class Plugin

class Plugin implements PluginInterface, EventSubscriberInterface {
    const KEY_MAX_DEPTH = 'phpcodesniffer-search-depth';
    const MESSAGE_ERROR_WRONG_MAX_DEPTH = 'The value of "%s" (in the composer.json "extra".section) must be an integer larger than %d, %s given.';
    const MESSAGE_NOT_INSTALLED = 'PHPCodeSniffer is not installed';
    const MESSAGE_NOTHING_TO_INSTALL = 'No PHPCS standards to install or update';
    const MESSAGE_PLUGIN_UNINSTALLED = 'PHPCodeSniffer Composer Installer is uninstalled';
    const MESSAGE_RUNNING_INSTALLER = 'Running PHPCodeSniffer Composer Installer';
    const PACKAGE_NAME = 'squizlabs/php_codesniffer';
    const PACKAGE_TYPE = 'phpcodesniffer-standard';
    const PHPCS_CONFIG_REGEX = '`%s:[^\\r\\n]+`';
    const PHPCS_CONFIG_KEY = 'installed_paths';
    const PLUGIN_NAME = 'dealerdirect/phpcodesniffer-composer-installer';
    
    /**
     * @var Composer
     */
    private $composer;
    
    /**
     * @var string
     */
    private $cwd;
    
    /**
     * @var Filesystem
     */
    private $filesystem;
    
    /**
     * @var array
     */
    private $installedPaths;
    
    /**
     * @var IOInterface
     */
    private $io;
    
    /**
     * @var ProcessExecutor
     */
    private $processExecutor;
    
    /**
     * Triggers the plugin's main functionality.
     *
     * Makes it possible to run the plugin as a custom command.
     *
     * @param Event $event
     *
     * @throws \InvalidArgumentException
     * @throws \RuntimeException
     * @throws LogicException
     * @throws ProcessFailedException
     * @throws RuntimeException
     */
    public static function run(Event $event) {
        $io = $event->getIO();
        $composer = $event->getComposer();
        $instance = new static();
        $instance->io = $io;
        $instance->composer = $composer;
        $instance->init();
        $instance->onDependenciesChangedEvent();
    }
    
    /**
     * {@inheritDoc}
     *
     * @throws \RuntimeException
     * @throws LogicException
     * @throws ProcessFailedException
     * @throws RuntimeException
     */
    public function activate(Composer $composer, IOInterface $io) {
        $this->composer = $composer;
        $this->io = $io;
        $this->init();
    }
    
    /**
     * {@inheritDoc}
     */
    public function deactivate(Composer $composer, IOInterface $io) {
    }
    
    /**
     * {@inheritDoc}
     */
    public function uninstall(Composer $composer, IOInterface $io) {
    }
    
    /**
     * Prepares the plugin so it's main functionality can be run.
     *
     * @throws \RuntimeException
     * @throws LogicException
     * @throws ProcessFailedException
     * @throws RuntimeException
     */
    private function init() {
        $this->cwd = getcwd();
        $this->installedPaths = array();
        $this->processExecutor = new ProcessExecutor($this->io);
        $this->filesystem = new Filesystem($this->processExecutor);
    }
    
    /**
     * {@inheritDoc}
     */
    public static function getSubscribedEvents() {
        return array(
            ScriptEvents::POST_INSTALL_CMD => array(
                array(
                    'onDependenciesChangedEvent',
                    0,
                ),
            ),
            ScriptEvents::POST_UPDATE_CMD => array(
                array(
                    'onDependenciesChangedEvent',
                    0,
                ),
            ),
        );
    }
    
