<?php
namespace HtmlObject\Traits;

/**
 * Static helpers used troughout the classes.
 */
class Helpers
{
    /**
     * Check if a string is an existing HTML tag.
     *
     * @param string $tag
     *
     * @return boolean
     */
    public static function isKnownTag($tag)
    {
        return in_array($tag, array(
            'a',
            'abbr',
            'acronym',
            'address',
            'applet',
            'area',
            'article',
            'aside',
            'audio',
            'b',
            'base',
            'basefont',
            'bdi',
            'bdo',
            'big',
            'blockquote',
            'body',
            'br',
            'button',
            'canvas',
            'caption',
            'center',
            'cite',
            'code',
            'col',
            'colgroup',
            'command',
            'datalist',
            'dd',
            'del',
            'details',
            'dfn',
            'dialog',
            'dir',
            'div',
            'dl',
            'dt',
            'em',
            'embed',
            'fieldset',
            'figcaption',
            'figure',
            'font',
            'footer',
            'form',
            'frame',
            'frameset',
            'h1',
            'head',
            'header',
            'hr',
            'html',
            'i',
            'iframe',
            'img',
            'input',
            'ins',
            'kbd',
            'keygen',
            'label',
            'legend',
            'li',
            'link',
            'map',
            'mark',
            'menu',
            'meta',
            'meter',
            'nav',
            'noframes',
            'noscript',
            'object',
            'ol',
            'optgroup',
            'option',
            'output',
            'p',
            'param',
            'pre',
            'progress',
            'q',
            'rp',
            'rt',
            'ruby',
            's',
            'samp',
            'script',
            'section',
            'select',
            'small',
            'source',
            'span',
            'strike',
            'strong',
            'style',
            'sub',
            'summary',
            'sup',
            'table',
            'tbody',
            'td',
            'textarea',
            'tfoot',
            'th',
            'thead',
            'time',
            'title',
            'tr',
            'track',
            'tt',
            'u',
            'ul',
            'var',
            'video',
            'wbr',
        ));
    }

    /**
     * Converts a string to hyphenated-casing.
     *
     * @param string $string
     *
     * @return string
     */
    public static function hyphenated($string)
    {
        return ctype_lower($string) ? $string : strtolower(preg_replace('/(.)([A-Z])/', '$1-$2', $string));
    }

    /**
     * Get a value from an array.
     *
     * @param array       $array
     * @param string      $key
     * @param string|null $fallback
     *
     * @return mixed
     */
    public static function arrayGet($array, $key, $fallback = null)
    {
        return isset($array[$key]) ? $array[$key] : $fallback;
    }

    /**
     * Build a list of HTML attributes from an array.
     *
     * @param array $attributes
     *
     * @return string
     */
    public static function parseAttributes($attributes)
    {
        $html = array();

        foreach ((array) $attributes as $key => $value) {

            // Valueless attributes
            if (is_numeric($key)) {
                $key = $value;
            }

            // Ignore some attributes
            if ((is_null($value) || $value === false) && !in_array($key, array('value', 'min', 'max'))) {
                continue;
            }

            // If set to boolean true, make the attribtue a property
            if ($value === true) {
                $html[] = $key;
                continue;
            }

            // Check for JSON attributes
            if (in_array(substr($value, 0, 1), array('{', '['))) {
                $html[] = $key."='".$value."'";
                continue;
            }

            $html[] = $key.'="'.$value.'"';
        }

        return (count($html) > 0) ? ' '.implode(' ', $html) : '';
    }
}
