/*

 * Copyright (c) 2010, 2014, 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.ECMAErrors.rangeError;

import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;

import static jdk.nashorn.internal.runtime.PropertyDescriptor.VALUE;

import static jdk.nashorn.internal.runtime.PropertyDescriptor.WRITABLE;

import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.isValidArrayIndex;

import static jdk.nashorn.internal.runtime.arrays.ArrayLikeIterator.arrayLikeIterator;

import static jdk.nashorn.internal.runtime.arrays.ArrayLikeIterator.reverseArrayLikeIterator;

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

import java.lang.invoke.MethodHandle;

import java.lang.invoke.SwitchPoint;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.Comparator;

import java.util.Iterator;

import java.util.List;

import java.util.concurrent.Callable;

import jdk.internal.dynalink.CallSiteDescriptor;

import jdk.internal.dynalink.linker.GuardedInvocation;

import jdk.internal.dynalink.linker.LinkRequest;

import jdk.nashorn.api.scripting.JSObject;

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

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

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

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

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

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

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

import jdk.nashorn.internal.objects.annotations.SpecializedFunction.LinkLogic;

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

import jdk.nashorn.internal.runtime.Context;

import jdk.nashorn.internal.runtime.Debug;

import jdk.nashorn.internal.runtime.JSType;

import jdk.nashorn.internal.runtime.OptimisticBuiltins;

import jdk.nashorn.internal.runtime.PropertyDescriptor;

import jdk.nashorn.internal.runtime.PropertyMap;

import jdk.nashorn.internal.runtime.ScriptFunction;

import jdk.nashorn.internal.runtime.ScriptObject;

import jdk.nashorn.internal.runtime.ScriptRuntime;

import jdk.nashorn.internal.runtime.Undefined;

import jdk.nashorn.internal.runtime.arrays.ArrayData;

import jdk.nashorn.internal.runtime.arrays.ArrayIndex;

import jdk.nashorn.internal.runtime.arrays.ArrayLikeIterator;

import jdk.nashorn.internal.runtime.arrays.ContinuousArrayData;

import jdk.nashorn.internal.runtime.arrays.IntElements;

import jdk.nashorn.internal.runtime.arrays.IntOrLongElements;

import jdk.nashorn.internal.runtime.arrays.IteratorAction;

import jdk.nashorn.internal.runtime.arrays.NumericElements;

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

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

/**

 * Runtime representation of a JavaScript array. NativeArray only holds numeric

 * keyed values. All other values are stored in spill.

 */

@ScriptClass("Array")

public final class NativeArray extends ScriptObject implements OptimisticBuiltins {

    private static final Object JOIN                     = new Object();

    private static final Object EVERY_CALLBACK_INVOKER   = new Object();

    private static final Object SOME_CALLBACK_INVOKER    = new Object();

    private static final Object FOREACH_CALLBACK_INVOKER = new Object();

    private static final Object MAP_CALLBACK_INVOKER     = new Object();

    private static final Object FILTER_CALLBACK_INVOKER  = new Object();

    private static final Object REDUCE_CALLBACK_INVOKER  = new Object();

    private static final Object CALL_CMP                 = new Object();

    private static final Object TO_LOCALE_STRING         = new Object();

    private SwitchPoint   lengthMadeNotWritableSwitchPoint;

    private PushLinkLogic pushLinkLogic;

    private PopLinkLogic  popLinkLogic;

    /**

     * Index for the modification SwitchPoint that triggers when length

     * becomes not writable

     */

    private static final int LENGTH_NOT_WRITABLE_SWITCHPOINT = 0;

    /*

     * Constructors.