    /**
     * Entry point for post install and post update events.
     *
     * @throws \InvalidArgumentException
     * @throws LogicException
     * @throws ProcessFailedException
     * @throws RuntimeException
     */
    public function onDependenciesChangedEvent() {
        $io = $this->io;
        $isVerbose = $io->isVerbose();
        $exitCode = 0;
        if ($isVerbose) {
            $io->write(sprintf('<info>%s</info>', self::MESSAGE_RUNNING_INSTALLER));
        }
        if ($this->isPHPCodeSnifferInstalled() === true) {
            $this->loadInstalledPaths();
            $installPathCleaned = $this->cleanInstalledPaths();
            $installPathUpdated = $this->updateInstalledPaths();
            if ($installPathCleaned === true || $installPathUpdated === true) {
                $exitCode = $this->saveInstalledPaths();
            }
            elseif ($isVerbose) {
                $io->write(sprintf('<info>%s</info>', self::MESSAGE_NOTHING_TO_INSTALL));
            }
        }
        else {
            $pluginPackage = $this->composer
                ->getRepositoryManager()
                ->getLocalRepository()
                ->findPackages(self::PLUGIN_NAME);
            $isPluginUninstalled = count($pluginPackage) === 0;
            if ($isPluginUninstalled) {
                if ($isVerbose) {
                    $io->write(sprintf('<info>%s</info>', self::MESSAGE_PLUGIN_UNINSTALLED));
                }
            }
            else {
                $exitCode = 1;
                if ($isVerbose) {
                    $io->write(sprintf('<error>%s</error>', self::MESSAGE_NOT_INSTALLED));
                }
            }
        }
        return $exitCode;
    }
    
    /**
     * Load all paths from PHP_CodeSniffer into an array.
     *
     * @throws LogicException
     * @throws ProcessFailedException
     * @throws RuntimeException
     */
    private function loadInstalledPaths() {
        if ($this->isPHPCodeSnifferInstalled() === true) {
            $this->processExecutor
                ->execute($this->getPhpcsCommand() . ' --config-show', $output, $this->getPHPCodeSnifferInstallPath());
            $regex = sprintf(self::PHPCS_CONFIG_REGEX, self::PHPCS_CONFIG_KEY);
            if (preg_match($regex, $output, $match) === 1) {
                $phpcsInstalledPaths = str_replace(self::PHPCS_CONFIG_KEY . ': ', '', $match[0]);
                $phpcsInstalledPaths = trim($phpcsInstalledPaths);
                if ($phpcsInstalledPaths !== '') {
                    $this->installedPaths = explode(',', $phpcsInstalledPaths);
                }
            }
        }
    }
    
    /**
     * Save all coding standard paths back into PHP_CodeSniffer
     *
     * @throws LogicException
     * @throws ProcessFailedException
     * @throws RuntimeException
     *
     * @return int Exit code. 0 for success, 1 or higher for failure.
     */
    private function saveInstalledPaths() {
        // Check if we found installed paths to set.
        if (count($this->installedPaths) !== 0) {
            sort($this->installedPaths);
            $paths = implode(',', $this->installedPaths);
            $arguments = array(
                '--config-set',
                self::PHPCS_CONFIG_KEY,
                $paths,
            );
            $configMessage = sprintf('PHP CodeSniffer Config <info>%s</info> <comment>set to</comment> <info>%s</info>', self::PHPCS_CONFIG_KEY, $paths);
        }
        else {
            // Delete the installed paths if none were found.
            $arguments = array(
                '--config-delete',
                self::PHPCS_CONFIG_KEY,
            );
            $configMessage = sprintf('PHP CodeSniffer Config <info>%s</info> <comment>delete</comment>', self::PHPCS_CONFIG_KEY);
        }
        // Prepare message in case of failure
        $failMessage = sprintf('Failed to set PHP CodeSniffer <info>%s</info> Config', self::PHPCS_CONFIG_KEY);
        // Okay, lets rock!
        $command = vsprintf('%s %s', array(
            'phpcs command' => $this->getPhpcsCommand(),
            'arguments' => implode(' ', $arguments),
        ));
        $exitCode = $this->processExecutor
            ->execute($command, $configResult, $this->getPHPCodeSnifferInstallPath());
        if ($exitCode === 0) {
            $exitCode = $this->verifySaveSuccess();
        }
        if ($exitCode === 0) {
            $this->io
                ->write($configMessage);
        }
        else {
            $this->io
                ->write($failMessage);
        }
        if ($this->io
            ->isVerbose() && !empty($configResult)) {
            $this->io
                ->write(sprintf('<info>%s</info>', $configResult));
        }
        return $exitCode;
    }
    
