// Copyright 2006-2014 The Apache Software Foundation
//
// 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.apache.tapestry5.ioc.internal.util;

import org.apache.tapestry5.func.F;
import org.apache.tapestry5.func.Mapper;
import org.apache.tapestry5.func.Predicate;
import org.apache.tapestry5.internal.plastic.PlasticInternalUtils;
import org.apache.tapestry5.ioc.*;
import org.apache.tapestry5.ioc.annotations.*;
import org.apache.tapestry5.ioc.def.*;
import org.apache.tapestry5.ioc.internal.NullAnnotationProvider;
import org.apache.tapestry5.ioc.internal.ServiceDefImpl;
import org.apache.tapestry5.ioc.services.Coercion;
import org.apache.tapestry5.ioc.services.PlasticProxyFactory;
import org.apache.tapestry5.ioc.util.ExceptionUtils;
import org.apache.tapestry5.plastic.PlasticUtils;
import org.slf4j.Logger;

import javax.annotation.PostConstruct;
import javax.inject.Named;

import java.io.Closeable;
import java.io.IOException;
import java.lang.annotation.Annotation;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.reflect.*;
import java.net.URL;
import java.util.*;
import java.util.concurrent.atomic.AtomicLong;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Utilities used within various internal implementations of the tapestry-ioc module.
 */
@SuppressWarnings("all")
public class InternalUtils
{
    /**
     * @since 5.2.2
     */
    public static final boolean SERVICE_CLASS_RELOADING_ENABLED = Boolean.parseBoolean(System.getProperty(
            IOCConstants.SERVICE_CLASS_RELOADING_ENABLED, "true"));


    /**
     * Pattern used to eliminate leading and trailing underscores and dollar signs.
     */
    private static final Pattern NAME_PATTERN = Pattern.compile("^[_|$]*([\\p{javaJavaIdentifierPart}]+?)[_|$]*$",
            Pattern.CASE_INSENSITIVE);

    /**
     * @since 5.3
     */
    public static AnnotationProvider NULL_ANNOTATION_PROVIDER = new NullAnnotationProvider();

    /**
     * Converts a method to a user presentable string using a {@link PlasticProxyFactory} to obtain a {@link Location}
     * (where possible). {@link #asString(Method)} is used under the covers, to present a detailed, but not excessive,
     * description of the class, method and parameters.
     *
     * @param method
     *         method to convert to a string
     * @param proxyFactory
     *         used to obtain the {@link Location}
     * @return the method formatted for presentation to the user
     */
    public static String asString(Method method, PlasticProxyFactory proxyFactory)
    {
        Location location = proxyFactory.getMethodLocation(method);

        return location != null ? location.toString() : asString(method);
    }

    /**
     * Converts a method to a user presentable string consisting of the containing class name, the method name, and the
     * short form of the parameter list (the class name of each parameter type, shorn of the package name portion).
     *
     * @param method
     * @return short string representation
     */
    public static String asString(Method method)
    {
        StringBuilder buffer = new StringBuilder();

        buffer.append(method.getDeclaringClass().getName());
        buffer.append(".");
        buffer.append(method.getName());
        buffer.append("(");

        for (int i = 0; i < method.getParameterTypes().length; i++)
        {
            if (i > 0)
                buffer.append(", ");

            String name = method.getParameterTypes()[i].getSimpleName();

            buffer.append(name);
        }

        return buffer.append(")").toString();
    }

    /**
     * Returns the size of an object array, or null if the array is empty.
     */

    public static int size(Object[] array)
    {
        return array == null ? 0 : array.length;
    }

    public static int size(Collection collection)
    {
        return collection == null ? 0 : collection.size();
    }

    /**
     * Strips leading "_" and "$" and trailing "_" from the name.
     */
    public static String stripMemberName(String memberName)
    {
        assert InternalUtils.isNonBlank(memberName);
        Matcher matcher = NAME_PATTERN.matcher(memberName);

        if (!matcher.matches())
            throw new IllegalArgumentException(String.format("Input '%s' is not a valid Java identifier.", memberName));

        return matcher.group(1);
    }

    /**
     * Converts an enumeration (of Strings) into a sorted list of Strings.
     */
    public static List<String> toList(Enumeration e)
    {
        List<String> result = CollectionFactory.newList();

        while (e.hasMoreElements())
        {
            String name = (String) e.nextElement();

            result.add(name);
        }

        Collections.sort(result);

        return result;
    }

    /**
     * Finds a specific annotation type within an array of annotations.
     *
     * @param <T>
     * @param annotations
     *         to search
     * @param annotationClass
     *         to match
     * @return the annotation instance, if found, or null otherwise
     */
    public static <T extends Annotation> T findAnnotation(Annotation[] annotations, Class<T> annotationClass)
    {
        for (Annotation a : annotations)
        {
            if (annotationClass.isInstance(a))
                return annotationClass.cast(a);
        }

        return null;
    }

    private static ObjectCreator<Object> asObjectCreator(final Object fixedValue)
    {
        return new ObjectCreator<Object>()
        {
            @Override
            public Object createObject()
            {
                return fixedValue;
            }
        };
    }

    private static ObjectCreator calculateInjection(final Class injectionType, Type genericType, final Annotation[] annotations,
                                                    final ObjectLocator locator, InjectionResources resources)
    {
        final AnnotationProvider provider = new AnnotationProvider()
        {
            @Override
            public <T extends Annotation> T getAnnotation(Class<T> annotationClass)
            {
                return findAnnotation(annotations, annotationClass);
            }
        };

        // At some point, it would be nice to eliminate InjectService, and rely
        // entirely on service interface type and point-of-injection markers.

