/*
 * Copyright (C) 2011 Igalia S.L.
 *
 * 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.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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 "AccessibilityCallbacks.h"

#if HAVE(ACCESSIBILITY)

#include "AccessibilityController.h"
#include "AccessibilityNotificationHandlerAtk.h"
#include "DumpRenderTree.h"
#include "JSRetainPtr.h"
#include <atk/atk.h>
#include <wtf/gobject/GUniquePtr.h>

#if PLATFORM(GTK)
#include "WebCoreSupport/DumpRenderTreeSupportGtk.h"
#include <webkit/webkit.h>
#endif

#if PLATFORM(EFL)
#include "DumpRenderTreeChrome.h"
#include "WebCoreSupport/DumpRenderTreeSupportEfl.h"
#endif

typedef HashMap<PlatformUIElement, AccessibilityNotificationHandler*> NotificationHandlersMap;

static guint stateChangeListenerId = 0;
static guint focusEventListenerId = 0;
static guint activeDescendantChangedListenerId = 0;
static guint childrenChangedListenerId = 0;
static guint propertyChangedListenerId = 0;
static guint visibleDataChangedListenerId = 0;
static guint loadCompleteListenerId = 0;
// Up to 2014 it was obligatory to mirror the changes from
// WebKitTestRunner/InjectedBundle/atk/AccessibilityNotificationHandlerAtk.cpp,
// but the habit has been dropped: https://bugs.webkit.org/show_bug.cgi?id=132527#c6
static NotificationHandlersMap notificationHandlers;
static AccessibilityNotificationHandler* globalNotificationHandler = 0;

extern bool loggingAccessibilityEvents;

static void printAccessibilityEvent(AtkObject* accessible, const gchar* signalName, const gchar* signalValue)
{
    // Do not handle state-change:defunct signals, as the AtkObject
    // associated to them will not be valid at this point already.
    if (!signalName || !g_strcmp0(signalName, "state-change:defunct"))
        return;

    if (!accessible || !ATK_IS_OBJECT(accessible))
        return;

    const gchar* objectName = atk_object_get_name(accessible);
    AtkRole objectRole = atk_object_get_role(accessible);

    // Try to always provide a name to be logged for the object.
    if (!objectName || *objectName == '\0')
        objectName = "(No name)";

    GUniquePtr<gchar> signalNameAndValue(signalValue ? g_strdup_printf("%s = %s", signalName, signalValue) : g_strdup(signalName));
    printf("Accessibility object emitted \"%s\" / Name: \"%s\" / Role: %d\n", signalNameAndValue.get(), objectName, objectRole);
}

static gboolean axObjectEventListener(GSignalInvocationHint *signalHint, guint numParamValues, const GValue *paramValues, gpointer data)
{
    // At least we should receive the instance emitting the signal.
    if (numParamValues < 1)
        return true;

    AtkObject* accessible = ATK_OBJECT(g_value_get_object(&paramValues[0]));
    if (!accessible || !ATK_IS_OBJECT(accessible))
        return true;

    GSignalQuery signalQuery;
    GUniquePtr<gchar> signalName;
    GUniquePtr<gchar> signalValue;
    String notificationName;

    g_signal_query(signalHint->signal_id, &signalQuery);

    if (!g_strcmp0(signalQuery.signal_name, "state-change")) {
        signalName.reset(g_strdup_printf("state-change:%s", g_value_get_string(&paramValues[1])));
        signalValue.reset(g_strdup_printf("%d", g_value_get_boolean(&paramValues[2])));
        if (!g_strcmp0(g_value_get_string(&paramValues[1]), "checked"))
            notificationName = "CheckedStateChanged";
        else if (!g_strcmp0(g_value_get_string(&paramValues[1]), "invalid-entry"))
            notificationName = "AXInvalidStatusChanged";
    } else if (!g_strcmp0(signalQuery.signal_name, "focus-event")) {
        signalName.reset(g_strdup("focus-event"));
        signalValue.reset(g_strdup_printf("%d", g_value_get_boolean(&paramValues[1])));
        if (g_value_get_boolean(&paramValues[1]))
            notificationName = "AXFocusedUIElementChanged";
    } else if (!g_strcmp0(signalQuery.signal_name, "children-changed")) {
        const gchar* childrenChangedDetail = g_quark_to_string(signalHint->detail);
        signalName.reset(g_strdup_printf("children-changed:%s", childrenChangedDetail));
        signalValue.reset(g_strdup_printf("%d", g_value_get_uint(&paramValues[1])));
        notificationName = !g_strcmp0(childrenChangedDetail, "add") ? "AXChildrenAdded" : "AXChildrenRemoved";
    } else if (!g_strcmp0(signalQuery.signal_name, "property-change")) {
        signalName.reset(g_strdup_printf("property-change:%s", g_quark_to_string(signalHint->detail)));
        if (!g_strcmp0(g_quark_to_string(signalHint->detail), "accessible-value"))
            notificationName = "AXValueChanged";
    } else if (!g_strcmp0(signalQuery.signal_name, "load-complete"))
        notificationName = "AXLoadComplete";
    else
        signalName.reset(g_strdup(signalQuery.signal_name));

