<?php

class WJECF_Sanitizer
{
    protected static $_instance;

    /**
     * Singleton Instance.
     *
     * @static
     *
     * @return Singleton Instance
     */
    public static function instance()
    {
        if (is_null(self::$_instance)) {
            self::$_instance = new self();
        }

        return self::$_instance;
    }

    /**
     * Sanitizes form input for database output.
     *
     * @param mixed      $value
     * @param string     $requested_format The output format requested
     * @param null|mixed $fallback_value   Value to return in case of invalid value
     *
     * @return mixed Sanitized
     */
    public function sanitize($value, $requested_format, $fallback_value = null)
    {
        switch ($requested_format) {
            case '':
                return (string) $value;

            case 'html':
                return wp_kses_post($value);

            case 'clean':
                // applies sanitize_text_field; or recursively if it's an array
                return wc_clean($value);

            case 'int,':
            case 'int[]':
                if (is_array($value)) {
                    $values = $value;
                } elseif ('' === $value || is_null($value) || false === $value) {
                    $values = [];
                } else {
                    $values = explode(',', $value); // int[] also accepts comma separated string
                }
                $retval = [];
                foreach ($values as $value) {
                    $sane = $this->sanitize($value, 'int');
                    if (!is_null($sane)) {
                        $retval[] = $sane;
                    }
                }
                if ('int,' === $requested_format) {
                    return implode(',', $retval);
                }

                return $retval;

            case 'int':
                return is_numeric($value) ? intval($value) : $fallback_value;

            case 'yesno':
                return 'yes' === $value ? 'yes' : 'no';

            case 'decimal':
                $value = wc_format_decimal($value);

                return ('' === $value || false === $value) ? $fallback_value : $value;
        }

        throw new Exception('Unknown sanitization rule '.$requested_format);
    }
}