/*
 * Copyright (C) 2020-2022 Sebastiano Vigna
 *
 * 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 PACKAGE;

import java.util.Objects;
import java.util.function.Predicate;

/** A type-specific {@link Predicate}; provides methods to test a primitive type both as object
 * and as primitive.
 *
 * <p>Except for the boolean case, this interface extends both a parameterized {@link java.util.function.Predicate}
 * and a type-specific JDK predicate (e.g., {@link java.util.function.IntPredicate}). For types missing
 * a type-specific JDK predicate (e.g., {@code short} or {@code float}), we extend the predicate associated with
 * the smallest primitive type that can represent the current type (e.g., {@code int} or {@code double}, respectively).
 *
 * @see Predicate
 * @since 8.5.0
 */

@FunctionalInterface
#if ! KEY_CLASS_Boolean
public interface KEY_PREDICATE KEY_GENERIC extends Predicate<KEY_GENERIC_CLASS>, JDK_PRIMITIVE_PREDICATE {
#else
public interface KEY_PREDICATE KEY_GENERIC extends Predicate<KEY_GENERIC_CLASS> {
#endif

#if ! KEYS_INT_LONG_DOUBLE
	/**
	 * Evaluates this predicate on the given input.
	 *
	 * @param t the input.
	 * @return {@code true} if the input matches the predicate,
	 * otherwise {@code false}
	 */
	boolean test(KEY_TYPE t);

#if ! KEY_CLASS_Boolean
	/** {@inheritDoc}
	 * @deprecated Please use the corresponding type-specific method instead. */
	@Deprecated
	@Override
	default boolean test(final KEY_TYPE_WIDENED t) {
		return test(KEY_NARROWING(t));
	}
#endif

#if KEY_CLASS_Boolean
	/**
	 * Returns a {@code BooleanPredicate} that returns the boolean to be tested unmodified.
	 * @see java.util.function.UnaryOperator#identity()
	 */
	public static KEY_PREDICATE identity() {
		// Java is smart enough to see this lambda is stateless and will return the same instance every time.
		return b -> b;
	}

	/** Returns a {@code BooleanPredicate} that returns the negation of the boolean to be tested. */
	public static KEY_PREDICATE negation() {
		return b -> !b;
	}
#endif

#endif

	/** {@inheritDoc}
	 * @deprecated Please use the corresponding type-specific method instead. */
	@Deprecated
	@Override
	default boolean test(final KEY_CLASS t) {
		return test(t.KEY_VALUE());
	}

    /**
	 * Returns a composed type-specific predicate that represents a short-circuiting logical
	 * AND of this type-specific predicate and another.
	 * @param other a predicate that will be logically-ANDed with this predicate.
     * @return a composed predicate that represents the short-circuiting logical
     * AND of this predicate and the {@code other} predicate.
	 * @see Predicate#and
	 * @apiNote Implementing classes should generally override this method and 
	 * keep the default implementation of the other overloads, which will 
	 * delegate to this method (after proper conversions).
	 */
	default KEY_PREDICATE and(final METHOD_ARG_PREDICATE other) {
		Objects.requireNonNull(other);
		return t -> test(t) && other.test(t);
	}

#if KEYS_INT_LONG_DOUBLE

	/**
	 * Returns a composed type-specific predicate that represents a short-circuiting logical
	 * AND of this type-specific predicate and another.
	 *
	 * <p><b>WARNING</b>: Overriding this method is almost always a mistake, as this
	 * overload only exists to disambiguate. Instead, override the {@code and()} overload
	 * that uses the JDK's primitive predicate type (e.g. {@link java.util.function.IntPredicate}).
	 *
	 * <p>If Java supported final default methods, this would be one, but sadly it does not.
	 *
	 * <p>If you checked and are overriding the version with {@code java.util.function.XPredicate}, and
	 * you still see this warning, then your IDE is incorrectly conflating this method with the proper
	 * method to override, and you can safely ignore this message.
	 *
	 * @param other a predicate that will be logically-ANDed with this predicate.
     * @return a composed predicate that represents the short-circuiting logical
     * AND of this predicate and the {@code other} predicate.
	 * @see Predicate#and
	 */
	default KEY_PREDICATE and(final KEY_PREDICATE other) {
		return and((JDK_PRIMITIVE_PREDICATE) other);
	}