        InjectService is = provider.getAnnotation(InjectService.class);

        if (is != null)
        {
            String serviceId = is.value();

            return asObjectCreator(locator.getService(serviceId, injectionType));
        }

        Named named = provider.getAnnotation(Named.class);

        if (named != null)
        {
            return asObjectCreator(locator.getService(named.value(), injectionType));
        }

        // In the absence of @InjectService, try some autowiring. First, does the
        // parameter type match one of the resources (the parameter defaults)?

        if (provider.getAnnotation(Inject.class) == null)
        {
            Object result = resources.findResource(injectionType, genericType);

            if (result != null)
            {
                return asObjectCreator(result);
            }
        }

        // TAP5-1765: For @Autobuild, special case where we always compute a fresh value
        // for the injection on every use.  Elsewhere, we compute once when generating the
        // construction plan and just use the singleton value repeatedly.

        if (provider.getAnnotation(Autobuild.class) != null)
        {
            return new ObjectCreator()
            {
                @Override
                public Object createObject()
                {
                    return locator.getObject(injectionType, provider);
                }
            };
        }

        // Otherwise, make use of the MasterObjectProvider service to resolve this type (plus
        // any other information gleaned from additional annotation) into the correct object.

        return asObjectCreator(locator.getObject(injectionType, provider));
    }

    public static ObjectCreator[] calculateParametersForMethod(Method method, ObjectLocator locator,
                                                               InjectionResources resources, OperationTracker tracker)
    {

        return calculateParameters(locator, resources, method.getParameterTypes(), method.getGenericParameterTypes(),
                method.getParameterAnnotations(), tracker);
    }

    public static ObjectCreator[] calculateParameters(final ObjectLocator locator, final InjectionResources resources,
                                                      Class[] parameterTypes, final Type[] genericTypes, Annotation[][] parameterAnnotations,
                                                      OperationTracker tracker)
    {
        int parameterCount = parameterTypes.length;

        ObjectCreator[] parameters = new ObjectCreator[parameterCount];

        for (int i = 0; i < parameterCount; i++)
        {
            final Class type = parameterTypes[i];
            final Type genericType = genericTypes[i];
            final Annotation[] annotations = parameterAnnotations[i];

            String description = String.format("Determining injection value for parameter #%d (%s)", i + 1,
                    PlasticUtils.toTypeName(type));

            final Invokable<ObjectCreator> operation = new Invokable<ObjectCreator>()
            {
                @Override
                public ObjectCreator invoke()
                {
                    return calculateInjection(type, genericType, annotations, locator, resources);
                }
            };

            parameters[i] = tracker.invoke(description, operation);
        }

        return parameters;
    }

    /**
     * Injects into the fields (of all visibilities) when the {@link org.apache.tapestry5.ioc.annotations.Inject} or
     * {@link org.apache.tapestry5.ioc.annotations.InjectService} annotations are present.
     *
     * @param object
     *         to be initialized
     * @param locator
     *         used to resolve external dependencies
     * @param resources
     *         provides injection resources for fields
     * @param tracker
     *         track operations
     */
    public static void injectIntoFields(final Object object, final ObjectLocator locator,
                                        final InjectionResources resources, OperationTracker tracker)
    {
        Class clazz = object.getClass();

        while (clazz != Object.class)
        {
            Field[] fields = clazz.getDeclaredFields();

            for (final Field f : fields)
            {
                // Ignore all static and final fields.

                int fieldModifiers = f.getModifiers();

                if (Modifier.isStatic(fieldModifiers) || Modifier.isFinal(fieldModifiers))
                    continue;

                final AnnotationProvider ap = new AnnotationProvider()
                {
                    @Override
                    public <T extends Annotation> T getAnnotation(Class<T> annotationClass)
                    {
                        return f.getAnnotation(annotationClass);
                    }
                };

                String description = String.format("Calculating possible injection value for field %s.%s (%s)",
                        clazz.getName(), f.getName(),
                        PlasticUtils.toTypeName(f.getType()));

                tracker.run(description, new Runnable()
                {
                    @Override
                    public void run()
                    {
                        final Class<?> fieldType = f.getType();

                        InjectService is = ap.getAnnotation(InjectService.class);
                        if (is != null)
                        {
                            inject(object, f, locator.getService(is.value(), fieldType));
                            return;
                        }

                        if (ap.getAnnotation(Inject.class) != null || ap.getAnnotation(InjectResource.class) != null)
                        {
                            Object value = resources.findResource(fieldType, f.getGenericType());

                            if (value != null)
                            {
                                inject(object, f, value);
                                return;
                            }

                            inject(object, f, locator.getObject(fieldType, ap));
                            return;
                        }

                        if (ap.getAnnotation(javax.inject.Inject.class) != null)
                        {
                            Named named = ap.getAnnotation(Named.class);

                            if (named == null)
                            {
                                Object value = resources.findResource(fieldType, f.getGenericType());

                                if (value != null)
                                {
                                    inject(object, f, value);
                                    return;
                                }

                                inject(object, f, locator.getObject(fieldType, ap));
                            } else
                            {
                                inject(object, f, locator.getService(named.value(), fieldType));
                            }

                            return;
                        }

                        // Ignore fields that do not have the necessary annotation.