     */

    NativeArray() {

        this(ArrayData.initialArray());

    }

    NativeArray(final long length) {

        // TODO assert valid index in long before casting

        this(ArrayData.allocate((int)length));

    }

    NativeArray(final int[] array) {

        this(ArrayData.allocate(array));

    }

    NativeArray(final long[] array) {

        this(ArrayData.allocate(array));

    }

    NativeArray(final double[] array) {

        this(ArrayData.allocate(array));

    }

    NativeArray(final Object[] array) {

        this(ArrayData.allocate(array.length));

        ArrayData arrayData = this.getArray();

        arrayData.ensure(array.length - 1);

        for (int index = 0; index < array.length; index++) {

            final Object value = array[index];

            if (value == ScriptRuntime.EMPTY) {

                arrayData = arrayData.delete(index);

            } else {

                arrayData = arrayData.set(index, value, false);

            }

        }

        this.setArray(arrayData);

    }

    NativeArray(final ArrayData arrayData) {

        this(arrayData, Global.instance());

    }

    NativeArray(final ArrayData arrayData, final Global global) {

        super(global.getArrayPrototype(), $nasgenmap$);

        setArray(arrayData);

        setIsArray();

    }

    @Override

    protected GuardedInvocation findGetMethod(final CallSiteDescriptor desc, final LinkRequest request, final String operator) {

        final GuardedInvocation inv = getArray().findFastGetMethod(getArray().getClass(), desc, request, operator);

        if (inv != null) {

            return inv;

        }

        return super.findGetMethod(desc, request, operator);

    }

    @Override

    protected GuardedInvocation findGetIndexMethod(final CallSiteDescriptor desc, final LinkRequest request) {

        final GuardedInvocation inv = getArray().findFastGetIndexMethod(getArray().getClass(), desc, request);

        if (inv != null) {

            return inv;

        }

        return super.findGetIndexMethod(desc, request);

    }

    @Override

    protected GuardedInvocation findSetIndexMethod(final CallSiteDescriptor desc, final LinkRequest request) {

        final GuardedInvocation inv = getArray().findFastSetIndexMethod(getArray().getClass(), desc, request);

        if (inv != null) {

            return inv;

        }

        return super.findSetIndexMethod(desc, request);

    }

    private static InvokeByName getJOIN() {

        return Global.instance().getInvokeByName(JOIN,

                new Callable<InvokeByName>() {

                    @Override

                    public InvokeByName call() {

                        return new InvokeByName("join", ScriptObject.class);

                    }

                });

    }

    private static MethodHandle createIteratorCallbackInvoker(final Object key, final Class<?> rtype) {

        return Global.instance().getDynamicInvoker(key,

            new Callable<MethodHandle>() {

                @Override

                public MethodHandle call() {

                    return Bootstrap.createDynamicInvoker("dyn:call", rtype, Object.class, Object.class, Object.class,

                        long.class, Object.class);

                }

            });

    }

    private static MethodHandle getEVERY_CALLBACK_INVOKER() {

        return createIteratorCallbackInvoker(EVERY_CALLBACK_INVOKER, boolean.class);

    }

    private static MethodHandle getSOME_CALLBACK_INVOKER() {

        return createIteratorCallbackInvoker(SOME_CALLBACK_INVOKER, boolean.class);

    }

    private static MethodHandle getFOREACH_CALLBACK_INVOKER() {

        return createIteratorCallbackInvoker(FOREACH_CALLBACK_INVOKER, void.class);

    }

    private static MethodHandle getMAP_CALLBACK_INVOKER() {

        return createIteratorCallbackInvoker(MAP_CALLBACK_INVOKER, Object.class);

    }

    private static MethodHandle getFILTER_CALLBACK_INVOKER() {

        return createIteratorCallbackInvoker(FILTER_CALLBACK_INVOKER, boolean.class);

    }

    private static MethodHandle getREDUCE_CALLBACK_INVOKER() {

        return Global.instance().getDynamicInvoker(REDUCE_CALLBACK_INVOKER,

                new Callable<MethodHandle>() {

                    @Override

                    public MethodHandle call() {

                        return Bootstrap.createDynamicInvoker("dyn:call", Object.class, Object.class,

                             Undefined.class, Object.class, Object.class, long.class, Object.class);

                    }

                });

    }

    private static MethodHandle getCALL_CMP() {

        return Global.instance().getDynamicInvoker(CALL_CMP,

                new Callable<MethodHandle>() {

                    @Override

                    public MethodHandle call() {

                        return Bootstrap.createDynamicInvoker("dyn:call", double.class,

                            ScriptFunction.class, Object.class, Object.class, Object.class);