#elif ! KEY_CLASS_Boolean

	/** {@inheritDoc}	
	 * @implNote Composing with a JDK type-specific predicate will be slightly less efficient than using a type-specific predicate, as the argument will have to be widened at each call.  */
	@Override
	default KEY_PREDICATE and(final JDK_PRIMITIVE_PREDICATE other) {
		return and(other instanceof KEY_PREDICATE ? (KEY_PREDICATE)other : (KEY_PREDICATE)other::test);
	}

#endif

	/** {@inheritDoc}
	 * @deprecated Please use the corresponding type-specific method instead. */
	@Deprecated
	@Override
	default Predicate<KEY_GENERIC_CLASS> and(final Predicate<? super KEY_GENERIC_CLASS> other) {
		return Predicate.super.and(other);
	}

	@Override
	/** {@inheritDoc} */
	default KEY_PREDICATE negate() {
		return t -> ! test(t);
	}

    /**
	 * Returns a composed type-specific predicate that represents a short-circuiting logical
	 * OR of this type-specific predicate and another. 
	 * @param other a predicate that will be logically-ORed with this predicate.
	 * @return a composed predicate that represents the short-circuiting logical
	 * OR of this predicate and the {@code other} predicate.
	 * @see Predicate#or
	 * @apiNote Implementing classes should generally override this method and 
	 * keep the default implementation of the other overloads, which will 
	 * delegate to this method (after proper conversions).
	 */
	default KEY_PREDICATE or(final METHOD_ARG_PREDICATE other) {
		Objects.requireNonNull(other);
		return t -> test(t) || other.test(t);
	}

#if KEYS_INT_LONG_DOUBLE

	/**
	 * Returns a composed type-specific predicate that represents a short-circuiting logical
	 * OR of this type-specific predicate and another. 
	 *
	 * <p><b>WARNING</b>: Overriding this method is almost always a mistake, as this
	 * overload only exists to disambiguate. Instead, override the {@code or()} overload
	 * that uses the JDK's primitive predicate type (e.g. {@link java.util.function.IntPredicate}).
	 *
	 * <p>If Java supported final default methods, this would be one, but sadly it does not.
	 *
	 * <p>If you checked and are overriding the version with {@code java.util.function.XPredicate}, and
	 * you still see this warning, then your IDE is incorrectly conflating this method with the proper
	 * method to override, and you can safely ignore this message.
	 *
	 * @param other a predicate that will be logically-ORed with this predicate.
	 * @return a composed predicate that represents the short-circuiting logical
	 * OR of this predicate and the {@code other} predicate.
	 * @see Predicate#or
	 */
	default KEY_PREDICATE or(final KEY_PREDICATE other) {
		return or((JDK_PRIMITIVE_PREDICATE) other);
	}

#elif ! KEY_CLASS_Boolean

	/** {@inheritDoc}	
	 * @implNote Composing with a JDK type-specific predicate will be slightly less efficient than using a type-specific predicate, as the argument will have to be widened at each call.  */
	@Override
	default KEY_PREDICATE or(final JDK_PRIMITIVE_PREDICATE other) {
		return or(other instanceof KEY_PREDICATE ? (KEY_PREDICATE)other : (KEY_PREDICATE)other::test);
	}

#endif

	/** {@inheritDoc}
	 * @deprecated Please use the corresponding type-specific method instead. */
	@Deprecated
	@Override
	default Predicate<KEY_GENERIC_CLASS> or(final Predicate<? super KEY_GENERIC_CLASS> other) {
		return Predicate.super.or(other);
	}

}
