#ifndef BOOST_NETWORK_PROTOCOL_HTTP_SERVER_ASYNC_SERVER_HPP_20101025
#define BOOST_NETWORK_PROTOCOL_HTTP_SERVER_ASYNC_SERVER_HPP_20101025

// Copyright 2010 Dean Michael Berris. 
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

#include <boost/network/detail/debug.hpp>
#include <boost/network/protocol/http/server/async_connection.hpp>
#include <boost/thread/mutex.hpp>
#include <boost/network/protocol/http/server/storage_base.hpp>
#include <boost/network/protocol/http/server/socket_options_base.hpp>
#include <boost/network/utils/thread_pool.hpp>

namespace boost { namespace network { namespace http {
    
    template <class Tag, class Handler>
    struct async_server_base : server_storage_base, socket_options_base {
        typedef basic_request<Tag> request;
        typedef basic_response<Tag> response;
        typedef typename string<Tag>::type string_type;
        typedef typename boost::network::http::response_header<Tag>::type response_header;
        typedef async_connection<Tag,Handler> connection;
        typedef shared_ptr<connection> connection_ptr;
        typedef boost::unique_lock<boost::mutex> scoped_mutex_lock;

        explicit async_server_base(server_options<Tag, Handler> const &options)
        : server_storage_base(options)
        , socket_options_base(options)
        , handler(options.handler())
        , address_(options.address())
        , port_(options.port())
        , thread_pool(options.thread_pool() ? options.thread_pool() : boost::make_shared<utils::thread_pool>())
        , acceptor(server_storage_base::service_)
        , stopping(false)
        , new_connection()
        , listening_mutex_()
        , stopping_mutex_()
        , listening(false)
        {}

        void run() {
            listen();
            service_.run();
        };

        void stop() {
            // stop accepting new requests and let all the existing
            // handlers finish.
            scoped_mutex_lock listening_lock(listening_mutex_);
            if (listening) { // we dont bother stopping if we arent currently listening
              scoped_mutex_lock stopping_lock(stopping_mutex_);
              stopping = true;
              system::error_code ignored;
              acceptor.close(ignored);
              listening = false;
              service_.post(boost::bind(&async_server_base::handle_stop, this));
            }
        }

        void listen() {
            scoped_mutex_lock listening_lock(listening_mutex_);
            BOOST_NETWORK_MESSAGE("Listening on " << address_ << ':' << port_);
            if (!listening) start_listening(); // we only initialize our acceptor/sockets if we arent already listening
            if (!listening) {
                BOOST_NETWORK_MESSAGE("Error listening on " << address_ << ':' << port_);
                boost::throw_exception(std::runtime_error("Error listening on provided port."));
            }
        }

    private:
        Handler & handler;
        string_type address_, port_;
        boost::shared_ptr<utils::thread_pool> thread_pool;
        asio::ip::tcp::acceptor acceptor;
        bool stopping;
        connection_ptr new_connection;
        boost::mutex listening_mutex_;
        boost::mutex stopping_mutex_;
        bool listening;
    
        void handle_stop() {
            scoped_mutex_lock stopping_lock(stopping_mutex_);
            if (stopping) service_.stop(); // a user may have started listening again before the stop command is reached
        }

        void handle_accept(boost::system::error_code const & ec) {
            {
              scoped_mutex_lock stopping_lock(stopping_mutex_);
              if (stopping) return;  // we dont want to add another handler instance, and we dont want to know about errors for a socket we dont need anymore
            }

            if (ec) {
              BOOST_NETWORK_MESSAGE("Error accepting connection, reason: "
                                    << ec);
            }

            socket_options_base::socket_options(new_connection->socket());
            new_connection->start();
            new_connection.reset(
                new connection(service_, handler, *thread_pool));
            acceptor.async_accept(
                new_connection->socket(),
                boost::bind(&async_server_base<Tag, Handler>::handle_accept,
                            this,
                            boost::asio::placeholders::error));
        }
        
        void start_listening() {
            using boost::asio::ip::tcp;
            system::error_code error;
            service_.reset(); // this allows repeated cycles of run -> stop -> run
            tcp::resolver resolver(service_);
            tcp::resolver::query query(address_, port_);
            tcp::resolver::iterator endpoint_iterator = resolver.resolve(query, error);
            if (error) {
                BOOST_NETWORK_MESSAGE("Error resolving '" << address_ << ':' << port_);
                return;
            }
            tcp::endpoint endpoint = *endpoint_iterator;
            acceptor.open(endpoint.protocol(), error);
            if (error) {
                BOOST_NETWORK_MESSAGE("Error opening socket: " << address_ << ":" << port_);
                return;
            }
            socket_options_base::acceptor_options(acceptor);
            acceptor.bind(endpoint, error);
            if (error) {
                BOOST_NETWORK_MESSAGE("Error binding socket: " << address_ << ":" << port_);
                return;
            }
            acceptor.listen(asio::socket_base::max_connections, error);
            if (error) {
                BOOST_NETWORK_MESSAGE("Error listening on socket: '" << error << "' on " << address_ << ":" << port_);
                return;
            }
            new_connection.reset(new connection(service_, handler, *thread_pool));
            acceptor.async_accept(new_connection->socket(),
                boost::bind(
                    &async_server_base<Tag,Handler>::handle_accept
                    , this
                    , boost::asio::placeholders::error));
            listening = true;
            scoped_mutex_lock stopping_lock(stopping_mutex_);
            stopping = false; // if we were in the process of stopping, we revoke that command and continue listening
            BOOST_NETWORK_MESSAGE("Now listening on socket: '" << address_ << ":" << port_ << "'");
        }
    };
    
} /* http */
    
} /* network */
    
} /* boost */

#endif /* BOOST_NETWORK_PROTOCOL_HTTP_SERVER_ASYNC_SERVER_HPP_20101025 */
