<?php

namespace App\Services;

use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
use Symfony\Component\ExpressionLanguage\ParsedExpression;

class RuleExpressionService
{
    protected ExpressionLanguage $language;

    /** @var array<string, ParsedExpression> */
    protected array $parsedCache = [];

    public function __construct()
    {
        $this->language = new ExpressionLanguage();
    }

    public function evaluate(string $expr, array $context = [])
    {
        $expr = trim($expr);
        if ($expr === '') {
            return null;
        }

        $names = array_keys($context);
        sort($names);
        $cacheKey = md5($expr . '|' . implode(',', $names));

        if (!isset($this->parsedCache[$cacheKey])) {
            $this->parsedCache[$cacheKey] = $this->language->parse($expr, $names);
        }

        return $this->language->evaluate($this->parsedCache[$cacheKey], $context);
    }

    public function evaluateBoolean(?string $expr, array $context = []): bool
    {
        if ($expr === null || trim($expr) === '') {
            return true;
        }

        return (bool) $this->evaluate($expr, $context);
    }
}