                    }
                });
            }

            clazz = clazz.getSuperclass();
        }
    }

    private synchronized static void inject(Object target, Field field, Object value)
    {
        try
        {
            if (!field.isAccessible())
                field.setAccessible(true);

            field.set(target, value);

            // Is there a need to setAccessible back to false?
        } catch (Exception ex)
        {
            throw new RuntimeException(String.format("Unable to set field '%s' of %s to %s: %s", field.getName(),
                    target, value, ExceptionUtils.toMessage(ex)));
        }
    }

    /**
     * Joins together some number of elements to form a comma separated list.
     */
    public static String join(List elements)
    {
        return join(elements, ", ");
    }

    /**
     * Joins together some number of elements. If a value in the list is the empty string, it is replaced with the
     * string "(blank)".
     *
     * @param elements
     *         objects to be joined together
     * @param separator
     *         used between elements when joining
     */
    public static String join(List elements, String separator)
    {
        switch (elements.size())
        {
            case 0:
                return "";

            case 1:
                return elements.get(0).toString();

            default:

                StringBuilder buffer = new StringBuilder();
                boolean first = true;

                for (Object o : elements)
                {
                    if (!first)
                        buffer.append(separator);

                    String string = String.valueOf(o);

                    if (string.equals(""))
                        string = "(blank)";

                    buffer.append(string);

                    first = false;
                }

                return buffer.toString();
        }
    }

    /**
     * Creates a sorted copy of the provided elements, then turns that into a comma separated list.
     *
     * @return the elements converted to strings, sorted, joined with comma ... or "(none)" if the elements are null or
     *         empty
     */
    public static String joinSorted(Collection elements)
    {
        if (elements == null || elements.isEmpty())
            return "(none)";

        List<String> list = CollectionFactory.newList();

        for (Object o : elements)
            list.add(String.valueOf(o));

        Collections.sort(list);

        return join(list);
    }

    /**
     * Returns true if the input is null, or is a zero length string (excluding leading/trailing whitespace).
     */

    public static boolean isBlank(String input)
    {
        return input == null || input.length() == 0 || input.trim().length() == 0;
    }

    /**
     * Returns true if the input is an empty collection.
     */

    public static boolean isEmptyCollection(Object input)
    {
        if (input instanceof Collection)
        {
            return ((Collection) input).isEmpty();
        }

        return false;
    }

    public static boolean isNonBlank(String input)
    {
        return !isBlank(input);
    }

    /**
     * Capitalizes a string, converting the first character to uppercase.
     */
    public static String capitalize(String input)
    {
        if (input.length() == 0)
            return input;

        return input.substring(0, 1).toUpperCase() + input.substring(1);
    }

    /**
     * Sniffs the object to see if it is a {@link Location} or {@link Locatable}. Returns null if null or not
     * convertable to a location.
     */

    public static Location locationOf(Object location)
    {
        if (location == null)
            return null;

        if (location instanceof Location)
            return (Location) location;

        if (location instanceof Locatable)
            return ((Locatable) location).getLocation();

        return null;
    }

    /**
     * Extracts the string keys from a map and returns them in sorted order. The keys are converted to strings.
     *
     * @param map
     *         the map to extract keys from (may be null)
     * @return the sorted keys, or the empty set if map is null
     */

    public static List<String> sortedKeys(Map map)
    {
        if (map == null)
            return Collections.emptyList();

        List<String> keys = CollectionFactory.newList();

        for (Object o : map.keySet())
            keys.add(String.valueOf(o));

        Collections.sort(keys);

        return keys;
    }

    public static <K, V> Set<K> keys(Map<K, V> map)
    {
        if (map == null)
            return Collections.emptySet();

        return map.keySet();
    }

    /**
     * Gets a value from a map (which may be null).
     *
     * @param <K>
     * @param <V>
     * @param map
     *         the map to extract from (may be null)
     * @param key
     * @return the value from the map, or null if the map is null
     */

    public static <K, V> V get(Map<K, V> map, K key)
    {
        if (map == null)
            return null;

        return map.get(key);
    }

    /**
     * Returns true if the method provided is a static method.
     */
    public static boolean isStatic(Method method)
    {
        return Modifier.isStatic(method.getModifiers());
    }

    public static <T> Iterator<T> reverseIterator(final List<T> list)
    {
        final ListIterator<T> normal = list.listIterator(list.size());

        return new Iterator<T>()
        {
            @Override
            public boolean hasNext()
            {
                return normal.hasPrevious();
            }

            @Override
            public T next()
            {
                return normal.previous();
            }

            @Override
            public void remove()
            {
                throw new UnsupportedOperationException();
            }
        };
    }

    /**
     * Return true if the input string contains the marker for symbols that must be expanded.
     */
    public static boolean containsSymbols(String input)
    {
        return input.contains("${");
    }

