class HtmlOutputLogger

final class HtmlOutputLogger implements Extension {
    
    /**
     * The status of the extension.
     */
    private bool $enabled = FALSE;
    
    /**
     * A file with list of links to HTML pages generated.
     */
    private ?string $browserOutputFile = NULL;
    
    /**
     * A file with list of links to HTML pages generated.
     */
    private string $outputDirectory;
    
    /**
     * Verbosity of the final report.
     *
     * If TRUE, a list of links generated will be output at the end of the test
     * run; if FALSE, only a summary with the count of pages generated.
     */
    private bool $outputVerbose;
    
    /**
     * {@inheritdoc}
     */
    public function bootstrap(Configuration $configuration, Facade $facade, ParameterCollection $parameters) : void {
        // Determine output directory.
        $envDirectory = getenv('BROWSERTEST_OUTPUT_DIRECTORY');
        if ($envDirectory === "") {
            print "HTML output disabled by BROWSERTEST_OUTPUT_DIRECTORY = ''.\n\n";
            return;
        }
        elseif ($envDirectory !== FALSE) {
            $directory = $envDirectory;
        }
        elseif ($parameters->has('outputDirectory')) {
            $directory = $parameters->get('outputDirectory');
        }
        else {
            print "HTML output directory not specified.\n\n";
            return;
        }
        $realDirectory = realpath($directory);
        if ($realDirectory === FALSE || !is_dir($realDirectory) || !is_writable($realDirectory)) {
            print "HTML output directory {$directory} is not a writable directory.\n\n";
            return;
        }
        $this->outputDirectory = $realDirectory;
        // Determine output verbosity.
        $envVerbose = getenv('BROWSERTEST_OUTPUT_VERBOSE');
        if ($envVerbose !== FALSE) {
            $verbose = $envVerbose;
        }
        elseif ($parameters->has('verbose')) {
            $verbose = $parameters->get('verbose');
        }
        else {
            $verbose = FALSE;
        }
        $this->outputVerbose = filter_var($verbose, \FILTER_VALIDATE_BOOLEAN);
        $facade->registerSubscriber(new TestRunnerStartedSubscriber($this));
        $facade->registerSubscriber(new TestRunnerFinishedSubscriber($this));
        $this->enabled = TRUE;
    }
    
    /**
     * Logs a link to a generated HTML page.
     *
     * @param string $logEntry
     *   A link to a generated HTML page, should not contain a trailing newline.
     *
     * @throws \RuntimeException
     */
    public static function log(string $logEntry) : void {
        $browserOutputFile = getenv('BROWSERTEST_OUTPUT_FILE');
        if ($browserOutputFile === FALSE) {
            throw new \RuntimeException("HTML output is not enabled");
        }
        file_put_contents($browserOutputFile, $logEntry . "\n", FILE_APPEND);
    }
    
    /**
     * Empties the list of the HTML output created during the test run.
     */
    public function testRunnerStarted(TestRunnerStarted $event) : void {
        if (!$this->enabled) {
            throw new \RuntimeException("HTML output is not enabled");
        }
        // Convert to a canonicalized absolute pathname just in case the current
        // working directory is changed.
        $this->browserOutputFile = tempnam($this->outputDirectory, 'browser_output_');
        if ($this->browserOutputFile) {
            touch($this->browserOutputFile);
            putenv('BROWSERTEST_OUTPUT_FILE=' . $this->browserOutputFile);
        }
        else {
            // Remove any environment variable.
            putenv('BROWSERTEST_OUTPUT_FILE');
            throw new \RuntimeException("Unable to create a temporary file in {$this->outputDirectory}.");
        }
    }
    
    /**
     * Prints the list of HTML output generated during the test.
     */
    public function testRunnerFinished(TestRunnerFinished $event) : void {
        if (!$this->enabled) {
            throw new \RuntimeException("HTML output is not enabled");
        }
        $contents = file_get_contents($this->browserOutputFile);
        if ($contents) {
            print "\n\n";
            if ($this->outputVerbose) {
                print "HTML output was generated.\n";
                print $contents;
            }
            else {
                print "HTML output was generated, " . count(explode("\n", $contents)) . " page(s).\n";
            }
        }
        // No need to keep the file around any more.
        unlink($this->browserOutputFile);
        putenv('BROWSERTEST_OUTPUT_FILE');
        $this->browserOutputFile = NULL;
    }

}