                    }

                });

    }

    private static InvokeByName getTO_LOCALE_STRING() {

        return Global.instance().getInvokeByName(TO_LOCALE_STRING,

                new Callable<InvokeByName>() {

                    @Override

                    public InvokeByName call() {

                        return new InvokeByName("toLocaleString", ScriptObject.class, String.class);

                    }

                });

    }

    // initialized by nasgen

    private static PropertyMap $nasgenmap$;

    @Override

    public String getClassName() {

        return "Array";

    }

    @Override

    public Object getLength() {

        final long length = getArray().length() & JSType.MAX_UINT;

        if(length < Integer.MAX_VALUE) {

            return (int)length;

        }

        return length;

    }

    /**

     * ECMA 15.4.5.1 [[DefineOwnProperty]] ( P, Desc, Throw )

     */

    @Override

    public boolean defineOwnProperty(final String key, final Object propertyDesc, final boolean reject) {

        final PropertyDescriptor desc = toPropertyDescriptor(Global.instance(), propertyDesc);

        // never be undefined as "length" is always defined and can't be deleted for arrays

        // Step 1

        final PropertyDescriptor oldLenDesc = (PropertyDescriptor) super.getOwnPropertyDescriptor("length");

        // Step 2

        // get old length and convert to long

        long oldLen = NativeArray.validLength(oldLenDesc.getValue(), true);

        // Step 3

        if ("length".equals(key)) {

            // check for length being made non-writable

            if (desc.has(WRITABLE) && !desc.isWritable()) {

                setIsLengthNotWritable();

            }

            // Step 3a

            if (!desc.has(VALUE)) {

                return super.defineOwnProperty("length", desc, reject);

            }

            // Step 3b

            final PropertyDescriptor newLenDesc = desc;

            // Step 3c and 3d - get new length and convert to long

            final long newLen = NativeArray.validLength(newLenDesc.getValue(), true);

            // Step 3e

            newLenDesc.setValue(newLen);

            // Step 3f

            // increasing array length - just need to set new length value (and attributes if any) and return

            if (newLen >= oldLen) {

                return super.defineOwnProperty("length", newLenDesc, reject);

            }

            // Step 3g

            if (!oldLenDesc.isWritable()) {

                if (reject) {

                    throw typeError("property.not.writable", "length", ScriptRuntime.safeToString(this));

                }

                return false;

            }

            // Step 3h and 3i

            final boolean newWritable = !newLenDesc.has(WRITABLE) || newLenDesc.isWritable();

            if (!newWritable) {

                newLenDesc.setWritable(true);

            }

            // Step 3j and 3k

            final boolean succeeded = super.defineOwnProperty("length", newLenDesc, reject);

            if (!succeeded) {

                return false;

            }

            // Step 3l

            // make sure that length is set till the point we can delete the old elements

            while (newLen < oldLen) {

                oldLen--;

                final boolean deleteSucceeded = delete(oldLen, false);

                if (!deleteSucceeded) {

                    newLenDesc.setValue(oldLen + 1);

                    if (!newWritable) {

                        newLenDesc.setWritable(false);

                    }

                    super.defineOwnProperty("length", newLenDesc, false);

                    if (reject) {

                        throw typeError("property.not.writable", "length", ScriptRuntime.safeToString(this));

                    }

                    return false;

                }

            }

            // Step 3m

            if (!newWritable) {

                // make 'length' property not writable

                final ScriptObject newDesc = Global.newEmptyInstance();

                newDesc.set(WRITABLE, false, 0);

                return super.defineOwnProperty("length", newDesc, false);

            }

            return true;

        }

        // Step 4a

        final int index = ArrayIndex.getArrayIndex(key);

        if (ArrayIndex.isValidArrayIndex(index)) {

            final long longIndex = ArrayIndex.toLongIndex(index);

            // Step 4b

            // setting an element beyond current length, but 'length' is not writable

            if (longIndex >= oldLen && !oldLenDesc.isWritable()) {

                if (reject) {

                    throw typeError("property.not.writable", Long.toString(longIndex), ScriptRuntime.safeToString(this));

