/*

 * Copyright (c) 2014, 2015, 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 java.lang.invoke;

import jdk.internal.vm.annotation.ForceInline;

import jdk.internal.vm.annotation.Stable;

import java.lang.invoke.VarHandle.AccessMode;

import java.lang.reflect.Method;

import java.lang.reflect.Modifier;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

/**

 * A var handle form containing a set of member name, one for each operation.

 * Each member characterizes a static method.

 */

final class VarForm {

    final @Stable MethodType[] methodType_table;

    final @Stable MemberName[] memberName_table;

    VarForm(Class<?> implClass, Class<?> receiver, Class<?> value, Class<?>... intermediate) {

        this.methodType_table = new MethodType[VarHandle.AccessType.values().length];

        // TODO lazily calculate

        this.memberName_table = linkFromStatic(implClass);

        // (Receiver, <Intermediates>)

        List<Class<?>> l = new ArrayList<>();

        if (receiver != null)

            l.add(receiver);

        l.addAll(Arrays.asList(intermediate));

        // (Receiver, <Intermediates>)Value

        methodType_table[VarHandle.AccessType.GET.ordinal()] =

                MethodType.methodType(value, l).erase();

        // (Receiver, <Intermediates>, Value)void

        l.add(value);

        methodType_table[VarHandle.AccessType.SET.ordinal()] =

                MethodType.methodType(void.class, l).erase();

        // (Receiver, <Intermediates>, Value)Value

        methodType_table[VarHandle.AccessType.GET_AND_UPDATE.ordinal()] =

                MethodType.methodType(value, l).erase();

        // (Receiver, <Intermediates>, Value, Value)boolean

        l.add(value);

        methodType_table[VarHandle.AccessType.COMPARE_AND_SWAP.ordinal()] =

                MethodType.methodType(boolean.class, l).erase();

        // (Receiver, <Intermediates>, Value, Value)Value

        methodType_table[VarHandle.AccessType.COMPARE_AND_EXCHANGE.ordinal()] =

                MethodType.methodType(value, l).erase();

    }

    @ForceInline

    final MethodType getMethodType(int type) {

        return methodType_table[type];

    }

    @ForceInline

    final MemberName getMemberName(int mode) {

        // TODO calculate lazily

        MemberName mn = memberName_table[mode];

        if (mn == null) {

            throw new UnsupportedOperationException();

        }

        return mn;

    }

    @Stable

    MethodType[] methodType_V_table;

    @ForceInline

    final MethodType[] getMethodType_V_init() {

        MethodType[] table = new MethodType[VarHandle.AccessType.values().length];

        for (int i = 0; i < methodType_table.length; i++) {

            MethodType mt = methodType_table[i];

            // TODO only adjust for sig-poly methods returning Object

            table[i] = mt.changeReturnType(void.class);

        }

        methodType_V_table = table;

        return table;

    }

    @ForceInline

    final MethodType getMethodType_V(int type) {

        MethodType[] table = methodType_V_table;

        if (table == null) {

            table = getMethodType_V_init();

        }

        return table[type];

    }

    /**

     * Link all signature polymorphic methods.

     */

    private static MemberName[] linkFromStatic(Class<?> implClass) {

        MemberName[] table = new MemberName[AccessMode.values().length];

        for (Class<?> c = implClass; c != VarHandle.class; c = c.getSuperclass()) {

            for (Method m : c.getDeclaredMethods()) {

                if (Modifier.isStatic(m.getModifiers())) {

                    AccessMode am = AccessMode.methodNameToAccessMode.get(m.getName());

                    if (am != null) {

                        assert table[am.ordinal()] == null;

                        table[am.ordinal()] = new MemberName(m);

                    }

                }

            }

        }

        return table;

    }

}