<?php

/**
 *
 * Function code for the complex cosh() function
 *
 * @copyright  Copyright (c) 2013-2018 Mark Baker (https://github.com/MarkBaker/PHPComplex)
 * @license    https://opensource.org/licenses/MIT    MIT
 */
namespace Complex;

/**
 * Returns the hyperbolic cosine of a complex number.
 *
 * @param     Complex|mixed    $complex    Complex number or a numeric value.
 * @return    Complex          The hyperbolic cosine of the complex argument.
 * @throws    Exception        If argument isn't a valid real or complex number.
 */
if (!function_exists(__NAMESPACE__ . '\\cosh')) {
    function cosh($complex): Complex
    {
        $complex = Complex::validateComplexArgument($complex);

        if ($complex->isReal()) {
            return new Complex(\cosh($complex->getReal()));
        }

        return new Complex(
            \cosh($complex->getReal()) * \cos($complex->getImaginary()),
            \sinh($complex->getReal()) * \sin($complex->getImaginary()),
            $complex->getSuffix()
        );
    }
}