    /**
     * Searches the string for the final period ('.') character and returns everything after that. The input string is
     * generally a fully qualified class name, though tapestry-core also uses this method for the occasional property
     * expression (which is also dot separated). Returns the input string unchanged if it does not contain a period
     * character.
     */
    public static String lastTerm(String input)
    {
        assert InternalUtils.isNonBlank(input);
        int dotx = input.lastIndexOf('.');

        if (dotx < 0)
            return input;

        return input.substring(dotx + 1);
    }

    /**
     * Searches a class for the "best" constructor, the public constructor with the most parameters. Returns null if
     * there are no public constructors. If there is more than one constructor with the maximum number of parameters, it
     * is not determined which will be returned (don't build a class like that!). In addition, if a constructor is
     * annotated with {@link org.apache.tapestry5.ioc.annotations.Inject}, it will be used (no check for multiple such
     * constructors is made, only at most a single constructor should have the annotation).
     *
     * @param clazz
     *         to search for a constructor for
     * @return the constructor to be used to instantiate the class, or null if no appropriate constructor was found
     */
    public static Constructor findAutobuildConstructor(Class clazz)
    {
        Constructor[] constructors = clazz.getConstructors();

        switch (constructors.length)
        {
            case 1:

                return constructors[0];

            case 0:

                return null;

            default:
                break;
        }

        Constructor standardConstructor = findConstructorByAnnotation(constructors, Inject.class);
        Constructor javaxConstructor = findConstructorByAnnotation(constructors, javax.inject.Inject.class);

        if (standardConstructor != null && javaxConstructor != null)
            throw new IllegalArgumentException(
                    String.format(
                            "Too many autobuild constructors found: use either @%s or @%s annotation to mark a single constructor for autobuilding.",
                            Inject.class.getName(), javax.inject.Inject.class.getName()));

        if (standardConstructor != null)
        {
            return standardConstructor;
        }

        if (javaxConstructor != null)
        {
            return javaxConstructor;
        }

        // Choose a constructor with the most parameters.

        Comparator<Constructor> comparator = new Comparator<Constructor>()
        {
            @Override
            public int compare(Constructor o1, Constructor o2)
            {
                return o2.getParameterTypes().length - o1.getParameterTypes().length;
            }
        };

        Arrays.sort(constructors, comparator);

        return constructors[0];
    }

    private static <T extends Annotation> Constructor findConstructorByAnnotation(Constructor[] constructors,
                                                                                  Class<T> annotationClass)
    {
        for (Constructor c : constructors)
        {
            if (c.getAnnotation(annotationClass) != null)
                return c;
        }

        return null;
    }

    /**
     * Adds a value to a specially organized map where the values are lists of objects. This somewhat simulates a map
     * that allows multiple values for the same key.
     *
     * @param map
     *         to store value into
     * @param key
     *         for which a value is added
     * @param value
     *         to add
     * @param <K>
     *         the type of key
     * @param <V>
     *         the type of the list
     */
    public static <K, V> void addToMapList(Map<K, List<V>> map, K key, V value)
    {
        List<V> list = map.get(key);

        if (list == null)
        {
            list = CollectionFactory.newList();
            map.put(key, list);
        }

        list.add(value);
    }

    /**
     * Validates that the marker annotation class had a retention policy of runtime.
     *
     * @param markerClass
     *         the marker annotation class
     */
    public static void validateMarkerAnnotation(Class markerClass)
    {
        Retention policy = (Retention) markerClass.getAnnotation(Retention.class);

        if (policy != null && policy.value() == RetentionPolicy.RUNTIME)
            return;

        throw new IllegalArgumentException(UtilMessages.badMarkerAnnotation(markerClass));
    }

    public static void validateMarkerAnnotations(Class[] markerClasses)
    {
        for (Class markerClass : markerClasses)
            validateMarkerAnnotation(markerClass);
    }

    public static void close(Closeable stream)
    {
        if (stream != null)
            try
            {
                stream.close();
            } catch (IOException ex)
            {
                // Ignore.
            }
    }

    /**
     * Extracts the message from an exception. If the exception's message is null, returns the exceptions class name.
     *
     * @param exception
     *         to extract message from
     * @return message or class name
     * @deprecated Deprecated in 5.4; use {@link ExceptionUtils#toMessage(Throwable)} instead.
     */
    // Cause it gets used a lot outside of Tapestry proper even though it is internal.
    public static String toMessage(Throwable exception)
    {
        return ExceptionUtils.toMessage(exception);
    }

    public static void validateConstructorForAutobuild(Constructor constructor)
    {
        Class clazz = constructor.getDeclaringClass();

        if (!Modifier.isPublic(clazz.getModifiers()))
            throw new IllegalArgumentException(String.format(
                    "Class %s is not a public class and may not be autobuilt.", clazz.getName()));

        if (!Modifier.isPublic(constructor.getModifiers()))
            throw new IllegalArgumentException(
                    String.format(
                            "Constructor %s is not public and may not be used for autobuilding an instance of the class. "
                                    + "You should make the constructor public, or mark an alternate public constructor with the @Inject annotation.",
                            constructor));
    }

    /**
     * @since 5.3
     */
    public static final Mapper<Class, AnnotationProvider> CLASS_TO_AP_MAPPER = new Mapper<Class, AnnotationProvider>()
    {
        @Override
        public AnnotationProvider map(final Class element)
        {
            return toAnnotationProvider(element);
        }