    if (loggingAccessibilityEvents)
        printAccessibilityEvent(accessible, signalName.get(), signalValue.get());

#if PLATFORM(GTK)
    JSGlobalContextRef jsContext = webkit_web_frame_get_global_context(mainFrame);
#elif PLATFORM(EFL)
    JSGlobalContextRef jsContext = DumpRenderTreeSupportEfl::globalContextRefForFrame(browser->mainFrame());
#else
    JSContextRef jsContext = 0;
#endif
    if (!jsContext)
        return true;

    if (notificationName.length()) {
        JSRetainPtr<JSStringRef> jsNotificationEventName(Adopt, JSStringCreateWithUTF8CString(notificationName.utf8().data()));
        JSValueRef notificationNameArgument = JSValueMakeString(jsContext, jsNotificationEventName.get());
        NotificationHandlersMap::iterator elementNotificationHandler = notificationHandlers.find(accessible);
        if (elementNotificationHandler != notificationHandlers.end()) {
            // Listener for one element just gets one argument, the notification name.
            JSObjectCallAsFunction(jsContext, elementNotificationHandler->value->notificationFunctionCallback(), 0, 1, &notificationNameArgument, 0);
        }

        if (globalNotificationHandler) {
            // A global listener gets the element and the notification name as arguments.
            JSValueRef arguments[2];
            arguments[0] = AccessibilityUIElement::makeJSAccessibilityUIElement(jsContext, AccessibilityUIElement(accessible));
            arguments[1] = notificationNameArgument;
            JSObjectCallAsFunction(jsContext, globalNotificationHandler->notificationFunctionCallback(), 0, 2, arguments, 0);
        }
    }

    return true;
}

void connectAccessibilityCallbacks()
{
    // Ensure no callbacks are connected before.
    if (!disconnectAccessibilityCallbacks())
        return;

    // Ensure that accessibility is initialized for the WebView by querying for
    // the root accessible object, which will create the full hierarchy.
#if PLATFORM(GTK)
    DumpRenderTreeSupportGtk::getRootAccessibleElement(mainFrame);
#elif PLATFORM(EFL)
    DumpRenderTreeSupportEfl::rootAccessibleElement(browser->mainFrame());
#endif

    // Add global listeners for AtkObject's signals.
    stateChangeListenerId = atk_add_global_event_listener(axObjectEventListener, "ATK:AtkObject:state-change");
    focusEventListenerId = atk_add_global_event_listener(axObjectEventListener, "ATK:AtkObject:focus-event");
    activeDescendantChangedListenerId = atk_add_global_event_listener(axObjectEventListener, "ATK:AtkObject:active-descendant-changed");
    childrenChangedListenerId = atk_add_global_event_listener(axObjectEventListener, "ATK:AtkObject:children-changed");
    propertyChangedListenerId = atk_add_global_event_listener(axObjectEventListener, "ATK:AtkObject:property-change");
    visibleDataChangedListenerId = atk_add_global_event_listener(axObjectEventListener, "ATK:AtkObject:visible-data-changed");
    loadCompleteListenerId = atk_add_global_event_listener(axObjectEventListener, "ATK:AtkDocument:load-complete");

