path: root/src/command.rs

#![allow(non_camel_case_types)]

use std::borrow::{ Cow, Borrow, ToOwned };
use std::borrow::Cow::*;
use std::iter::Extend;

use message::{ Message, MsgType };

#[derive(Debug, Hash, Clone, PartialEq, Eq)]
pub enum Command {
    /// ```text
    /// 3.1.1 Password message
    ///
    /// Command: PASS
    /// Parameters: <password>
    ///
    /// The PASS command is used to set a 'connection password'.  The
    /// optional password can and MUST be set before any attempt to register
    /// the connection is made.  Currently this requires that user send a
    /// PASS command before sending the NICK/USER combination.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NEEDMOREPARAMS              ERR_ALREADYREGISTRED
    ///
    /// Example:
    ///
    ///    PASS secretpasswordhere
    /// ```
    PASS(String),

    /// ```text
    /// 3.1.2 Nick message
    ///
    /// Command: NICK
    /// Parameters: <nickname>
    ///
    /// NICK command is used to give user a nickname or change the existing
    /// one.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NONICKNAMEGIVEN             ERR_ERRONEUSNICKNAME
    ///    ERR_NICKNAMEINUSE               ERR_NICKCOLLISION
    ///    ERR_UNAVAILRESOURCE             ERR_RESTRICTED
    ///
    /// Examples:
    ///
    ///    NICK Wiz                ; Introducing new nick "Wiz" if session is
    ///                            still unregistered, or user changing his
    ///                            nickname to "Wiz"
    ///
    ///    :WiZ!jto@tolsun.oulu.fi NICK Kilroy
    ///                            ; Server telling that WiZ changed his
    ///                            nickname to Kilroy.
    /// ```
    NICK(String),

    /// ```text
    /// 3.1.3 User message
    ///
    /// Command: USER
    /// Parameters: <user> <mode> <unused> <realname>
    ///
    /// The USER command is used at the beginning of connection to specify
    /// the username, hostname and realname of a new user.
    ///
    /// The <mode> parameter should be a numeric, and can be used to
    /// automatically set user modes when registering with the server.  This
    /// parameter is a bitmask, with only 2 bits having any signification: if
    /// the bit 2 is set, the user mode 'w' will be set and if the bit 3 is
    /// set, the user mode 'i' will be set.  (See Section 3.1.5 "User
    /// Modes").
    ///
    /// The <realname> may contain space characters.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NEEDMOREPARAMS              ERR_ALREADYREGISTRED
    ///
    /// Example:
    ///
    ///    USER guest 0 * :Ronnie Reagan   ; User registering themselves with a
    ///                                    username of "guest" and real name
    ///                                    "Ronnie Reagan".
    ///
    ///    USER guest 8 * :Ronnie Reagan   ; User registering themselves with a
    ///                                    username of "guest" and real name
    ///                                    "Ronnie Reagan", and asking to be set
    ///                                    invisible.
    /// ```
    USER(String, String, String, String),

    /// ```text
    /// 3.1.4 Oper message
    ///
    /// Command: OPER
    /// Parameters: <name> <password>
    ///
    /// A normal user uses the OPER command to obtain operator privileges.
    /// The combination of <name> and <password> are REQUIRED to gain
    /// Operator privileges.  Upon success, the user will receive a MODE
    /// message (see section 3.1.5) indicating the new user modes.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NEEDMOREPARAMS              RPL_YOUREOPER
    ///    ERR_NOOPERHOST                  ERR_PASSWDMISMATCH
    ///
    /// Example:
    ///
    ///    OPER foo bar                    ; Attempt to register as an operator
    ///                                    using a username of "foo" and "bar"
    ///                                    as the password.
    /// ```
    OPER(String, String),

    /// ```text
    /// 3.1.5 User mode message
    ///
    /// Command: MODE
    /// Parameters: <nickname>
    ///             *( ( "+" / "-" ) *( "i" / "w" / "o" / "O" / "r" ) )
    ///
    /// The user MODE's are typically changes which affect either how the
    /// client is seen by others or what 'extra' messages the client is sent.
    ///
    /// A user MODE command MUST only be accepted if both the sender of the
    /// message and the nickname given as a parameter are both the same.  If
    /// no other parameter is given, then the server will return the current
    /// settings for the nick.
    ///
    /// The available modes are as follows:
    ///
    ///    a - user is flagged as away;
    ///    i - marks a users as invisible;
    ///    w - user receives wallops;
    ///    r - restricted user connection;
    ///    o - operator flag;
    ///    O - local operator flag;
    ///    s - marks a user for receipt of server notices.
    ///
    /// Additional modes may be available later on.
    ///
    /// The flag 'a' SHALL NOT be toggled by the user using the MODE command,
    /// instead use of the AWAY command is REQUIRED.
    ///
    /// If a user attempts to make themselves an operator using the "+o" or
    /// "+O" flag, the attempt SHOULD be ignored as users could bypass the
    /// authentication mechanisms of the OPER command.  There is no
    /// restriction, however, on anyone `deopping' themselves (using "-o" or
    /// "-O").
    ///
    /// On the other hand, if a user attempts to make themselves unrestricted
    /// using the "-r" flag, the attempt SHOULD be ignored.  There is no
    /// restriction, however, on anyone `deopping' themselves (using "+r").
    /// This flag is typically set by the server upon connection for
    /// administrative reasons.  While the restrictions imposed are left up
    /// to the implementation, it is typical that a restricted user not be
    /// allowed to change nicknames, nor make use of the channel operator
    /// status on channels.
    ///
    /// The flag 's' is obsolete but MAY still be used.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NEEDMOREPARAMS              ERR_USERSDONTMATCH
    ///    ERR_UMODEUNKNOWNFLAG            RPL_UMODEIS
    ///
    /// Examples:
    ///
    ///    MODE WiZ -w                     ; Command by WiZ to turn off
    ///                                    reception of WALLOPS messages.
    ///
    ///    MODE Angel +i                   ; Command from Angel to make herself
    ///                                    invisible.
    ///
    ///    MODE WiZ -o                     ; WiZ 'deopping' (removing operator
    ///                                    status).
    /// ```
    UMODE(String),

    /// ```text
    /// 3.1.6 Service message
    ///
    /// Command: SERVICE
    /// Parameters: <nickname> <reserved> <distribution> <type>
    ///             <reserved> <info>
    ///
    /// The SERVICE command to register a new service.  Command parameters
    /// specify the service nickname, distribution, type and info of a new
    /// service.
    ///
    /// The <distribution> parameter is used to specify the visibility of a
    /// service.  The service may only be known to servers which have a name
    /// matching the distribution.  For a matching server to have knowledge
    /// of the service, the network path between that server and the server
    /// on which the service is connected MUST be composed of servers which
    /// names all match the mask.
    ///
    /// The <type> parameter is currently reserved for future usage.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_ALREADYREGISTRED            ERR_NEEDMOREPARAMS
    ///    ERR_ERRONEUSNICKNAME
    ///    RPL_YOURESERVICE                RPL_YOURHOST
    ///    RPL_MYINFO
    ///
    /// Example:
    ///
    ///    SERVICE dict * *.fr 0 0 :French Dictionary ; Service registering
    ///                                    itself with a name of "dict".  This
    ///                                    service will only be available on
    ///                                    servers which name matches "*.fr".
    /// ```
    SERVICE(String, String, String, String, String, String),

    /// ```text
    /// 3.1.7 Quit
    ///
    /// Command: QUIT
    /// Parameters: [ <Quit Message> ]
    ///
    /// A client session is terminated with a quit message.  The server
    /// acknowledges this by sending an ERROR message to the client.
    ///
    /// Numeric Replies:
    ///
    ///    None.
    ///
    /// Example:
    ///
    ///    QUIT :Gone to have lunch        ; Preferred message format.
    ///
    ///    :syrk!kalt@millennium.stealth.net QUIT :Gone to have lunch ; User
    ///                                    syrk has quit IRC to have lunch.
    /// ```
    QUIT(Option<String>),

