/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org Code.
 *
 * The Initial Developer of the Original Code is
 * Aaron Leventhal.
 * Portions created by the Initial Developer are Copyright (C) 2001
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "nsCOMPtr.h"
#include "nsMemory.h"
#include "nsIServiceManager.h"
#include "nsIObserverService.h"
#include "nsIGenericFactory.h"
#include "nsIWebProgress.h"
#include "nsIDocumentLoader.h"
#include "nsCURILoader.h"
#include "nsIDocShell.h"
#include "nsIDOMWindow.h"
#include "nsIDOMWindowInternal.h"
#include "nsIDOMEventTarget.h"
#include "nsIDOMNSEvent.h"
#include "nsIPrefBranch.h"
#include "nsIPrefService.h"

#include "nsIRegistry.h"
#include "nsString.h"

#include "nsIDOMNode.h"
#include "nsIPresShell.h"
#include "nsIDOMDocument.h"
#include "nsIDocument.h"
#include "nsISelection.h"
#include "nsISelectionController.h"
#include "nsICaret.h"

// Header for this class
#include "nsAccessProxy.h"

// #define NS_DEBUG_ACCESS_BUILTIN 1


////////////////////////////////////////////////////////////////////////


NS_IMPL_ISUPPORTS4(nsAccessProxy, nsIObserver, nsISupportsWeakReference, nsIWebProgressListener, nsIDOMEventListener)

nsAccessProxy* nsAccessProxy::mInstance = nsnull;

nsAccessProxy::nsAccessProxy()
{
}

nsAccessProxy::~nsAccessProxy()
{
}

nsAccessProxy *nsAccessProxy::GetInstance()
{
  if (mInstance == nsnull) {
    mInstance = new nsAccessProxy();
    // Will be released in the module destructor
    NS_IF_ADDREF(mInstance);
  }

  NS_IF_ADDREF(mInstance);
  return mInstance;
}

void nsAccessProxy::ReleaseInstance()
{
  NS_IF_RELEASE(nsAccessProxy::mInstance);
}


NS_IMETHODIMP nsAccessProxy::HandleEvent(nsIDOMEvent* aEvent)
{
  nsresult rv;

  //////// Get Type of Event into a string called eventName ///////
  nsAutoString eventNameStr;
  rv=aEvent->GetType(eventNameStr);
  if (NS_FAILED(rv))
    return rv;
  // Print event name and styles debugging messages
  #ifdef NS_DEBUG_ACCESS_BUILTIN
  printf("\n==== %s event occurred ====\n",NS_ConvertUCS2toUTF8(eventNameStr).get());
  #endif

  ////////// Get Target Node - place in document where event was fired ////////////
  nsCOMPtr<nsIDOMEventTarget> targetNode;

  nsCOMPtr<nsIDOMNSEvent> nsevent(do_QueryInterface(aEvent));

  if (nsevent) {
    rv = nsevent->GetOriginalTarget(getter_AddRefs(targetNode));

    if (NS_FAILED(rv))
      return rv;
  }

  if (!targetNode)
    return NS_ERROR_NULL_POINTER;
  nsCOMPtr<nsIDOMNode> domNode = do_QueryInterface(targetNode);
  if (!domNode)
    return NS_OK;

  // get the Document and PresShell
  nsCOMPtr<nsIDOMDocument> domDoc;
  nsIPresShell *presShell = nsnull;
  nsCOMPtr<nsIDocument> doc;
  domNode->GetOwnerDocument(getter_AddRefs(domDoc));
  if (domDoc) {
    doc = do_QueryInterface(domDoc);
    if (doc && doc->GetNumberOfShells()>0) {
      presShell = doc->GetShellAt(0);
    }
  }
  //return  NS_OK;
  /*
  if (presShell && eventNameStr.EqualsLiteral("click")) {
    nsCOMPtr<nsISelection> domSelection;
    presShell->FrameSelection()->GetSelection(nsISelectionController::SELECTION_NORMAL,
                            getter_AddRefs(domSelection));
    if (!domSelection)
      return NS_OK;
    nsCOMPtr<nsIDOMNode> focusDomNode;
    domSelection->GetAnchorNode(getter_AddRefs(focusDomNode));
    if (focusDomNode) domNode=focusDomNode;
    // first, tell the caret which selection to use
    nsCOMPtr<nsICaret> caret;
    presShell->GetCaret(getter_AddRefs(caret));
    if (!caret) return NS_OK;
    caret->SetCaretDOMSelection(domSelection);
    // tell the pres shell to enable the caret, rather than settings its visibility directly.
    // this way the presShell's idea of caret visibility is maintained.
    nsCOMPtr<nsISelectionController> selCon = do_QueryInterface(presShell);
    if (!selCon) return NS_ERROR_NO_INTERFACE;
    selCon->SetCaretEnabled(PR_TRUE);
    caret->SetCaretVisible(PR_TRUE);
  }
  */

  return NS_OK;
}


// This method gets called on application startup
NS_IMETHODIMP nsAccessProxy::Observe(nsISupports *aSubject, const char *aTopic, const PRUnichar *aData) 
{
  static PRBool accessProxyInstalled;

  nsresult rv = NS_OK;
  nsDependentCString aTopicString(aTopic);

  if (accessProxyInstalled && aTopicString.EqualsLiteral(NS_XPCOM_SHUTDOWN_OBSERVER_ID))
    return Release();

  if (!accessProxyInstalled && aTopicString.EqualsLiteral(APPSTARTUP_CATEGORY)) {
    accessProxyInstalled = PR_TRUE; // Set to TRUE even for failure cases - we don't want to try more than once
    nsCOMPtr<nsIWebProgress> progress(do_GetService(NS_DOCUMENTLOADER_SERVICE_CONTRACTID));
    rv = NS_ERROR_FAILURE;
    if (progress) {
      rv = progress->AddProgressListener(NS_STATIC_CAST(nsIWebProgressListener*,this),
                                         nsIWebProgress::NOTIFY_STATE_DOCUMENT);
      if (NS_SUCCEEDED(rv))
        AddRef();
    }
     // install xpcom shutdown observer
    if (NS_SUCCEEDED(rv)) {
      nsCOMPtr<nsIObserverService> observerService(do_GetService("@mozilla.org/observer-service;1", &rv));
      if (NS_SUCCEEDED(rv)) 
        rv = observerService->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, PR_TRUE);
    }
  }
  return rv;
}