    };

    /**
     * @since 5.3
     */
    public static AnnotationProvider toAnnotationProvider(final Class element)
    {
        return new AnnotationProvider()
        {
            @Override
            public <T extends Annotation> T getAnnotation(Class<T> annotationClass)
            {
                return annotationClass.cast(element.getAnnotation(annotationClass));
            }
        };
    }

    ;

    /**
     * @since 5.3
     */
    public static final Mapper<Method, AnnotationProvider> METHOD_TO_AP_MAPPER = new Mapper<Method, AnnotationProvider>()
    {
        @Override
        public AnnotationProvider map(final Method element)
        {
            return toAnnotationProvider(element);
        }
    };

    public static final Method findMethod(Class containingClass, String methodName, Class... parameterTypes)
    {
        if (containingClass == null)
            return null;

        try
        {
            return containingClass.getMethod(methodName, parameterTypes);
        } catch (SecurityException ex)
        {
            throw new RuntimeException(ex);
        } catch (NoSuchMethodException ex)
        {
            return null;
        }
    }

    /**
     * @since 5.3
     */
    public static ServiceDef3 toServiceDef3(ServiceDef sd)
    {
        if (sd instanceof ServiceDef3)
            return (ServiceDef3) sd;

        final ServiceDef2 sd2 = toServiceDef2(sd);

        return new ServiceDef3()
        {
            // ServiceDef3 methods:

            @Override
            public AnnotationProvider getClassAnnotationProvider()
            {
                return toAnnotationProvider(getServiceInterface());
            }

            @Override
            public AnnotationProvider getMethodAnnotationProvider(final String methodName, final Class... argumentTypes)
            {
                return toAnnotationProvider(findMethod(getServiceInterface(), methodName, argumentTypes));
            }
            
            @Override
            public Class getServiceImplementation() 
            {
                return null;
            }

            // ServiceDef2 methods:

            @Override
            public boolean isPreventDecoration()
            {
                return sd2.isPreventDecoration();
            }

            @Override
            public ObjectCreator createServiceCreator(ServiceBuilderResources resources)
            {
                return sd2.createServiceCreator(resources);
            }

            @Override
            public String getServiceId()
            {
                return sd2.getServiceId();
            }

            @Override
            public Set<Class> getMarkers()
            {
                return sd2.getMarkers();
            }

            @Override
            public Class getServiceInterface()
            {
                return sd2.getServiceInterface();
            }

            @Override
            public String getServiceScope()
            {
                return sd2.getServiceScope();
            }

            @Override
            public boolean isEagerLoad()
            {
                return sd2.isEagerLoad();
            }

        };
    }

    public static ServiceDef2 toServiceDef2(final ServiceDef sd)
    {
        if (sd instanceof ServiceDef2)
            return (ServiceDef2) sd;

        return new ServiceDef2()
        {
            // ServiceDef2 methods:

            @Override
            public boolean isPreventDecoration()
            {
                return false;
            }

            // ServiceDef methods:

            @Override
            public ObjectCreator createServiceCreator(ServiceBuilderResources resources)
            {
                return sd.createServiceCreator(resources);
            }

            @Override
            public String getServiceId()
            {
                return sd.getServiceId();
            }

            @Override
            public Set<Class> getMarkers()
            {
                return sd.getMarkers();
            }

            @Override
            public Class getServiceInterface()
            {
                return sd.getServiceInterface();
            }

            @Override
            public String getServiceScope()
            {
                return sd.getServiceScope();
            }

            @Override
            public boolean isEagerLoad()
            {
                return sd.isEagerLoad();
            }

            @Override
            public String toString()
            {
                return sd.toString();
            }
            
            @Override
            public int hashCode()
            {
                final int prime = 31;
                int result = 1;
                result = prime * result + ((getServiceId() == null) ? 0 : getServiceId().hashCode());
                return result;
            }

            @Override
            public boolean equals(Object obj)
            {
                if (this == obj) { return true; }
                if (obj == null) { return false; }
                if (!(obj instanceof ServiceDefImpl)) { return false; }
                ServiceDef other = (ServiceDef) obj;
                if (getServiceId() == null)
                {
                    if (other.getServiceId() != null) { return false; }
                }
                else if (!getServiceId().equals(other.getServiceId())) { return false; }
                return true;
            }

        };
    }

    public static ModuleDef2 toModuleDef2(final ModuleDef md)
    {
        if (md instanceof ModuleDef2)
            return (ModuleDef2) md;

        return new ModuleDef2()
        {
            @Override
            public Set<AdvisorDef> getAdvisorDefs()
            {
                return Collections.emptySet();
            }

            @Override
            public Class getBuilderClass()
            {
                return md.getBuilderClass();
            }

            @Override
            public Set<ContributionDef> getContributionDefs()
            {
                return md.getContributionDefs();
            }

            @Override
            public Set<DecoratorDef> getDecoratorDefs()
            {
                return md.getDecoratorDefs();
            }

            @Override
            public String getLoggerName()
            {
                return md.getLoggerName();
            }

            @Override
            public ServiceDef getServiceDef(String serviceId)
            {
                return md.getServiceDef(serviceId);
            }