    /// ```text
    /// 3.1.8 Squit
    ///
    /// Command: SQUIT
    /// Parameters: <server> <comment>
    ///
    /// The SQUIT command is available only to operators.  It is used to
    /// disconnect server links.  Also servers can generate SQUIT messages on
    /// error conditions.  A SQUIT message may also target a remote server
    /// connection.  In this case, the SQUIT message will simply be sent to
    /// the remote server without affecting the servers in between the
    /// operator and the remote server.
    ///
    /// The <comment> SHOULD be supplied by all operators who execute a SQUIT
    /// for a remote server.  The server ordered to disconnect its peer
    /// generates a WALLOPS message with <comment> included, so that other
    /// users may be aware of the reason of this action.
    ///
    /// Numeric replies:
    ///
    ///    ERR_NOPRIVILEGES                ERR_NOSUCHSERVER
    ///    ERR_NEEDMOREPARAMS
    ///
    /// Examples:
    ///
    ///    SQUIT tolsun.oulu.fi :Bad Link ?  ; Command to uplink of the server
    ///                                    tolson.oulu.fi to terminate its
    ///                                    connection with comment "Bad Link".
    ///
    ///    :Trillian SQUIT cm22.eng.umd.edu :Server out of control ; Command
    ///                                    from Trillian from to disconnect
    ///                                    "cm22.eng.umd.edu" from the net with
    ///                                    comment "Server out of control".
    /// ```
    SQUIT(String, String),

    /// ```text
    /// 3.2.1 Join message
    ///
    /// Command: JOIN
    /// Parameters: ( <channel> *( "," <channel> ) [ <key> *( "," <key> ) ] )
    ///             / "0"
    ///
    /// The JOIN command is used by a user to request to start listening to
    /// the specific channel.  Servers MUST be able to parse arguments in the
    /// form of a list of target, but SHOULD NOT use lists when sending JOIN
    /// messages to clients.
    ///
    /// Once a user has joined a channel, he receives information about
    /// all commands his server receives affecting the channel.  This
    /// includes JOIN, MODE, KICK, PART, QUIT and of course PRIVMSG/NOTICE.
    /// This allows channel members to keep track of the other channel
    /// members, as well as channel modes.
    ///
    /// If a JOIN is successful, the user receives a JOIN message as
    /// confirmation and is then sent the channel's topic (using RPL_TOPIC) and
    /// the list of users who are on the channel (using RPL_NAMREPLY), which
    /// MUST include the user joining.
    ///
    /// Note that this message accepts a special argument ("0"), which is
    /// a special request to leave all channels the user is currently a member
    /// of.  The server will process this message as if the user had sent
    /// a PART command (See Section 3.2.2) for each channel he is a member
    /// of.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NEEDMOREPARAMS              ERR_BANNEDFROMCHAN
    ///    ERR_INVITEONLYCHAN              ERR_BADCHANNELKEY
    ///    ERR_CHANNELISFULL               ERR_BADCHANMASK
    ///    ERR_NOSUCHCHANNEL               ERR_TOOMANYCHANNELS
    ///    ERR_TOOMANYTARGETS              ERR_UNAVAILRESOURCE
    ///    RPL_TOPIC
    ///
    /// Examples:
    ///
    ///    JOIN #foobar                    ; Command to join channel #foobar.
    ///
    ///    JOIN &foo fubar                 ; Command to join channel &foo using
    ///                                    key "fubar".
    ///
    ///    JOIN #foo,&bar fubar            ; Command to join channel #foo using
    ///                                    key "fubar" and &bar using no key.
    ///
    ///    JOIN #foo,#bar fubar,foobar     ; Command to join channel #foo using
    ///                                    key "fubar", and channel #bar using
    ///                                    key "foobar".
    ///
    ///    JOIN #foo,#bar                  ; Command to join channels #foo and
    ///                                    #bar.
    ///
    ///    JOIN 0                          ; Leave all currently joined
    ///                                    channels.
    ///
    ///    :WiZ!jto@tolsun.oulu.fi JOIN #Twilight_zone ; JOIN message from WiZ
    ///                                    on channel #Twilight_zone
    /// ```
    JOIN(Vec<String>, Vec<String>),

    /// ```text
    /// 3.2.2 Part message
    ///
    /// Command: PART
    /// Parameters: <channel> *( "," <channel> ) [ <Part Message> ]
    ///
    /// The PART command causes the user sending the message to be removed
    /// from the list of active members for all given channels listed in the
    /// parameter string.  If a "Part Message" is given, this will be sent
    /// instead of the default message, the nickname.  This request is always
    /// granted by the server.
    ///
    /// Servers MUST be able to parse arguments in the form of a list of
    /// target, but SHOULD NOT use lists when sending PART messages to
    /// clients.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NEEDMOREPARAMS              ERR_NOSUCHCHANNEL
    ///    ERR_NOTONCHANNEL
    ///
    /// Examples:
    ///
    ///    PART #twilight_zone             ; Command to leave channel
    ///                                    "#twilight_zone"
    ///
    ///    PART #oz-ops,&group5            ; Command to leave both channels
    ///                                    "&group5" and "#oz-ops".
    ///
    ///    :WiZ!jto@tolsun.oulu.fi PART #playzone :I lost
    ///                                    ; User WiZ leaving channel
    ///                                    "#playzone" with the message "I
    ///                                    lost".
    /// ```
    PART(Vec<String>, Option<String>),

    /// ```text
    /// 3.2.3 Channel mode message
    ///
    /// Command: MODE
    /// Parameters: <channel> *( ( "-" / "+" ) *<modes> *<modeparams> )
    ///
    /// The MODE command is provided so that users may query and change the
    /// characteristics of a channel.  For more details on available modes
    /// and their uses, see "Internet Relay Chat: Channel Management" [IRC-
    /// CHAN].  Note that there is a maximum limit of three (3) changes per
    /// command for modes that take a parameter.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NEEDMOREPARAMS              ERR_KEYSET
    ///    ERR_NOCHANMODES                 ERR_CHANOPRIVSNEEDED
    ///    ERR_USERNOTINCHANNEL            ERR_UNKNOWNMODE
    ///    RPL_CHANNELMODEIS
    ///    RPL_BANLIST                     RPL_ENDOFBANLIST
    ///    RPL_EXCEPTLIST                  RPL_ENDOFEXCEPTLIST
    ///    RPL_INVITELIST                  RPL_ENDOFINVITELIST
    ///    RPL_UNIQOPIS
    ///
    /// The following examples are given to help understanding the syntax of
    /// the MODE command, but refer to modes defined in "Internet Relay Chat:
    /// Channel Management" [IRC-CHAN].
    ///
    /// Examples:
    ///
    ///    MODE #Finnish +imI *!*@*.fi     ; Command to make #Finnish channel
    ///                                    moderated and 'invite-only' with user
    ///                                    with a hostname matching *.fi
    ///                                    automatically invited.
    ///
    ///    MODE #Finnish +o Kilroy         ; Command to give 'chanop' privileges
    ///                                    to Kilroy on channel #Finnish.
    ///
    ///    MODE #Finnish +v Wiz            ; Command to allow WiZ to speak on
    ///                                    #Finnish.
    ///
    ///    MODE #Fins -s                   ; Command to remove 'secret' flag
    ///                                    from channel #Fins.
    ///
    ///    MODE #42 +k oulu                ; Command to set the channel key to
    ///                                    "oulu".
    ///
    ///    MODE #42 -k oulu                ; Command to remove the "oulu"
    ///                                    channel key on channel "#42".
    ///
    ///    MODE #eu-opers +l 10            ; Command to set the limit for the
    ///                                    number of users on channel
    ///                                    "#eu-opers" to 10.
    ///
    ///    :WiZ!jto@tolsun.oulu.fi MODE #eu-opers -l
    ///                                    ; User "WiZ" removing the limit for
    ///                                    the number of users on channel "#eu-
    ///                                    opers".
    ///
    ///    MODE &oulu +b                   ; Command to list ban masks set for
    ///                                    the channel "&oulu".
    ///
    ///    MODE &oulu +b *!*@*             ; Command to prevent all users from
    ///                                    joining.
    ///
    ///    MODE &oulu +b *!*@*.edu +e *!*@*.bu.edu
    ///                                    ; Command to prevent any user from a
    ///                                    hostname matching *.edu from joining,
    ///                                    except if matching *.bu.edu
    ///
    ///    MODE #bu +be *!*@*.edu *!*@*.bu.edu
    ///                                    ; Comment to prevent any user from a
    ///                                    hostname matching *.edu from joining,
    ///                                    except if matching *.bu.edu
    ///
    ///    MODE #meditation e              ; Command to list exception masks set
    ///                                    for the channel "#meditation".
    ///
    ///    MODE #meditation I              ; Command to list invitations masks
    ///                                    set for the channel "#meditation".
    ///
    ///    MODE !12345ircd O               ; Command to ask who the channel
    ///                                    creator for "!12345ircd" is
    /// ```
    MODE(String, Vec<(String, String)>),

