//
// (C) Copyright 2003-2010 by Autodesk, Inc.
//
// Permission to use, copy, modify, and distribute this software in
// object code form for any purpose and without fee is hereby granted,
// provided that the above copyright notice appears in all copies and
// that both that copyright notice and the limited warranty and
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// documentation.
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// restrictions set forth in FAR 52.227-19 (Commercial Computer
// Software - Restricted Rights) and DFAR 252.227-7013(c)(1)(ii)
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//

using System;
using System.Collections.Generic;
using System.Text;

using Autodesk.Revit;
using Autodesk.Revit.DB.Events;
using System.Windows.Forms;
using Autodesk.Revit.DB;
using Autodesk.Revit.UI;
using Autodesk.Revit.ApplicationServices;


namespace Revit.SDK.Samples.CancelSave.CS
{
    /// <summary>
    /// This class is an external application which checks whether "Project Status" is updated 
    /// once the project is about to be saved. If updated pass the save else cancel the save and inform user with one message.
    /// </summary>
    [Autodesk.Revit.Attributes.Transaction(Autodesk.Revit.Attributes.TransactionMode.Automatic)]
    [Autodesk.Revit.Attributes.Regeneration(Autodesk.Revit.Attributes.RegenerationOption.Automatic)]
    [Autodesk.Revit.Attributes.Journaling(Autodesk.Revit.Attributes.JournalingMode.NoCommandData)]
    public class CancelSave : IExternalApplication
    {
        #region Memeber Variables

        // The dictionary contains document hashcode and its original "Project Status" pair.
        Dictionary<int, string> documentOriginalStatusDic = new Dictionary<int, string>();

        #endregion

        #region IExternalApplication Members

        /// <summary>
        /// Implement OnStartup method of IExternalApplication interface.
        /// This method subscribes to DocumentOpened, DocumentCreated, DocumentSaving and DocumentSavingAs events.
        /// The first two events are used to reserve "Project Status" original value; 
        /// The last two events are used to check whether "Project Status" has been updated, and re-reserve current value as new original value for next compare.
        /// </summary>
        /// <param name="application">Controlled application to be loaded to Revit process.</param>
        /// <returns>The status of the external application</returns>
        public Autodesk.Revit.UI.Result OnStartup(UIControlledApplication application)
        {
            // subscribe to DocumentOpened, DocumentCreated, DocumentSaving and DocumentSavingAs events
            application.ControlledApplication.DocumentOpened   += new EventHandler<DocumentOpenedEventArgs>(ReservePojectOriginalStatus);
            application.ControlledApplication.DocumentCreated  += new EventHandler<DocumentCreatedEventArgs>(ReservePojectOriginalStatus);
            application.ControlledApplication.DocumentSaving   += new EventHandler<DocumentSavingEventArgs>(CheckProjectStatusUpdate);
            application.ControlledApplication.DocumentSavingAs += new EventHandler<DocumentSavingAsEventArgs>(CheckProjectStatusUpdate);

            return Autodesk.Revit.UI.Result.Succeeded;
        }

        /// <summary>
        /// Implement OnShutdown method of IExternalApplication interface. 
        /// </summary>
        /// <param name="application">Controlled application to be shutdown.</param>
        /// <returns>The status of the external application.</returns>
        public Autodesk.Revit.UI.Result OnShutdown(UIControlledApplication application)
        {
            // unsubscribe to DocumentOpened, DocumentCreated, DocumentSaving and DocumentSavingAs events
            application.ControlledApplication.DocumentOpened   -= new EventHandler<DocumentOpenedEventArgs>(ReservePojectOriginalStatus);
            application.ControlledApplication.DocumentCreated  -= new EventHandler<DocumentCreatedEventArgs>(ReservePojectOriginalStatus);
            application.ControlledApplication.DocumentSaving   -= new EventHandler<DocumentSavingEventArgs>(CheckProjectStatusUpdate);
            application.ControlledApplication.DocumentSavingAs -= new EventHandler<DocumentSavingAsEventArgs>(CheckProjectStatusUpdate);

