/*

 * 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.ECMAErrors.typeError;

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

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

import java.lang.invoke.MethodHandle;

import java.lang.invoke.MethodHandles;

import java.util.Arrays;

import java.util.BitSet;

import jdk.nashorn.internal.runtime.Property;

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.arrays.ArrayData;

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

/**

 * ECMA 10.6 Arguments Object.

 *

 * Arguments object used for non-strict mode functions. For strict mode, we use

 * a different implementation (@see NativeStrictArguments). In non-strict mode,

 * named argument access and index argument access (arguments[i]) are linked.

 * Modifications reflect on each other access -- till arguments indexed element

 * is deleted. After delete, there is no link between named access and indexed

 * access for that deleted index alone.

 */

public final class NativeArguments extends ScriptObject {

    private static final MethodHandle G$LENGTH = findOwnMH("G$length", Object.class, Object.class);

    private static final MethodHandle S$LENGTH = findOwnMH("S$length", void.class, Object.class, Object.class);

    private static final MethodHandle G$CALLEE = findOwnMH("G$callee", Object.class, Object.class);

    private static final MethodHandle S$CALLEE = findOwnMH("S$callee", void.class, Object.class, Object.class);

    private static final PropertyMap nasgenmap$;

    static {

        PropertyMap map = PropertyMap.newMap(NativeArguments.class);

        map = Lookup.newProperty(map, "length", Property.NOT_ENUMERABLE, G$LENGTH, S$LENGTH);

        map = Lookup.newProperty(map, "callee", Property.NOT_ENUMERABLE, G$CALLEE, S$CALLEE);

        nasgenmap$ = map;

    }

    private Object length;

    private Object callee;

    private ArrayData namedArgs;

    // This is lazily initialized - only when delete is invoked at all

    private BitSet deleted;

    NativeArguments(final Object[] arguments, final Object callee, final int numParams) {

        super(nasgenmap$);

        setIsArguments();

        setArray(ArrayData.allocate(arguments));

        this.length = arguments.length;

        this.callee = callee;

        /**

         * Declared number of parameters may be more or less than the actual passed

         * runtime arguments count. We need to truncate or extend with undefined values.

         *

         * Example:

         *

         * // less declared params

         * (function (x) { print(arguments); })(20, 44);

         *

         * // more declared params

         * (function (x, y) { print(arguments); })(3);

         */

        final Object[] newValues = new Object[numParams];

        if (numParams > arguments.length) {

            Arrays.fill(newValues, UNDEFINED);

        }

        System.arraycopy(arguments, 0, newValues, 0, Math.min(newValues.length, arguments.length));

        this.namedArgs = ArrayData.allocate(newValues);

        // set Object.prototype as __proto__

        this.setProto(Global.objectPrototype());

    }

    @Override

    public String getClassName() {

        return "Arguments";

    }

    /**

     * getArgument is used for named argument access.

     */

    @Override

    public Object getArgument(final int key) {

        return namedArgs.has(key) ? namedArgs.getObject(key) : UNDEFINED;

    }

    /**

     * setArgument is used for named argument set.

     */

    @Override

    public void setArgument(final int key, final Object value) {

        if (namedArgs.has(key)) {

            namedArgs.set(key, value, false);

        }

    }

    @Override

    public int getInt(final Object key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getInt(index) : super.getInt(key);

    }

    @Override

    public int getInt(final double key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getInt(index) : super.getInt(key);

    }

    @Override

    public int getInt(final long key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getInt(index) : super.getInt(key);

    }

    @Override

    public int getInt(final int key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getInt(index) : super.getInt(key);

    }

    @Override

    public long getLong(final Object key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getLong(index) : super.getLong(key);

    }

    @Override

    public long getLong(final double key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getLong(index) : super.getLong(key);

    }

    @Override

    public long getLong(final long key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getLong(index) : super.getLong(key);

    }

    @Override

    public long getLong(final int key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getLong(index) : super.getLong(key);

    }

    @Override

    public double getDouble(final Object key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getDouble(index) : super.getDouble(key);

