/*
 * %CopyrightBegin%
 *
 * Copyright Ericsson AB 2009. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * %CopyrightEnd%
 */
package com.ericsson.otp.erlang;

public class OtpErlangExternalFun extends OtpErlangObject {
    // don't change this!
    private static final long serialVersionUID = 6443965570641913886L;

    private final String module;
    private final String function;
    private final int arity;

    public OtpErlangExternalFun(final String module, final String function,
            final int arity) {
        super();
        this.module = module;
        this.function = function;
        this.arity = arity;
    }

    public OtpErlangExternalFun(final OtpInputStream buf)
            throws OtpErlangDecodeException {
        final OtpErlangExternalFun f = buf.read_external_fun();
        module = f.module;
        function = f.function;
        arity = f.arity;
    }

    @Override
    public void encode(final OtpOutputStream buf) {
        buf.write_external_fun(module, function, arity);
    }

    @Override
    public boolean equals(final Object o) {
        if (!(o instanceof OtpErlangExternalFun)) {
            return false;
        }
        final OtpErlangExternalFun f = (OtpErlangExternalFun) o;
        return module.equals(f.module) && function.equals(f.function)
                && arity == f.arity;
    }

    @Override
    protected int doHashCode() {
        final OtpErlangObject.Hash hash = new OtpErlangObject.Hash(14);
        hash.combine(module.hashCode(), function.hashCode());
        hash.combine(arity);
        return hash.valueOf();
    }

    @Override
    public String toString() {
        return "#Fun<" + module + "." + function + "." + arity + ">";
    }

}