    /// ```text```
    /// 3.2.4 Topic message
    ///
    /// Command: TOPIC
    /// Parameters: <channel> [ <topic> ]
    ///
    /// The TOPIC command is used to change or view the topic of a channel.
    /// The topic for channel <channel> is returned if there is no <topic>
    /// given.  If the <topic> parameter is present, the topic for that
    /// channel will be changed, if this action is allowed for the user
    /// requesting it.  If the <topic> parameter is an empty string, the
    /// topic for that channel will be removed.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NEEDMOREPARAMS              ERR_NOTONCHANNEL
    ///    RPL_NOTOPIC                     RPL_TOPIC
    ///    ERR_CHANOPRIVSNEEDED            ERR_NOCHANMODES
    ///
    /// Examples:
    ///
    ///    :WiZ!jto@tolsun.oulu.fi TOPIC #test :New topic ; User Wiz setting the
    ///                                    topic.
    ///
    ///    TOPIC #test :another topic      ; Command to set the topic on #test
    ///                                    to "another topic".
    ///
    ///    TOPIC #test :                   ; Command to clear the topic on
    ///                                    #test.
    ///
    ///    TOPIC #test                     ; Command to check the topic for
    ///                                    #test.
    /// ```
    TOPIC(String, Option<String>),

    /// ```text
    /// 3.2.5 Names message
    ///
    /// Command: NAMES
    /// Parameters: [ <channel> *( "," <channel> ) [ <target> ] ]
    ///
    /// By using the NAMES command, a user can list all nicknames that are
    /// visible to him. For more details on what is visible and what is not,
    /// see "Internet Relay Chat: Channel Management" [IRC-CHAN].  The
    /// <channel> parameter specifies which channel(s) to return information
    /// about.  There is no error reply for bad channel names.
    ///
    /// If no <channel> parameter is given, a list of all channels and their
    /// occupants is returned.  At the end of this list, a list of users who
    /// are visible but either not on any channel or not on a visible channel
    /// are listed as being on `channel' "*".
    ///
    /// If the <target> parameter is specified, the request is forwarded to
    /// that server which will generate the reply.
    ///
    /// Wildcards are allowed in the <target> parameter.
    ///
    /// Numerics:
    ///
    ///    ERR_TOOMANYMATCHES              ERR_NOSUCHSERVER
    ///    RPL_NAMREPLY                    RPL_ENDOFNAMES
    ///
    /// Examples:
    ///
    ///    NAMES #twilight_zone,#42        ; Command to list visible users on
    ///                                    #twilight_zone and #42
    ///
    ///    NAMES                           ; Command to list all visible
    ///                                    channels and users
    /// ```
    NAMES(Vec<String>, Option<String>),

    /// ```text
    /// 3.2.6 List message
    ///
    /// Command: LIST
    /// Parameters: [ <channel> *( "," <channel> ) [ <target> ] ]
    ///
    /// The list command is used to list channels and their topics.  If the
    /// <channel> parameter is used, only the status of that channel is
    /// displayed.
    ///
    /// If the <target> parameter is specified, the request is forwarded to
    /// that server which will generate the reply.
    ///
    /// Wildcards are allowed in the <target> parameter.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_TOOMANYMATCHES              ERR_NOSUCHSERVER
    ///    RPL_LIST                        RPL_LISTEND
    ///
    /// Examples:
    ///
    ///    LIST                            ; Command to list all channels.
    ///
    ///    LIST #twilight_zone,#42         ; Command to list channels
    ///                                    #twilight_zone and #42
    /// ```
    LIST(Vec<String>, Option<String>),

    /// ```text
    /// 3.2.7 Invite message
    ///
    /// Command: INVITE
    /// Parameters: <nickname> <channel>
    ///
    /// The INVITE command is used to invite a user to a channel.  The
    /// parameter <nickname> is the nickname of the person to be invited to
    /// the target channel <channel>.  There is no requirement that the
    /// channel the target user is being invited to must exist or be a valid
    /// channel.  However, if the channel exists, only members of the channel
    /// are allowed to invite other users.  When the channel has invite-only
    /// flag set, only channel operators may issue INVITE command.
    ///
    /// Only the user inviting and the user being invited will receive
    /// notification of the invitation.  Other channel members are not
    /// notified.  (This is unlike the MODE changes, and is occasionally the
    /// source of trouble for users.)
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NEEDMOREPARAMS              ERR_NOSUCHNICK
    ///    ERR_NOTONCHANNEL                ERR_USERONCHANNEL
    ///    ERR_CHANOPRIVSNEEDED
    ///    RPL_INVITING                    RPL_AWAY
    ///
    /// Examples:
    ///
    ///    :Angel!wings@irc.org INVITE Wiz #Dust
    ///                                    ; Message to WiZ when he has been
    ///                                    invited by user Angel to channel
    ///                                    #Dust
    ///
    ///    INVITE Wiz #Twilight_Zone       ; Command to invite WiZ to
    ///                                    #Twilight_zone
    /// ```
    INVITE(String, String),

    /// ```text
    /// 3.2.8 Kick command
    ///
    /// Command: KICK
    /// Parameters: <channel> *( "," <channel> ) <user> *( "," <user> )
    ///             [<comment>]
    ///
    /// The KICK command can be used to request the forced removal of a user
    /// from a channel.  It causes the <user> to PART from the <channel> by
    /// force.  For the message to be syntactically correct, there MUST be
    /// either one channel parameter and multiple user parameter, or as many
    /// channel parameters as there are user parameters.  If a "comment" is
    /// given, this will be sent instead of the default message, the nickname
    /// of the user issuing the KICK.
    ///
    /// The server MUST NOT send KICK messages with multiple channels or
    /// users to clients.  This is necessarily to maintain backward
    /// compatibility with old client software.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NEEDMOREPARAMS              ERR_NOSUCHCHANNEL
    ///    ERR_BADCHANMASK                 ERR_CHANOPRIVSNEEDED
    ///    ERR_USERNOTINCHANNEL            ERR_NOTONCHANNEL
    ///
    /// Examples:
    ///
    ///    KICK &Melbourne Matthew         ; Command to kick Matthew from
    ///                                    &Melbourne
    ///
    ///    KICK #Finnish John :Speaking English
    ///                                    ; Command to kick John from #Finnish
    ///                                    using "Speaking English" as the
    ///                                    reason (comment).
    ///
    ///    :WiZ!jto@tolsun.oulu.fi KICK #Finnish John
    ///                                    ; KICK message on channel #Finnish
    ///                                    from WiZ to remove John from channel
    /// ```
    KICK(Vec<String>, Vec<String>, Option<String>),

    /// ```text
    /// 3.3.1 Private messages
    ///
    /// Command: PRIVMSG
    /// Parameters: <msgtarget> <text to be sent>
    ///
    /// PRIVMSG is used to send private messages between users, as well as to
    /// send messages to channels.  <msgtarget> is usually the nickname of
    /// the recipient of the message, or a channel name.
    ///
    /// The <msgtarget> parameter may also be a host mask (#<mask>) or server
    /// mask ($<mask>).  In both cases the server will only send the PRIVMSG
    /// to those who have a server or host matching the mask.  The mask MUST
    /// have at least 1 (one) "." in it and no wildcards following the last
    /// ".".  This requirement exists to prevent people sending messages to
    /// "#*" or "$*", which would broadcast to all users.  Wildcards are the
    /// '*' and '?'  characters.  This extension to the PRIVMSG command is
    /// only available to operators.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NORECIPIENT                 ERR_NOTEXTTOSEND
    ///    ERR_CANNOTSENDTOCHAN            ERR_NOTOPLEVEL
    ///    ERR_WILDTOPLEVEL                ERR_TOOMANYTARGETS
    ///    ERR_NOSUCHNICK
    ///    RPL_AWAY
    ///
    /// Examples:
    ///
    ///    :Angel!wings@irc.org PRIVMSG Wiz :Are you receiving this message ?
    ///                                    ; Message from Angel to Wiz.
    ///
    ///    PRIVMSG Angel :yes I'm receiving it !
    ///                                    ; Command to send a message to Angel.
    ///
    ///    PRIVMSG jto@tolsun.oulu.fi :Hello !
    ///                                    ; Command to send a message to a user
    ///                                    on server tolsun.oulu.fi with
    ///                                    username of "jto".
    ///
    ///    PRIVMSG kalt%millennium.stealth.net@irc.stealth.net :Are you a frog?
    ///                                    ; Message to a user on server
    ///                                    irc.stealth.net with username of
    ///                                    "kalt", and connected from the host
    ///                                    millennium.stealth.net.
    ///
    ///    PRIVMSG kalt%millennium.stealth.net :Do you like cheese?
    ///                                    ; Message to a user on the local
    ///                                    server with username of "kalt", and
    ///                                    connected from the host
    ///                                    millennium.stealth.net.
    ///
    ///    PRIVMSG Wiz!jto@tolsun.oulu.fi :Hello !
    ///                                    ; Message to the user with nickname
    ///                                    Wiz who is connected from the host
    ///                                    tolsun.oulu.fi and has the username
    ///                                    "jto".
    ///
    ///    PRIVMSG $*.fi :Server tolsun.oulu.fi rebooting.
    ///                                    ; Message to everyone on a server
    ///                                    which has a name matching *.fi.
    ///
    ///    PRIVMSG #*.edu :NSFNet is undergoing work, expect interruptions
    ///                                    ; Message to all users who come from
    ///                                    a host which has a name matching
    ///                                    *.edu.
    /// ```
    PRIVMSG(String, String),