    /**
     * Verify that the paths which were expected to be saved, have been.
     *
     * @return int Exit code. 0 for success, 1 for failure.
     */
    private function verifySaveSuccess() {
        $exitCode = 1;
        $expectedPaths = $this->installedPaths;
        // Request the currently set installed paths after the save.
        $this->loadInstalledPaths();
        $registeredPaths = array_intersect($this->installedPaths, $expectedPaths);
        $registeredCount = count($registeredPaths);
        $expectedCount = count($expectedPaths);
        if ($expectedCount === $registeredCount) {
            $exitCode = 0;
        }
        if ($exitCode === 1 && $this->io
            ->isVerbose()) {
            $verificationMessage = sprintf("Paths to external standards found by the plugin: <info>%s</info>\n" . 'Actual paths registered with PHPCS: <info>%s</info>', implode(', ', $expectedPaths), implode(', ', $this->installedPaths));
            $this->io
                ->write($verificationMessage);
        }
        return $exitCode;
    }
    
    /**
     * Get the command to call PHPCS.
     */
    protected function getPhpcsCommand() {
        // Determine the path to the main PHPCS file.
        $phpcsPath = $this->getPHPCodeSnifferInstallPath();
        if (file_exists($phpcsPath . '/bin/phpcs') === true) {
            // PHPCS 3.x.
            $phpcsExecutable = './bin/phpcs';
        }
        else {
            // PHPCS 2.x.
            $phpcsExecutable = './scripts/phpcs';
        }
        return vsprintf('%s %s', array(
            'php executable' => $this->getPhpExecCommand(),
            'phpcs executable' => $phpcsExecutable,
        ));
    }
    
    /**
     * Get the path to the current PHP version being used.
     *
     * Duplicate of the same in the EventDispatcher class in Composer itself.
     */
    protected function getPhpExecCommand() {
        $finder = new PhpExecutableFinder();
        $phpPath = $finder->find(false);
        if ($phpPath === false) {
            throw new \RuntimeException('Failed to locate PHP binary to execute ' . $phpPath);
        }
        $phpArgs = $finder->findArguments();
        $phpArgs = $phpArgs ? ' ' . implode(' ', $phpArgs) : '';
        $command = ProcessExecutor::escape($phpPath) . $phpArgs . ' -d allow_url_fopen=' . ProcessExecutor::escape(ini_get('allow_url_fopen')) . ' -d disable_functions=' . ProcessExecutor::escape(ini_get('disable_functions')) . ' -d memory_limit=' . ProcessExecutor::escape(ini_get('memory_limit'));
        return $command;
    }
    
    /**
     * Iterate trough all known paths and check if they are still valid.
     *
     * If path does not exists, is not an directory or isn't readable, the path
     * is removed from the list.
     *
     * @return bool True if changes where made, false otherwise
     */
    private function cleanInstalledPaths() {
        $changes = false;
        foreach ($this->installedPaths as $key => $path) {
            // This might be a relative path as well
            $alternativePath = realpath($this->getPHPCodeSnifferInstallPath() . \DIRECTORY_SEPARATOR . $path);
            if ((is_dir($path) === false || is_readable($path) === false) && ($alternativePath === false || is_dir($alternativePath) === false || is_readable($alternativePath) === false)) {
                unset($this->installedPaths[$key]);
                $changes = true;
            }
        }
        return $changes;
    }
    
    /**
     * Check all installed packages (including the root package) against
     * the installed paths from PHP_CodeSniffer and add the missing ones.
     *
     * @return bool True if changes where made, false otherwise
     *
     * @throws \InvalidArgumentException
     * @throws \RuntimeException
     */
    private function updateInstalledPaths() {
        $changes = false;
        $searchPaths = array();
        // Add root package only if it has the expected package type.
        if ($this->composer
            ->getPackage() instanceof RootPackageInterface && $this->composer
            ->getPackage()
            ->getType() === self::PACKAGE_TYPE) {
            $searchPaths[] = $this->cwd;
        }
        $codingStandardPackages = $this->getPHPCodingStandardPackages();
        foreach ($codingStandardPackages as $package) {
            $installPath = $this->composer
                ->getInstallationManager()
                ->getInstallPath($package);
            if ($this->filesystem
                ->isAbsolutePath($installPath) === false) {
                $installPath = $this->filesystem
                    ->normalizePath($this->cwd . \DIRECTORY_SEPARATOR . $installPath);
            }
            $searchPaths[] = $installPath;
        }
        // Nothing to do.
        if ($searchPaths === array()) {
            return false;
        }
        $finder = new Finder();
        $finder->files()
            ->depth('<= ' . $this->getMaxDepth())
            ->depth('>= ' . $this->getMinDepth())
            ->ignoreUnreadableDirs()
            ->ignoreVCS(true)
            ->in($searchPaths)
            ->name('ruleset.xml');
        // Process each found possible ruleset.
        foreach ($finder as $ruleset) {
            $standardsPath = $ruleset->getPath();
            // Pick the directory above the directory containing the standard, unless this is the project root.
            if ($standardsPath !== $this->cwd) {
                $standardsPath = dirname($standardsPath);
            }
            // Use relative paths for local project repositories.
            if ($this->isRunningGlobally() === false) {
                $standardsPath = $this->filesystem
                    ->findShortestPath($this->getPHPCodeSnifferInstallPath(), $standardsPath, true);
            }
            // De-duplicate and add when directory is not configured.
            if (in_array($standardsPath, $this->installedPaths, true) === false) {
                $this->installedPaths[] = $standardsPath;
                $changes = true;
            }
        }
        return $changes;
    }
    
