/*
 * 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.
 */

/*
 * This is a modified version of the original Apache class.  It has had unused
 * members removed.
 */
package org.ehcache.impl.internal.classes.commonslang.reflect;

import org.ehcache.impl.internal.classes.commonslang.ArrayUtils;
import org.ehcache.impl.internal.classes.commonslang.ClassUtils;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Modifier;
import java.util.Objects;

 Utility reflection methods focused on constructors, modeled after MethodUtils. 
Known Limitations
 
Accessing Public Constructors In A Default
Access Superclass
 
There is an issue when invoking public constructors contained in a default access superclass. Reflection correctly locates these constructors and assigns them as public. However, an IllegalAccessException is thrown if the constructor is invoked.
ConstructorUtils contains a workaround for this situation: it will attempt to call AccessibleObject.setAccessible(boolean) on this constructor. If this call succeeds, then the method can be invoked as normal. This call will only succeed when the application has sufficient security privileges. If this call fails then a warning will be logged and the method may fail.
Since:
2.5/**
 * <p> Utility reflection methods focused on constructors, modeled after
 * {@link MethodUtils}. </p>
 *
 * <h3>Known Limitations</h3> <h4>Accessing Public Constructors In A Default
 * Access Superclass</h4> <p>There is an issue when invoking {@code public} constructors
 * contained in a default access superclass. Reflection correctly locates these
 * constructors and assigns them as {@code public}. However, an
 * {@link IllegalAccessException} is thrown if the constructor is
 * invoked.</p>
 *
 * <p>{@link ConstructorUtils} contains a workaround for this situation: it
 * will attempt to call {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} on this constructor. If this
 * call succeeds, then the method can be invoked as normal. This call will only
 * succeed when the application has sufficient security privileges. If this call
 * fails then a warning will be logged and the method may fail.</p>
 *
 * @since 2.5
 */
public class ConstructorUtils {

    
Returns a new instance of the specified class inferring the right constructor
from the types of the arguments.
This locates and calls a constructor.
The constructor signature must match the argument types by assignment compatibility.
Params:
cls –  the class to be constructed, not null
args –  the array of arguments, null treated as empty
Type parameters:
<T> – the type to be constructed
Throws:
NullPointerException – if cls is null
NoSuchMethodException – if a matching constructor cannot be found
IllegalAccessException – if invocation is not permitted by security
InvocationTargetException – if an error occurs on invocation
InstantiationException – if an error occurs on instantiation
See Also:
invokeConstructor(Class<Object>, Object[], Class<?>[])
Returns:
new instance of cls, not null/**
     * <p>Returns a new instance of the specified class inferring the right constructor
     * from the types of the arguments.</p>
     *
     * <p>This locates and calls a constructor.
     * The constructor signature must match the argument types by assignment compatibility.</p>
     *
     * @param <T> the type to be constructed
     * @param cls  the class to be constructed, not {@code null}
     * @param args  the array of arguments, {@code null} treated as empty
     * @return new instance of {@code cls}, not {@code null}
     *
     * @throws NullPointerException if {@code cls} is {@code null}
     * @throws NoSuchMethodException if a matching constructor cannot be found
     * @throws IllegalAccessException if invocation is not permitted by security
     * @throws InvocationTargetException if an error occurs on invocation
     * @throws InstantiationException if an error occurs on instantiation
     * @see #invokeConstructor(Class, Object[], Class[])
     */
    public static <T> T invokeConstructor(final Class<T> cls, Object... args)
            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException,
            InstantiationException {
        args = ArrayUtils.nullToEmpty(args);
        final Class<?> parameterTypes[] = ClassUtils.toClass(args);
        return invokeConstructor(cls, args, parameterTypes);
    }

    
Returns a new instance of the specified class choosing the right constructor
from the list of parameter types.
This locates and calls a constructor.
The constructor signature must match the parameter types by assignment compatibility.
Params:
cls –  the class to be constructed, not null
args –  the array of arguments, null treated as empty
parameterTypes –  the array of parameter types, null treated as empty
Type parameters:
<T> – the type to be constructed
Throws:
NullPointerException – if cls is null
NoSuchMethodException – if a matching constructor cannot be found
IllegalAccessException – if invocation is not permitted by security
InvocationTargetException – if an error occurs on invocation
InstantiationException – if an error occurs on instantiation
See Also:
Constructor.newInstance
Returns:
new instance of cls, not null/**
     * <p>Returns a new instance of the specified class choosing the right constructor
     * from the list of parameter types.</p>
     *
     * <p>This locates and calls a constructor.
     * The constructor signature must match the parameter types by assignment compatibility.</p>
     *
     * @param <T> the type to be constructed
     * @param cls  the class to be constructed, not {@code null}
     * @param args  the array of arguments, {@code null} treated as empty
     * @param parameterTypes  the array of parameter types, {@code null} treated as empty
     * @return new instance of {@code cls}, not {@code null}
     *
     * @throws NullPointerException if {@code cls} is {@code null}
     * @throws NoSuchMethodException if a matching constructor cannot be found
     * @throws IllegalAccessException if invocation is not permitted by security
     * @throws InvocationTargetException if an error occurs on invocation
     * @throws InstantiationException if an error occurs on instantiation
     * @see Constructor#newInstance
     */
    public static <T> T invokeConstructor(final Class<T> cls, Object[] args, Class<?>[] parameterTypes)
            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException,
            InstantiationException {
        args = ArrayUtils.nullToEmpty(args);
        parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
        final Constructor<T> ctor = getMatchingAccessibleConstructor(cls, parameterTypes);
        if (ctor == null) {
            throw new NoSuchMethodException(
                "No such accessible constructor on object: " + cls.getName());
        }
        if (ctor.isVarArgs()) {
            final Class<?>[] methodParameterTypes = ctor.getParameterTypes();
            args = MethodUtils.getVarArgs(args, methodParameterTypes);
        }
        return ctor.newInstance(args);
    }

