class Fixtures

class Fixtures {
    
    /**
     * Keep a persistent prefix to help group our tmp directories together.
     *
     * @var string
     */
    protected static $randomPrefix = '';
    
    /**
     * Directories to delete when we are done.
     *
     * @var string[]
     */
    protected $tmpDirs = [];
    
    /**
     * A Composer IOInterface to write to.
     *
     * @var \Composer\IO\IOInterface
     */
    protected $io;
    
    /**
     * The composer object.
     *
     * @var \Composer\Composer
     */
    protected $composer;
    
    /**
     * Gets an IO fixture.
     *
     * @return \Composer\IO\IOInterface
     *   A Composer IOInterface to write to; output may be retrieved via
     *   Fixtures::getOutput().
     */
    public function io() {
        if (!$this->io) {
            $this->io = new BufferIO();
        }
        return $this->io;
    }
    
    /**
     * Gets the Composer object.
     *
     * @return \Composer\Composer
     *   The main Composer object, needed by the scaffold Handler, etc.
     */
    public function getComposer() {
        if (!$this->composer) {
            $this->composer = Factory::create($this->io(), NULL, TRUE);
        }
        return $this->composer;
    }
    
    /**
     * Gets the output from the io() fixture.
     *
     * @return string
     *   Output captured from tests that write to Fixtures::io().
     */
    public function getOutput() {
        return $this->io()
            ->getOutput();
    }
    
    /**
     * Gets the path to Scaffold component.
     *
     * Used to inject the component into composer.json files.
     *
     * @return string
     *   Path to the root of this project.
     */
    public function projectRoot() {
        return realpath(__DIR__) . '/../../../../../../../composer/Plugin/Scaffold';
    }
    
    /**
     * Gets the path to the project fixtures.
     *
     * @return string
     *   Path to project fixtures
     */
    public function allFixturesDir() {
        return realpath(__DIR__ . '/fixtures');
    }
    
    /**
     * Gets the path to one particular project fixture.
     *
     * @param string $project_name
     *   The project name to get the path for.
     *
     * @return string
     *   Path to project fixture.
     */
    public function projectFixtureDir($project_name) {
        $dir = $this->allFixturesDir() . '/' . $project_name;
        if (!is_dir($dir)) {
            throw new \RuntimeException("Requested fixture project {$project_name} that does not exist.");
        }
        return $dir;
    }
    
    /**
     * Gets the path to one particular bin path.
     *
     * @param string $bin_name
     *   The bin name to get the path for.
     *
     * @return string
     *   Path to project fixture.
     */
    public function binFixtureDir($bin_name) {
        $dir = $this->allFixturesDir() . '/scripts/' . $bin_name;
        if (!is_dir($dir)) {
            throw new \RuntimeException("Requested fixture bin dir {$bin_name} that does not exist.");
        }
        return $dir;
    }
    
    /**
     * Gets a path to a source scaffold fixture.
     *
     * Use in place of ScaffoldFilePath::sourcePath().
     *
     * @param string $project_name
     *   The name of the project to fetch; $package_name is
     *   "fixtures/$project_name".
     * @param string $source
     *   The name of the asset; path is "assets/$source".
     *
     * @return \Drupal\Composer\Plugin\Scaffold\ScaffoldFilePath
     *   The full and relative path to the desired asset
     *
     * @see \Drupal\Composer\Plugin\Scaffold\ScaffoldFilePath::sourcePath()
     */
    public function sourcePath($project_name, $source) {
        $package_name = "fixtures/{$project_name}";
        $source_rel_path = "assets/{$source}";
        $package_path = $this->projectFixtureDir($project_name);
        return ScaffoldFilePath::sourcePath($package_name, $package_path, 'unknown', $source_rel_path);
    }
    