NS_IMETHODIMP nsAccessProxy::OnStateChange(nsIWebProgress *aWebProgress,
  nsIRequest *aRequest, PRUint32 aStateFlags, nsresult aStatus)
{
/* PRUint32 aStateFlags ...
 *
 * ===== What has happened =====	
 * STATE_START, STATE_REDIRECTING, STATE_TRANSFERRING,
 * STATE_NEGOTIATING, STATE_STOP

 * ===== Where did it occur? =====
 * STATE_IS_REQUEST, STATE_IS_DOCUMENT, STATE_IS_NETWORK, STATE_IS_WINDOW

 * ===== Security info =====
 * STATE_IS_INSECURE, STATE_IS_BROKEN, STATE_IS_SECURE, STATE_SECURE_HIGH
 * STATE_SECURE_MED, STATE_SECURE_LOW
 *
 */

  if ((aStateFlags & (STATE_STOP|STATE_START)) && (aStateFlags & STATE_IS_DOCUMENT)) {
    // Test for built in text to speech or braille display usage preference
    // If so, attach event handlers to window. If not, don't.
    nsCOMPtr<nsIPrefBranch> prefBranch(do_GetService(NS_PREFSERVICE_CONTRACTID));
    nsXPIDLCString textToSpeechEngine, brailleDisplayEngine;
    if (prefBranch) {
      prefBranch->GetCharPref("accessibility.usetexttospeech", getter_Copies(textToSpeechEngine));
      prefBranch->GetCharPref("accessibility.usebrailledisplay", getter_Copies(brailleDisplayEngine));
    }

    if ((textToSpeechEngine && *textToSpeechEngine) || (brailleDisplayEngine && *brailleDisplayEngine)) {  
      // Yes, prefs say we will need handlers for this 
      nsCOMPtr<nsIDOMWindow> domWindow;
      aWebProgress->GetDOMWindow(getter_AddRefs(domWindow));

      if (domWindow) {
        nsCOMPtr<nsIDOMEventTarget> eventTarget = do_QueryInterface(domWindow);
        nsCOMPtr<nsIDOMWindowInternal> windowInternal = do_QueryInterface(domWindow);
        nsCOMPtr<nsIDOMWindowInternal> opener;
        if (windowInternal)
          windowInternal->GetOpener(getter_AddRefs(opener));
        if (eventTarget && opener) {
          eventTarget->AddEventListener(NS_LITERAL_STRING("keyup"), this, PR_FALSE);
          eventTarget->AddEventListener(NS_LITERAL_STRING("keypress"), this, PR_FALSE);
          eventTarget->AddEventListener(NS_LITERAL_STRING("focus"), this, PR_FALSE);
          eventTarget->AddEventListener(NS_LITERAL_STRING("load"), this, PR_FALSE);
          eventTarget->AddEventListener(NS_LITERAL_STRING("click"), this, PR_FALSE); // for debugging
        }
      }
    }
  }

  return NS_OK;
}

/* void onProgressChange (in nsIWebProgress aWebProgress, in nsIRequest aRequest, in long aCurSelfProgress, in long aMaxSelfProgress, in long aCurTotalProgress, in long aMaxTotalProgress); */
NS_IMETHODIMP nsAccessProxy::OnProgressChange(nsIWebProgress *aWebProgress,
  nsIRequest *aRequest, PRInt32 aCurSelfProgress, PRInt32 aMaxSelfProgress,
  PRInt32 aCurTotalProgress, PRInt32 aMaxTotalProgress)
{
  // We can use this to report the percentage done
  NS_NOTREACHED("notification excluded in AddProgressListener(...)");
  return NS_OK;
}

/* void onLocationChange (in nsIWebProgress aWebProgress, in nsIRequest aRequest, in nsIURI location); */
NS_IMETHODIMP nsAccessProxy::OnLocationChange(nsIWebProgress *aWebProgress,
  nsIRequest *aRequest, nsIURI *location)
{
  // Load has been verified, it will occur, about to commence
  NS_NOTREACHED("notification excluded in AddProgressListener(...)");
  return NS_OK;
}

/* void onStatusChange (in nsIWebProgress aWebProgress, in nsIRequest aRequest, in nsresult aStatus, in wstring aMessage); */
NS_IMETHODIMP nsAccessProxy::OnStatusChange(nsIWebProgress *aWebProgress,
  nsIRequest *aRequest, nsresult aStatus, const PRUnichar *aMessage)
{
  // Status bar has changed
  NS_NOTREACHED("notification excluded in AddProgressListener(...)");
  return NS_OK;
}

/* void onSecurityChange (in nsIWebProgress aWebProgress, in nsIRequest aRequest, in unsigned long state); */
NS_IMETHODIMP nsAccessProxy::OnSecurityChange(nsIWebProgress *aWebProgress,
  nsIRequest *aRequest, PRUint32 state)
{
  // Security setting has changed
  NS_NOTREACHED("notification excluded in AddProgressListener(...)");
  return NS_OK;
}