/*

 * 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.api.scripting;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.util.AbstractMap;

import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.LinkedHashSet;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.Set;

import java.util.concurrent.Callable;

import javax.script.Bindings;

import jdk.nashorn.internal.runtime.Context;

import jdk.nashorn.internal.runtime.ScriptFunction;

import jdk.nashorn.internal.runtime.ScriptObject;

import jdk.nashorn.internal.runtime.ScriptRuntime;

/**

 * Mirror object that wraps a given ScriptObject instance. User can

 * access ScriptObject via the javax.script.Bindings interface or

 * netscape.javascript.JSObject interface.

 */

public final class ScriptObjectMirror extends JSObject implements Bindings {

    private final ScriptObject sobj;

    private final ScriptObject global;

    @Override

    public boolean equals(final Object other) {

        if (other instanceof ScriptObjectMirror) {

            return sobj.equals(((ScriptObjectMirror)other).sobj);

        }

        return false;

    }

    @Override

    public int hashCode() {

        return sobj.hashCode();

    }

    @Override

    public String toString() {

        return inGlobal(new Callable<String>() {

            @Override

            public String call() {

                return ScriptRuntime.safeToString(sobj);

            }

        });

    }

    // JSObject methods

    @Override

    public Object call(final String functionName, final Object... args) {

        final ScriptObject oldGlobal = Context.getGlobal();

        final boolean globalChanged = (oldGlobal != global);

        try {

            if (globalChanged) {

                Context.setGlobal(global);

            }

            final Object val = functionName == null? sobj : sobj.get(functionName);

            if (! (val instanceof ScriptFunction)) {

                throw new NoSuchMethodException("No such function " + ((functionName != null)? functionName : ""));

            }

            final Object[] modArgs = globalChanged? wrapArray(args, oldGlobal) : args;

            return wrap(ScriptRuntime.checkAndApply((ScriptFunction)val, sobj, unwrapArray(modArgs, global)), global);

        } catch (final RuntimeException | Error e) {

            throw e;

        } catch (final Throwable t) {

            throw new RuntimeException(t);

        } finally {

            if (globalChanged) {

                Context.setGlobal(oldGlobal);

            }

        }

    }

    @Override

    public Object newObject(final String functionName, final Object... args) {

        final ScriptObject oldGlobal = Context.getGlobal();

        final boolean globalChanged = (oldGlobal != global);

        try {

            if (globalChanged) {

                Context.setGlobal(global);

            }

            final Object val = functionName == null? sobj : sobj.get(functionName);

            if (! (val instanceof ScriptFunction)) {

                throw new RuntimeException("not a constructor " + ((functionName != null)? functionName : ""));

            }

            final Object[] modArgs = globalChanged? wrapArray(args, oldGlobal) : args;

            return wrap(ScriptRuntime.checkAndConstruct((ScriptFunction)val, unwrapArray(modArgs, global)), global);

        } catch (final RuntimeException | Error e) {

            throw e;

        } catch (final Throwable t) {

            throw new RuntimeException(t);

        } finally {

            if (globalChanged) {

                Context.setGlobal(oldGlobal);

            }

        }

    }

    @Override

    public Object eval(final String s) {

        return inGlobal(new Callable<Object>() {

            @Override

            public Object call() {

                final Context context = AccessController.doPrivileged(

                        new PrivilegedAction<Context>() {

                            @Override

                            public Context run() {

                                return Context.getContext();

                            }

                        });

                return wrap(context.eval(global, s, null, null, false), global);

            }

        });

    }

    @Override

    public Object getMember(final String name) {

        return inGlobal(new Callable<Object>() {

            @Override public Object call() {

                return wrap(sobj.get(name), global);

            }

        });

    }

    @Override

    public Object getSlot(final int index) {

        return inGlobal(new Callable<Object>() {

            @Override public Object call() {

                return wrap(sobj.get(index), global);

            }

        });

    }

    @Override

    public void removeMember(final String name) {

        remove(name);

    }

    @Override

    public void setMember(final String name, final Object value) {

        put(name, value);

