<?php
/**
 * @package         Sourcerer
 * @version         9.8.0
 * 
 * @author          Peter van Westen <info@regularlabs.com>
 * @link            https://regularlabs.com
 * @copyright       Copyright © 2023 Regular Labs All Rights Reserved
 * @license         GNU General Public License version 2 or later
 */

namespace RegularLabs\Plugin\System\Sourcerer;

defined('_JEXEC') or die;

use RegularLabs\Library\Condition\Php as RL_Php;
use RegularLabs\Library\RegEx as RL_RegEx;

class Code
{
    public static function run($src_string, &$src_variables, $tmp_path = '')
    {
        if ( ! is_string($src_string) || $src_string == '')
        {
            return '';
        }

        $src_pre_variables = array_keys(get_defined_vars());

        ob_start();
        $src_post_variables = self::execute($src_string, $src_variables, $tmp_path);
        $src_output         = ob_get_contents();
        ob_end_clean();

        if ( ! is_array($src_post_variables))
        {
            return $src_output;
        }

        $src_diff_variables = array_diff(array_keys($src_post_variables), $src_pre_variables);

        foreach ($src_diff_variables as $src_diff_key)
        {
            if (
                in_array($src_diff_key, ['Itemid', 'mainframe', 'app', 'document', 'doc', 'database', 'db', 'user'])
                || substr($src_diff_key, 0, 4) == 'src_'
            )
            {
                continue;
            }

            $src_variables[$src_diff_key] = $src_post_variables[$src_diff_key];
        }

        return $src_output;
    }

    private static function execute($string, $src_variables, $tmp_path = '')
    {
        if ( ! $function_name = self::getFunctionName($string))
        {
            // Something went wrong!
            return [];
        }

        return $function_name($src_variables);
    }

    private static function extractUseStatements(&$string)
    {
        $use_statements = [];

        $string = trim($string);

        RL_RegEx::matchAll('^use\s+[^\s;]+\s*;', $string, $matches, 'm');

        foreach ($matches as $match)
        {
            $use_statements[] = $match[0];
            $string           = str_replace($match[0], '', $string);
        }

        $string = trim($string);

        return implode("\n", $use_statements);
    }

    private static function generateFileContents($function_name = 'src_function', $string = '')
    {
        $use_statements = self::extractUseStatements($string);

        $init = RL_Php::getVarInits();

        $init[] =
            'if (is_array($src_variables)) {'
            . 'foreach ($src_variables as $src_key => $src_value) {'
            . '${$src_key} = $src_value;'
            . '}'
            . '}';

        $contents = [
            '<?php',
            'defined(\'_JEXEC\') or die;',
            $use_statements,
            'function ' . $function_name . '($src_variables){',
            implode("\n", $init),
            $string . ';',
            'return get_defined_vars();',
            ';}',
        ];

        return implode("\n", $contents);
    }

    private static function getFunctionName($string)
    {
        $function_name = 'regularlabs_php_' . md5($string);

        if (function_exists($function_name))
        {
            return $function_name;
        }

        $contents = self::generateFileContents($function_name, $string);
        RL_Php::createFunctionInMemory($contents);

        if ( ! function_exists($function_name))
        {
            // Something went wrong!
            return false;
        }

        return $function_name;
    }
}