/*
 * 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
 *
 *      https://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.commons.lang3.reflect;

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

import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.ClassUtils;

/**
 * Utility reflection methods focused on constructors, modeled after {@link MethodUtils}.
 *
 * <h2>Known Limitations</h2>
 * <h3>Accessing Public Constructors In A Default Access Superclass</h3>
 * <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 {

    /**
     * Finds a constructor given a class and signature, checking accessibility.
     *
     * <p>
     * This finds the constructor and ensures that it is accessible. The constructor signature must match the parameter types exactly.
     * </p>
     *
     * @param <T>            the constructor type.
     * @param cls            the class to find a constructor for, not {@code null}.
     * @param parameterTypes the array of parameter types, {@code null} treated as empty.
     * @return the constructor, {@code null} if no matching accessible constructor found.
     * @throws NullPointerException if {@code cls} is {@code null}
     * @throws SecurityException    Thrown if a security manager is present and the caller's class loader is not the same as or an ancestor of the class loader
     *                              for the class and invocation of {@link SecurityManager#checkPackageAccess(String)} denies access to the package of the
     *                              class.
     * @see Class#getConstructor
     * @see #getAccessibleConstructor(java.lang.reflect.Constructor)
     */
    public static <T> Constructor<T> getAccessibleConstructor(final Class<T> cls, final Class<?>... parameterTypes) {
        Objects.requireNonNull(cls, "cls");
        try {
            return getAccessibleConstructor(cls.getConstructor(parameterTypes));
        } catch (final NoSuchMethodException e) {
            return null;
        }
    }

    /**
     * Checks if the specified constructor is accessible.
     *
     * <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}
     * @throws SecurityException    Thrown if a security manager is present and a caller's class loader is not the same as or an ancestor of the class loader
     *                              for a class and invocation of {@link SecurityManager#checkPackageAccess(String)} denies access to the package of the class.
     */
    public static <T> Constructor<T> getAccessibleConstructor(final Constructor<T> ctor) {
        Objects.requireNonNull(ctor, "ctor");
        return MemberUtils.isAccessible(ctor) && isAccessible(ctor.getDeclaringClass()) ? ctor : null;
    }

    /**
     * Finds an accessible constructor with compatible parameters.
     *
     * <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 Thrown if {@code cls} is {@code null}
     * @throws SecurityException    Thrown if a security manager is present and the caller's class loader is not the same as or an ancestor of the class loader for the
     *                              class and invocation of {@link SecurityManager#checkPackageAccess(String)} denies access to the package of the class.
     * @see SecurityManager#checkPackageAccess(String)
     */
    public static <T> Constructor<T> getMatchingAccessibleConstructor(final Class<T> cls, final Class<?>... parameterTypes) {
        Objects.requireNonNull(cls, "cls");
        // see if we can find the constructor directly
        // most of the time this works and it's much faster
        try {
            return MemberUtils.setAccessibleWorkaround(cls.getConstructor(parameterTypes));
        } catch (final NoSuchMethodException ignored) {
            // ignore
        }
        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;
    }

    /**
     * Returns a new instance of the specified class inferring the right constructor from the types of the arguments.
     *
     * <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        Thrown if {@code cls} is {@code null}.
     * @throws NoSuchMethodException       Thrown if a matching constructor cannot be found.
     * @throws IllegalAccessException      Thrown if the found {@code Constructor} is enforcing Java language access control and the underlying constructor is
     *                                     inaccessible.
     * @throws IllegalArgumentException    Thrown if:
     *                                     <ul>
     *                                     <li>the number of actual and formal parameters differ; or</li>
     *                                     <li>an unwrapping conversion for primitive arguments fails; or</li>
     *                                     <li>after possible unwrapping, a parameter value cannot be converted to the corresponding formal parameter type by a
     *                                     method invocation conversion; if this constructor pertains to an enum type.
     *                                     </ul>
     * @throws InstantiationException      Thrown if the class that declares the underlying constructor represents an abstract class.
     * @throws InvocationTargetException   Thrown if the underlying constructor throws an exception.
     * @throws ExceptionInInitializerError Thrown if the initialization provoked by this method fails.
     * @throws SecurityException           Thrown if a security manager is present and the caller's class loader is not the same as or an ancestor of the class
     *                                     loader for the class and invocation of {@link SecurityManager#checkPackageAccess(String)} denies access to the
     *                                     package of the class.
     * @see #invokeConstructor(Class, Object[], Class[])
     */
    public static <T> T invokeConstructor(final Class<T> cls, final Object... args)
            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
        final Object[] actuals = ArrayUtils.nullToEmpty(args);
        return invokeConstructor(cls, actuals, ClassUtils.toClass(actuals));
    }

    /**
     * Returns a new instance of the specified class choosing the right constructor from the list of parameter types.
     *
     * <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        Thrown if {@code cls} is {@code null}.
     * @throws NoSuchMethodException       Thrown if a matching constructor cannot be found.
     * @throws IllegalAccessException      Thrown if the found {@code Constructor} is enforcing Java language access control and the underlying constructor is
     *                                     inaccessible.
     * @throws IllegalArgumentException    Thrown if:
     *                                     <ul>
     *                                     <li>the number of actual and formal parameters differ; or</li>
     *                                     <li>an unwrapping conversion for primitive arguments fails; or</li>
     *                                     <li>after possible unwrapping, a parameter value cannot be converted to the corresponding formal parameter type by a
     *                                     method invocation conversion; if this constructor pertains to an enum type.
     *                                     </ul>
     * @throws InstantiationException      Thrown if the class that declares the underlying constructor represents an abstract class.
     * @throws InvocationTargetException   Thrown if the underlying constructor throws an exception.
     * @throws ExceptionInInitializerError Thrown if the initialization provoked by this method fails.
     * @throws SecurityException           Thrown if a security manager is present and the caller's class loader is not the same as or an ancestor of the class
     *                                     loader for the class and invocation of {@link SecurityManager#checkPackageAccess(String)} denies access to the
     *                                     package of the class.
     * @see Constructor#newInstance(Object...)
     * @see Constructor#newInstance
     */
    public static <T> T invokeConstructor(final Class<T> cls, final Object[] args, final Class<?>[] parameterTypes)
            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
        final Object[] actuals = ArrayUtils.nullToEmpty(args);
        final Constructor<T> ctor = getMatchingAccessibleConstructor(cls, ArrayUtils.nullToEmpty(parameterTypes));
        if (ctor == null) {
            throw new NoSuchMethodException("No such accessible constructor on object: " + cls.getName());
        }
        return ctor.newInstance(MethodUtils.toVarArgs(ctor, actuals));
    }

