/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.camel.test.junit4;

import java.io.File;
import java.util.Collection;
import java.util.List;
import java.util.Locale;

import org.apache.camel.CamelContext;
import org.apache.camel.Channel;
import org.apache.camel.Endpoint;
import org.apache.camel.Exchange;
import org.apache.camel.Expression;
import org.apache.camel.InvalidPayloadException;
import org.apache.camel.Message;
import org.apache.camel.Predicate;
import org.apache.camel.Processor;
import org.apache.camel.Route;
import org.apache.camel.builder.Builder;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.builder.ValueBuilder;
import org.apache.camel.impl.DefaultCamelContext;
import org.apache.camel.impl.DefaultExchange;
import org.apache.camel.processor.DelegateProcessor;
import org.apache.camel.util.ExchangeHelper;
import org.apache.camel.util.PredicateAssertHelper;
import org.junit.Assert;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A bunch of useful testing methods
 *
 * @version 
 */
public abstract class TestSupport extends Assert {
    private static final Logger LOG = LoggerFactory.getLogger(TestSupport.class);    
    protected transient Logger log = LoggerFactory.getLogger(getClass());    
    
    // Builder methods for expressions used when testing
    // -------------------------------------------------------------------------

    /**
     * Returns a value builder for the given header
     */
    public static ValueBuilder header(String name) {
        return Builder.header(name);
    }

    /**
     * Returns a value builder for the given property
     */
    public static ValueBuilder property(String name) {
        return Builder.property(name);
    }    
    
    /**
     * Returns a predicate and value builder for the inbound body on an exchange
     */
    public static ValueBuilder body() {
        return Builder.body();
    }

    /**
     * Returns a predicate and value builder for the inbound message body as a
     * specific type
     */
    public static <T> ValueBuilder bodyAs(Class<T> type) {
        return Builder.bodyAs(type);
    }

    /**
     * Returns a predicate and value builder for the outbound body on an
     * exchange
     */
    public static ValueBuilder outBody() {
        return Builder.outBody();
    }

    /**
     * Returns a predicate and value builder for the outbound message body as a
     * specific type
     */
    public static <T> ValueBuilder outBodyAs(Class<T> type) {
        return Builder.outBodyAs(type);
    }

    /**
     * Returns a predicate and value builder for the fault body on an
     * exchange
     */
    public static ValueBuilder faultBody() {
        return Builder.faultBody();
    }

    /**
     * Returns a predicate and value builder for the fault message body as a
     * specific type
     */
    public static <T> ValueBuilder faultBodyAs(Class<T> type) {
        return Builder.faultBodyAs(type);
    }

    /**
     * Returns a value builder for the given system property
     */
    public static ValueBuilder systemProperty(String name) {
        return Builder.systemProperty(name);
    }

    /**
     * Returns a value builder for the given system property
     */
    public static ValueBuilder systemProperty(String name, String defaultValue) {
        return Builder.systemProperty(name, defaultValue);
    }

    // Assertions
    // -----------------------------------------------------------------------

    public static <T> T assertIsInstanceOf(Class<T> expectedType, Object value) {
        assertNotNull("Expected an instance of type: " + expectedType.getName() + " but was null", value);
        assertTrue("object should be a " + expectedType.getName() + " but was: " + value + " with type: "
                   + value.getClass().getName(), expectedType.isInstance(value));
        return expectedType.cast(value);
    }

    public static void assertEndpointUri(Endpoint endpoint, String uri) {
        assertNotNull("Endpoint is null when expecting endpoint for: " + uri, endpoint);
        assertEquals("Endoint uri for: " + endpoint, uri, endpoint.getEndpointUri());
    }

    /**
     * Asserts the In message on the exchange contains the expected value
     */
    public static Object assertInMessageHeader(Exchange exchange, String name, Object expected) {
        return assertMessageHeader(exchange.getIn(), name, expected);
    }

    /**
     * Asserts the Out message on the exchange contains the expected value
     */
    public static Object assertOutMessageHeader(Exchange exchange, String name, Object expected) {
        return assertMessageHeader(exchange.getOut(), name, expected);
    }

    /**
     * Asserts that the given exchange has an OUT message of the given body value
     *
     * @param exchange the exchange which should have an OUT message
     * @param expected the expected value of the OUT message
     * @throws InvalidPayloadException is thrown if the payload is not the expected class type
     */
    public static void assertInMessageBodyEquals(Exchange exchange, Object expected) throws InvalidPayloadException {
        assertNotNull("Should have a response exchange!", exchange);

        Object actual;
        if (expected == null) {
            actual = ExchangeHelper.getMandatoryInBody(exchange);
            assertEquals("in body of: " + exchange, expected, actual);
        } else {
            actual = ExchangeHelper.getMandatoryInBody(exchange, expected.getClass());
        }
        assertEquals("in body of: " + exchange, expected, actual);