    /**
     * Gets an Interpolator with 'web-root' and 'package-name' set.
     *
     * Use in place of ManageOptions::getLocationReplacements().
     *
     * @return \Drupal\Composer\Plugin\Scaffold\Interpolator
     *   An interpolator with location replacements, including 'web-root'.
     *
     * @see \Drupal\Composer\Plugin\Scaffold\ManageOptions::getLocationReplacements()
     */
    public function getLocationReplacements() {
        $destinationTmpDir = $this->mkTmpDir('location-replacements');
        $interpolator = new Interpolator();
        $interpolator->setData([
            'web-root' => $destinationTmpDir,
            'package-name' => 'fixtures/tmp-destination',
        ]);
        return $interpolator;
    }
    
    /**
     * Creates a ReplaceOp fixture.
     *
     * @param string $project_name
     *   The name of the project to fetch; $package_name is
     *   "fixtures/$project_name".
     * @param string $source
     *   The name of the asset; path is "assets/$source".
     *
     * @return \Drupal\Composer\Plugin\Scaffold\Operations\ReplaceOp
     *   A replace operation object.
     */
    public function replaceOp($project_name, $source) {
        $source_path = $this->sourcePath($project_name, $source);
        return new ReplaceOp($source_path, TRUE);
    }
    
    /**
     * Creates an AppendOp fixture.
     *
     * @param string $project_name
     *   The name of the project to fetch; $package_name is
     *   "fixtures/$project_name".
     * @param string $source
     *   The name of the asset; path is "assets/$source".
     *
     * @return \Drupal\Composer\Plugin\Scaffold\Operations\AppendOp
     *   An append operation object.
     */
    public function appendOp($project_name, $source) {
        $source_path = $this->sourcePath($project_name, $source);
        return new AppendOp(NULL, $source_path);
    }
    
    /**
     * Gets a destination path in a tmp dir.
     *
     * Use in place of ScaffoldFilePath::destinationPath().
     *
     * @param string $destination
     *   Destination path; should be in the form '[web-root]/robots.txt', where
     *   '[web-root]' is always literally '[web-root]', with any arbitrarily
     *   desired filename following.
     * @param \Drupal\Composer\Plugin\Scaffold\Interpolator $interpolator
     *   Location replacements. Obtain via Fixtures::getLocationReplacements()
     *   when creating multiple scaffold destinations.
     * @param string $package_name
     *   (optional) The name of the fixture package that this path came from.
     *   Taken from interpolator if not provided.
     *
     * @return \Drupal\Composer\Plugin\Scaffold\ScaffoldFilePath
     *   A destination scaffold file backed by temporary storage.
     *
     * @see \Drupal\Composer\Plugin\Scaffold\ScaffoldFilePath::destinationPath()
     */
    public function destinationPath($destination, ?Interpolator $interpolator = NULL, $package_name = NULL) {
        $interpolator = $interpolator ?: $this->getLocationReplacements();
        $package_name = $package_name ?: $interpolator->interpolate('[package-name]');
        return ScaffoldFilePath::destinationPath($package_name, $destination, $interpolator);
    }
    
    /**
     * Generates a path to a temporary location, but do not create the directory.
     *
     * @param string $prefix
     *   A prefix for the temporary directory name.
     *
     * @return string
     *   Path to temporary directory
     */
    public function tmpDir($prefix) {
        $prefix .= static::persistentPrefix();
        $tmpDir = sys_get_temp_dir() . '/scaffold-' . $prefix . uniqid(md5($prefix . microtime()), TRUE);
        $this->tmpDirs[] = $tmpDir;
        return $tmpDir;
    }
    
    /**
     * Generates a persistent prefix to use with all of our temporary directories.
     *
     * The presumption is that this should reduce collisions in highly-parallel
     * tests. We prepend the process id to play nicely with phpunit process
     * isolation.
     *
     * @return string
     *   A random string that will remain the same for the entire process run.
     */
    protected static function persistentPrefix() {
        if (empty(static::$randomPrefix)) {
            static::$randomPrefix = getmypid() . md5(microtime());
        }
        return static::$randomPrefix;
    }
    
