/**
 * Copyright (C) 2012-2014 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 ninja;

import ninja.jpa.JpaInitializer;
import ninja.jpa.JpaModule;
import ninja.utils.NinjaMode;
import ninja.utils.NinjaModeHelper;
import ninja.utils.NinjaPropertiesImpl;

import org.junit.After;
import org.junit.Before;

import com.google.common.base.Optional;
import com.google.inject.Guice;
import com.google.inject.Injector;

/**
 * Base class for testing JPA-based DAOs
 * 
 * How to use: Extend the Class and call getInstace(Class<SomeDao>) method to
 * get a real DAO. Then use JUnit assertions to test it (Example:
 * assertEquals(0,someDao.getAll().size());)
 * 
 * @author emiguelt
 * 
 */
public abstract class NinjaDaoTestBase {
    /**
     * Persistence Service initializer
     */
    private JpaInitializer jpaInitializer;
    /**
     * Guice Injector to get DAOs
     */
    private Injector injector;

    private NinjaMode ninjaMode;

    /**
     * Constructor checks if NinjaMode was set in System properties, if not,
     * NinjaMode.test is used as default
     */
    public NinjaDaoTestBase() {
        Optional<NinjaMode> mode = NinjaModeHelper
                .determineModeFromSystemProperties();
        ninjaMode = mode.isPresent() ? mode.get() : NinjaMode.test;

    }

    /**
     * Constructor, receives the test mode to choose the database
     * 
     * @param testMode
     */
    public NinjaDaoTestBase(NinjaMode testMode) {
        ninjaMode = testMode;
    }

    @Before
    public final void initialize() {
        NinjaPropertiesImpl ninjaProperties = new NinjaPropertiesImpl(ninjaMode);
        injector = Guice.createInjector(new JpaModule(ninjaProperties));
        jpaInitializer = injector.getInstance(JpaInitializer.class);
        jpaInitializer.start();
    }

    @After
    public final void stop() {
        jpaInitializer.stop();
    }

    /**
     * Get the DAO instances ready to use
     * 
     * @param clazz
     * @return DAO
     */
    protected <T> T getInstance(Class<T> clazz) {
        return injector.getInstance(clazz);
    }

}