    /// ```text
    /// 3.3.2 Notice
    ///
    /// Command: NOTICE
    /// Parameters: <msgtarget> <text>
    ///
    /// The NOTICE command is used similarly to PRIVMSG.  The difference
    /// between NOTICE and PRIVMSG is that automatic replies MUST NEVER be
    /// sent in response to a NOTICE message.  This rule applies to servers
    /// too - they MUST NOT send any error reply back to the client on
    /// receipt of a notice.  The object of this rule is to avoid loops
    /// between clients automatically sending something in response to
    /// something it received.
    ///
    /// This command is available to services as well as users.
    ///
    /// This is typically used by services, and automatons (clients with
    /// either an AI or other interactive program controlling their actions).
    ///
    /// See PRIVMSG for more details on replies and examples.
    /// ```
    NOTICE(String, String),

    /// ```text
    /// 3.4.1 Motd message
    ///
    /// Command: MOTD
    /// Parameters: [ <target> ]
    ///
    /// The MOTD command is used to get the "Message Of The Day" of the given
    /// server, or current server if <target> is omitted.
    ///
    /// Wildcards are allowed in the <target> parameter.
    ///
    /// Numeric Replies:
    ///    RPL_MOTDSTART                   RPL_MOTD
    ///    RPL_ENDOFMOTD                   ERR_NOMOTD
    /// ```
    MOTD(Option<String>),

    /// ```text
    /// 3.4.2 Lusers message
    ///
    /// Command: LUSERS
    /// Parameters: [ <mask> [ <target> ] ]
    ///
    /// The LUSERS command is used to get statistics about the size of the
    /// IRC network.  If no parameter is given, the reply will be about the
    /// whole net.  If a <mask> is specified, then the reply will only
    /// concern the part of the network formed by the servers matching the
    /// mask.  Finally, if the <target> parameter is specified, the request
    /// is forwarded to that server which will generate the reply.
    ///
    /// Wildcards are allowed in the <target> parameter.
    ///
    /// Numeric Replies:
    ///
    ///    RPL_LUSERCLIENT                 RPL_LUSEROP
    ///    RPL_LUSERUNKOWN                 RPL_LUSERCHANNELS
    ///    RPL_LUSERME                     ERR_NOSUCHSERVER
    /// ```
    LUSERS(Option<(String, Option<String>)>),

    /// ```text
    /// 3.4.3 Version message
    ///
    /// Command: VERSION
    /// Parameters: [ <target> ]
    ///
    /// The VERSION command is used to query the version of the server
    /// program.  An optional parameter <target> is used to query the version
    /// of the server program which a client is not directly connected to.
    ///
    /// Wildcards are allowed in the <target> parameter.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOSUCHSERVER                RPL_VERSION
    ///
    /// Examples:
    ///
    ///    VERSION tolsun.oulu.fi          ; Command to check the version of
    ///                                    server "tolsun.oulu.fi".
    /// ```
    VERSION(Option<String>),

    /// ```text
    /// 3.4.4 Stats message
    ///
    /// Command: STATS
    /// Parameters: [ <query> [ <target> ] ]
    ///
    /// The stats command is used to query statistics of certain server.  If
    /// <query> parameter is omitted, only the end of stats reply is sent
    /// back.
    ///
    /// A query may be given for any single letter which is only checked by
    /// the destination server and is otherwise passed on by intermediate
    /// servers, ignored and unaltered.
    ///
    /// Wildcards are allowed in the <target> parameter.
    ///
    /// Except for the ones below, the list of valid queries is
    /// implementation dependent.  The standard queries below SHOULD be
    /// supported by the server:
    ///
    ///    l - returns a list of the server's connections, showing how
    ///        long each connection has been established and the
    ///        traffic over that connection in Kbytes and messages for
    ///        each direction;
    ///    m - returns the usage count for each of commands supported
    ///        by the server; commands for which the usage count is
    ///        zero MAY be omitted;
    ///    o - returns a list of configured privileged users,
    ///        operators;
    ///    u - returns a string showing how long the server has been
    ///        up.
    ///
    /// It is also RECOMMENDED that client and server access configuration be
    /// published this way.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOSUCHSERVER
    ///    RPL_STATSLINKINFO                RPL_STATSUPTIME
    ///    RPL_STATSCOMMANDS                RPL_STATSOLINE
    ///    RPL_ENDOFSTATS
    ///
    /// Examples:
    ///
    ///    STATS m      ; Command to check the command usage
    ///                   for the server you are connected to
    /// ```
    STATS(Option<(String, Option<String>)>),

    /// ```text
    /// 3.4.5 Links message
    ///
    /// Command: LINKS
    /// Parameters: [ [ <remote server> ] <server mask> ]
    ///
    /// With LINKS, a user can list all servernames, which are known by the
    /// server answering the query.  The returned list of servers MUST match
    /// the mask, or if no mask is given, the full list is returned.
    ///
    /// If <remote server> is given in addition to <server mask>, the LINKS
    /// command is forwarded to the first server found that matches that name
    /// (if any), and that server is then required to answer the query.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOSUCHSERVER
    ///    RPL_LINKS                        RPL_ENDOFLINKS
    ///
    /// Examples:
    ///
    ///    LINKS *.au                      ; Command to list all servers which
    ///                                    have a name that matches *.au;
    ///
    ///    LINKS *.edu *.bu.edu            ; Command to list servers matching
    ///                                    *.bu.edu as seen by the first server
    ///                                    matching *.edu.
    /// ```
    LINKS(Option<(Option<String>, String)>),

    /// ```text
    /// 3.4.6 Time message
    ///
    /// Command: TIME
    /// Parameters: [ <target> ]
    ///
    /// The time command is used to query local time from the specified
    /// server. If the <target> parameter is not given, the server receiving
    /// the command must reply to the query.
    ///
    /// Wildcards are allowed in the <target> parameter.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOSUCHSERVER              RPL_TIME
    ///
    /// Examples:
    ///    TIME tolsun.oulu.fi             ; check the time on the server
    ///                                    "tolson.oulu.fi"
    /// ```
    TIME(Option<String>),

    /// ```text
    /// 3.4.7 Connect message
    ///
    /// Command: CONNECT
    /// Parameters: <target server> <port> [ <remote server> ]
    ///
    /// The CONNECT command can be used to request a server to try to
    /// establish a new connection to another server immediately.  CONNECT is
    /// a privileged command and SHOULD be available only to IRC Operators.
    /// If a <remote server> is given and its mask doesn't match name of the
    /// parsing server, the CONNECT attempt is sent to the first match of
    /// remote server. Otherwise the CONNECT attempt is made by the server
    /// processing the request.
    ///
    /// The server receiving a remote CONNECT command SHOULD generate a
    /// WALLOPS message describing the source and target of the request.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOSUCHSERVER              ERR_NOPRIVILEGES
    ///    ERR_NEEDMOREPARAMS
    ///
    /// Examples:
    ///
    ///    CONNECT tolsun.oulu.fi 6667     ; Command to attempt to connect local
    ///                                    server to tolsun.oulu.fi on port 6667
    ///
    CONNECT(String, i16, Option<String>),