    // Ensure the Atk interface types are registered, otherwise
    // the AtkDocument signal handlers below won't get registered.
    GObject* dummyAxObject = G_OBJECT(g_object_new(ATK_TYPE_OBJECT, 0));
    AtkObject* dummyNoOpAxObject = atk_no_op_object_new(dummyAxObject);
    g_object_unref(G_OBJECT(dummyNoOpAxObject));
    g_object_unref(dummyAxObject);
}

bool disconnectAccessibilityCallbacks()
{
    // Only disconnect if logging is off and there is no notification handler.
    if (loggingAccessibilityEvents || !notificationHandlers.isEmpty() || globalNotificationHandler)
        return false;

    // AtkObject signals.
    if (stateChangeListenerId) {
        atk_remove_global_event_listener(stateChangeListenerId);
        stateChangeListenerId = 0;
    }
    if (focusEventListenerId) {
        atk_remove_global_event_listener(focusEventListenerId);
        focusEventListenerId = 0;
    }
    if (activeDescendantChangedListenerId) {
        atk_remove_global_event_listener(activeDescendantChangedListenerId);
        activeDescendantChangedListenerId = 0;
    }
    if (childrenChangedListenerId) {
        atk_remove_global_event_listener(childrenChangedListenerId);
        childrenChangedListenerId = 0;
    }
    if (propertyChangedListenerId) {
        atk_remove_global_event_listener(propertyChangedListenerId);
        propertyChangedListenerId = 0;
    }
    if (visibleDataChangedListenerId) {
        atk_remove_global_event_listener(visibleDataChangedListenerId);
        visibleDataChangedListenerId = 0;
    }
    if (loadCompleteListenerId) {
        atk_remove_global_event_listener(loadCompleteListenerId);
        loadCompleteListenerId = 0;
    }

    return true;
}

void addAccessibilityNotificationHandler(AccessibilityNotificationHandler* notificationHandler)
{
    if (!notificationHandler)
        return;

#if PLATFORM(GTK)
    JSGlobalContextRef jsContext = webkit_web_frame_get_global_context(mainFrame);
#elif PLATFORM(EFL)
    JSGlobalContextRef jsContext = DumpRenderTreeSupportEfl::globalContextRefForFrame(browser->mainFrame());
#else
    JSContextRef jsContext = 0;
#endif
    if (!jsContext)
        return;

    JSValueProtect(jsContext, notificationHandler->notificationFunctionCallback());
    // Check if this notification handler is related to a specific element.
    if (notificationHandler->platformElement()) {
        NotificationHandlersMap::iterator currentNotificationHandler = notificationHandlers.find(notificationHandler->platformElement());
        if (currentNotificationHandler != notificationHandlers.end()) {
            ASSERT(currentNotificationHandler->value->platformElement());
            JSValueUnprotect(jsContext, currentNotificationHandler->value->notificationFunctionCallback());
            notificationHandlers.remove(currentNotificationHandler->value->platformElement());
        }
        notificationHandlers.add(notificationHandler->platformElement(), notificationHandler);
    } else {
        if (globalNotificationHandler)
            JSValueUnprotect(jsContext, globalNotificationHandler->notificationFunctionCallback());
        globalNotificationHandler = notificationHandler;
    }

    connectAccessibilityCallbacks();
}

void removeAccessibilityNotificationHandler(AccessibilityNotificationHandler* notificationHandler)
{
    if (!notificationHandler)
        return;

#if PLATFORM(GTK)
    JSGlobalContextRef jsContext = webkit_web_frame_get_global_context(mainFrame);
#elif PLATFORM(EFL)
    JSGlobalContextRef jsContext = DumpRenderTreeSupportEfl::globalContextRefForFrame(browser->mainFrame());
#else
    JSGlobalContextRef jsContext = 0;
#endif
    if (!jsContext)
        return;

    if (globalNotificationHandler == notificationHandler) {
        JSValueUnprotect(jsContext, globalNotificationHandler->notificationFunctionCallback());
        globalNotificationHandler = 0;
    } else if (notificationHandler->platformElement()) {
        NotificationHandlersMap::iterator removeNotificationHandler = notificationHandlers.find(notificationHandler->platformElement());
        if (removeNotificationHandler != notificationHandlers.end()) {
            JSValueUnprotect(jsContext, removeNotificationHandler->value->notificationFunctionCallback());
            notificationHandlers.remove(removeNotificationHandler);
        }
    }
}

#endif
