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package com.graphaware.reco.generic.util;

import java.util.Collection;
import java.util.Map;

public final class Assert {

    private Assert() {
    }

    /**
     * Assert a boolean expression, throwing {@code IllegalArgumentException}
     * if the test result is {@code false}.
     * Assert.isTrue(i > 0, "The value must be greater than zero");
     *
     * @param expression a boolean expression
     * @param message    the exception message to use if the assertion fails
     * @throws IllegalArgumentException if expression is {@code false}
     */
    public static void isTrue(boolean expression, String message) {
        if (!expression) {
            throw new IllegalArgumentException(message);
        }
    }

    /**
     * Assert a boolean expression, throwing {@code IllegalArgumentException}
     * if the test result is {@code false}.
     * Assert.isTrue(i > 0);
     *
     * @param expression a boolean expression
     * @throws IllegalArgumentException if expression is {@code false}
     */
    public static void isTrue(boolean expression) {
        isTrue(expression, "[Assertion failed] - this expression must be true");
    }

    /**
     * Assert that an object is {@code null} .
     * Assert.isNull(value, "The value must be null");
     *
     * @param object  the object to check
     * @param message the exception message to use if the assertion fails
     * @throws IllegalArgumentException if the object is not {@code null}
     */
    public static void isNull(Object object, String message) {
        if (object != null) {
            throw new IllegalArgumentException(message);
        }
    }

    /**
     * Assert that an object is {@code null} .
     * Assert.isNull(value);
     *
     * @param object the object to check
     * @throws IllegalArgumentException if the object is not {@code null}
     */
    public static void isNull(Object object) {
        isNull(object, "[Assertion failed] - the object argument must be null");
    }

    /**
     * Assert that an object is not {@code null} .
     * Assert.notNull(clazz, "The class must not be null");
     *
     * @param object  the object to check
     * @param message the exception message to use if the assertion fails
     * @throws IllegalArgumentException if the object is {@code null}
     */
    public static void notNull(Object object, String message) {
        if (object == null) {
            throw new IllegalArgumentException(message);
        }
    }

    /**
     * Assert that an object is not {@code null} .
     * Assert.notNull(clazz);
     *
     * @param object the object to check
     * @throws IllegalArgumentException if the object is {@code null}
     */
    public static void notNull(Object object) {
        notNull(object, "[Assertion failed] - this argument is required; it must not be null");
    }

    /**
     * Assert that the given String is not empty; that is,
     * it must not be {@code null} and not the empty String.
     * Assert.hasLength(name, "Name must not be empty");
     *
     * @param text    the String to check
     * @param message the exception message to use if the assertion fails
     * @throws IllegalArgumentException if the text is empty
     */
    public static void hasLength(String text, String message) {
        if ((text != null && text.length() > 0)) {
            return;
        }

        throw new IllegalArgumentException(message);
    }

    /**
     * Assert that the given String is not empty; that is,
     * it must not be {@code null} and not the empty String.
     * Assert.hasLength(name);
     *
     * @param text the String to check
     * @throws IllegalArgumentException if the text is empty
     */
    public static void hasLength(String text) {
        hasLength(text,
                "[Assertion failed] - this String argument must have length; it must not be null or empty");
    }



    /**
     * Assert that an array has no null elements.
     * Note: Does not complain if the array is empty!
     * Assert.noNullElements(array, "The array must have non-null elements");
     *
     * @param array   the array to check
     * @param message the exception message to use if the assertion fails
     * @throws IllegalArgumentException if the object array contains a {@code null} element
     */
    public static void noNullElements(Object[] array, String message) {
        if (array != null) {
            for (Object element : array) {
                if (element == null) {
                    throw new IllegalArgumentException(message);
                }
            }
        }
    }

    /**
     * Assert a boolean expression, throwing {@code IllegalStateException}
     * if the test result is {@code false}. Call isTrue if you wish to
     * throw IllegalArgumentException on an assertion failure.
     * Assert.state(id == null, "The id property must not already be initialized");
     *
     * @param expression a boolean expression
     * @param message    the exception message to use if the assertion fails
     * @throws IllegalStateException if expression is {@code false}
     */
    public static void state(boolean expression, String message) {
        if (!expression) {
            throw new IllegalStateException(message);
        }
    }

    /**
     * Assert a boolean expression, throwing {@link IllegalStateException}
     * if the test result is {@code false}.
     * Call {@link #isTrue(boolean)} if you wish to
     * throw {@link IllegalArgumentException} on an assertion failure.
     * 
Assert.state(id == null);
     *
     * @param expression a boolean expression
     * @throws IllegalStateException if the supplied expression is {@code false}
     */
    public static void state(boolean expression) {
        state(expression, "[Assertion failed] - this state invariant must be true");
    }
}