            // finalize the log file.
            LogManager.LogFinalize();

            return Autodesk.Revit.UI.Result.Succeeded;
        }

        #endregion

        #region EventHandler

        /// <summary>
        /// Event handler method for DocumentOpened and DocumentCreated events.
        /// This method will reserve "Project Status" value after document has been opened or created.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="args">Event arguments that contains the event data.</param>
        private void ReservePojectOriginalStatus(Object sender, PostDocEventArgs args)
        {
            // The document associated with the event. Here means which document has been created or opened.
            Document doc = args.Document;

            // Project information is unavailable for Family document.
            if (doc.IsFamilyDocument)
            {
                return;
            }

            // write log file. 
            LogManager.WriteLog(args, doc);
            
            // get the hashCode of this document.
            int docHashCode = doc.GetHashCode();

            // retrieve the current value of "Project Status". 
            string currentProjectStatus = RetrieveProjectCurrentStatus(doc);
            // reserve "Project Status" current value in one dictionary, and use this project's hashCode as key.
            documentOriginalStatusDic.Add(docHashCode, currentProjectStatus);

            // write log file. 
            LogManager.WriteLog("   Current Project Status: " + currentProjectStatus);
        }

        /// <summary>
        /// Event handler method for DocumentSaving and DocumentSavingAs events.
        /// This method will check whether "Project Status" has been updated, and reserve current value as original value.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="args">Event arguments that contains the event data.</param>
        private void CheckProjectStatusUpdate(Object sender, PreDocEventArgs args)
        {
            // The document associated with the event. Here means which document is about to save / save as.
            Document doc = args.Document;

            // Project information is unavailable for Family document.
            if (doc.IsFamilyDocument)
            {
                return;
            }

            // write log file.
            LogManager.WriteLog(args, doc);

            // retrieve the current value of "Project Status". 
            string currentProjectStatus = RetrieveProjectCurrentStatus(args.Document);

            // get the old value of "Project Status" for one dictionary.
            string originalProjectStatus = documentOriginalStatusDic[doc.GetHashCode()];

            // write log file.
            LogManager.WriteLog("   Current Project Status: " + currentProjectStatus + "; Original Project Status: " + originalProjectStatus);

            // project status has not been updated.
            if ((string.IsNullOrEmpty(currentProjectStatus) && string.IsNullOrEmpty(originalProjectStatus)) || 
                (0 == string.Compare(currentProjectStatus, originalProjectStatus,true)))
            {
                DealNotUpdate(args);
                return;
            }

            // update "Project Status" value reserved in the dictionary.
            documentOriginalStatusDic.Remove(doc.GetHashCode());
            documentOriginalStatusDic.Add(doc.GetHashCode(), currentProjectStatus);
        }

        #endregion

        /// <summary>
        /// Deal with the case that the project status wasn't updated.
        /// If the event is Cancellable, cancel it and inform user else just inform user the status.
        /// </summary>
        /// <param name="args">Event arguments that contains the event data.</param>
        private static void DealNotUpdate(PreDocEventArgs args)
        {
            string infoMessage;
            if (args.Cancellable)
            {
                args.Cancel = true; // cancel this event if it is cancellable. 
                infoMessage = " can't be saved, please update project status firstly."; // prompt to user.              
            }
            else
            {
                // will not cancel this event since it isn't cancellable. 
                // prompt to user.
                infoMessage = " is about to save, but you forget to update project status.";
            }

            // MessageBox will not show when do regression test.
            if (!LogManager.RegressionTestNow)
            {
                // use one messageBox to inform user current situation.     
                MessageBox.Show(args.Document.Title + infoMessage, "Project Status Check");
            }

            // write log file.
            LogManager.WriteLog("   Project Status is not updated, MessageBox informs user: " + infoMessage);
        }

        /// <summary>
        /// Retrieve current value of Project Status.
        /// </summary>
        /// <param name="doc">Document of which the Project Status will be retrieved.</param>
        /// <returns>Current value of Project Status.</returns>
        private static string RetrieveProjectCurrentStatus(Document doc)
        {
            // Project information is unavailable for Family document.
            if (doc.IsFamilyDocument)
            {
                return null;
            }

            // get project status stored in project information object and return it.
            return doc.ProjectInformation.Status;
        }
    }
}