<?php
/**
 * PHPCompatibility, an external standard for PHP_CodeSniffer.
 *
 * @package   PHPCompatibility
 * @copyright 2012-2020 PHPCompatibility Contributors
 * @license   https://opensource.org/licenses/LGPL-3.0 LGPL3
 * @link      https://github.com/PHPCompatibility/PHPCompatibility
 */

namespace PHPCompatibility\Sniffs\Syntax;

use PHPCompatibility\Helpers\ScannedCode;
use PHPCompatibility\Sniff;
use PHP_CodeSniffer\Files\File;
use PHP_CodeSniffer\Util\Tokens;
use PHPCSUtils\Tokens\Collections;

/**
 * Detect dynamic access to static methods and properties, as well as class constants.
 *
 * As of PHP 5.3, static properties and methods as well as class constants
 * can be accessed using a dynamic (variable) class name.
 *
 * PHP version 5.3
 *
 * @link https://www.php.net/manual/en/migration53.new-features.php
 *
 * @since 8.1.0
 * @since 9.0.0  Renamed from `DynamicAccessToStaticSniff` to `NewDynamicAccessToStaticSniff`.
 * @since 10.0.0 This class is now `final`.
 */
final class NewDynamicAccessToStaticSniff extends Sniff
{

    /**
     * Returns an array of tokens this test wants to listen for.
     *
     * @since 8.1.0
     *
     * @return array<int|string>
     */
    public function register()
    {
        return [
            \T_DOUBLE_COLON,
        ];
    }

    /**
     * Processes this test, when one of its tokens is encountered.
     *
     * @since 8.1.0
     *
     * @param \PHP_CodeSniffer\Files\File $phpcsFile The file being scanned.
     * @param int                         $stackPtr  The position of the current token in the
     *                                               stack passed in $tokens.
     *
     * @return void
     */
    public function process(File $phpcsFile, $stackPtr)
    {
        if (ScannedCode::shouldRunOnOrBelow('5.2') === false) {
            return;
        }

        $tokens       = $phpcsFile->getTokens();
        $prevNonEmpty = $phpcsFile->findPrevious(Tokens::$emptyTokens, ($stackPtr - 1), null, true);

        // Disregard `static::` as well. Late static binding is reported by another sniff.
        if ($tokens[$prevNonEmpty]['code'] === \T_SELF
            || $tokens[$prevNonEmpty]['code'] === \T_PARENT
            || $tokens[$prevNonEmpty]['code'] === \T_STATIC
        ) {
            return;
        }

        if ($tokens[$prevNonEmpty]['code'] === \T_STRING) {
            $prevPrevNonEmpty = $phpcsFile->findPrevious(Tokens::$emptyTokens, ($prevNonEmpty - 1), null, true);

            if ($tokens[$prevPrevNonEmpty]['code'] !== \T_OBJECT_OPERATOR
                && $tokens[$prevPrevNonEmpty]['code'] !== \T_NULLSAFE_OBJECT_OPERATOR
            ) {
                return;
            }
        }

        if (isset(Collections::nameTokens()[$tokens[$prevNonEmpty]['code']]) === true
            && $tokens[$prevNonEmpty]['code'] !== \T_STRING
        ) {
            return;
        }

        $phpcsFile->addError(
            'Static class properties and methods, as well as class constants, could not be accessed using a dynamic (variable) classname in PHP 5.2 or earlier.',
            $stackPtr,
            'Found'
        );
    }
}