    /**
     * Returns a new instance of the specified class inferring the right constructor from the types of the arguments.
     *
     * <p>
     * This locates and calls a constructor. The constructor signature must match the argument types exactly.
     * </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        Thrown if {@code cls} is {@code null}.
     * @throws NoSuchMethodException       Thrown if a matching constructor cannot be found.
     * @throws IllegalAccessException      Thrown if the found {@code Constructor} is enforcing Java language access control and the underlying constructor is
     *                                     inaccessible.
     * @throws IllegalArgumentException    Thrown if:
     *                                     <ul>
     *                                     <li>the number of actual and formal parameters differ; or</li>
     *                                     <li>an unwrapping conversion for primitive arguments fails; or</li>
     *                                     <li>after possible unwrapping, a parameter value cannot be converted to the corresponding formal parameter type by a
     *                                     method invocation conversion; if this constructor pertains to an enum type.
     *                                     </ul>
     * @throws InstantiationException      Thrown if the class that declares the underlying constructor represents an abstract class.
     * @throws InvocationTargetException   Thrown if the underlying constructor throws an exception.
     * @throws ExceptionInInitializerError Thrown if the initialization provoked by this method fails.
     * @throws SecurityException           Thrown if a security manager is present and the caller's class loader is not the same as or an ancestor of the class
     *                                     loader for the class and invocation of {@link SecurityManager#checkPackageAccess(String)} denies access to the
     *                                     package of the class.
     * @see Constructor#newInstance(Object...)
     * @see #invokeExactConstructor(Class, Object[], Class[])
     */
    public static <T> T invokeExactConstructor(final Class<T> cls, final Object... args)
            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
        final Object[] actuals = ArrayUtils.nullToEmpty(args);
        return invokeExactConstructor(cls, actuals, ClassUtils.toClass(actuals));
    }

    /**
     * Returns a new instance of the specified class choosing the right constructor from the list of parameter types.
     *
     * <p>
     * This locates and calls a constructor. The constructor signature must match the parameter types exactly.
     * </p>
     *
     * @param <T>            the type to construct.
     * @param cls            the class to construct, 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        Thrown if {@code cls} is {@code null}.
     * @throws NoSuchMethodException       Thrown if a matching constructor cannot be found.
     * @throws IllegalAccessException      Thrown if the found {@code Constructor} is enforcing Java language access control and the underlying constructor is
     *                                     inaccessible.
     * @throws IllegalArgumentException    Thrown if:
     *                                     <ul>
     *                                     <li>the number of actual and formal parameters differ; or</li>
     *                                     <li>an unwrapping conversion for primitive arguments fails; or</li>
     *                                     <li>after possible unwrapping, a parameter value cannot be converted to the corresponding formal parameter type by a
     *                                     method invocation conversion; if this constructor pertains to an enum type.
     *                                     </ul>
     * @throws InstantiationException      Thrown if the class that declares the underlying constructor represents an abstract class.
     * @throws InvocationTargetException   Thrown if the underlying constructor throws an exception.
     * @throws ExceptionInInitializerError Thrown if the initialization provoked by this method fails.
     * @throws SecurityException           Thrown if a security manager is present and the caller's class loader is not the same as or an ancestor of the class
     *                                     loader for the class and invocation of {@link SecurityManager#checkPackageAccess(String)} denies access to the
     *                                     package of the class.
     * @see Constructor#newInstance(Object...)
     */
    public static <T> T invokeExactConstructor(final Class<T> cls, final Object[] args, final Class<?>[] parameterTypes)
            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
        final Constructor<T> ctor = getAccessibleConstructor(cls, ArrayUtils.nullToEmpty(parameterTypes));
        if (ctor == null) {
            throw new NoSuchMethodException("No such accessible constructor on object: " + cls.getName());
        }
        return ctor.newInstance(ArrayUtils.nullToEmpty(args));
    }

    /**
     * Tests 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}.
     * @throws SecurityException Thrown if a security manager is present and a caller's class loader is not the same as or an ancestor of the class loader for a
     *                           class and invocation of {@link SecurityManager#checkPackageAccess(String)} denies access to the package of the class.
     */
    private static boolean isAccessible(final Class<?> type) {
        Class<?> cls = type;
        while (cls != null) {
            if (!ClassUtils.isPublic(cls)) {
                return false;
            }
            cls = cls.getEnclosingClass();
        }
        return true;
    }

    /**
     * ConstructorUtils instances should NOT be constructed in standard programming. Instead, the class should be used as
     * {@code ConstructorUtils.invokeConstructor(cls, args)}.
     *
     * <p>
     * This constructor is {@code public} to permit tools that require a JavaBean instance to operate.
     * </p>
     *
     * @deprecated TODO Make private in 4.0.
     */
    @Deprecated
    public ConstructorUtils() {
        // empty
    }
}