            @Override
            public Set<String> getServiceIds()
            {
                return md.getServiceIds();
            }

            @Override
            public Set<StartupDef> getStartups()
            {
                return Collections.emptySet();
            }
        };
    }

    /**
     * @since 5.1.0.2
     */
    public static ServiceLifecycle2 toServiceLifecycle2(final ServiceLifecycle lifecycle)
    {
        if (lifecycle instanceof ServiceLifecycle2)
            return (ServiceLifecycle2) lifecycle;

        return new ServiceLifecycle2()
        {
            @Override
            public boolean requiresProxy()
            {
                return true;
            }

            @Override
            public Object createService(ServiceResources resources, ObjectCreator creator)
            {
                return lifecycle.createService(resources, creator);
            }

            @Override
            public boolean isSingleton()
            {
                return lifecycle.isSingleton();
            }
        };
    }

    /**
     * @since 5.2.0
     */
    public static <T extends Comparable<T>> List<T> matchAndSort(Collection<? extends T> collection,
                                                                 Predicate<T> predicate)
    {
        assert predicate != null;

        List<T> result = CollectionFactory.newList();

        for (T object : collection)
        {
            if (predicate.accept(object))
                result.add(object);
        }

        Collections.sort(result);

        return result;
    }

    /**
     * @since 5.2.0
     */
    public static ContributionDef2 toContributionDef2(final ContributionDef contribution)
    {
        if (contribution instanceof ContributionDef2)
            return (ContributionDef2) contribution;

        return new ContributionDef2()
        {

            @Override
            public Set<Class> getMarkers()
            {
                return Collections.emptySet();
            }

            @Override
            public Class getServiceInterface()
            {
                return null;
            }

            @Override
            public void contribute(ModuleBuilderSource moduleSource, ServiceResources resources,
                                   Configuration configuration)
            {
                contribution.contribute(moduleSource, resources, configuration);
            }

            @Override
            public void contribute(ModuleBuilderSource moduleSource, ServiceResources resources,
                                   OrderedConfiguration configuration)
            {
                contribution.contribute(moduleSource, resources, configuration);
            }

            @Override
            public void contribute(ModuleBuilderSource moduleSource, ServiceResources resources,
                                   MappedConfiguration configuration)
            {
                contribution.contribute(moduleSource, resources, configuration);
            }

            @Override
            public String getServiceId()
            {
                return contribution.getServiceId();
            }

            @Override
            public String toString()
            {
                return contribution.toString();
            }
        };
    }

    public static ContributionDef3 toContributionDef3(ContributionDef contribution)
    {

        if (contribution instanceof ContributionDef2)
        {
            return (ContributionDef3) contribution;
        }

        final ContributionDef2 cd2 = toContributionDef2(contribution);

        return new ContributionDef3()
        {
            @Override
            public boolean isOptional()
            {
                return false;
            }

            @Override
            public String getServiceId()
            {
                return cd2.getServiceId();
            }

            @Override
            public void contribute(ModuleBuilderSource moduleSource, ServiceResources resources, Configuration configuration)
            {
                cd2.contribute(moduleSource, resources, configuration);
            }

            @Override
            public void contribute(ModuleBuilderSource moduleSource, ServiceResources resources, OrderedConfiguration configuration)
            {
                cd2.contribute(moduleSource, resources, configuration);
            }

            @Override
            public void contribute(ModuleBuilderSource moduleSource, ServiceResources resources, MappedConfiguration configuration)
            {
                cd2.contribute(moduleSource, resources, configuration);
            }

            @Override
            public Set<Class> getMarkers()
            {
                return cd2.getMarkers();
            }

            @Override
            public Class getServiceInterface()
            {
                return cd2.getServiceInterface();
            }

            @Override
            public String toString()
            {
                return cd2.toString();
            }
        };
    }

    /**
     * @since 5.2.2
     */
    public static AdvisorDef2 toAdvisorDef2(final AdvisorDef advisor)
    {
        if (advisor instanceof AdvisorDef2)
            return (AdvisorDef2) advisor;

        return new AdvisorDef2()
        {

            @Override
            public ServiceAdvisor createAdvisor(ModuleBuilderSource moduleSource, ServiceResources resources)
            {
                return advisor.createAdvisor(moduleSource, resources);
            }

            @Override
            public String getAdvisorId()
            {
                return advisor.getAdvisorId();
            }

            @Override
            public String[] getConstraints()
            {
                return advisor.getConstraints();
            }

            @Override
            public boolean matches(ServiceDef serviceDef)
            {
                return advisor.matches(serviceDef);
            }

            @Override
            public Set<Class> getMarkers()
            {
                return Collections.emptySet();
            }

            @Override
            public Class getServiceInterface()
            {
                return null;
            }

            @Override
            public String toString()
            {
                return advisor.toString();
            }
        };
    }

    /**
     * @since 5.2.2
     */
    public static DecoratorDef2 toDecoratorDef2(final DecoratorDef decorator)
    {
        if (decorator instanceof DecoratorDef2)
            return (DecoratorDef2) decorator;

        return new DecoratorDef2()
        {

            @Override
            public ServiceDecorator createDecorator(ModuleBuilderSource moduleSource, ServiceResources resources)
            {
                return decorator.createDecorator(moduleSource, resources);
            }

