgr.BuildInProgress) ? 0 : 1;
            return VSConstants.S_OK;
        }

        public virtual int QueryStatus(out int done) {
            done = (this.config.ProjectMgr.BuildInProgress) ? 0 : 1;
            return VSConstants.S_OK;
        }

        public virtual int StartBuild(IVsOutputWindowPane pane, uint options) {
            this.vsopts = options;

            config.PrepareBuild(options, false);

            // Current version of MSBuild wish to be called in an STA
            uint flags = VSConstants.VS_BUILDABLEPROJECTCFGOPTS_REBUILD;

            // If we are not asked for a rebuild, then we build the default target (by passing null)
            this.Build(options, pane, ((options & flags) != 0) ? MsBuildTarget.Rebuild : null, null);

            return VSConstants.S_OK;
        }

        public virtual int StartClean(IVsOutputWindowPane pane, uint options) {
            this.vsopts = options;

            config.PrepareBuild(options, true);
            // Current version of MSBuild wish to be called in an STA
            this.Build(options, pane, MsBuildTarget.Clean, null);
            return VSConstants.S_OK;
        }

        public virtual int StartUpToDateCheck(IVsOutputWindowPane pane, uint options) {
            return VSConstants.E_NOTIMPL;
        }

        public virtual int Stop(int fsync) 
        {
            return this.config.ProjectMgr.StopBuild(this.vsopts, fsync != 0);
        }

        public virtual int UnadviseBuildStatusCallback(uint cookie) {
            callbacks.RemoveAt(cookie);
            return VSConstants.S_OK;
        }

        public virtual int Wait(uint ms, int fTickWhenMessageQNotEmpty) {
            return VSConstants.E_NOTIMPL;
        }
        #endregion

        #region helpers

        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes")]
        private bool NotifyBuildBegin() {
            int shouldContinue = 1;
            foreach (IVsBuildStatusCallback cb in callbacks) {
                try {
                    ErrorHandler.ThrowOnFailure(cb.BuildBegin(ref shouldContinue));
                    if (shouldContinue == 0) {
                        return false;
                    }
                } catch (Exception e) {
                    // If those who ask for status have bugs in their code it should not prevent the build/notification from happening
                    Debug.Fail(String.Format(CultureInfo.CurrentCulture, SR.GetString(SR.BuildEventError, CultureInfo.CurrentUICulture), e.Message));
                }
            }

            return true;
    }

        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes")]
        private void NotifyBuildEnd(MSBuildResult result, string buildTarget) {
            int success = ((result == MSBuildResult.Successful) ? 1 : 0);

            foreach (IVsBuildStatusCallback cb in callbacks) {
                OnNotifyBuildEnd(result, buildTarget, cb, success);
            }
        }

        protected virtual void OnNotifyBuildEnd(MSBuildResult result, string buildTarget, IVsBuildStatusCallback cb, int success)
        {
            try
            {
                ErrorHandler.ThrowOnFailure(cb.BuildEnd(success));
            }
            catch (Exception e)
            {
                // If those who ask for status have bugs in their code it should not prevent the build/notification from happening
                Debug.Fail(String.Format(CultureInfo.CurrentCulture, SR.GetString(SR.BuildEventError, CultureInfo.CurrentUICulture), e.Message));
            }
            finally
            {
                // We want to refresh the references if we are building with the Build or Rebuild target or if the project was opened for browsing only.
                bool shouldRepaintReferences = (buildTarget == null || buildTarget == MsBuildTarget.Build || buildTarget == MsBuildTarget.Rebuild);

                // Now repaint references if that is needed. 
                // We hardly rely here on the fact the ResolveAssemblyReferences target has been run as part of the build.
                // One scenario to think at is when an assembly reference is renamed on disk thus becomming unresolvable, 
                // but msbuild can actually resolve it.
                // Another one if the project was opened only for browsing and now the user chooses to build or rebuild.
                if (shouldRepaintReferences && (result == MSBuildResult.Successful))
                {
                    this.RefreshReferences();
                }
            }
        }

        public void Build(uint options, IVsOutputWindowPane output, string target, IEnumerable<string> files) {
            if (!this.NotifyBuildBegin()) {
                return;
            }

            try {
                config.ProjectMgr.BuildAsync(options, this.config.ConfigName, this.config.PlatformName, output, target, files, (result, buildTarget) => this.NotifyBuildEnd(result, buildTarget));
            } catch (Exception e) {
                Trace.WriteLine("Exception : " + e.Message);
                ErrorHandler.ThrowOnFailure(output.OutputStringThreadSafe("Unhandled Exception:" + e.Message + "\n"));
                this.NotifyBuildEnd(MSBuildResult.Failed, target);
                throw;
            } finally {
                ErrorHandler.ThrowOnFailure(output.FlushToTaskList());
            }
        }

        /// <summary>
        /// Refreshes references and redraws them correctly.
        /// </summary>
        protected virtual void RefreshReferences() {
            // Refresh the reference container node for assemblies that could be resolved.
            IReferenceContainer referenceContainer = this.config.ProjectMgr.GetReferenceContainer();
            if (referenceContainer != null) {
                foreach (ReferenceNode referenceNode in referenceContainer.EnumReferences()) {
                    referenceNode.RefreshReference();
                }
            }
        }
        #endregion
    }

}