    }

    @Override

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

        inGlobal(new Callable<Void>() {

            @Override public Void call() {

                sobj.set(index, unwrap(value, global), global.isStrictContext());

                return null;

            }

        });

    }

    // javax.script.Bindings methods

    @Override

    public void clear() {

        inGlobal(new Callable<Object>() {

            @Override public Object call() {

                sobj.clear();

                return null;

            }

        });

    }

    @Override

    public boolean containsKey(final Object key) {

        return inGlobal(new Callable<Boolean>() {

            @Override public Boolean call() {

                return sobj.containsKey(unwrap(key, global));

            }

        });

    }

    @Override

    public boolean containsValue(final Object value) {

        return inGlobal(new Callable<Boolean>() {

            @Override public Boolean call() {

                return sobj.containsValue(unwrap(value, global));

            }

        });

    }

    @Override

    public Set<Map.Entry<String, Object>> entrySet() {

        return inGlobal(new Callable<Set<Map.Entry<String, Object>>>() {

            @Override public Set<Map.Entry<String, Object>> call() {

                final Iterator<String>               iter    = sobj.propertyIterator();

                final Set<Map.Entry<String, Object>> entries = new LinkedHashSet<>();

                while (iter.hasNext()) {

                    final String key   = iter.next();

                    final Object value = translateUndefined(wrap(sobj.get(key), global));

                    entries.add(new AbstractMap.SimpleImmutableEntry<>(key, value));

                }

                return Collections.unmodifiableSet(entries);

            }

        });

    }

    @Override

    public Object get(final Object key) {

        return inGlobal(new Callable<Object>() {

            @Override public Object call() {

                return translateUndefined(wrap(sobj.get(key), global));

            }

        });

    }

    @Override

    public boolean isEmpty() {

        return inGlobal(new Callable<Boolean>() {

            @Override public Boolean call() {

                return sobj.isEmpty();

            }

        });

    }

    @Override

    public Set<String> keySet() {

        return inGlobal(new Callable<Set<String>>() {

            @Override public Set<String> call() {

                final Iterator<String> iter   = sobj.propertyIterator();

                final Set<String>      keySet = new LinkedHashSet<>();

                while (iter.hasNext()) {

                    keySet.add(iter.next());

                }

                return Collections.unmodifiableSet(keySet);

            }

        });

    }

    @Override

    public Object put(final String key, final Object value) {

        final ScriptObject oldGlobal = Context.getGlobal();

        final boolean globalChanged = (oldGlobal != global);

        return inGlobal(new Callable<Object>() {

            @Override public Object call() {

                final Object modValue = globalChanged? wrap(value, oldGlobal) : value;

                return translateUndefined(wrap(sobj.put(key, unwrap(modValue, global)), global));

            }

        });

    }

    @Override

    public void putAll(final Map<? extends String, ? extends Object> map) {

        final ScriptObject oldGlobal = Context.getGlobal();

        final boolean globalChanged = (oldGlobal != global);

        inGlobal(new Callable<Object>() {

            @Override public Object call() {

                final boolean strict = global.isStrictContext();

                for (final Map.Entry<? extends String, ? extends Object> entry : map.entrySet()) {

                    final Object value = entry.getValue();

                    final Object modValue = globalChanged? wrap(value, oldGlobal) : value;

                    sobj.set(entry.getKey(), unwrap(modValue, global), strict);

                }

                return null;

            }

        });

    }

    @Override

    public Object remove(final Object key) {

        return inGlobal(new Callable<Object>() {

            @Override public Object call() {

                return wrap(sobj.remove(unwrap(key, global)), global);

            }

        });

    }

    /**

     * Delete a property from this object.

