/*

 * Copyright (C) 2008, 2009, 2010 Apple Inc. All Rights Reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 */

#include "config.h"

#include "AccessibilityController.h"

#include "AccessibilityUIElement.h"

#include "DumpRenderTree.h"

#include "FrameLoadDelegate.h"

#include <JavaScriptCore/Assertions.h>

#include <JavaScriptCore/JSRetainPtr.h>

#include <JavaScriptCore/JSStringRef.h>

#include <WebCore/COMPtr.h>

#include <WebKit/WebKit.h>

#include <oleacc.h>

#include <string>

using namespace std;

AccessibilityController::AccessibilityController()

    : m_focusEventHook(0)

    , m_scrollingStartEventHook(0)

    , m_valueChangeEventHook(0)

    , m_allEventsHook(0)

{

}

AccessibilityController::~AccessibilityController()

{

    setLogFocusEvents(false);

    setLogValueChangeEvents(false);

    if (m_allEventsHook)

        UnhookWinEvent(m_allEventsHook);

    for (HashMap<PlatformUIElement, JSObjectRef>::iterator it = m_notificationListeners.begin(); it != m_notificationListeners.end(); ++it)

        JSValueUnprotect(frame->globalContext(), it->second);

}

AccessibilityUIElement AccessibilityController::elementAtPoint(int x, int y)

{

    // FIXME: implement

    return 0;

}

AccessibilityUIElement AccessibilityController::focusedElement()

{

    COMPtr<IAccessible> rootAccessible = rootElement().platformUIElement();

    VARIANT vFocus;

    if (FAILED(rootAccessible->get_accFocus(&vFocus)))

        return 0;

    if (V_VT(&vFocus) == VT_I4) {

        ASSERT(V_I4(&vFocus) == CHILDID_SELF);

        // The root accessible object is the focused object.

        return rootAccessible;

    }

    ASSERT(V_VT(&vFocus) == VT_DISPATCH);

    // We have an IDispatch; query for IAccessible.

    return COMPtr<IAccessible>(Query, V_DISPATCH(&vFocus));

}

AccessibilityUIElement AccessibilityController::rootElement()

{

    COMPtr<IWebView> view;

    if (FAILED(frame->webView(&view)))

        return 0;

    COMPtr<IWebViewPrivate> viewPrivate(Query, view);

    if (!viewPrivate)

        return 0;

    HWND webViewWindow;

    if (FAILED(viewPrivate->viewWindow((OLE_HANDLE*)&webViewWindow)))

        return 0;

    // Get the root accessible object by querying for the accessible object for the

    // WebView's window.

    COMPtr<IAccessible> rootAccessible;

    if (FAILED(AccessibleObjectFromWindow(webViewWindow, static_cast<DWORD>(OBJID_CLIENT), __uuidof(IAccessible), reinterpret_cast<void**>(&rootAccessible))))

        return 0;

    return rootAccessible;

}

static void CALLBACK logEventProc(HWINEVENTHOOK, DWORD event, HWND hwnd, LONG idObject, LONG idChild, DWORD, DWORD)

{

    // Get the accessible object for this event.

    COMPtr<IAccessible> parentObject;

    VARIANT vChild;

    VariantInit(&vChild);

    HRESULT hr = AccessibleObjectFromEvent(hwnd, idObject, idChild, &parentObject, &vChild);

    ASSERT(SUCCEEDED(hr));

    // Get the name of the focused element, and log it to stdout.

    BSTR nameBSTR;

    hr = parentObject->get_accName(vChild, &nameBSTR);

    ASSERT(SUCCEEDED(hr));

    wstring name(nameBSTR, ::SysStringLen(nameBSTR));

    SysFreeString(nameBSTR);

    switch (event) {

        case EVENT_OBJECT_FOCUS:

            printf("Received focus event for object '%S'.\n", name.c_str());

            break;

        case EVENT_OBJECT_VALUECHANGE: {

            BSTR valueBSTR;

            hr = parentObject->get_accValue(vChild, &valueBSTR);

            ASSERT(SUCCEEDED(hr));

            wstring value(valueBSTR, ::SysStringLen(valueBSTR));

            SysFreeString(valueBSTR);

            printf("Received value change event for object '%S', value '%S'.\n", name.c_str(), value.c_str());

            break;

        }

        case EVENT_SYSTEM_SCROLLINGSTART:

            printf("Received scrolling start event for object '%S'.\n", name.c_str());

            break;

        default:

            printf("Received unknown event for object '%S'.\n", name.c_str());

            break;

    }

    VariantClear(&vChild);

}

void AccessibilityController::setLogFocusEvents(bool logFocusEvents)

{

    if (!!m_focusEventHook == logFocusEvents)

        return;

    if (!logFocusEvents) {

        UnhookWinEvent(m_focusEventHook);

        m_focusEventHook = 0;

        return;

    }

    // Ensure that accessibility is initialized for the WebView by querying for

    // the root accessible object.