    /**
     * Iterates through Composers' local repository looking for valid Coding
     * Standard packages.
     *
     * @return array Composer packages containing coding standard(s)
     */
    private function getPHPCodingStandardPackages() {
        $codingStandardPackages = array_filter($this->composer
            ->getRepositoryManager()
            ->getLocalRepository()
            ->getPackages(), function (PackageInterface $package) {
            if ($package instanceof AliasPackage) {
                return false;
            }
            return $package->getType() === Plugin::PACKAGE_TYPE;
        });
        return $codingStandardPackages;
    }
    
    /**
     * Searches for the installed PHP_CodeSniffer Composer package
     *
     * @param null|string|\Composer\Semver\Constraint\ConstraintInterface $versionConstraint to match against
     *
     * @return PackageInterface|null
     */
    private function getPHPCodeSnifferPackage($versionConstraint = null) {
        $packages = $this->composer
            ->getRepositoryManager()
            ->getLocalRepository()
            ->findPackages(self::PACKAGE_NAME, $versionConstraint);
        return array_shift($packages);
    }
    
    /**
     * Returns the path to the PHP_CodeSniffer package installation location
     *
     * @return string
     */
    private function getPHPCodeSnifferInstallPath() {
        return $this->composer
            ->getInstallationManager()
            ->getInstallPath($this->getPHPCodeSnifferPackage());
    }
    
    /**
     * Simple check if PHP_CodeSniffer is installed.
     *
     * @param null|string|\Composer\Semver\Constraint\ConstraintInterface $versionConstraint to match against
     *
     * @return bool Whether PHP_CodeSniffer is installed
     */
    private function isPHPCodeSnifferInstalled($versionConstraint = null) {
        return $this->getPHPCodeSnifferPackage($versionConstraint) !== null;
    }
    
    /**
     * Test if composer is running "global"
     * This check kinda dirty, but it is the "Composer Way"
     *
     * @return bool Whether Composer is running "globally"
     *
     * @throws \RuntimeException
     */
    private function isRunningGlobally() {
        return $this->composer
            ->getConfig()
            ->get('home') === $this->cwd;
    }
    
    /**
     * Determines the maximum search depth when searching for Coding Standards.
     *
     * @return int
     *
     * @throws \InvalidArgumentException
     */
    private function getMaxDepth() {
        $maxDepth = 3;
        $extra = $this->composer
            ->getPackage()
            ->getExtra();
        if (array_key_exists(self::KEY_MAX_DEPTH, $extra)) {
            $maxDepth = $extra[self::KEY_MAX_DEPTH];
            $minDepth = $this->getMinDepth();
            if ((string) (int) $maxDepth !== (string) $maxDepth || $maxDepth <= $minDepth || is_float($maxDepth) === true) {
                $message = vsprintf(self::MESSAGE_ERROR_WRONG_MAX_DEPTH, array(
                    'key' => self::KEY_MAX_DEPTH,
                    'min' => $minDepth,
                    'given' => var_export($maxDepth, true),
                ));
                throw new \InvalidArgumentException($message);
            }
        }
        return (int) $maxDepth;
    }
    
    /**
     * Returns the minimal search depth for Coding Standard packages.
     *
     * Usually this is 0, unless PHP_CodeSniffer >= 3 is used.
     *
     * @return int
     */
    private function getMinDepth() {
        if ($this->isPHPCodeSnifferInstalled('>= 3.0.0') !== true) {
            return 1;
        }
        return 0;
    }

}