/**
 * ean validator
 *
 * @link        http://formvalidation.io/validators/ean/
 * @author      https://twitter.com/nghuuphuoc
 * @copyright   (c) 2013 - 2015 Nguyen Huu Phuoc
 * @license     http://formvalidation.io/license/
 */
(function($) {
    FormValidation.I18n = $.extend(true, FormValidation.I18n || {}, {
        'en_US': {
            ean: {
                'default': 'Please enter a valid EAN number'
            }
        }
    });

    FormValidation.Validator.ean = {
        /**
         * Validate EAN (International Article Number)
         * Examples:
         * - Valid: 73513537, 9780471117094, 4006381333931
         * - Invalid: 73513536
         *
         * @see http://en.wikipedia.org/wiki/European_Article_Number
         * @param {FormValidation.Base} validator The validator plugin instance
         * @param {jQuery} $field Field element
         * @param {Object} options Can consist of the following keys:
         * - message: The invalid message
         * @returns {Boolean}
         */
        validate: function(validator, $field, options) {
            var value = validator.getFieldValue($field, 'ean');
            if (value === '') {
                return true;
            }

            if (!/^(\d{8}|\d{12}|\d{13})$/.test(value)) {
                return false;
            }

            var length = value.length,
                sum    = 0,
                weight = (length === 8) ? [3, 1] : [1, 3];
            for (var i = 0; i < length - 1; i++) {
                sum += parseInt(value.charAt(i), 10) * weight[i % 2];
            }
            sum = (10 - sum % 10) % 10;
            return (sum + '' === value.charAt(length - 1));
        }
    };
}(jQuery));