            @Override
            public String[] getConstraints()
            {
                return decorator.getConstraints();
            }

            @Override
            public String getDecoratorId()
            {
                return decorator.getDecoratorId();
            }

            @Override
            public boolean matches(ServiceDef serviceDef)
            {
                return decorator.matches(serviceDef);
            }

            @Override
            public Set<Class> getMarkers()
            {
                return Collections.emptySet();
            }

            @Override
            public Class getServiceInterface()
            {
                return null;
            }

            @Override
            public String toString()
            {
                return decorator.toString();
            }
        };
    }

    /**
     * Determines if the indicated class is stored as a locally accessible file
     * (and not, typically, as a file inside a JAR). This is related to automatic
     * reloading of services.
     *
     * @since 5.2.0
     */
    public static boolean isLocalFile(Class clazz)
    {
        String path = PlasticInternalUtils.toClassPath(clazz.getName());

        ClassLoader loader = clazz.getClassLoader();

        // System classes have no visible class loader, and are not local files.

        if (loader == null)
            return false;

        URL classFileURL = loader.getResource(path);

        return classFileURL != null && classFileURL.getProtocol().equals("file");
    }

    /**
     * Wraps a {@link Coercion} as a {@link Mapper}.
     *
     * @since 5.2.0
     */
    public static <S, T> Mapper<S, T> toMapper(final Coercion<S, T> coercion)
    {
        assert coercion != null;

        return new Mapper<S, T>()
        {
            @Override
            public T map(S value)
            {
                return coercion.coerce(value);
            }
        };
    }

    private static final AtomicLong uuidGenerator = new AtomicLong(System.nanoTime());

    /**
     * Generates a unique value for the current execution of the application. This initial UUID value
     * is not easily predictable; subsequent UUIDs are allocated in ascending series.
     *
     * @since 5.2.0
     */
    public static long nextUUID()
    {
        return uuidGenerator.incrementAndGet();
    }

    /**
     * Extracts the service id from the passed annotated element. First the {@link ServiceId} annotation is checked.
     * If present, its value is returned. Otherwise {@link Named} annotation is checked. If present, its value is
     * returned.
     * If neither of the annotations is present, <code>null</code> value is returned
     *
     * @param annotated
     *         annotated element to get annotations from
     * @since 5.3
     */
    public static String getServiceId(AnnotatedElement annotated)
    {
        ServiceId serviceIdAnnotation = annotated.getAnnotation(ServiceId.class);

        if (serviceIdAnnotation != null)
        {
            return serviceIdAnnotation.value();
        }

        Named namedAnnotation = annotated.getAnnotation(Named.class);

        if (namedAnnotation != null)
        {
            String value = namedAnnotation.value();

            if (InternalUtils.isNonBlank(value))
            {
                return value;
            }
        }

        return null;
    }


    public static AnnotationProvider toAnnotationProvider(final Method element)
    {
        if (element == null)
            return NULL_ANNOTATION_PROVIDER;

        return new AnnotationProvider()
        {
            @Override
            public <T extends Annotation> T getAnnotation(Class<T> annotationClass)
            {
                return element.getAnnotation(annotationClass);
            }
        };
    }

    public static <T> ObjectCreator<T> createConstructorConstructionPlan(final OperationTracker tracker, final ObjectLocator locator,
                                                                         final InjectionResources resources,
                                                                         final Logger logger,
                                                                         final String description,
                                                                         final Constructor<T> constructor)
    {
        return tracker.invoke(String.format("Creating plan to instantiate %s via %s",
                constructor.getDeclaringClass().getName(),
                constructor), new Invokable<ObjectCreator<T>>()
        {
            @Override
            public ObjectCreator<T> invoke()
            {
                validateConstructorForAutobuild(constructor);

                ObjectCreator[] constructorParameters = calculateParameters(locator, resources, constructor.getParameterTypes(), constructor.getGenericParameterTypes(), constructor.getParameterAnnotations(), tracker);

                Invokable<T> core = new ConstructorInvoker<T>(constructor, constructorParameters);

                Invokable<T> wrapped = logger == null ? core : new LoggingInvokableWrapper<T>(logger, description, core);

                ConstructionPlan<T> plan = new ConstructionPlan(tracker, description, wrapped);

                extendPlanForInjectedFields(plan, tracker, locator, resources, constructor.getDeclaringClass());

                extendPlanForPostInjectionMethods(plan, tracker, locator, resources, constructor.getDeclaringClass());

                return plan;
            }
        });
    }

    private static <T> void extendPlanForInjectedFields(final ConstructionPlan<T> plan, OperationTracker tracker, final ObjectLocator locator, final InjectionResources resources, Class<T> instantiatedClass)
    {
        Class clazz = instantiatedClass;

        while (clazz != Object.class)
        {
            Field[] fields = clazz.getDeclaredFields();

            for (final Field f : fields)
            {
                // Ignore all static and final fields.

                int fieldModifiers = f.getModifiers();

                if (Modifier.isStatic(fieldModifiers) || Modifier.isFinal(fieldModifiers))
                    continue;

                final AnnotationProvider ap = new AnnotationProvider()
                {
                    @Override
                    public <T extends Annotation> T getAnnotation(Class<T> annotationClass)
                    {
                        return f.getAnnotation(annotationClass);
                    }
                };

