<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\CssSelector\XPath\Extension;

use Symfony\Component\CssSelector\Exception\ExpressionErrorException;
use Symfony\Component\CssSelector\Exception\SyntaxErrorException;
use Symfony\Component\CssSelector\Node\FunctionNode;
use Symfony\Component\CssSelector\Parser\Parser;
use Symfony\Component\CssSelector\XPath\Translator;
use Symfony\Component\CssSelector\XPath\XPathExpr;

/**
 * XPath expression translator function extension.
 *
 * This component is a port of the Python cssselect library,
 * which is copyright Ian Bicking, @see https://github.com/SimonSapin/cssselect.
 *
 * @author Jean-François Simon <jeanfrancois.simon@sensiolabs.com>
 *
 * @internal
 */
class FunctionExtension extends AbstractExtension
{
    /**
     * {@inheritdoc}
     */
    public function getFunctionTranslators(): array
    {
        return [
            'nth-child' => [$this, 'translateNthChild'],
            'nth-last-child' => [$this, 'translateNthLastChild'],
            'nth-of-type' => [$this, 'translateNthOfType'],
            'nth-last-of-type' => [$this, 'translateNthLastOfType'],
            'contains' => [$this, 'translateContains'],
            'lang' => [$this, 'translateLang'],
        ];
    }

    /**
     * @throws ExpressionErrorException
     */
    public function translateNthChild(XPathExpr $xpath, FunctionNode $function, bool $last = false, bool $addNameTest = true): XPathExpr
    {
        try {
            [$a, $b] = Parser::parseSeries($function->getArguments());
        } catch (SyntaxErrorException $e) {
            throw new ExpressionErrorException(sprintf('Invalid series: "%s".', implode('", "', $function->getArguments())), 0, $e);
        }

        $xpath->addStarPrefix();
        if ($addNameTest) {
            $xpath->addNameTest();
        }

        if (0 === $a) {
            return $xpath->addCondition('position() = '.($last ? 'last() - '.($b - 1) : $b));
        }

        if ($a < 0) {
            if ($b < 1) {
                return $xpath->addCondition('false()');
            }

            $sign = '<=';
        } else {
            $sign = '>=';
        }

        $expr = 'position()';

        if ($last) {
            $expr = 'last() - '.$expr;
            --$b;
        }

        if (0 !== $b) {
            $expr .= ' - '.$b;
        }

        $conditions = [sprintf('%s %s 0', $expr, $sign)];

        if (1 !== $a && -1 !== $a) {
            $conditions[] = sprintf('(%s) mod %d = 0', $expr, $a);
        }

        return $xpath->addCondition(implode(' and ', $conditions));

        // todo: handle an+b, odd, even
        // an+b means every-a, plus b, e.g., 2n+1 means odd
        // 0n+b means b
        // n+0 means a=1, i.e., all elements
        // an means every a elements, i.e., 2n means even
        // -n means -1n
        // -1n+6 means elements 6 and previous
    }

    public function translateNthLastChild(XPathExpr $xpath, FunctionNode $function): XPathExpr
    {
        return $this->translateNthChild($xpath, $function, true);
    }

    public function translateNthOfType(XPathExpr $xpath, FunctionNode $function): XPathExpr
    {
        return $this->translateNthChild($xpath, $function, false, false);
    }

    /**
     * @throws ExpressionErrorException
     */
    public function translateNthLastOfType(XPathExpr $xpath, FunctionNode $function): XPathExpr
    {
        if ('*' === $xpath->getElement()) {
            throw new ExpressionErrorException('"*:nth-of-type()" is not implemented.');
        }

        return $this->translateNthChild($xpath, $function, true, false);
    }

    /**
     * @throws ExpressionErrorException
     */
    public function translateContains(XPathExpr $xpath, FunctionNode $function): XPathExpr
    {
        $arguments = $function->getArguments();
        foreach ($arguments as $token) {
            if (!($token->isString() || $token->isIdentifier())) {
                throw new ExpressionErrorException('Expected a single string or identifier for :contains(), got '.implode(', ', $arguments));
            }
        }

        return $xpath->addCondition(sprintf(
            'contains(string(.), %s)',
            Translator::getXpathLiteral($arguments[0]->getValue())
        ));
    }

    /**
     * @throws ExpressionErrorException
     */
    public function translateLang(XPathExpr $xpath, FunctionNode $function): XPathExpr
    {
        $arguments = $function->getArguments();
        foreach ($arguments as $token) {
            if (!($token->isString() || $token->isIdentifier())) {
                throw new ExpressionErrorException('Expected a single string or identifier for :lang(), got '.implode(', ', $arguments));
            }
        }

        return $xpath->addCondition(sprintf(
            'lang(%s)',
            Translator::getXpathLiteral($arguments[0]->getValue())
        ));
    }

    /**
     * {@inheritdoc}
     */
    public function getName(): string
    {
        return 'function';
    }
}

• [F] AbstractExtension.php
  Delete
• [F] AttributeMatchingExtension.php
  Delete
• [F] CombinationExtension.php
  Delete
• [F] ExtensionInterface.php
  Delete
• [F] FunctionExtension.php
  Delete
• [F] HtmlExtension.php
  Delete
• [F] NodeExtension.php
  Delete
• [F] PseudoClassExtension.php
  Delete

How To Payment

Simple Steps to Complete Your Payment Securely and Efficiently

Making a payment on our website is quick and secure. Start by logging in or creating an account. Select your preferred payment method, input the required details, and review the information. Once you confirm everything is correct, click on the "Submit Payment" button. You’ll receive instant confirmation and can track your payment status through your account dashboard. It’s an easy and secure process.

• Go to the Payment Section: Access the payment area on our website or app.
• Choose Your Payment Method: Select your preferred payment option.
• Enter Payment Details: Provide the necessary payment information.
• Verify Your Information: Check that all details are correct.
• Confirm Your Payment: Click "Submit Payment" to complete the transaction.