        LOG.debug("Received response: " + exchange + " with in: " + exchange.getIn());
    }

    /**
     * Asserts that the given exchange has an OUT message of the given body value
     *
     * @param exchange the exchange which should have an OUT message
     * @param expected the expected value of the OUT message
     * @throws InvalidPayloadException is thrown if the payload is not the expected class type
     */
    public static void assertOutMessageBodyEquals(Exchange exchange, Object expected) throws InvalidPayloadException {
        assertNotNull("Should have a response exchange!", exchange);

        Object actual;
        if (expected == null) {
            actual = ExchangeHelper.getMandatoryOutBody(exchange);
            assertEquals("output body of: " + exchange, expected, actual);
        } else {
            actual = ExchangeHelper.getMandatoryOutBody(exchange, expected.getClass());
        }
        assertEquals("output body of: " + exchange, expected, actual);

        LOG.debug("Received response: " + exchange + " with out: " + exchange.getOut());
    }

    public static Object assertMessageHeader(Message message, String name, Object expected) {
        Object value = message.getHeader(name);
        assertEquals("Header: " + name + " on Message: " + message, expected, value);
        return value;
    }

    /**
     * Asserts that the given expression when evaluated returns the given answer
     */
    public static Object assertExpression(Expression expression, Exchange exchange, Object expected) {
        Object value;
        if (expected != null) {
            value = expression.evaluate(exchange, expected.getClass());
        } else {
            value = expression.evaluate(exchange, Object.class);
        }

        LOG.debug("Evaluated expression: " + expression + " on exchange: " + exchange + " result: " + value);

        assertEquals("Expression: " + expression + " on Exchange: " + exchange, expected, value);
        return value;
    }

    /**
     * Asserts that the predicate returns the expected value on the exchange
     */
    public static void assertPredicateMatches(Predicate predicate, Exchange exchange) {
        assertPredicate(predicate, exchange, true);
    }

    /**
     * Asserts that the predicate returns the expected value on the exchange
     */
    public static void assertPredicateDoesNotMatch(Predicate predicate, Exchange exchange) {
        try {
            PredicateAssertHelper.assertMatches(predicate, "Predicate should match: ", exchange);
        } catch (AssertionError e) {
            LOG.debug("Caught expected assertion error: " + e);
        }
        assertPredicate(predicate, exchange, false);
    }

    /**
     * Asserts that the predicate returns the expected value on the exchange
     */
    public static boolean assertPredicate(final Predicate predicate, Exchange exchange, boolean expected) {
        if (expected) {
            PredicateAssertHelper.assertMatches(predicate, "Predicate failed: ", exchange);
        }
        boolean value = predicate.matches(exchange);

        LOG.debug("Evaluated predicate: " + predicate + " on exchange: " + exchange + " result: " + value);

        assertEquals("Predicate: " + predicate + " on Exchange: " + exchange, expected, value);
        return value;
    }

    /**
     * Resolves an endpoint and asserts that it is found
     */
    public static Endpoint resolveMandatoryEndpoint(CamelContext context, String uri) {
        Endpoint endpoint = context.getEndpoint(uri);

        assertNotNull("No endpoint found for URI: " + uri, endpoint);

        return endpoint;
    }

    /**
     * Resolves an endpoint and asserts that it is found
     */
    public static <T extends Endpoint> T resolveMandatoryEndpoint(CamelContext context, String uri,
                                                              Class<T> endpointType) {
        T endpoint = context.getEndpoint(uri, endpointType);

        assertNotNull("No endpoint found for URI: " + uri, endpoint);

        return endpoint;
    }

    /**
     * Creates an exchange with the given body
     */
    protected Exchange createExchangeWithBody(CamelContext camelContext, Object body) {
        Exchange exchange = new DefaultExchange(camelContext);
        Message message = exchange.getIn();        
        message.setHeader("testClass", getClass().getName());
        message.setBody(body);
        return exchange;
    }

    public static <T> T assertOneElement(List<T> list) {
        assertEquals("Size of list should be 1: " + list, 1, list.size());
        return list.get(0);
    }

    /**
     * Asserts that a list is of the given size
     */
    public static <T> List<T> assertListSize(List<T> list, int size) {
        return assertListSize("List", list, size);
    }

    /**
     * Asserts that a list is of the given size
     */
    public static <T> List<T> assertListSize(String message, List<T> list, int size) {
        assertEquals(message + " should be of size: "
                + size + " but is: " + list, size, list.size());
        return list;
    }

    /**
     * Asserts that a list is of the given size
     */
    public static <T> Collection<T> assertCollectionSize(Collection<T> list, int size) {
        return assertCollectionSize("List", list, size);
    }

    /**
     * Asserts that a list is of the given size
     */
    public static <T> Collection<T> assertCollectionSize(String message, Collection<T> list, int size) {
        assertEquals(message + " should be of size: "
                + size + " but is: " + list, size, list.size());
        return list;
    }

