/*

 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.nashorn.internal.objects;

import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;

import java.io.PrintWriter;

import java.util.LinkedList;

import java.util.Objects;

import jdk.nashorn.internal.objects.annotations.Attribute;

import jdk.nashorn.internal.objects.annotations.Function;

import jdk.nashorn.internal.objects.annotations.ScriptClass;

import jdk.nashorn.internal.objects.annotations.Where;

import jdk.nashorn.internal.runtime.Context;

import jdk.nashorn.internal.runtime.JSType;

import jdk.nashorn.internal.runtime.PropertyListeners;

import jdk.nashorn.internal.runtime.PropertyMap;

import jdk.nashorn.internal.runtime.ScriptFunction;

import jdk.nashorn.internal.runtime.ScriptObject;

import jdk.nashorn.internal.runtime.events.RuntimeEvent;

import jdk.nashorn.internal.runtime.linker.LinkerCallSite;

import jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor;

/**

 * Nashorn specific debug utils. This is meant for Nashorn developers.

 * The interface is subject to change without notice!!

 *

 */

@ScriptClass("Debug")

public final class NativeDebug extends ScriptObject {

    // initialized by nasgen

    @SuppressWarnings("unused")

    private static PropertyMap $nasgenmap$;

    private NativeDebug() {

        // don't create me!

        throw new UnsupportedOperationException();

    }

    @Override

    public String getClassName() {

        return "Debug";

    }

    /**

     * Nashorn extension: get context, context utility

     *

     * @param self self reference

     * @return context

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static Object getContext(final Object self) {

        final SecurityManager sm = System.getSecurityManager();

        if (sm != null) {

            sm.checkPermission(new RuntimePermission(Context.NASHORN_GET_CONTEXT));

        }

        return Global.getThisContext();

    }

    /**

     * Nashorn extension: get map from {@link ScriptObject}

     *

     * @param self self reference

     * @param obj script object

     * @return the map for the current ScriptObject

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static Object map(final Object self, final Object obj) {

        if (obj instanceof ScriptObject) {

            return ((ScriptObject)obj).getMap();

        }

        return UNDEFINED;

    }

    /**

     * Check object identity comparison regardless of type

     *

     * @param self self reference

     * @param obj1 first object in comparison

     * @param obj2 second object in comparison

     * @return true if reference identity

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static boolean identical(final Object self, final Object obj1, final Object obj2) {

        return obj1 == obj2;

    }

    /**

     * Returns true if if the two objects are both property maps, and they have identical properties in the same order,

     * but allows the properties to differ in their types.

     * @param self self

     * @param m1 first property map

     * @param m2 second property map

     * @return true if they have identical properties in same order, with possibly different types.

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static Object equalWithoutType(final Object self, final Object m1, final Object m2) {

        return ((PropertyMap)m1).equalsWithoutType((PropertyMap)m2);

    }

    /**

     * Returns a diagnostic string representing the difference of two property maps.

     * @param self self

     * @param m1 first property map

     * @param m2 second property map

     * @return a diagnostic string representing the difference of two property maps.

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static Object diffPropertyMaps(final Object self, final Object m1, final Object m2) {

        return PropertyMap.diff((PropertyMap)m1, (PropertyMap)m2);

    }

    /**

     * Object util - getClass

     *

     * @param self self reference

     * @param obj  object

     * @return class of {@code obj}

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static Object getClass(final Object self, final Object obj) {

        if (obj != null) {

            return obj.getClass();

        }

        return UNDEFINED;

    }

    /**

     * Object util - equals

     *

     * @param self self reference

     * @param obj1 first object in comparison

     * @param obj2 second object in comparison

     * @return return {@link Object#equals(Object)} for objects.

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static boolean equals(final Object self, final Object obj1, final Object obj2) {

        return Objects.equals(obj1, obj2);

    }

    /**

     * Object util - toJavaString

     *

     * @param self self reference

     * @param obj  object to represent as a string

     * @return Java string representation of {@code obj}

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static String toJavaString(final Object self, final Object obj) {

        return Objects.toString(obj);

    }

    /**

     * Do not call overridden toString -- use default toString impl

     *

     * @param self self reference

     * @param obj  object to represent as a string

     * @return string representation

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static String toIdentString(final Object self, final Object obj) {

        if (obj == null) {

            return "null";

        }

        final int hash = System.identityHashCode(obj);

        return obj.getClass() + "@" + Integer.toHexString(hash);

    }

    /**

     * Returns the property listener count for a script object

     *

     * @param self self reference

     * @param obj  script object whose listener count is returned

     * @return listener count

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static int getListenerCount(final Object self, final Object obj) {

        return (obj instanceof ScriptObject) ? PropertyListeners.getListenerCount((ScriptObject) obj) : 0;

    }

    /**

     * Dump all Nashorn debug mode counters. Calling this may be better if

     * you want to print all counters. This way you can avoid too many callsites

     * due to counter access itself!!