                String description = String.format("Calculating possible injection value for field %s.%s (%s)",
                        clazz.getName(), f.getName(),
                        PlasticUtils.toTypeName(f.getType()));

                tracker.run(description, new Runnable()
                {
                    @Override
                    public void run()
                    {
                        final Class<?> fieldType = f.getType();

                        InjectService is = ap.getAnnotation(InjectService.class);
                        if (is != null)
                        {
                            addInjectPlan(plan, f, locator.getService(is.value(), fieldType));
                            return;
                        }

                        if (ap.getAnnotation(Inject.class) != null || ap.getAnnotation(InjectResource.class) != null)
                        {
                            Object value = resources.findResource(fieldType, f.getGenericType());

                            if (value != null)
                            {
                                addInjectPlan(plan, f, value);
                                return;
                            }

                            addInjectPlan(plan, f, locator.getObject(fieldType, ap));
                            return;
                        }

                        if (ap.getAnnotation(javax.inject.Inject.class) != null)
                        {
                            Named named = ap.getAnnotation(Named.class);

                            if (named == null)
                            {
                                addInjectPlan(plan, f, locator.getObject(fieldType, ap));
                            } else
                            {
                                addInjectPlan(plan, f, locator.getService(named.value(), fieldType));
                            }

                            return;
                        }

                        // Ignore fields that do not have the necessary annotation.

                    }
                });
            }

            clazz = clazz.getSuperclass();
        }
    }

    private static <T> void addInjectPlan(ConstructionPlan<T> plan, final Field field, final Object injectedValue)
    {
        plan.add(new InitializationPlan<T>()
        {
            @Override
            public String getDescription()
            {
                return String.format("Injecting %s into field %s of class %s.",
                        injectedValue,
                        field.getName(),
                        field.getDeclaringClass().getName());
            }

            @Override
            public void initialize(T instance)
            {
                inject(instance, field, injectedValue);
            }
        });
    }

    private static boolean hasAnnotation(AccessibleObject member, Class<? extends Annotation> annotationType)
    {
        return member.getAnnotation(annotationType) != null;
    }

    private static <T> void extendPlanForPostInjectionMethods(ConstructionPlan<T> plan, OperationTracker tracker, ObjectLocator locator, InjectionResources resources, Class<T> instantiatedClass)
    {
        for (Method m : instantiatedClass.getMethods())
        {
            if (hasAnnotation(m, PostInjection.class) || hasAnnotation(m, PostConstruct.class))
            {
                extendPlanForPostInjectionMethod(plan, tracker, locator, resources, m);
            }
        }
    }

    private static void extendPlanForPostInjectionMethod(final ConstructionPlan<?> plan, final OperationTracker tracker, final ObjectLocator locator, final InjectionResources resources, final Method method)
    {
        tracker.run("Computing parameters for post-injection method " + method,
                new Runnable()
                {
                    @Override
                    public void run()
                    {
                        final ObjectCreator[] parameters = InternalUtils.calculateParametersForMethod(method, locator,
                                resources, tracker);

                        plan.add(new InitializationPlan<Object>()
                        {
                            @Override
                            public String getDescription()
                            {
                                return "Invoking " + method;
                            }

                            @Override
                            public void initialize(Object instance)
                            {
                                Throwable fail = null;

                                Object[] realized = realizeObjects(parameters);

                                try
                                {
                                    method.invoke(instance, realized);
                                } catch (InvocationTargetException ex)
                                {
                                    fail = ex.getTargetException();
                                } catch (Exception ex)
                                {
                                    fail = ex;
                                }

                                if (fail != null)
                                {
                                    throw new RuntimeException(String
                                            .format("Exception invoking method %s: %s", method, ExceptionUtils.toMessage(fail)), fail);
                                }
                            }
                        });
                    }
                });
    }


    public static <T> ObjectCreator<T> createMethodInvocationPlan(final OperationTracker tracker, final ObjectLocator locator,
                                                                  final InjectionResources resources,
                                                                  final Logger logger,
                                                                  final String description,
                                                                  final Object instance,
                                                                  final Method method)
    {

        return tracker.invoke("Creating plan to invoke " + method, new Invokable<ObjectCreator<T>>()
        {
            @Override
            public ObjectCreator<T> invoke()
            {
                ObjectCreator[] methodParameters = calculateParametersForMethod(method, locator, resources, tracker);

                Invokable<T> core = new MethodInvoker<T>(instance, method, methodParameters);

                Invokable<T> wrapped = logger == null ? core : new LoggingInvokableWrapper<T>(logger, description, core);

                return new ConstructionPlan(tracker, description, wrapped);
            }
        });
    }

    /**
     * @since 5.3.1, 5.4
     */
    public static Mapper<ObjectCreator, Object> CREATE_OBJECT = new Mapper<ObjectCreator, Object>()
    {
        @Override
        public Object map(ObjectCreator element)
        {
            return element.createObject();
        }
    };

    /**
     * @since 5.3.1, 5.4
     */
    public static Object[] realizeObjects(ObjectCreator[] creators)
    {
        return F.flow(creators).map(CREATE_OBJECT).toArray(Object.class);
    }
}