/*
 * Copyright (c) 2015, Peter Thorson. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the WebSocket++ Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL PETER THORSON BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#ifndef WEBSOCKETPP_TRANSPORT_SECURITY_NONE_HPP
#define WEBSOCKETPP_TRANSPORT_SECURITY_NONE_HPP

#include <websocketpp/uri.hpp>

#include <websocketpp/transport/base/connection.hpp>
#include <websocketpp/transport/asio/security/base.hpp>

#include <websocketpp/common/asio.hpp>
#include <websocketpp/common/memory.hpp>

#include <sstream>
#include <string>

namespace websocketpp {
namespace transport {
namespace asio {
/// A socket policy for the asio transport that implements a plain, unencrypted
/// socket
namespace basic_socket {

/// The signature of the socket init handler for this socket policy
typedef lib::function<void(connection_hdl,lib::asio::ip::tcp::socket&)>
    socket_init_handler;

/// Basic Asio connection socket component
/**
 * transport::asio::basic_socket::connection implements a connection socket
 * component using Asio ip::tcp::socket.
 */
class connection : public lib::enable_shared_from_this<connection> {
public:
    /// Type of this connection socket component
    typedef connection type;
    /// Type of a shared pointer to this connection socket component
    typedef lib::shared_ptr<type> ptr;

    /// Type of a pointer to the Asio io_context being used
    typedef lib::asio::io_context* io_context_ptr;
    /// Type of a pointer to the Asio io_context strand being used
    typedef lib::shared_ptr<lib::asio::io_context::strand> strand_ptr;
    /// Type of the ASIO socket being used
    typedef lib::asio::ip::tcp::socket socket_type;
    /// Type of a shared pointer to the socket being used.
    typedef lib::shared_ptr<socket_type> socket_ptr;

    explicit connection() : m_state(UNINITIALIZED) {
        //std::cout << "transport::asio::basic_socket::connection constructor"
        //          << std::endl;
    }

    /// Get a shared pointer to this component
    ptr get_shared() {
        return shared_from_this();
    }

    /// Check whether or not this connection is secure
    /**
     * @return Whether or not this connection is secure
     */
    bool is_secure() const {
        return false;
    }

    /// Set the socket initialization handler
    /**
     * The socket initialization handler is called after the socket object is
     * created but before it is used. This gives the application a chance to
     * set any Asio socket options it needs.
     *
     * @param h The new socket_init_handler
     */
    void set_socket_init_handler(socket_init_handler h) {
        m_socket_init_handler = h;
    }

    /// Retrieve a pointer to the underlying socket
    /**
     * This is used internally. It can also be used to set socket options, etc
     */
    lib::asio::ip::tcp::socket & get_socket() {
        return *m_socket;
    }

    /// Retrieve a pointer to the underlying socket
    /**
     * This is used internally.
     */
    lib::asio::ip::tcp::socket & get_next_layer() {
        return *m_socket;
    }

    /// Retrieve a pointer to the underlying socket
    /**
     * This is used internally. It can also be used to set socket options, etc
     */
    lib::asio::ip::tcp::socket & get_raw_socket() {
        return *m_socket;
    }

    /// Get the remote endpoint address
    /**
     * The iostream transport has no information about the ultimate remote
     * endpoint. It will return the string "iostream transport". To indicate
     * this.
     *
     * TODO: allow user settable remote endpoint addresses if this seems useful
     *
     * @return A string identifying the address of the remote endpoint
     */
    std::string get_remote_endpoint(lib::error_code & ec) const {
        std::stringstream s;

        lib::asio::error_code aec;
        lib::asio::ip::tcp::endpoint ep = m_socket->remote_endpoint(aec);

        if (aec) {
            ec = error::make_error_code(error::pass_through);
            s << "Error getting remote endpoint: " << aec
               << " (" << aec.message() << ")";
            return s.str();
        } else {
            ec = lib::error_code();
            s << ep;
            return s.str();
        }
    }
protected:
    /// Perform one time initializations
    /**
     * init_asio is called once immediately after construction to initialize
     * Asio components to the io_context
     *
     * @param context A pointer to the endpoint's io_context
     * @param strand A shared pointer to the connection's asio strand
     * @param is_server Whether or not the endpoint is a server or not.
     */
    lib::error_code init_asio (io_context_ptr context, strand_ptr, bool)
    {
        if (m_state != UNINITIALIZED) {
            return socket::make_error_code(socket::error::invalid_state);
        }

        m_socket.reset(new lib::asio::ip::tcp::socket(*context));

        if (m_socket_init_handler) {
            m_socket_init_handler(m_hdl, *m_socket);
        }

        m_state = READY;

        return lib::error_code();
    }

    /// Set uri hook
    /**
     * Called by the transport as a connection is being established to provide
     * the uri being connected to to the security/socket layer.
     *
     * This socket policy doesn't use the uri so it is ignored.
     *
     * @since 0.6.0
     *
     * @param u The uri to set
     */
    void set_uri(uri_ptr) {}