     * @param self self reference

     * @return undefined

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static Object dumpCounters(final Object self) {

        final PrintWriter out = Context.getCurrentErr();

        out.println("ScriptObject count " + ScriptObject.getCount());

        out.println("Scope count " + ScriptObject.getScopeCount());

        out.println("ScriptObject listeners added " + PropertyListeners.getListenersAdded());

        out.println("ScriptObject listeners removed " + PropertyListeners.getListenersRemoved());

        out.println("ScriptFunction constructor calls " + ScriptFunction.getConstructorCount());

        out.println("ScriptFunction invokes " + ScriptFunction.getInvokes());

        out.println("ScriptFunction allocations " + ScriptFunction.getAllocations());

        out.println("PropertyMap count " + PropertyMap.getCount());

        out.println("PropertyMap cloned " + PropertyMap.getClonedCount());

        out.println("PropertyMap history hit " + PropertyMap.getHistoryHit());

        out.println("PropertyMap proto invalidations " + PropertyMap.getProtoInvalidations());

        out.println("PropertyMap proto history hit " + PropertyMap.getProtoHistoryHit());

        out.println("PropertyMap setProtoNewMapCount " + PropertyMap.getSetProtoNewMapCount());

        out.println("Callsite count " + LinkerCallSite.getCount());

        out.println("Callsite misses " + LinkerCallSite.getMissCount());

        out.println("Callsite misses by site at " + LinkerCallSite.getMissSamplingPercentage() + "%");

        LinkerCallSite.getMissCounts(out);

        return UNDEFINED;

    }

    /*

     * Framework for logging runtime events

     */

    private static final String EVENT_QUEUE          = "__eventQueue__";

    private static final String EVENT_QUEUE_CAPACITY = "__eventQueueCapacity__";

    /**

     * Get the capacity of the event queue

     * @param self self reference

     * @return capacity of event queue as an integer

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static Object getEventQueueCapacity(final Object self) {

        final ScriptObject sobj = (ScriptObject)self;

        Integer cap;

        if (sobj.has(EVENT_QUEUE_CAPACITY)) {

            cap = JSType.toInt32(sobj.get(EVENT_QUEUE_CAPACITY));

        } else {

            setEventQueueCapacity(self, cap = RuntimeEvent.RUNTIME_EVENT_QUEUE_SIZE);

        }

        return cap;

    }

    /**

     * Set the event queue capacity

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static void setEventQueueCapacity(final Object self, final Object newCapacity) {

        ((ScriptObject)self).set(EVENT_QUEUE_CAPACITY, newCapacity, NashornCallSiteDescriptor.CALLSITE_STRICT);

    }

    /**

     * Add a runtime event to the runtime event queue. The queue has a fixed

     * size {@link RuntimeEvent#RUNTIME_EVENT_QUEUE_SIZE} and the oldest

     * entry will be thrown out of the queue is about to overflow

     * @param self self reference

     * @param event event to add

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static void addRuntimeEvent(final Object self, final Object event) {

        final LinkedList<RuntimeEvent<?>> q = getEventQueue(self);

        final int cap = (Integer)getEventQueueCapacity(self);

        while (q.size() >= cap) {

            q.removeFirst();

        }

        q.addLast(getEvent(event));

    }

    /**

     * Expands the event queue capacity, or truncates if capacity is lower than

     * current capacity. Then only the newest entries are kept

     * @param self self reference

     * @param newCapacity new capacity

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static void expandEventQueueCapacity(final Object self, final Object newCapacity) {

        final LinkedList<RuntimeEvent<?>> q = getEventQueue(self);

        final int nc = JSType.toInt32(newCapacity);

        while (q.size() > nc) {

            q.removeFirst();

        }

        setEventQueueCapacity(self, nc);

    }

    /**

     * Clear the runtime event queue

     * @param self self reference

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static void clearRuntimeEvents(final Object self) {

        final LinkedList<RuntimeEvent<?>> q = getEventQueue(self);

        q.clear();

    }

    /**

     * Remove a specific runtime event from the event queue

     * @param self self reference

     * @param event event to remove

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static void removeRuntimeEvent(final Object self, final Object event) {

        final LinkedList<RuntimeEvent<?>> q  = getEventQueue(self);

        final RuntimeEvent<?>             re = getEvent(event);

        if (!q.remove(re)) {

            throw new IllegalStateException("runtime event " + re + " was not in event queue");

        }

    }

    /**

     * Return all runtime events in the queue as an array

     * @param self self reference

     * @return array of events

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static Object getRuntimeEvents(final Object self) {

        final LinkedList<RuntimeEvent<?>> q = getEventQueue(self);

        return q.toArray(new RuntimeEvent<?>[q.size()]);

    }

    /**

     * Return the last runtime event in the queue

     * @param self self reference

     * @return the freshest event, null if queue is empty

     */

    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)

    public static Object getLastRuntimeEvent(final Object self) {

        final LinkedList<RuntimeEvent<?>> q = getEventQueue(self);

        return q.isEmpty() ? null : q.getLast();

    }

    @SuppressWarnings("unchecked")

    private static LinkedList<RuntimeEvent<?>> getEventQueue(final Object self) {

        final ScriptObject sobj = (ScriptObject)self;

        LinkedList<RuntimeEvent<?>> q;

        if (sobj.has(EVENT_QUEUE)) {

            q = (LinkedList<RuntimeEvent<?>>)((ScriptObject)self).get(EVENT_QUEUE);

        } else {

            ((ScriptObject)self).set(EVENT_QUEUE, q = new LinkedList<>(), NashornCallSiteDescriptor.CALLSITE_STRICT);

        }

        return q;

    }

    private static RuntimeEvent<?> getEvent(final Object event) {

        return (RuntimeEvent<?>)event;

    }

}