// Copyright 2012 ESRI
// 
// All rights reserved under the copyright laws of the United States
// and applicable international laws, treaties, and conventions.
// 
// You may freely redistribute and use this sample code, with or
// without modification, provided you include the original copyright
// notice and use restrictions.
// 
// See the use restrictions.
// 

using System;
using System.Runtime.InteropServices;
using ESRI.ArcGIS.Framework;
using ESRI.ArcGIS.ArcMapUI;
using ESRI.ArcGIS.esriSystem;
using ESRI.ArcGIS.ADF.CATIDs;


namespace ACME.GIS.SampleExt
{

  [Guid("148C17C0-C680-4269-B358-09A59A771822")]
  [ClassInterface(ClassInterfaceType.None)]
  [ProgId("ACME.Extension")]
  public class AcmeExt : IExtension, IExtensionConfig, IPersistVariant
  {
    #region COM Registration Functions
    // Register the Extension in the ESRI MxExtensions Component Category
    [ComRegisterFunction()]
    [ComVisible(false)]
    static void RegisterFunction(Type registerType)
    {
      string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
      MxExtension.Register(regKey);
    }

    [ComUnregisterFunction()]
    [ComVisible(false)]
    static void UnregisterFunction(Type registerType)
    {
      string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
      MxExtension.Unregister(regKey);
    }
    #endregion

    private IApplication m_application;
    private IApplicationStatus m_appStatus;
    private esriExtensionState m_extensionState = esriExtensionState.esriESDisabled;
    private bool m_isMenuPresent = false;

    private IDocumentEvents_Event m_docEvents;
    private IApplicationStatusEvents_Event m_mapStatusEvents;

    private const string c_extName = "ACME Extension (C#)";
    private const string c_menuID = "ACME.MainMenu";
    private const string c_mainMenuID = "{1E739F59-E45F-11D1-9496-080009EEBECB}";  // Main menubar

    #region IExtension Members

    public string Name
    {
      get { return c_extName; }
    }

    public void Shutdown()
    {
      m_docEvents = null;
      m_application = null;
    }

    public void Startup(ref object initializationData)
    {
      m_application = initializationData as IApplication;
      m_appStatus = m_application as IApplicationStatus;
      // Wireup the events
      SetupEvents();
    }

    #endregion

    #region IExtensionConfig Members

    public string Description
    {
      get { return "Sample extension showing IApplicationStatusEvents"; }
    }

    public string ProductName
    {
      get { return c_extName; }
    }

    public esriExtensionState State
    {
      get
      {
        return m_extensionState;
      }
      set
      {
        // Bail if requested state matches current state
        if (value == m_extensionState)
          return;

        // Cache the state
        m_extensionState = value;

        if (m_application == null) // Don't assume Startup has been called (JIT extensions)
          return;
        
        // Enable, add the menu
        if (m_extensionState == esriExtensionState.esriESEnabled)
        {
          if (!m_isMenuPresent)
            CheckMenuValidity();
          return;
        }

        // Disable, remove the menu
        if (m_extensionState == esriExtensionState.esriESDisabled)
        {
          if (m_isMenuPresent)
            UnLoadCustomizations();
          return;
        }
      }
    }

    #endregion

    #region IPersistVariant Members

    public UID ID
    {
      get
      {
        UID extUID = new UIDClass();
        extUID.Value = GetType().GUID.ToString("B");
        return extUID; ;
      }
    }

    public void Load(IVariantStream Stream)
    {
    }

    public void Save(IVariantStream Stream)
    {
    }

    #endregion

    # region Events

    private void SetupEvents()
    {
      // Make sure we're dealing with ArcMap
      if (m_application.Document.Parent is IMxApplication)
      {
        m_docEvents = m_application.Document as IDocumentEvents_Event;
        m_docEvents.NewDocument += new IDocumentEvents_NewDocumentEventHandler(OnNewDocument);
        m_docEvents.OpenDocument += new IDocumentEvents_OpenDocumentEventHandler(OnOpenDocument);

        m_mapStatusEvents = m_application.Document.Parent as IApplicationStatusEvents_Event;
        m_mapStatusEvents.Initialized += new IApplicationStatusEvents_InitializedEventHandler(OnInitialized);
      }
    }

    void OnOpenDocument()
    {
      CheckMenuValidity();
    }

    void OnNewDocument()
    {
      CheckMenuValidity();
    }

    // Called when the framework is fully initialized
    // After this event fires, it is safe to make UI customizations
    void OnInitialized()
    {
      CheckMenuValidity();
    }
    #endregion

    private void CheckMenuValidity()
    {
      // Wait for framework to initialize before making ui customizations
      // Check framework initialization flag
      if (!m_appStatus.Initialized)
        return;

      // Make sure the extension is enabled
      if (m_extensionState != esriExtensionState.esriESEnabled)
        return;

      // Perform the customization
      LoadCustomizations();
    }

    private void LoadCustomizations()
    {
      ICommandBar topMenuBar = GetMainBar();

      if (topMenuBar == null)
        return;

      // Add AcmeMenu
      UID uid = new UIDClass();
      uid.Value = c_menuID;
      Object indexObj = Type.Missing;
      ICommandBar myMenu = topMenuBar.Add(uid, ref indexObj) as ICommandBar;
      ((ICommandItem)topMenuBar).Refresh();

      m_isMenuPresent = true;
    }

    private void UnLoadCustomizations()
    {
      ICommandBar topMenuBar = GetMainBar();

      if (topMenuBar == null)
        return;

      // Remove AcmeMenu
      UID uid = new UIDClass();
      uid.Value = c_menuID;
      ICommandBar myMenu = topMenuBar.Find(uid, false) as ICommandBar;
      ICommandItem myMenuItem = myMenu as ICommandItem;

      myMenuItem.Delete();

      ((ICommandItem)topMenuBar).Refresh();

      m_isMenuPresent = false;
    }

    private ICommandBar GetMainBar()
    {
      try
      {
        //Grab the root menu bar
        UID uid = new UIDClass();
        uid.Value = c_mainMenuID;
        MxDocument mx = (MxDocument)m_application.Document;
        ICommandBars cmdBars = mx.CommandBars;
        ICommandItem x = cmdBars.Find(uid, false, false);
        return cmdBars.Find(uid, false, false) as ICommandBar;
      }
      catch
      {
        return null;
      }
    }
  }
}