<?php

namespace Orbit;

use Monolog\Logger;
use Monolog\Handler\StreamHandler;

class Server
{
    public static $version = "0.3";

    public $config;
    public $cert;
    public $timeout = 60;

    private $ssl_context;
    private $logger;

    public function __construct(Config $config = null, Cert $cert = null, Logger $logger = null)
    {
        if ($config == null) {
            $this->config = new Config();
        } else {
            $this->config = $config;
        }

        if ($logger !== null) {
            $this->setLogger($logger);
        } else {
            $this->getLogger();
        }

        if ($cert == null) {
            $this->cert = new Cert($config, $this->getLogger());
        } else {
            $this->cert = $cert;
        }

        $this->timeout = ini_get("default_socket_timeout");

        $this->ssl_context = $this->createSslContext();
    }

    public function setLogger(Logger $logger)
    {
        $this->logger = $logger;
    }

    public function getLogger()
    {
        if (!$this->logger) {
            $this->logger = new Logger('orbit');
            $this->logger->pushHandler(new StreamHandler($this->config->log_file, Logger::INFO));
        }

        return $this->logger;
    }

    public function listen($root_dir = null)
    {
        if (null == $root_dir) {
            $root_dir = $this->config->root_dir;
        }

        if (!is_dir($root_dir)) {
            throw new \Exception("Error: Root directory '$root_dir' not a directory");
        }

        $path = realpath($root_dir);

        $this->logger->debug("Root directory '$path'");

        $server = stream_socket_server(
            $this->getListenAddress(),
            $errno, $errstr,
            STREAM_SERVER_BIND|STREAM_SERVER_LISTEN,
            $this->ssl_context
        );

        if (!$server) {
            throw new \Exception("Error " . $errno . ": " . $errstr);
        }

        $protocol = "gemini";
        $name = stream_socket_get_name($server, false);
        $this->logger->info("Listening on $protocol://$name ...");

        while (true) {
            # This is to swallow up the `timeout` warning
            set_error_handler([$this, 'onWarning']);
            $client = stream_socket_accept($server, $this->timeout, $client_name);
            restore_error_handler();

            if ($client) {
                $time = ['start' => microtime(true)];

                $this->logger->debug("$client_name Accepted");
                $request_buffer = stream_get_line($client, 1024, "\r\n");
                $this->logger->info("REQ: $request_buffer", ["client" => $client_name]);
                $request = new Request($request_buffer);

                // Respond to client
                $response = $this->handleResponse($request, $path);
                $size = $response->send($client);
                $time['end'] = microtime(true);
                $this->logger->debug(
                    "RSP: " . trim($response->getHeader()),
                    ['size' => $size, 'time' => $time['end'] - $time['start']]
                );

                fclose($client);
                $this->logger->debug("$client_name Closed");
            }
        }
    }

    public function handleResponse($request, $dir)
    {
        $resource_path = rtrim($dir, "/") . $request->path;

        $response = new Response();
        if (is_dir($resource_path)) {
            // If missing the final slash, issue a redirect
            if ($resource_path[-1] != "/") {
                $response->setStatus(Response::STATUS_REDIRECT_PERMANENT);
                $response->setMeta($request->getUrlAppendPath('/'));
                return $response;
            }

            // Check if index file exists
            if (file_exists($resource_path . DIRECTORY_SEPARATOR . $this->config->index_file)) {
                $resource_path = $resource_path . DIRECTORY_SEPARATOR . $this->config->index_file;
            } else {
                if (!$this->config->enable_directory_index) {
                    $response->setStatus(Response::STATUS_BAD_REQUEST);
                    $response->setMeta('Path not available');
                    return $response;
                } else {
                    $response->setStatus(Response::STATUS_SUCCESS);
                    $response->setMeta('text/gemini');
                    $response->setBody($this->makeDirectoryIndex($resource_path, $dir));
                    return $response;
                }
            }
        }

        // File exists and is world readable
        if (file_exists($resource_path) && (fileperms($resource_path) & 0x0004)) {
            $response->setStatus(Response::STATUS_SUCCESS);

            $pathinfo = pathinfo($resource_path);
            if (!isset($pathinfo['extension'])) {
                $response->setStatus(Response::STATUS_TEMPORARY_FAILURE);
                $response->setMeta('Error reading resource');
                return $response;
            }

            if ($pathinfo['extension'] == 'gmi' || $pathinfo['extension'] == 'gemini') {
                $response->setMeta('text/gemini');
            } elseif ($pathinfo['extension'] == 'md' || $pathinfo['extension'] == 'markdown') {
                $response->setMeta('text/gemini');
            } else {
                $response->setMeta(mime_content_type($resource_path));
            }

            $response->setStaticFile($resource_path);
        } else {
            $response->setStatus(Response::STATUS_NOT_FOUND);
            $response->setMeta('Not found!');
        }

        return $response;
    }

    public function log($level, $message, $context = [])
    {
        $this->getLogger()->log($level, $message, $context);
    }

    public function onWarning($id, $message)
    {
        if (strpos($message, "timed out") !== false) {
            // Do nothing
            return;
        }

        // Something else happened.
        $error = sprintf("Error %s: %s", $id, $message);
        $this->logger->error($error);
        throw new \Exception($error);
    }

    public function getListenAddress()
    {
        return sprintf('tls://%s:%s', $this->config->host, $this->config->port);
    }

    public function makeDirectoryIndex($path, $root)
    {
        $files = glob($path . "*");

        $body = "# Directory listing " . str_replace($root, '', $path) . "\n\n";
        $body .= "=> " . str_replace($root, '', dirname($path)) . " ..\n";

        foreach ($files as $file) {
            $relative_path = str_replace($path, '', $file);

            $is_dir = false;
            if (is_dir($file)) {
                $is_dir = true;
                $size = '';
            } else {
                $size = filesize($file);
            }

            $body .= sprintf(
                "=> %s%s %s%s%s\n",
                urlencode($relative_path),
                ($is_dir ? '/' : ''),
                $relative_path,
                ($is_dir ? '/' : ''),
                ($size ? " ($size)" : '')
            );
        }

        return $body;
    }

    public function createSslContext()
    {
        $context = stream_context_create();

        // local_cert must be in PEM format
        stream_context_set_option($context, 'ssl', 'local_cert', $this->cert->tls_certfile);
        stream_context_set_option($context, 'ssl', 'local_pk', $this->cert->tls_keyfile);
        stream_context_set_option($context, 'ssl', 'passphrase', $this->cert->key_passphrase);

        stream_context_set_option($context, 'ssl', 'allow_self_signed', true);
        stream_context_set_option($context, 'ssl', 'verify_peer', false);

        return $context;
    }
}