    /// ```text
    /// 3.4.8 Trace message
    ///
    /// Command: TRACE
    /// Parameters: [ <target> ]
    ///
    /// TRACE command is used to find the route to specific server and
    /// information about its peers.  Each server that processes this command
    /// MUST report to the sender about it.  The replies from pass-through
    /// links form a chain, which shows route to destination.  After sending
    /// this reply back, the query MUST be sent to the next server until
    /// given <target> server is reached.
    ///
    /// TRACE command is used to find the route to specific server.  Each
    /// server that processes this message MUST tell the sender about it by
    /// sending a reply indicating it is a pass-through link, forming a chain
    /// of replies.  After sending this reply back, it MUST then send the
    /// TRACE message to the next server until given server is reached.  If
    /// the <target> parameter is omitted, it is RECOMMENDED that TRACE
    /// command sends a message to the sender telling which servers the local
    /// server has direct connection to.
    ///
    /// If the destination given by <target> is an actual server, the
    /// destination server is REQUIRED to report all servers, services and
    /// operators which are connected to it; if the command was issued by an
    /// operator, the server MAY also report all users which are connected to
    /// it.  If the destination given by <target> is a nickname, then only a
    /// reply for that nickname is given.  If the <target> parameter is
    /// omitted, it is RECOMMENDED that the TRACE command is parsed as
    /// targeted to the processing server.
    ///
    /// Wildcards are allowed in the <target> parameter.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOSUCHSERVER
    ///
    /// If the TRACE message is destined for another server, all
    /// intermediate servers must return a RPL_TRACELINK reply to indicate
    /// that the TRACE passed through it and where it is going next.
    ///
    ///    RPL_TRACELINK
    ///
    /// A TRACE reply may be composed of any number of the following
    /// numeric replies.
    ///
    ///    RPL_TRACECONNECTING           RPL_TRACEHANDSHAKE
    ///    RPL_TRACEUNKNOWN              RPL_TRACEOPERATOR
    ///    RPL_TRACEUSER                 RPL_TRACESERVER
    ///    RPL_TRACESERVICE              RPL_TRACENEWTYPE
    ///    RPL_TRACECLASS                RPL_TRACELOG
    ///    RPL_TRACEEND
    ///
    /// Examples:
    ///
    ///    TRACE *.oulu.fi                 ; TRACE to a server matching
    ///                                    *.oulu.fi
    /// ```
    TRACE(Option<String>),

    /// ```text
    /// 3.4.9 Admin command
    ///
    /// Command: ADMIN
    /// Parameters: [ <target> ]
    ///
    /// The admin command is used to find information about the administrator
    /// of the given server, or current server if <target> parameter is
    /// omitted.  Each server MUST have the ability to forward ADMIN messages
    /// to other servers.
    ///
    /// Wildcards are allowed in the <target> parameter.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOSUCHSERVER
    ///    RPL_ADMINME                   RPL_ADMINLOC1
    ///    RPL_ADMINLOC2                 RPL_ADMINEMAIL
    ///
    /// Examples:
    ///
    ///    ADMIN tolsun.oulu.fi            ; request an ADMIN reply from
    ///                                    tolsun.oulu.fi
    ///
    ///    ADMIN syrk                      ; ADMIN request for the server to
    ///                                    which the user syrk is connected
    /// ```
    ADMIN(Option<String>),

    /// ```text
    /// 3.4.10 Info command
    ///
    /// Command: INFO
    /// Parameters: [ <target> ]
    ///
    /// The INFO command is REQUIRED to return information describing the
    /// server: its version, when it was compiled, the patchlevel, when it
    /// was started, and any other miscellaneous information which may be
    /// considered to be relevant.
    ///
    /// Wildcards are allowed in the <target> parameter.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOSUCHSERVER
    ///    RPL_INFO                      RPL_ENDOFINFO
    ///
    /// Examples:
    ///
    ///    INFO csd.bu.edu                 ; request an INFO reply from
    ///                                    csd.bu.edu
    ///
    ///    INFO Angel                      ; request info from the server that
    ///                                    Angel is connected to.
    /// ```
    INFO(Option<String>),

    /// ```text
    /// 3.5.1 Servlist message
    ///
    /// Command: SERVLIST
    /// Parameters: [ <mask> [ <type> ] ]
    ///
    /// The SERVLIST command is used to list services currently connected to
    /// the network and visible to the user issuing the command.  The
    /// optional parameters may be used to restrict the result of the query
    /// (to matching services names, and services type).
    ///
    /// Numeric Replies:
    ///
    ///    RPL_SERVLIST                  RPL_SERVLISTEND
    /// ```
    SERVLIST(Option<(String, Option<String>)>),

    /// ```text
    /// 3.5.2 Squery
    ///
    /// Command: SQUERY
    /// Parameters: <servicename> <text>
    ///
    /// The SQUERY command is used similarly to PRIVMSG.  The only difference
    /// is that the recipient MUST be a service.  This is the only way for a
    /// text message to be delivered to a service.
    ///
    /// See PRIVMSG for more details on replies and example.
    ///
    /// Examples:
    ///
    ///    SQUERY irchelp :HELP privmsg
    ///                                    ; Message to the service with
    ///                                    nickname irchelp.
    ///
    ///    SQUERY dict@irc.fr :fr2en blaireau
    ///                                    ; Message to the service with name
    ///                                    dict@irc.fr.
    /// ```
    SQUERY(String, String),

    /// ```text
    /// 3.6.1 Who query
    ///
    /// Command: WHO
    /// Parameters: [ <mask> [ "o" ] ]
    ///
    /// The WHO command is used by a client to generate a query which returns
    /// a list of information which 'matches' the <mask> parameter given by
    /// the client.  In the absence of the <mask> parameter, all visible
    /// (users who aren't invisible (user mode +i) and who don't have a
    /// common channel with the requesting client) are listed.  The same
    /// result can be achieved by using a <mask> of "0" or any wildcard which
    /// will end up matching every visible user.
    ///
    /// The <mask> passed to WHO is matched against users' host, server, real
    /// name and nickname if the channel <mask> cannot be found.
    ///
    /// If the "o" parameter is passed only operators are returned according
    /// to the <mask> supplied.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOSUCHSERVER
    ///    RPL_WHOREPLY                  RPL_ENDOFWHO
    ///
    /// Examples:
    ///
    ///    WHO *.fi                        ; Command to list all users who match
    ///                                    against "*.fi".
    ///
    ///    WHO jto* o                      ; Command to list all users with a
    ///                                    match against "jto*" if they are an
    ///                                    operator.
    /// ```
    WHO(Option<String>, bool),

    /// ```text
    /// 3.6.2 Whois query
    ///
    /// Command: WHOIS
    /// Parameters: [ <target> ] <mask> *( "," <mask> )
    ///
    /// This command is used to query information about particular user.
    /// The server will answer this command with several numeric messages
    /// indicating different statuses of each user which matches the mask (if
    /// you are entitled to see them).  If no wildcard is present in the
    /// <mask>, any information about that nick which you are allowed to see
    /// is presented.
    ///
    /// If the <target> parameter is specified, it sends the query to a
    /// specific server.  It is useful if you want to know how long the user
    /// in question has been idle as only local server (i.e., the server the
    /// user is directly connected to) knows that information, while
    /// everything else is globally known.
    ///
    /// Wildcards are allowed in the <target> parameter.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOSUCHSERVER              ERR_NONICKNAMEGIVEN
    ///    RPL_WHOISUSER                 RPL_WHOISCHANNELS
    ///    RPL_WHOISCHANNELS             RPL_WHOISSERVER
    ///    RPL_AWAY                      RPL_WHOISOPERATOR
    ///    RPL_WHOISIDLE                 ERR_NOSUCHNICK
    ///    RPL_ENDOFWHOIS
    ///
    ///  Examples:
    ///
    ///    WHOIS wiz                       ; return available user information
    ///                                    about nick WiZ
    ///
    ///    WHOIS eff.org trillian          ; ask server eff.org for user
    ///                                    information  about trillian
    /// ```
    WHOIS(Option<String>, Vec<String>),

    /// ```text
    /// 3.6.3 Whowas
    ///
    /// Command: WHOWAS
    /// Parameters: <nickname> *( "," <nickname> ) [ <count> [ <target> ] ]
    ///
    /// Whowas asks for information about a nickname which no longer exists.
    /// This may either be due to a nickname change or the user leaving IRC.
    /// In response to this query, the server searches through its nickname
    /// history, looking for any nicks which are lexically the same (no wild
    /// card matching here).  The history is searched backward, returning the
    /// most recent entry first.  If there are multiple entries, up to
    /// <count> replies will be returned (or all of them if no <count>
    /// parameter is given).  If a non-positive number is passed as being
    /// <count>, then a full search is done.
    ///
    /// Wildcards are allowed in the <target> parameter.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NONICKNAMEGIVEN           ERR_WASNOSUCHNICK
    ///    RPL_WHOWASUSER                RPL_WHOISSERVER
    ///    RPL_ENDOFWHOWAS
    ///
    /// Examples:
    ///
    ///    WHOWAS Wiz                      ; return all information in the nick
    ///                                    history about nick "WiZ";
    ///
    ///    WHOWAS Mermaid 9                ; return at most, the 9 most recent
    ///                                    entries in the nick history for
    ///                                    "Mermaid";
    ///
    ///    WHOWAS Trillian 1 *.edu         ; return the most recent history for
    ///                                    "Trillian" from the first server
    ///                                    found to match "*.edu".
    /// ```
    WHOWAS(Vec<String>, Option<(String, Option<String>)>),

