/**
 * Copyright 2017-2018 Amazon.com,
 * Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Amazon Software License (the "License").
 * You may not use this file except in compliance with the
 * License. A copy of the License is located at
 *
 *     http://aws.amazon.com/asl/
 *
 * or in the "license" file accompanying this file. This file is
 * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
 * CONDITIONS OF ANY KIND, express or implied. See the License
 * for the specific language governing permissions and
 * limitations under the License.
 */

package com.amazonaws.kinesisvideo.common.preconditions;

import androidx.annotation.Nullable;

public final class Preconditions {
    private Preconditions() {}

    /**
     * Validates the expression is true.
     *
     * @param expression a boolean expression
     * @throws IllegalArgumentException if {@code expression} is false
     */
    public static void checkArgument(boolean expression) {
        if (!expression) {
            throw new IllegalArgumentException();
        }
    }

    /**
     * Validates the expression is true.
     *
     * @param expression a boolean expression
     * @param errorMessage Error message to use.
     * @throws IllegalArgumentException if {@code expression} is false
     */
    public static void checkArgument(boolean expression, @Nullable Object errorMessage) {
        if (!expression) {
            throw new IllegalArgumentException(String.valueOf(errorMessage));
        }
    }

    /**
     * Validates the expression is true.
     *
     * @param expression a boolean expression
     * @param errorMessageTemplate String template
     * @param errorMessageArgs Arguments for the string template
     * @throws IllegalArgumentException if {@code expression} is false
     * @throws NullPointerException if the check fails and either {@code errorMessageTemplate} or
     *     {@code errorMessageArgs} is null (don't let this happen)
     */
    public static void checkArgument(
            boolean expression,
            @Nullable String errorMessageTemplate,
            @Nullable Object... errorMessageArgs) {
        if (!expression) {
            throw new IllegalArgumentException(String.format(errorMessageTemplate, errorMessageArgs));
        }
    }

    /**
     * Validates the object is not null.
     *
     * @param reference an object reference
     * @return the non-null reference that was validated
     * @throws NullPointerException if {@code reference} is null
     */
    public static <T> T checkNotNull(T reference) {
        if (reference == null) {
            throw new NullPointerException();
        }
        return reference;
    }

    /**
     * Validates the object is not null.
     *
     * @param reference an object reference
     * @param errorMessage the exception message to use if the check fails; will be converted to a
     *     string using {@link String#valueOf(Object)}
     * @return the non-null reference that was validated
     * @throws NullPointerException if {@code reference} is null
     */
    public static <T> T checkNotNull(T reference, @Nullable Object errorMessage) {
        if (reference == null) {
            throw new NullPointerException(String.valueOf(errorMessage));
        }
        return reference;
    }

    /**
     * Validates the object is not null.
     *
     * @param reference an object reference
     * @param errorMessageTemplate Template to be used in the message.
     * @param errorMessageArgs Arguments to be supplied to the message
     * @return the non-null reference that was validated
     * @throws NullPointerException if {@code reference} is null
     */
    public static <T> T checkNotNull(
            T reference, @Nullable String errorMessageTemplate, @Nullable Object... errorMessageArgs) {
        if (reference == null) {
            throw new NullPointerException(String.format(errorMessageTemplate, errorMessageArgs));
        }
        return reference;
    }


    /**
     * Ensures the truth of an expression involving the state of the calling instance, but not
     * involving any parameters to the calling method.
     *
     * @param expression a boolean expression
     * @throws IllegalStateException if {@code expression} is false
     */
    public static void checkState(boolean expression) {
        if (!expression) {
            throw new IllegalStateException();
        }
    }

    /**
     * Ensures the truth of an expression involving the state of the calling instance, but not
     * involving any parameters to the calling method.
     *
     * @param expression a boolean expression
     * @param errorMessage the exception message to use if the check fails; will be converted to a
     *     string using {@link String#valueOf(Object)}
     * @throws IllegalStateException if {@code expression} is false
     */
    public static void checkState(boolean expression, @Nullable Object errorMessage) {
        if (!expression) {
            throw new IllegalStateException(String.valueOf(errorMessage));
        }
    }
}