                }

                return false;

            }

            // Step 4c

            // set the new array element

            final boolean succeeded = super.defineOwnProperty(key, desc, false);

            // Step 4d

            if (!succeeded) {

                if (reject) {

                    throw typeError("cant.redefine.property", key, ScriptRuntime.safeToString(this));

                }

                return false;

            }

            // Step 4e -- adjust new length based on new element index that is set

            if (longIndex >= oldLen) {

                oldLenDesc.setValue(longIndex + 1);

                super.defineOwnProperty("length", oldLenDesc, false);

            }

            // Step 4f

            return true;

        }

        // not an index property

        return super.defineOwnProperty(key, desc, reject);

    }

    /**

     * Spec. mentions use of [[DefineOwnProperty]] for indexed properties in

     * certain places (eg. Array.prototype.map, filter). We can not use ScriptObject.set

     * method in such cases. This is because set method uses inherited setters (if any)

     * from any object in proto chain such as Array.prototype, Object.prototype.

     * This method directly sets a particular element value in the current object.

     *

     * @param index key for property

     * @param value value to define

     */

    @Override

    public final void defineOwnProperty(final int index, final Object value) {

        assert isValidArrayIndex(index) : "invalid array index";

        final long longIndex = ArrayIndex.toLongIndex(index);

        if (longIndex >= getArray().length()) {

            // make array big enough to hold..

            setArray(getArray().ensure(longIndex));

        }

        setArray(getArray().set(index, value, false));

    }

    /**

     * Return the array contents upcasted as an ObjectArray, regardless of

     * representation

     *

     * @return an object array

     */

    public Object[] asObjectArray() {

        return getArray().asObjectArray();

    }

    @Override

    public void setIsLengthNotWritable() {

        super.setIsLengthNotWritable();

        /*

         * Switchpoints are created lazily. If we link any push or pop site,

         * we need to create the "length made not writable" switchpoint, if it

         * doesn't exist.

         *

         * If the switchpoint already exists, we will find it here, and invalidate

         * it, invalidating all previous callsites that use it.

         *

         * If the switchpoint doesn't exist, no push/pop has been linked so far,

         * because that would create it too. We invalidate it immediately and the

         * check link logic for all future callsites will fail immediately at link

         * time

         */

        if (lengthMadeNotWritableSwitchPoint == null) {

            lengthMadeNotWritableSwitchPoint = new SwitchPoint();

        }

        SwitchPoint.invalidateAll(new SwitchPoint[] { lengthMadeNotWritableSwitchPoint });

    }

    /**

     * ECMA 15.4.3.2 Array.isArray ( arg )

     *

     * @param self self reference

     * @param arg  argument - object to check

     * @return true if argument is an array

     */

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

    public static boolean isArray(final Object self, final Object arg) {

        return isArray(arg) || (arg instanceof JSObject && ((JSObject)arg).isArray());

    }

    /**

     * Length getter

     * @param self self reference

     * @return the length of the object

     */

    @Getter(attributes = Attribute.NOT_ENUMERABLE | Attribute.NOT_CONFIGURABLE)

    public static Object length(final Object self) {

        if (isArray(self)) {

            return ((ScriptObject) self).getArray().length() & JSType.MAX_UINT;

        }

        return 0;

    }

    /**

     * Length setter

     * @param self   self reference

     * @param length new length property

     */

    @Setter(attributes = Attribute.NOT_ENUMERABLE | Attribute.NOT_CONFIGURABLE)

    public static void length(final Object self, final Object length) {

        if (isArray(self)) {

            ((ScriptObject) self).setLength(validLength(length, true));

        }

    }

    /**

     * Prototype length getter

     * @param self self reference

     * @return the length of the object

     */

    @Getter(name = "length", where = Where.PROTOTYPE, attributes = Attribute.NOT_ENUMERABLE | Attribute.NOT_CONFIGURABLE)

    public static Object getProtoLength(final Object self) {

        return length(self);  // Same as instance getter but we can't make nasgen use the same method for prototype

    }