/*
 * 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"

#include "AccessibilityController.h"
#include "DumpRenderTree.h"
#include "WebCoreSupport/DumpRenderTreeSupportGtk.h"
#include <gtk/gtk.h>
#include <webkit/webkit.h>
#include <wtf/gobject/GOwnPtr.h>

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 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)";

    GOwnPtr<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 signal_query;
    GOwnPtr<gchar> signalName;
    GOwnPtr<gchar> signalValue;

    g_signal_query(signalHint->signal_id, &signal_query);

    if (!g_strcmp0(signal_query.signal_name, "state-change")) {
        signalName.set(g_strdup_printf("state-change:%s", g_value_get_string(&paramValues[1])));
        signalValue.set(g_strdup_printf("%d", g_value_get_boolean(&paramValues[2])));
    } else if (!g_strcmp0(signal_query.signal_name, "focus-event")) {
        signalName.set(g_strdup("focus-event"));
        signalValue.set(g_strdup_printf("%d", g_value_get_boolean(&paramValues[1])));
    } else if (!g_strcmp0(signal_query.signal_name, "children-changed")) {
        signalName.set(g_strdup("children-changed"));
        signalValue.set(g_strdup_printf("%d", g_value_get_uint(&paramValues[1])));
    } else if (!g_strcmp0(signal_query.signal_name, "property-change")) {
        signalName.set(g_strdup_printf("property-change:%s", g_quark_to_string(signalHint->detail)));
    } else
        signalName.set(g_strdup(signal_query.signal_name));

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

    return TRUE;
}

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

    // Ensure that accessibility is initialized for the WebView by querying for
    // the root accessible object, which will create the full hierarchy.
    DumpRenderTreeSupportGtk::getRootAccessibleElement(mainFrame);

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

    // 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);
}

void disconnectAccessibilityCallbacks()
{
    // 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;
    }
}