/*
 *
 *  * Copyright 2010,  Unitils.org
 *  *
 *  * 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.
 *
 */
package org.unitils.mock.argumentmatcher.impl;

import org.unitils.mock.argumentmatcher.ArgumentMatcher;

import static org.unitils.mock.argumentmatcher.ArgumentMatcher.MatchResult.*;

/**
 * A matcher for checking whether an argument equals a given value.
 *
 * @author Kenny Claes
 * @author Filip Neven
 * @author Tim Ducheyne
 */
public class EqualsArgumentMatcher implements ArgumentMatcher {

    /* The excepted value */
    private final Object value;


    /**
     * Creates a matcher for the given value.
     *
     * @param value The expected value
     */
    public EqualsArgumentMatcher(Object value) {
        this.value = value;
    }


    /**
     * Returns true if the given object matches the expected argument, false otherwise.
     *
     * The argumentAtInvocationTime is a copy (deep clone) of the arguments at the time of
     * the invocation. This way the original values can still be used later-on even when changes
     * occur to the original values (pass-by-value vs pass-by-reference).
     *
     * @param argument                 The argument that were used by reference, not null
     * @param argumentAtInvocationTime Copy of the argument, taken at the time that the invocation was performed, not null
     * @return The match result, not null
     */
    public MatchResult matches(Object argument, Object argumentAtInvocationTime) {
        if (value == null) {
            if (argument == null) {
                return SAME;
            }
            return NO_MATCH;
        }
        if (value.equals(argument)) {
            return MATCH;
        }
        return NO_MATCH;
    }
}