    /// ```text
    /// 3.7.1 Kill message
    ///
    /// Command: KILL
    /// Parameters: <nickname> <comment>
    ///
    /// The KILL command is used to cause a client-server connection to be
    /// closed by the server which has the actual connection.  Servers
    /// generate KILL messages on nickname collisions.  It MAY also be
    /// available available to users who have the operator status.
    ///
    /// Clients which have automatic reconnect algorithms effectively make
    /// this command useless since the disconnection is only brief.  It does
    /// however break the flow of data and can be used to stop large amounts
    /// of 'flooding' from abusive users or accidents.  Abusive users usually
    /// don't care as they will reconnect promptly and resume their abusive
    /// behaviour.  To prevent this command from being abused, any user may
    /// elect to receive KILL messages generated for others to keep an 'eye'
    /// on would be trouble spots.
    ///
    /// In an arena where nicknames are REQUIRED to be globally unique at all
    /// times, KILL messages are sent whenever 'duplicates' are detected
    /// (that is an attempt to register two users with the same nickname) in
    /// the hope that both of them will disappear and only 1 reappear.
    ///
    /// When a client is removed as the result of a KILL message, the server
    /// SHOULD add the nickname to the list of unavailable nicknames in an
    /// attempt to avoid clients to reuse this name immediately which is
    /// usually the pattern of abusive behaviour often leading to useless
    /// "KILL loops".  See the "IRC Server Protocol" document [IRC-SERVER]
    /// for more information on this procedure.
    ///
    /// The comment given MUST reflect the actual reason for the KILL.  For
    /// server-generated KILLs it usually is made up of details concerning
    /// the origins of the two conflicting nicknames.  For users it is left
    /// up to them to provide an adequate reason to satisfy others who see
    /// it.  To prevent/discourage fake KILLs from being generated to hide
    /// the identify of the KILLer, the comment also shows a 'kill-path'
    /// which is updated by each server it passes through, each prepending
    /// its name to the path.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOPRIVILEGES              ERR_NEEDMOREPARAMS
    ///    ERR_NOSUCHNICK                ERR_CANTKILLSERVER
    ///
    /// NOTE:
    ///    It is RECOMMENDED that only Operators be allowed to kill other users
    ///    with KILL command.  This command has been the subject of many
    ///    controversies over the years, and along with the above
    ///    recommendation, it is also widely recognized that not even operators
    ///    should be allowed to kill users on remote servers.
    /// ```
    KILL(String, String),

    /// ```text
    /// 3.7.2 Ping message
    ///
    /// Command: PING
    /// Parameters: <server1> [ <server2> ]
    ///
    /// The PING command is used to test the presence of an active client or
    /// server at the other end of the connection.  Servers send a PING
    /// message at regular intervals if no other activity detected coming
    /// from a connection.  If a connection fails to respond to a PING
    /// message within a set amount of time, that connection is closed.  A
    /// PING message MAY be sent even if the connection is active.
    ///
    /// When a PING message is received, the appropriate PONG message MUST be
    /// sent as reply to <server1> (server which sent the PING message out)
    /// as soon as possible.  If the <server2> parameter is specified, it
    /// represents the target of the ping, and the message gets forwarded
    /// there.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOORIGIN                  ERR_NOSUCHSERVER
    ///
    /// Examples:
    ///
    ///    PING tolsun.oulu.fi             ; Command to send a PING message to
    ///                                    server
    ///
    ///    PING WiZ tolsun.oulu.fi         ; Command from WiZ to send a PING
    ///                                    message to server "tolsun.oulu.fi"
    ///
    ///    PING :irc.funet.fi              ; Ping message sent by server
    ///                                    "irc.funet.fi"
    /// ```
    PING(String, Option<String>),

    /// ```text
    /// 3.7.3 Pong message
    ///
    /// Command: PONG
    /// Parameters: <server> [ <server2> ]
    ///
    /// PONG message is a reply to ping message.  If parameter <server2> is
    /// given, this message MUST be forwarded to given target.  The <server>
    /// parameter is the name of the entity who has responded to PING message
    /// and generated this message.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOORIGIN                  ERR_NOSUCHSERVER
    ///
    /// Example:
    ///
    ///    PONG csd.bu.edu tolsun.oulu.fi  ; PONG message from csd.bu.edu to
    ///                                    tolsun.oulu.fi
    /// ```
    PONG(String, Option<String>),

    /// ```text
    /// 3.7.4 Error
    ///
    /// Command: ERROR
    /// Parameters: <error message>
    ///
    /// The ERROR command is for use by servers when reporting a serious or
    /// fatal error to its peers.  It may also be sent from one server to
    /// another but MUST NOT be accepted from any normal unknown clients.
    ///
    /// Only an ERROR message SHOULD be used for reporting errors which occur
    /// with a server-to-server link.  An ERROR message is sent to the server
    /// at the other end (which reports it to appropriate local users and
    /// logs) and to appropriate local users and logs.  It is not to be
    /// passed onto any other servers by a server if it is received from a
    /// server.
    ///
    /// The ERROR message is also used before terminating a client
    /// connection.
    ///
    /// When a server sends a received ERROR message to its operators, the
    /// message SHOULD be encapsulated inside a NOTICE message, indicating
    /// that the client was not responsible for the error.
    ///
    /// Numerics:
    ///
    ///    None.
    ///
    /// Examples:
    ///
    ///    ERROR :Server *.fi already exists ; ERROR message to the other server
    ///                                    which caused this error.
    ///
    ///    NOTICE WiZ :ERROR from csd.bu.edu -- Server *.fi already exists
    ///                                    ; Same ERROR message as above but
    ///                                    sent to user WiZ on the other server.
    /// ```
    ERROR(String),

    /// ```text
    /// 4.1 Away
    ///
    /// Command: AWAY
    /// Parameters: [ <text> ]
    ///
    /// With the AWAY command, clients can set an automatic reply string for
    /// any PRIVMSG commands directed at them (not to a channel they are on).
    /// The server sends an automatic reply to the client sending the PRIVMSG
    /// command.  The only replying server is the one to which the sending
    /// client is connected to.
    ///
    /// The AWAY command is used either with one parameter, to set an AWAY
    /// message, or with no parameters, to remove the AWAY message.
    ///
    /// Because of its high cost (memory and bandwidth wise), the AWAY
    /// message SHOULD only be used for client-server communication.  A
    /// server MAY choose to silently ignore AWAY messages received from
    /// other servers.  To update the away status of a client across servers,
    /// the user mode 'a' SHOULD be used instead.  (See Section 3.1.5)
    ///
    /// Numeric Replies:
    ///
    ///    RPL_UNAWAY                    RPL_NOWAWAY
    ///
    /// Example:
    ///
    ///    AWAY :Gone to lunch.  Back in 5 ; Command to set away message to
    ///                                    "Gone to lunch.  Back in 5".
    /// ```
    AWAY(Option<String>),

    /// ```text
    /// 4.2 Rehash message
    ///
    /// Command: REHASH
    /// Parameters: None
    ///
    /// The rehash command is an administrative command which can be used by
    /// an operator to force the server to re-read and process its
    /// configuration file.
    ///
    /// Numeric Replies:
    ///
    ///    RPL_REHASHING                 ERR_NOPRIVILEGES
    ///
    /// Example:
    ///
    ///    REHASH                          ; message from user with operator
    ///                                    status to server asking it to reread
    ///                                    its configuration file.
    /// ```
    REHASH,

    /// ```text
    /// 4.3 Die message
    ///
    /// Command: DIE
    /// Parameters: None
    ///
    /// An operator can use the DIE command to shutdown the server.  This
    /// message is optional since it may be viewed as a risk to allow
    /// arbitrary people to connect to a server as an operator and execute
    /// this command.
    ///
    /// The DIE command MUST always be fully processed by the server to which
    /// the sending client is connected and MUST NOT be passed onto other
    /// connected servers.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOPRIVILEGES
    ///
    /// Example:
    ///
    ///    DIE                             ; no parameters required.
    /// ```
    DIE,