    /**
     * A helper method to create a list of Route objects for a given route builder
     */
    public static List<Route> getRouteList(RouteBuilder builder) throws Exception {
        CamelContext context = new DefaultCamelContext();
        context.addRoutes(builder);
        context.start();
        List<Route> answer = context.getRoutes();
        context.stop();
        return answer;
    }

    /**
     * Asserts that the text contains the given string
     *
     * @param text the text to compare
     * @param containedText the text which must be contained inside the other text parameter
     */
    public static void assertStringContains(String text, String containedText) {
        assertNotNull("Text should not be null!", text);
        assertTrue("Text: " + text + " does not contain: " + containedText, text.contains(containedText));
    }

    /**
     * If a processor is wrapped with a bunch of DelegateProcessor or DelegateAsyncProcessor objects
     * this call will drill through them and return the wrapped Processor.
     */
    public static Processor unwrap(Processor processor) {
        while (true) {
            if (processor instanceof DelegateProcessor) {
                processor = ((DelegateProcessor)processor).getProcessor();
            } else {
                return processor;
            }
        }
    }

    /**
     * If a processor is wrapped with a bunch of DelegateProcessor or DelegateAsyncProcessor objects
     * this call will drill through them and return the Channel.
     * <p/>
     * Returns null if no channel is found.
     */
    public static Channel unwrapChannel(Processor processor) {
        while (true) {
            if (processor instanceof Channel) {
                return (Channel) processor;
            } else if (processor instanceof DelegateProcessor) {
                processor = ((DelegateProcessor)processor).getProcessor();
            } else {
                return null;
            }
        }
    }

    /**
     * Recursively delete a directory, useful to zapping test data
     *
     * @param file the directory to be deleted
     */
    public static void deleteDirectory(String file) {
        deleteDirectory(new File(file));
    }

    /**
     * Recursively delete a directory, useful to zapping test data
     *
     * @param file the directory to be deleted
     */
    public static void deleteDirectory(File file) {
        if (file.isDirectory()) {
            File[] files = file.listFiles();
            for (int i = 0; i < files.length; i++) {
                deleteDirectory(files[i]);
            }
        }
        file.delete();
    }

    /**
     * create the directory
     *
     * @param file the directory to be created
     */
    public static void createDirectory(String file) {
        File dir = new File(file);
        dir.mkdirs();
    }

    /**
     * To be used for folder/directory comparison that works across different platforms such
     * as Window, Mac and Linux.
     */
    public static void assertDirectoryEquals(String expected, String actual) {
        assertDirectoryEquals(null, expected, actual);
    }

    /**
     * To be used for folder/directory comparison that works across different platforms such
     * as Window, Mac and Linux.
     */
    public static void assertDirectoryEquals(String message, String expected, String actual) {
        // must use single / as path separators
        String expectedPath = expected.replace('\\', '/');
        String actualPath = actual.replace('\\', '/');

        if (message != null) {
            assertEquals(message, expectedPath, actualPath);
        } else {
            assertEquals(expectedPath, actualPath);
        }
    }

    /**
     * To be used to check is a file is found in the file system
     */
    public static void assertFileExists(String filename) {
        File file = new File(filename).getAbsoluteFile();
        assertTrue("File " + filename + " should exist", file.exists());
    }

    /**
     * Is this OS the given platform.
     * <p/>
     * Uses <tt>os.name</tt> from the system properties to determine the OS.
     *
     * @param platform such as Windows
     * @return <tt>true</tt> if its that platform.
     */
    public static boolean isPlatform(String platform) {
        String osName = System.getProperty("os.name").toLowerCase(Locale.US);
        return osName.indexOf(platform.toLowerCase(Locale.US)) > -1;
    }

    /**
     * Is this Java by the given vendor.
     * <p/>
     * Uses <tt>java.vendor</tt> from the system properties to determine the vendor.
     *
     * @param vendor such as IBM
     * @return <tt>true</tt> if its that vendor.
     */
    public static boolean isJavaVendor(String vendor) {
        String javaVendor = System.getProperty("java.vendor").toLowerCase(Locale.US);
        return javaVendor.indexOf(vendor.toLowerCase(Locale.US)) > -1;
    }

    /**
     * Is this Java 1.5
     *
     * @return <tt>true</tt> if its Java 1.5, <tt>false</tt> if its not (for example Java 1.6 or better)
     */
    public static boolean isJava15() {
        String javaVersion = System.getProperty("java.version").toLowerCase(Locale.US);
        return javaVersion.startsWith("1.5");
    }

    /**
     * Gets the current test method name
     *
     * @return the method name
     */
    public String getTestMethodName() {
        // TODO: When using latest junit we can use @Rule to remember the test name
        // http://kentbeck.github.com/junit/javadoc/latest/org/junit/rules/TestName.html
        return "";
    }

}