    //-----------------------------------------------------------------------

    
Checks if the specified constructor is accessible.
This simply ensures that the constructor is accessible.
Params:
ctor –  the prototype constructor object, not null
Type parameters:
<T> – the constructor type
Throws:
NullPointerException – if ctor is null
See Also:
SecurityManager
Returns:
the constructor, null if no matching accessible constructor found/**
     * <p>Checks if the specified constructor is accessible.</p>
     *
     * <p>This simply ensures that the constructor is accessible.</p>
     *
     * @param <T> the constructor type
     * @param ctor  the prototype constructor object, not {@code null}
     * @return the constructor, {@code null} if no matching accessible constructor found
     * @see SecurityManager
     * @throws NullPointerException if {@code ctor} is {@code null}
     */
    public static <T> Constructor<T> getAccessibleConstructor(final Constructor<T> ctor) {
        Objects.requireNonNull(ctor, "constructor cannot be null");
        return MemberUtils.isAccessible(ctor)
                && isAccessible(ctor.getDeclaringClass()) ? ctor : null;
    }

    
Finds an accessible constructor with compatible parameters.
This checks all the constructor and finds one with compatible parameters
This requires that every parameter is assignable from the given parameter types.
This is a more flexible search than the normal exact matching algorithm.
First it checks if there is a constructor matching the exact signature.
If not then all the constructors of the class are checked to see if their
signatures are assignment-compatible with the parameter types.
The first assignment-compatible matching constructor is returned.
Params:
cls –  the class to find a constructor for, not null
parameterTypes – find method with compatible parameters
Type parameters:
<T> – the constructor type
Throws:
NullPointerException – if cls is null
Returns:
the constructor, null if no matching accessible constructor found/**
     * <p>Finds an accessible constructor with compatible parameters.</p>
     *
     * <p>This checks all the constructor and finds one with compatible parameters
     * This requires that every parameter is assignable from the given parameter types.
     * This is a more flexible search than the normal exact matching algorithm.</p>
     *
     * <p>First it checks if there is a constructor matching the exact signature.
     * If not then all the constructors of the class are checked to see if their
     * signatures are assignment-compatible with the parameter types.
     * The first assignment-compatible matching constructor is returned.</p>
     *
     * @param <T> the constructor type
     * @param cls  the class to find a constructor for, not {@code null}
     * @param parameterTypes find method with compatible parameters
     * @return the constructor, null if no matching accessible constructor found
     * @throws NullPointerException if {@code cls} is {@code null}
     */
    public static <T> Constructor<T> getMatchingAccessibleConstructor(final Class<T> cls,
            final Class<?>... parameterTypes) {
        Objects.requireNonNull(cls, "class cannot be null");
        // see if we can find the constructor directly
        // most of the time this works and it's much faster
        try {
            final Constructor<T> ctor = cls.getConstructor(parameterTypes);
            MemberUtils.setAccessibleWorkaround(ctor);
            return ctor;
        } catch (final NoSuchMethodException e) { // NOPMD - Swallow
        }
        Constructor<T> result = null;
        /*
         * (1) Class.getConstructors() is documented to return Constructor<T> so as
         * long as the array is not subsequently modified, everything's fine.
         */
        final Constructor<?>[] ctors = cls.getConstructors();

        // return best match:
        for (Constructor<?> ctor : ctors) {
            // compare parameters
            if (MemberUtils.isMatchingConstructor(ctor, parameterTypes)) {
                // get accessible version of constructor
                ctor = getAccessibleConstructor(ctor);
                if (ctor != null) {
                    MemberUtils.setAccessibleWorkaround(ctor);
                    if (result == null || MemberUtils.compareConstructorFit(ctor, result, parameterTypes) < 0) {
                        // temporary variable for annotation, see comment above (1)
                        @SuppressWarnings("unchecked")
                        final
                        Constructor<T> constructor = (Constructor<T>)ctor;
                        result = constructor;
                    }
                }
            }
        }
        return result;
    }

    
Learn whether the specified class is generally accessible, i.e. is declared in an entirely public manner. 
Params:
type – to check
Returns:
true if type and any enclosing classes are public./**
     * Learn whether the specified class is generally accessible, i.e. is
     * declared in an entirely {@code public} manner.
     * @param type to check
     * @return {@code true} if {@code type} and any enclosing classes are
     *         {@code public}.
     */
    private static boolean isAccessible(final Class<?> type) {
        Class<?> cls = type;
        while (cls != null) {
            if (!Modifier.isPublic(cls.getModifiers())) {
                return false;
            }
            cls = cls.getEnclosingClass();
        }
        return true;
    }

}