    rootElement();

    m_focusEventHook = SetWinEventHook(EVENT_OBJECT_FOCUS, EVENT_OBJECT_FOCUS, GetModuleHandle(0), logEventProc, GetCurrentProcessId(), 0, WINEVENT_INCONTEXT);

    ASSERT(m_focusEventHook);

}

void AccessibilityController::setLogValueChangeEvents(bool logValueChangeEvents)

{

    if (!!m_valueChangeEventHook == logValueChangeEvents)

        return;

    if (!logValueChangeEvents) {

        UnhookWinEvent(m_valueChangeEventHook);

        m_valueChangeEventHook = 0;

        return;

    }

    // Ensure that accessibility is initialized for the WebView by querying for

    // the root accessible object.

    rootElement();

    m_valueChangeEventHook = SetWinEventHook(EVENT_OBJECT_VALUECHANGE, EVENT_OBJECT_VALUECHANGE, GetModuleHandle(0), logEventProc, GetCurrentProcessId(), 0, WINEVENT_INCONTEXT);

    ASSERT(m_valueChangeEventHook);

}

void AccessibilityController::setLogScrollingStartEvents(bool logScrollingStartEvents)

{

    if (!!m_scrollingStartEventHook == logScrollingStartEvents)

        return;

    if (!logScrollingStartEvents) {

        UnhookWinEvent(m_scrollingStartEventHook);

        m_scrollingStartEventHook = 0;

        return;

    }

    // Ensure that accessibility is initialized for the WebView by querying for

    // the root accessible object.

    rootElement();

    m_scrollingStartEventHook = SetWinEventHook(EVENT_SYSTEM_SCROLLINGSTART, EVENT_SYSTEM_SCROLLINGSTART, GetModuleHandle(0), logEventProc, GetCurrentProcessId(), 0, WINEVENT_INCONTEXT);

    ASSERT(m_scrollingStartEventHook);

}

static string stringEvent(DWORD event)

{

    switch(event) {

        case EVENT_OBJECT_VALUECHANGE:

            return "value change event";

        default:

            return "unknown event";

    }

}

static void CALLBACK notificationListenerProc(HWINEVENTHOOK, DWORD event, HWND hwnd, LONG idObject, LONG idChild, DWORD, DWORD)

{

    // Get the accessible object for this event.

    COMPtr<IAccessible> parentObject;

    VARIANT vChild;

    VariantInit(&vChild);

    HRESULT hr = AccessibleObjectFromEvent(hwnd, idObject, idChild, &parentObject, &vChild);

    ASSERT(SUCCEEDED(hr));

    COMPtr<IDispatch> childDispatch;

    if (FAILED(parentObject->get_accChild(vChild, &childDispatch))) {

        VariantClear(&vChild);

        return;

    }

    COMPtr<IAccessible> childAccessible(Query, childDispatch);

    sharedFrameLoadDelegate->accessibilityController()->notificationReceived(childAccessible, stringEvent(event));

    VariantClear(&vChild);

}

static COMPtr<IAccessibleComparable> comparableObject(const COMPtr<IServiceProvider>& serviceProvider)

{

    COMPtr<IAccessibleComparable> comparable;

    serviceProvider->QueryService(SID_AccessibleComparable, __uuidof(IAccessibleComparable), reinterpret_cast<void**>(&comparable));

    return comparable;

}

void AccessibilityController::notificationReceived(PlatformUIElement element, const string& eventName)

{

    for (HashMap<PlatformUIElement, JSObjectRef>::iterator it = m_notificationListeners.begin(); it != m_notificationListeners.end(); ++it) {

        COMPtr<IServiceProvider> thisServiceProvider(Query, it->first);

        if (!thisServiceProvider)

            continue;

        COMPtr<IAccessibleComparable> thisComparable = comparableObject(thisServiceProvider);

        if (!thisComparable)

            continue;

        COMPtr<IServiceProvider> elementServiceProvider(Query, element);

        if (!elementServiceProvider)

            continue;

        COMPtr<IAccessibleComparable> elementComparable = comparableObject(elementServiceProvider);

        if (!elementComparable)

            continue;

        BOOL isSame = FALSE;

        thisComparable->isSameObject(elementComparable.get(), &isSame);

        if (!isSame)

            continue;

        JSRetainPtr<JSStringRef> jsNotification(Adopt, JSStringCreateWithUTF8CString(eventName.c_str()));

        JSValueRef argument = JSValueMakeString(frame->globalContext(), jsNotification.get());

        JSObjectCallAsFunction(frame->globalContext(), it->second, NULL, 1, &argument, NULL);

    }

}

void AccessibilityController::addNotificationListener(PlatformUIElement element, JSObjectRef functionCallback)

{

    if (!m_allEventsHook)

        m_allEventsHook = SetWinEventHook(EVENT_MIN, EVENT_MAX, GetModuleHandle(0), notificationListenerProc, GetCurrentProcessId(), 0, WINEVENT_INCONTEXT);

    JSValueProtect(frame->globalContext(), functionCallback);

    m_notificationListeners.add(element, functionCallback);

}