    }

    @Override

    public double getDouble(final double key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getDouble(index) : super.getDouble(key);

    }

    @Override

    public double getDouble(final long key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getDouble(index) : super.getDouble(key);

    }

    @Override

    public double getDouble(final int key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getDouble(index) : super.getDouble(key);

    }

    @Override

    public Object get(final Object key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getObject(index) : super.get(key);

    }

    @Override

    public Object get(final double key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getObject(index) : super.get(key);

    }

    @Override

    public Object get(final long key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getObject(index) : super.get(key);

    }

    @Override

    public Object get(final int key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) ? namedArgs.getObject(index) : super.get(key);

    }

    @Override

    public void set(final Object key, final int value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final Object key, final long value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final Object key, final double value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final Object key, final Object value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final double key, final int value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final double key, final long value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final double key, final double value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final double key, final Object value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final long key, final int value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final long key, final long value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final long key, final double value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final long key, final Object value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final int key, final int value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final int key, final long value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final int key, final double value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public void set(final int key, final Object value, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        if (isMapped(index)) {

            namedArgs = namedArgs.set(index, value, strict);

        } else {

            super.set(key, value, strict);

        }

    }

    @Override

    public boolean has(final Object key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) || super.has(key);

    }

    @Override

    public boolean has(final double key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) || super.has(key);

    }

    @Override

    public boolean has(final long key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) || super.has(key);

    }

    @Override

    public boolean has(final int key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) || super.has(key);

    }

    @Override

    public boolean hasOwnProperty(final Object key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) || super.hasOwnProperty(key);

    }

    @Override

    public boolean hasOwnProperty(final int key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) || super.hasOwnProperty(key);

    }

    @Override

    public boolean hasOwnProperty(final long key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) || super.hasOwnProperty(key);

    }

    @Override

    public boolean hasOwnProperty(final double key) {

        final int index = getArrayIndexNoThrow(key);

        return isMapped(index) || super.hasOwnProperty(key);

    }

    @Override

    public boolean delete(final int key, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        final boolean success = super.delete(key, strict);

        if (success && namedArgs.has(index)) {

            setDeleted(index);

        }

        return success;

    }

    @Override

    public boolean delete(final long key, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        final boolean success = super.delete(key, strict);

        if (success && namedArgs.has(index)) {

            setDeleted(index);

        }

        return success;

    }

    @Override

    public boolean delete(final double key, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        final boolean success = super.delete(key, strict);

        if (success && namedArgs.has(index)) {

            setDeleted(index);

        }

        return success;

    }

    @Override

    public boolean delete(final Object key, final boolean strict) {

        final int index = getArrayIndexNoThrow(key);

        final boolean success = super.delete(key, strict);

        if (success && namedArgs.has(index)) {

            setDeleted(index);

        }

        return success;

    }

    /**

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

     * ECMA 10.6 for Arguments object.

     */

    @Override

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

        final int index = ArrayIndex.getArrayIndexNoThrow(key);

        if (index >= 0) {

            final boolean allowed = super.defineOwnProperty(key, propertyDesc, false);

            if (!allowed) {

                if (reject) {

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

                }

                return false;

            }

            if (isMapped(index)) {

                // When mapped argument is redefined, if new descriptor is accessor property

                // or data-non-writable property, we have to "unmap" (unlink).

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

                if (desc.type() == PropertyDescriptor.ACCESSOR) {

                    setDeleted(index);

                } else {

                    // set "value" from new descriptor to named args

                    if (desc.has(PropertyDescriptor.VALUE)) {

                        namedArgs = namedArgs.set(index, desc.getValue(), false);

                    }

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

                        setDeleted(index);

                    }

                }

            }

            return true;

        }

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

    }

    // Internals below this point

    // We track deletions using a bit set (delete arguments[index])

    private boolean isDeleted(final int index) {

        return (deleted != null) ? deleted.get(index) : false;

    }

    private void setDeleted(final int index) {

        if (deleted == null) {

            deleted = new BitSet((int)namedArgs.length());

        }

        deleted.set(index, true);