/* SPDX-License-Identifier: MPL-2.0 */

#ifndef __ZMQ_MECHANISM_HPP_INCLUDED__

#define __ZMQ_MECHANISM_HPP_INCLUDED__

#include "stdint.hpp"

#include "options.hpp"

#include "blob.hpp"

#include "metadata.hpp"

namespace zmq

{

class msg_t;

class session_base_t;

//  Abstract class representing security mechanism.

//  Different mechanism extends this class.

class mechanism_t

{

  public:

    enum status_t

    {

        handshaking,

        ready,

        error

    };

    mechanism_t (const options_t &options_);

    virtual ~mechanism_t ();

    //  Prepare next handshake command that is to be sent to the peer.

    virtual int next_handshake_command (msg_t *msg_) = 0;

    //  Process the handshake command received from the peer.

    virtual int process_handshake_command (msg_t *msg_) = 0;

    virtual int encode (msg_t *) { return 0; }

    virtual int decode (msg_t *) { return 0; }

    //  Notifies mechanism about availability of ZAP message.

    virtual int zap_msg_available () { return 0; }

    //  Returns the status of this mechanism.

    virtual status_t status () const = 0;

    void set_peer_routing_id (const void *id_ptr_, size_t id_size_);

    void peer_routing_id (msg_t *msg_);

    void set_user_id (const void *user_id_, size_t size_);

    const blob_t &get_user_id () const;

    const metadata_t::dict_t &get_zmtp_properties () const

    {

        return _zmtp_properties;

    }

    const metadata_t::dict_t &get_zap_properties () const

    {

        return _zap_properties;

    }

  protected:

    //  Only used to identify the socket for the Socket-Type

    //  property in the wire protocol.

    static const char *socket_type_string (int socket_type_);

    static size_t add_property (unsigned char *ptr_,

                                size_t ptr_capacity_,

                                const char *name_,

                                const void *value_,

                                size_t value_len_);

    static size_t property_len (const char *name_, size_t value_len_);

    size_t add_basic_properties (unsigned char *ptr_,

                                 size_t ptr_capacity_) const;

    size_t basic_properties_len () const;

    void make_command_with_basic_properties (msg_t *msg_,

                                             const char *prefix_,

                                             size_t prefix_len_) const;

    //  Parses a metadata.

    //  Metadata consists of a list of properties consisting of

    //  name and value as size-specified strings.

    //  Returns 0 on success and -1 on error, in which case errno is set.

    int parse_metadata (const unsigned char *ptr_,

                        size_t length_,

                        bool zap_flag_ = false);

    //  This is called by parse_property method whenever it

    //  parses a new property. The function should return 0

    //  on success and -1 on error, in which case it should

    //  set errno. Signaling error prevents parser from

    //  parsing remaining data.

    //  Derived classes are supposed to override this

    //  method to handle custom processing.

    virtual int

    property (const std::string &name_, const void *value_, size_t length_);

    const options_t options;

  private:

    //  Properties received from ZMTP peer.

    metadata_t::dict_t _zmtp_properties;

    //  Properties received from ZAP server.

    metadata_t::dict_t _zap_properties;

    blob_t _routing_id;

    blob_t _user_id;

    //  Returns true iff socket associated with the mechanism

    //  is compatible with a given socket type 'type_'.

    bool check_socket_type (const char *type_, size_t len_) const;

};

}

#endif