/*
 * Copyright 2006 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.test;

import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import junit.framework.TestCase;

/**
 * Useful assertions for use in test cases.
 *
 * @author Erik Brakkee
 */
public final class AssertionUtils {

    /**
     * Disabled constructor.
     * 
     */
    private AssertionUtils() {
        // Empty
    }
    
    /**
     * Asserts that two collections are equal including equality of the elements. 
     * @param aExpected
     * @param aActual
     */
    public static void assertEquals(List aExpected, List aActual) { 
    	assertEquals(aExpected.toArray(), aActual.toArray());
    }
    
    /**
     * Asserts that two collections are equal including equality of the elements. 
     * @param aMsg
     * @param aExpected
     * @param aActual
     */
    public static void assertEquals(String aMsg, List aExpected, List aActual) { 
    	assertEquals(aMsg, aExpected.toArray(), aActual.toArray());
    }

    /**
     * Asserts that two object arrays are equal.
     * 
     * @param aExpected
     *            Expected object array.
     * @param aActual
     *            Actual object array.
     */
    public static void assertEquals(Object[] aExpected, Object[] aActual) {
        assertEquals("", aExpected, aActual);
    }

    /**
     * Asserts that two object arrays are equal.
     * 
     * @param aMsg
     *            Message.
     * @param aExpected
     *            Expected array.
     * @param aActual
     *            Actual array.
     */
    public static void assertEquals(String aMsg, Object[] aExpected,
            Object[] aActual) {
        TestCase.assertEquals(aMsg + ": Array lengths ", aExpected.length,
                aActual.length);

        for (int i = 0; i < aExpected.length; i++) {
            TestCase.assertEquals(aMsg + ": Element " + i, aExpected[i],
                    aActual[i]);
        }
    }

    /**
     * Asserts that two objects are equal, and in case the object is an Object[]
     * delegates to {@link #assertEquals(String, Object[], Object[]).
     * 
     * @param aMsg
     *            Message.
     * @param aExpected
     *            Expected result.
     * @param aActual
     *            Actual result.
     */
    public static void assertEquals(String aMsg, Object aExpected,
            Object aActual) {
        if (aExpected instanceof Object[]) {
            AssertionUtils.assertEquals(aMsg, (Object[]) aExpected,
                    (Object[]) aActual);

            return;
        }

        TestCase.assertEquals(aMsg, aExpected, aActual);
    }

    /**
     * Asserts that two maps are equal by comparing all keys and by checking
     * that the values for the same keys are the same.
     * 
     * @param aMsg
     *            Message.
     * @param aExpectedMap
     *            Expected result.
     * @param aActual
     *            Actual result.
     */
    public static void assertEquals(String aMsg, Map aExpectedMap, Map aActual) {
        TestCase.assertEquals("Map sizes differ", aExpectedMap.size(), aActual
                .size());

        Set keys = aExpectedMap.keySet();

        for (Iterator i = keys.iterator(); i.hasNext();) {
            String key = (String) i.next();
            TestCase.assertTrue("Map does not containg entry for key:" + key,
                    aActual.containsKey(key));
            AssertionUtils.assertEquals("Value of key " + key + " of map",
                    aExpectedMap.get(key), aActual.get(key));
        }
    }
   
    public static interface ErroneousCode { 
    	void run() throws Exception; 
    }
    
    /** 
     * Asserts that an exception occurs.
     * @param aRunnable Test cases should create a subclass of this which contains the 
     * code that should throw an exception.   
     * @param aType Type of exception that is expected.   
     */
    public static void assertException(ErroneousCode aObject, Class aType) { 
    	try { 
    		aObject.run();
    	} catch (Throwable t) { 
    		if ( aType.isInstance(t)) { 
    			return; // ok 
    		}
    		else { 
    			throw new RuntimeException(t);
    		}
    	}
    }
}