/*
 * Copyright 2005-2010 the original author or authors.
 * 
 * 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.wamblee.persistence;

import static org.mockito.Mockito.*;

import org.junit.Before;
import org.junit.Test;

import static junit.framework.TestCase.*;

public class AbstractDetachableTest {

    public static class X {

    }

    public static interface DetachableMethods {
        Integer getReference(X aObject);

        X load(Integer aReference);
    }

    public class MyDetachable extends AbstractDetachable<X, Integer> {

        public MyDetachable(X aObj) {
            super(aObj);
        }

        @Override
        protected Integer getReference(X aObject) {
            return methods.getReference(aObject);
        }

        @Override
        protected X load(Integer aReference) {
            return methods.load(aReference);
        }

    }

    private DetachableMethods methods;
    private AbstractDetachable<X, Integer> detachable;
    private X x;

    @Before
    public void setUp() {
        methods = mock(DetachableMethods.class);
    }

    @Test(expected = IllegalArgumentException.class)
    public void testNullPassedIn() {
        detachable = new MyDetachable(null);
    }

    @Test
    public void testDetach() {
        x = new X();
        Integer ref = 100;
        when(methods.getReference(any(X.class))).thenReturn(ref);
        detachable = new MyDetachable(x);
        verifyNoMoreInteractions(methods);
        detachable.detach();
        verify(methods).getReference(same(x));
        assertNull(detachable.getObject());
        assertEquals(ref, detachable.getReference());
    }

    @Test
    public void testDetachTwice() {
        reset(methods);
        testDetach();
        detachable.detach();
        detachable.detach();
        verifyNoMoreInteractions(methods);
    }

    @Test(expected = IllegalStateException.class)
    public void testDetachWithNullReference() {
        x = new X();
        Integer ref = 100;
        when(methods.getReference(any(X.class))).thenReturn(null);
        detachable = new MyDetachable(x);
        verifyNoMoreInteractions(methods);
        detachable.detach();
    }

    @Test
    public void testReattach() {
        testDetach();
        reset(methods);

        X x2 = new X(); // the new X loaded from persistent storage.
        when(methods.load(detachable.getReference())).thenReturn(x2);

        X x3 = detachable.get();
        verify(methods).load(100);
        assertSame(x2, x3);

        assertSame(x2, detachable.getObject());
    }

    @Test
    public void testGetInvokedTwiceNoLoads() {
        testReattach();
        reset(methods);
        detachable.get();
        detachable.get();
        verifyNoMoreInteractions(methods);
    }

}