    /// ```text
    /// 4.4 Restart message
    ///
    /// Command: RESTART
    /// Parameters: None
    ///
    /// An operator can use the restart command to force the server to
    /// restart itself.  This message is optional since it may be viewed as a
    /// risk to allow arbitrary people to connect to a server as an operator
    /// and execute this command, causing (at least) a disruption to service.
    ///
    /// The RESTART command MUST always be fully processed by the server to
    /// which the sending client is connected and MUST NOT be passed onto
    /// other connected servers.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOPRIVILEGES
    ///
    /// Example:
    ///
    ///    RESTART                         ; no parameters required.
    /// ```
    RESTART,

    /// ```text
    /// 4.5 Summon message
    ///
    /// Command: SUMMON
    /// Parameters: <user> [ <target> [ <channel> ] ]
    ///
    /// The SUMMON command can be used to give users who are on a host
    /// running an IRC server a message asking them to please join IRC.  This
    /// message is only sent if the target server (a) has SUMMON enabled, (b)
    /// the user is logged in and (c) the server process can write to the
    /// user's tty (or similar).
    ///
    /// If no <server> parameter is given it tries to summon <user> from the
    /// server the client is connected to is assumed as the target.
    ///
    /// If summon is not enabled in a server, it MUST return the
    /// ERR_SUMMONDISABLED numeric.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NORECIPIENT               ERR_FILEERROR
    ///    ERR_NOLOGIN                   ERR_NOSUCHSERVER
    ///    ERR_SUMMONDISABLED            RPL_SUMMONING
    ///
    /// Examples:
    ///
    ///    SUMMON jto                      ; summon user jto on the server's
    ///                                    host
    ///
    ///    SUMMON jto tolsun.oulu.fi       ; summon user jto on the host which a
    ///                                    server named "tolsun.oulu.fi" is
    ///                                    running.
    /// ```
    SUMMON(String, Option<(String, Option<String>)>),

    /// ```text
    /// 4.6 Users
    ///
    /// Command: USERS
    /// Parameters: [ <target> ]
    ///
    /// The USERS command returns a list of users logged into the server in a
    /// format similar to the UNIX commands who(1), rusers(1) and finger(1).
    /// If disabled, the correct numeric MUST be returned to indicate this.
    ///
    /// Because of the security implications of such a command, it SHOULD be
    /// disabled by default in server implementations.  Enabling it SHOULD
    /// require recompiling the server or some equivalent change rather than
    /// simply toggling an option and restarting the server.  The procedure
    /// to enable this command SHOULD also include suitable large comments.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NOSUCHSERVER              ERR_FILEERROR
    ///    RPL_USERSSTART                RPL_USERS
    ///    RPL_NOUSERS                   RPL_ENDOFUSERS
    ///    ERR_USERSDISABLED
    ///
    /// Disabled Reply:
    ///
    ///    ERR_USERSDISABLED
    ///
    /// Example:
    ///
    ///    USERS eff.org                   ; request a list of users logged in
    ///                                    on server eff.org
    /// ```
    USERS(Option<String>),

    /// ```text
    /// 4.7 Operwall message
    ///
    /// Command: WALLOPS
    /// Parameters: <Text to be sent>
    ///
    /// The WALLOPS command is used to send a message to all currently
    /// connected users who have set the 'w' user mode for themselves.  (See
    /// Section 3.1.5 "User modes").
    ///
    /// After implementing WALLOPS as a user command it was found that it was
    /// often and commonly abused as a means of sending a message to a lot of
    /// people.  Due to this, it is RECOMMENDED that the implementation of
    /// WALLOPS allows and recognizes only servers as the originators of
    /// WALLOPS.
    ///
    /// Numeric Replies:
    ///
    ///    ERR_NEEDMOREPARAMS
    ///
    /// Example:
    ///
    ///    :csd.bu.edu WALLOPS :Connect '*.uiuc.edu 6667' from Joshua ; WALLOPS
    ///                                    message from csd.bu.edu announcing a
    ///                                    CONNECT message it received from
    ///                                    Joshua and acted upon.
    /// ```
    WALLOPS(String),

    /// ```text
    /// 4.8 Userhost message
    ///
    /// Command: USERHOST
    /// Parameters: <nickname> *( SPACE <nickname> )
    ///
    /// The USERHOST command takes a list of up to 5 nicknames, each
    /// separated by a space character and returns a list of information
    /// about each nickname that it found.  The returned list has each reply
    /// separated by a space.
    ///
    /// Numeric Replies:
    ///
    ///    RPL_USERHOST                  ERR_NEEDMOREPARAMS
    ///
    /// Example:
    ///
    ///    USERHOST Wiz Michael syrk       ; USERHOST request for information on
    ///                                    nicks "Wiz", "Michael", and "syrk"
    ///
    ///    :ircd.stealth.net 302 yournick :syrk=+syrk@millennium.stealth.net
    ///                                    ; Reply for user syrk
    /// ```
    USERHOST(Vec<String>),
}

