<?php

declare(strict_types=1);

/*
 * This file is part of PHP CS Fixer.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *     Dariusz Rumiński <dariusz.ruminski@gmail.com>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

namespace PhpCsFixer\Linter;

use PhpCsFixer\FileReader;
use PhpCsFixer\FileRemoval;
use Symfony\Component\Filesystem\Exception\IOException;
use Symfony\Component\Process\PhpExecutableFinder;
use Symfony\Component\Process\Process;

/**
 * Handle PHP code linting using separated process of `php -l _file_`.
 *
 * @author Dariusz Rumiński <dariusz.ruminski@gmail.com>
 *
 * @internal
 */
final class ProcessLinter implements LinterInterface
{
    private FileRemoval $fileRemoval;

    private ProcessLinterProcessBuilder $processBuilder;

    /**
     * Temporary file for code linting.
     *
     * @var null|string
     */
    private $temporaryFile;

    /**
     * @param null|string $executable PHP executable, null for autodetection
     */
    public function __construct(?string $executable = null)
    {
        if (null === $executable) {
            $executableFinder = new PhpExecutableFinder();
            $executable = $executableFinder->find(false);

            if (false === $executable) {
                throw new UnavailableLinterException('Cannot find PHP executable.');
            }

            if ('phpdbg' === \PHP_SAPI) {
                if (!str_contains($executable, 'phpdbg')) {
                    throw new UnavailableLinterException('Automatically found PHP executable is non-standard phpdbg. Could not find proper PHP executable.');
                }

                // automatically found executable is `phpdbg`, let us try to fallback to regular `php`
                $executable = str_replace('phpdbg', 'php', $executable);

                if (!is_executable($executable)) {
                    throw new UnavailableLinterException('Automatically found PHP executable is phpdbg. Could not find proper PHP executable.');
                }
            }
        }

        $this->processBuilder = new ProcessLinterProcessBuilder($executable);
        $this->fileRemoval = new FileRemoval();
    }

    public function __destruct()
    {
        if (null !== $this->temporaryFile) {
            $this->fileRemoval->delete($this->temporaryFile);
        }
    }

    /**
     * This class is not intended to be serialized,
     * and cannot be deserialized (see __wakeup method).
     */
    public function __sleep(): array
    {
        throw new \BadMethodCallException('Cannot serialize '.self::class);
    }

    /**
     * Disable the deserialization of the class to prevent attacker executing
     * code by leveraging the __destruct method.
     *
     * @see https://owasp.org/www-community/vulnerabilities/PHP_Object_Injection
     */
    public function __wakeup(): void
    {
        throw new \BadMethodCallException('Cannot unserialize '.self::class);
    }

    public function isAsync(): bool
    {
        return true;
    }

    public function lintFile(string $path): LintingResultInterface
    {
        return new ProcessLintingResult($this->createProcessForFile($path), $path);
    }

    public function lintSource(string $source): LintingResultInterface
    {
        return new ProcessLintingResult($this->createProcessForSource($source), $this->temporaryFile);
    }

    /**
     * @param string $path path to file
     */
    private function createProcessForFile(string $path): Process
    {
        // in case php://stdin
        if (!is_file($path)) {
            return $this->createProcessForSource(FileReader::createSingleton()->read($path));
        }

        $process = $this->processBuilder->build($path);
        $process->setTimeout(10);
        $process->start();

        return $process;
    }

    /**
     * Create process that lint PHP code.
     *
     * @param string $source code
     */
    private function createProcessForSource(string $source): Process
    {
        if (null === $this->temporaryFile) {
            $this->temporaryFile = tempnam(sys_get_temp_dir(), 'cs_fixer_tmp_');
            $this->fileRemoval->observe($this->temporaryFile);
        }

        if (false === @file_put_contents($this->temporaryFile, $source)) {
            throw new IOException(\sprintf('Failed to write file "%s".', $this->temporaryFile), 0, null, $this->temporaryFile);
        }

        return $this->createProcessForFile($this->temporaryFile);
    }
}