    /// Pre-initialize security policy
    /**
     * Called by the transport after a new connection is created to initialize
     * the socket component of the connection. This method is not allowed to
     * write any bytes to the wire. This initialization happens before any
     * proxies or other intermediate wrappers are negotiated.
     *
     * @param callback Handler to call back with completion information
     */
    void pre_init(init_handler callback) {
        if (m_state != READY) {
            callback(socket::make_error_code(socket::error::invalid_state));
            return;
        }

        m_state = READING;

        callback(lib::error_code());
    }

    /// Post-initialize security policy
    /**
     * Called by the transport after all intermediate proxies have been
     * negotiated. This gives the security policy the chance to talk with the
     * real remote endpoint for a bit before the websocket handshake.
     *
     * @param callback Handler to call back with completion information
     */
    void post_init(init_handler callback) {
        callback(lib::error_code());
    }

    /// Sets the connection handle
    /**
     * The connection handle is passed to any handlers to identify the
     * connection
     *
     * @param hdl The new handle
     */
    void set_handle(connection_hdl hdl) {
        m_hdl = hdl;
    }

    /// Cancel all async operations on this socket
    /**
     * Attempts to cancel all async operations on this socket and reports any
     * failures.
     *
     * NOTE: Windows XP and earlier do not support socket cancellation.
     *
     * @return The error that occurred, if any.
     */
    lib::asio::error_code cancel_socket() {
        lib::asio::error_code ec;
        m_socket->cancel(ec);
        return ec;
    }

    void async_shutdown(socket::shutdown_handler h) {
        lib::asio::error_code ec;
        m_socket->shutdown(lib::asio::ip::tcp::socket::shutdown_both, ec);
        h(ec);
    }

    lib::error_code get_ec() const {
        return lib::error_code();
    }

public:
    /// Translate any security policy specific information about an error code
    /**
     * Translate_ec takes an Asio error code and attempts to convert its value 
     * to an appropriate websocketpp error code. In the case that the Asio and
     * Websocketpp error types are the same (such as using boost::asio and
     * boost::system_error or using standalone asio and std::system_error the
     * code will be passed through natively.
     *
     * In the case of a mismatch (boost::asio with std::system_error) a
     * translated code will be returned. The plain socket policy does not have 
     * any additional information so all such errors will be reported as the
     * generic transport pass_through error.
     *
     * @since 0.3.0
     *
     * @param ec The error code to translate_ec
     * @return The translated error code
     */
    template <typename ErrorCodeType>
    static
    lib::error_code translate_ec(ErrorCodeType) {
        // We don't know any more information about this error so pass through
        return make_error_code(transport::error::pass_through);
    }

    static
    /// Overload of translate_ec to catch cases where lib::error_code is the 
    /// same type as lib::asio::error_code
    lib::error_code translate_ec(lib::error_code ec) {
        // We don't know any more information about this error, but the error is
        // the same type as the one we are translating to, so pass through
        // untranslated.
        return ec;
    }
private:
    enum state {
        UNINITIALIZED = 0,
        READY = 1,
        READING = 2
    };

    socket_ptr          m_socket;
    state               m_state;

    connection_hdl      m_hdl;
    socket_init_handler m_socket_init_handler;
};

/// Basic ASIO endpoint socket component
/**
 * transport::asio::basic_socket::endpoint implements an endpoint socket
 * component that uses Boost ASIO's ip::tcp::socket.
 */
class endpoint {
public:
    /// The type of this endpoint socket component
    typedef endpoint type;

    /// The type of the corresponding connection socket component
    typedef connection socket_con_type;
    /// The type of a shared pointer to the corresponding connection socket
    /// component.
    typedef socket_con_type::ptr socket_con_ptr;

    explicit endpoint() {}

    /// Checks whether the endpoint creates secure connections
    /**
     * @return Whether or not the endpoint creates secure connections
     */
    bool is_secure() const {
        return false;
    }

    /// Set socket init handler
    /**
     * The socket init handler is called after a connection's socket is created
     * but before it is used. This gives the end application an opportunity to
     * set asio socket specific parameters.
     *
     * @param h The new socket_init_handler
     */
    void set_socket_init_handler(socket_init_handler h) {
        m_socket_init_handler = h;
    }
protected:
    /// Initialize a connection
    /**
     * Called by the transport after a new connection is created to initialize
     * the socket component of the connection.
     *
     * @param scon Pointer to the socket component of the connection
     *
     * @return Error code (empty on success)
     */
    lib::error_code init(socket_con_ptr scon) {
        scon->set_socket_init_handler(m_socket_init_handler);
        return lib::error_code();
    }
private:
    socket_init_handler m_socket_init_handler;
};

} // namespace basic_socket
} // namespace asio
} // namespace transport
} // namespace websocketpp

#endif // WEBSOCKETPP_TRANSPORT_SECURITY_NONE_HPP