     *

     * @param key the property to be deleted

     *

     * @return if the delete was successful or not

     */

    public boolean delete(final Object key) {

        return inGlobal(new Callable<Boolean>() {

            @Override public Boolean call() {

                return sobj.delete(unwrap(key, global));

            }

        });

    }

    @Override

    public int size() {

        return inGlobal(new Callable<Integer>() {

            @Override public Integer call() {

                return sobj.size();

            }

        });

    }

    @Override

    public Collection<Object> values() {

        return inGlobal(new Callable<Collection<Object>>() {

            @Override public Collection<Object> call() {

                final List<Object>     values = new ArrayList<>(size());

                final Iterator<Object> iter   = sobj.valueIterator();

                while (iter.hasNext()) {

                    values.add(translateUndefined(wrap(iter.next(), global)));

                }

                return Collections.unmodifiableList(values);

            }

        });

    }

    // Support for ECMAScript Object API on mirrors

    /**

     * Return the __proto__ of this object.

     * @return __proto__ object.

     */

    public Object getProto() {

        return inGlobal(new Callable<Object>() {

            @Override public Object call() {

                return wrap(sobj.getProto(), global);

            }

        });

    }

    /**

     * ECMA 8.12.1 [[GetOwnProperty]] (P)

     *

     * @param key property key

     *

     * @return Returns the Property Descriptor of the named own property of this

     * object, or undefined if absent.

     */

    public Object getOwnPropertyDescriptor(final String key) {

        return inGlobal(new Callable<Object>() {

            @Override public Object call() {

                return wrap(sobj.getOwnPropertyDescriptor(key), global);

            }

        });

    }

    /**

     * return an array of own property keys associated with the object.

     *

     * @param all True if to include non-enumerable keys.

     * @return Array of keys.

     */

    public String[] getOwnKeys(final boolean all) {

        return inGlobal(new Callable<String[]>() {

            @Override public String[] call() {

                return sobj.getOwnKeys(all);

            }

        });

    }

    /**

     * Flag this script object as non extensible

     *

     * @return the object after being made non extensible

     */

    public ScriptObjectMirror preventExtensions() {

        return inGlobal(new Callable<ScriptObjectMirror>() {

            @Override public ScriptObjectMirror call() {

                sobj.preventExtensions();

                return ScriptObjectMirror.this;

            }

        });

    }

    /**

     * Check if this script object is extensible

     * @return true if extensible

     */

    public boolean isExtensible() {

        return inGlobal(new Callable<Boolean>() {

            @Override public Boolean call() {

                return sobj.isExtensible();

            }

        });

    }

    /**

     * ECMAScript 15.2.3.8 - seal implementation

     * @return the sealed script object

     */

    public ScriptObjectMirror seal() {

        return inGlobal(new Callable<ScriptObjectMirror>() {

            @Override public ScriptObjectMirror call() {

                sobj.seal();

                return ScriptObjectMirror.this;

            }

        });

    }

    /**

     * Check whether this script object is sealed

     * @return true if sealed

     */

    public boolean isSealed() {

        return inGlobal(new Callable<Boolean>() {

            @Override public Boolean call() {

                return sobj.isSealed();

            }

        });

    }

    /**

     * ECMA 15.2.39 - freeze implementation. Freeze this script object

     * @return the frozen script object

     */

    public ScriptObjectMirror freeze() {

        return inGlobal(new Callable<ScriptObjectMirror>() {

            @Override public ScriptObjectMirror call() {

                sobj.freeze();

                return ScriptObjectMirror.this;

            }

        });

    }

    /**

     * Check whether this script object is frozen

     * @return true if frozen

     */

    public boolean isFrozen() {

        return inGlobal(new Callable<Boolean>() {

            @Override public Boolean call() {

                return sobj.isFrozen();

            }

        });

    }

    // ECMAScript instanceof check

    /**

     * Checking whether a script object is an instance of another by

     * walking the proto chain

     *

     * @param instance instace to check

     * @return true if 'instance' is an instance of this object

     */

    public boolean isInstance(final ScriptObjectMirror instance) {

        // if not belongs to my global scope, return false

        if (instance == null || global != instance.global) {

            return false;

        }

        return inGlobal(new Callable<Boolean>() {

            @Override public Boolean call() {

                return sobj.isInstance(instance.sobj);

            }

        });

    }

    /**

     * is this a function object?

     *

     * @return if this mirror wraps a ECMAScript function instance

     */

    public boolean isFunction() {

        return sobj instanceof ScriptFunction;