    /**
     * Creates a temporary directory.
     *
     * @param string $prefix
     *   A prefix for the temporary directory name.
     *
     * @return string
     *   Path to temporary directory
     */
    public function mkTmpDir($prefix) {
        $tmpDir = $this->tmpDir($prefix);
        $filesystem = new Filesystem();
        $filesystem->ensureDirectoryExists($tmpDir);
        return $tmpDir;
    }
    
    /**
     * Create an isolated cache directory for Composer.
     */
    public function createIsolatedComposerCacheDir() {
        $cacheDir = $this->mkTmpDir('composer-cache');
        putenv("COMPOSER_CACHE_DIR={$cacheDir}");
    }
    
    /**
     * Calls 'tearDown' in any test that copies fixtures to transient locations.
     */
    public function tearDown() {
        // Remove any temporary directories that were created.
        $filesystem = new Filesystem();
        foreach ($this->tmpDirs as $dir) {
            $filesystem->remove($dir);
        }
        // Clear out variables from the previous pass.
        $this->tmpDirs = [];
        $this->io = NULL;
        // Clear the composer cache dir, if it was set
        putenv('COMPOSER_CACHE_DIR=');
    }
    
    /**
     * Creates a temporary copy of all of the fixtures projects into a temp dir.
     *
     * The fixtures remain dirty if they already exist. Individual tests should
     * first delete any fixture directory that needs to remain pristine. Since all
     * temporary directories are removed in tearDown, this is only an issue when
     * a) the FIXTURE_DIR environment variable has been set, or b) tests are
     * calling cloneFixtureProjects more than once per test method.
     *
     * @param string $fixturesDir
     *   The directory to place fixtures in.
     * @param array $replacements
     *   Key : value mappings for placeholders to replace in composer.json
     *   templates.
     */
    public function cloneFixtureProjects($fixturesDir, array $replacements = []) {
        $filesystem = new Filesystem();
        // We will replace 'SYMLINK' with the string 'true' in our composer.json
        // fixture.
        $replacements += [
            'SYMLINK' => 'true',
        ];
        $interpolator = new Interpolator('__', '__');
        $interpolator->setData($replacements);
        $filesystem->copy($this->allFixturesDir(), $fixturesDir);
        $composer_json_templates = glob($fixturesDir . "/*/composer.json.tmpl");
        foreach ($composer_json_templates as $composer_json_tmpl) {
            // Inject replacements into composer.json.
            if (file_exists($composer_json_tmpl)) {
                $composer_json_contents = file_get_contents($composer_json_tmpl);
                $composer_json_contents = $interpolator->interpolate($composer_json_contents, [], FALSE);
                file_put_contents(dirname($composer_json_tmpl) . "/composer.json", $composer_json_contents);
                @unlink($composer_json_tmpl);
            }
        }
    }
    
    /**
     * Runs the scaffold operation.
     *
     * This is equivalent to running `composer composer-scaffold`, but we do the
     * equivalent operation by instantiating a Handler object in order to continue
     * running in the same process, so that coverage may be calculated for the
     * code executed by these tests.
     *
     * @param string $cwd
     *   The working directory to run the scaffold command in.
     *
     * @return string
     *   Output captured from tests that write to Fixtures::io().
     */
    public function runScaffold($cwd) {
        chdir($cwd);
        $handler = new Handler($this->getComposer(), $this->io());
        $handler->scaffold();
        return $this->getOutput();
    }
    
    /**
     * Runs a `composer` command.
     *
     * @param string $cmd
     *   The Composer command to execute (escaped as required)
     * @param string $cwd
     *   The current working directory to run the command from.
     *
     * @return string
     *   Standard output and standard error from the command.
     */
    public function runComposer($cmd, $cwd) {
        chdir($cwd);
        $input = new StringInput($cmd);
        $output = new BufferedOutput();
        $application = new Application();
        $application->setAutoExit(FALSE);
        $exitCode = $application->run($input, $output);
        $output = $output->fetch();
        if ($exitCode != 0) {
            throw new \Exception("Fixtures::runComposer failed to set up fixtures.\n\nCommand: '{$cmd}'\nExit code: {$exitCode}\nOutput: \n\n{$output}");
        }
        return $output;
    }

}