/*impl<'a> Clone for Command<'a> {
    fn clone(&self) -> Command<'a> {
        use self::Command::*;
        match self {
            &PASS(ref pw) => PASS(pw.to_owned().clone()),
            /*&NICK(ref nick) =>
                Message::format(None, Borrowed("NICK"), vec![], Some(nick.clone()), MsgType::Irc),
            &USER(ref user, ref mode, ref unused, ref realname) =>
                Message::format(None, Borrowed("USER"),
                    vec![user.clone(), mode.clone(), unused.clone()],
                    Some(realname.clone()), MsgType::Irc),
            &OPER(ref name, ref pw) =>
                Message::format(None, Borrowed("OPER"),
                    vec![name.clone(), pw.clone()], None, MsgType::Irc),
            &UMODE(ref mode) =>
                Message::format(None, Borrowed("MODE"), vec![], Some(mode.clone()), MsgType::Irc),
            &SERVICE(ref nick, ref reserved, ref distribution, ref type_, ref reserved2, ref info) =>
                Message::format(None, Borrowed("SERVICE"),
                    vec![nick.clone(), reserved.clone(), distribution.clone(),
                    type_.clone(), reserved2.clone()], Some(info.clone()), MsgType::Irc),
            &QUIT(ref msg) =>
                Message::format(None, Borrowed("QUIT"), vec![], msg.clone(), MsgType::Irc),
            &SQUIT(ref server, ref comment) =>
                Message::format(None, Borrowed("SQUIT"),
                    vec![server.clone()], Some(comment.clone()), MsgType::Irc),
            &JOIN(ref ch, ref pw) =>
                Message::format(None, Borrowed("JOIN"),
                    vec![Owned(ch.connect(",")), Owned(pw.connect(","))], None, MsgType::Irc),
            &PART(ref ch, ref reason) =>
                Message::format(None, Borrowed("PART"),
                    vec![Owned(ch.connect(","))], reason.clone(), MsgType::Irc),
            &MODE(ref channel, ref modes) =>
                // Screw this, folding will have to do.
                Message::format(None, Borrowed("MODE"),
                    modes.iter().fold(vec![channel.clone()], |mut v, &(ref a, ref b)| {
                        v.push(a.clone());
                        v.push(b.clone());
                        v
                    }), None, MsgType::Irc),
            &TOPIC(ref channel, ref topic) =>
                Message::format(None, Borrowed("TOPIC"),
                    vec![channel.clone()], topic.clone(), MsgType::Irc),
            &NAMES(ref ch, ref target) =>
                Message::format(None, Borrowed("NAMES"),
                    vec![Owned(ch.connect(","))], target.clone(), MsgType::Irc),
            &LIST(ref ch, ref target) =>
                Message::format(None, Borrowed("LIST"),
                    vec![Owned(ch.connect(","))], target.clone(), MsgType::Irc),
            &INVITE(ref nick, ref channel) =>
                Message::format(None, Borrowed("INVITE"),
                    vec![nick.clone()], Some(channel.clone()), MsgType::Irc),
            &KICK(ref ch, ref users, ref comment) =>
                Message::format(None, Borrowed("KICK"),
                    vec![Owned(ch.connect(",")), Owned(users.connect(","))],
                    comment.clone(), MsgType::Irc),
            &PRIVMSG(ref target, ref msg) =>
                Message::format(None, Borrowed("PRIVMSG"),
                    vec![target.clone()], Some(msg.clone()), MsgType::Irc),
            &NOTICE(ref target, ref text) =>
                Message::format(None, Borrowed("NOTICE"),
                    vec![target.clone()], Some(text.clone()), MsgType::Irc),
            &MOTD(ref target) =>
                Message::format(None, Borrowed("MOTD"), vec![], target.clone(), MsgType::Irc),
            &LUSERS(ref lu) =>
                Message::format(None, Borrowed("LUSERS"),
                    lu.as_ref().map(|&(ref mask, _)| vec![mask.clone()]).unwrap_or(vec![]),
                    lu.as_ref().and_then(|&(_, ref target)| target.clone()), MsgType::Irc),
            &VERSION(ref target) =>
                Message::format(None, Borrowed("VERSION"), vec![], target.clone(), MsgType::Irc),
            &STATS(ref st) =>
                Message::format(None, Borrowed("STATS"),
                    st.as_ref().map(|&(ref query, _)| vec![query.clone()]).unwrap_or(vec![]),
                    st.as_ref().and_then(|&(_, ref target)| target.clone()), MsgType::Irc),
            &LINKS(ref l) =>
                Message::format(None, Borrowed("LINKS"),
                    l.as_ref().map(|&(ref remote, ref mask)| if remote.is_some() {
                    vec![remote.clone().unwrap(), mask.clone()] } else { vec![mask.clone()] }).unwrap_or(vec![]),
                    None, MsgType::Irc),
            &TIME(ref target) =>
                Message::format(None, Borrowed("TIME"), vec![], target.clone(), MsgType::Irc),
            &CONNECT(ref server, ref port, ref remote) =>
                Message::format(None, Borrowed("CONNECT"),
                    vec![server.clone(), Owned(format!("{}", port))], remote.clone(), MsgType::Irc),
            &TRACE(ref target) =>
                Message::format(None, Borrowed("TRACE"), vec![], target.clone(), MsgType::Irc),
            &ADMIN(ref target) =>
                Message::format(None, Borrowed("ADMIN"), vec![], target.clone(), MsgType::Irc),
            &INFO(ref target) =>
                Message::format(None, Borrowed("INFO"), vec![], target.clone(), MsgType::Irc),
            &SERVLIST(ref sl) =>
                Message::format(None, Borrowed("SERVLIST"),
                    sl.as_ref().map(|&(ref mask, ref target)| target.as_ref()
                    .map(|t| vec![mask.clone(), t.clone()])
                    .unwrap_or_else(|| vec![mask.clone()]))
                    .unwrap_or(vec![]), None, MsgType::Irc),
            &SQUERY(ref name, ref text) =>
                Message::format(None, Borrowed("SQUERY"),
                    vec![name.clone()], Some(text.clone()), MsgType::Irc),
            &WHO(ref mask, o) =>
                Message::format(None, Borrowed("WHO"),
                    match (mask, o) {
                        (&Some(ref m), true) => vec![m.clone(), Borrowed("o")],
                        (&Some(ref m), false) => vec![m.clone()],
                        (&None, _) => vec![]
                    }, None, MsgType::Irc),
            &WHOIS(ref target,  ref masks) =>
                Message::format(None, Borrowed("WHOIS"),
                    target.as_ref().map(|t| vec![t.clone(), Owned(masks.connect(","))])
                    .unwrap_or_else(|| vec![Owned(masks.connect(","))]), None, MsgType::Irc),
            &WHOWAS(ref nick, ref count) =>
                Message::format(None, Borrowed("WHOWAS"), match count {
                        &Some((ref c, Some(ref t))) => vec![Owned(nick.connect(",")), c.clone(), t.clone()],
                        &Some((ref c, None)) => vec![Owned(nick.connect(",")), c.clone()],
                        &None => vec![Owned(nick.connect(","))]
                    }, None, MsgType::Irc),
            &PING(ref s1, ref s2) =>
                Message::format(None, Borrowed("PING"), vec![s1.clone()], s2.clone(), MsgType::Irc),
            &PONG(ref s1, ref s2) =>
                Message::format(None, Borrowed("PONG"), vec![s1.clone()], s2.clone(), MsgType::Irc),
             */           /*&Command::PING(ref server1, ref server2) => {
                let mut c = Vec::new();
                c.push(server1.clone());
                if let &Some(ref s) = server2 { c.push(s.clone()) }
                Message::format(None, "PING", c, None, MsgType::Irc)
            },
            &Command::PONG(ref server1, ref server2) => {
                let mut c = Vec::new();
                c.push(server1.clone());
                if let &Some(ref s) = server2 { c.push(s.clone()) }
                Message::format(None, "PONG", c, None, MsgType::Irc)
            },*/
            _ => unimplemented!()
        }

    }
}*/

impl<'a> Command<'a> {
    pub fn from_message(msg: &'a Message) -> Option<Command<'a>> {
        use self::Command::*;
        match msg.command() {
            "PASS" => msg.elements().last().map(|&m| m).map(Borrowed).map(PASS),
            "NICK" => msg.suffix().or_else(|| msg.content().last().map(|&m| m))
                .map(Borrowed).map(NICK),
            "USER" => if let [user, mode, unused, realname, ..] = msg.elements().as_ref() {
                    Some(USER(Borrowed(user), Borrowed(mode),
                              Borrowed(unused), Borrowed(realname)))
            } else { None },
            "OPER" => if let [name, pw, ..] = msg.elements().as_ref() {
                Some(OPER(Borrowed(name), Borrowed(pw)))
            } else { None },
            "PING" => {
                let e = msg.elements();
                e.first().map(|s1| PING(Borrowed(s1), e.get(1).map(|&m| m).map(Borrowed)))
            },
            "PONG" => {
                let e = msg.elements();
                e.first().map(|s1| PONG(Borrowed(s1), e.get(1).map(|&m| m).map(Borrowed)))
            },
            "JOIN" => if let [ch, pw, ..] = msg.elements().as_ref() {
                Some(JOIN(ch.split(",").map(Borrowed).collect(),
                          pw.split(",").map(Borrowed).collect()))
            } else { None },
            "PART" => if let [ch, reason..] = msg.elements().as_ref() {
                Some(PART(ch.split(",").map(Borrowed).collect(),
                          reason.first().map(|&m| m).map(Borrowed)))
            } else { None },
            "PRIVMSG" => if let [target, msg, ..] = msg.elements().as_ref() {
                Some(PRIVMSG(Borrowed(target), Borrowed(msg)))
            } else { None },
            "NOTICE" => if let [target, msg, ..] = msg.elements().as_ref() {
                Some(NOTICE(Borrowed(target), Borrowed(msg)))
            } else { None },
            _ => None
        }
    }

    /// It started out pretty, but was quickly infested with `ref` and cloning.
    /// I'm sorry, this one might not make it.
    pub fn to_message(&'a self) -> Message {
        use self::Command::*;
        match self {
            &PASS(ref pw) =>
                Message::format(None, Borrowed("PASS"), vec![], Some(pw.clone()), MsgType::Irc),
            &NICK(ref nick) =>
                Message::format(None, Borrowed("NICK"), vec![], Some(nick.clone()), MsgType::Irc),
            &USER(ref user, ref mode, ref unused, ref realname) =>
                Message::format(None, Borrowed("USER"),
                    vec![user.clone(), mode.clone(), unused.clone()],
                    Some(realname.clone()), MsgType::Irc),
            &OPER(ref name, ref pw) =>
                Message::format(None, Borrowed("OPER"),
                    vec![name.clone(), pw.clone()], None, MsgType::Irc),
            &UMODE(ref mode) =>
                Message::format(None, Borrowed("MODE"), vec![], Some(mode.clone()), MsgType::Irc),
            &SERVICE(ref nick, ref reserved, ref distribution, ref type_, ref reserved2, ref info) =>
                Message::format(None, Borrowed("SERVICE"),
                    vec![nick.clone(), reserved.clone(), distribution.clone(),
                    type_.clone(), reserved2.clone()], Some(info.clone()), MsgType::Irc),
            &QUIT(ref msg) =>
                Message::format(None, Borrowed("QUIT"), vec![], msg.clone(), MsgType::Irc),
            &SQUIT(ref server, ref comment) =>
                Message::format(None, Borrowed("SQUIT"),
                    vec![server.clone()], Some(comment.clone()), MsgType::Irc),
            &JOIN(ref ch, ref pw) =>
                Message::format(None, Borrowed("JOIN"),
                    vec![Owned(ch.connect(",")), Owned(pw.connect(","))], None, MsgType::Irc),
            &PART(ref ch, ref reason) =>
                Message::format(None, Borrowed("PART"),
                    vec![Owned(ch.connect(","))], reason.clone(), MsgType::Irc),
            &MODE(ref channel, ref modes) =>
                // Screw this, folding will have to do.
                Message::format(None, Borrowed("MODE"),
                    modes.iter().fold(vec![channel.clone()], |mut v, &(ref a, ref b)| {
                        v.push(a.clone());
                        v.push(b.clone());
                        v
                    }), None, MsgType::Irc),
            &TOPIC(ref channel, ref topic) =>
                Message::format(None, Borrowed("TOPIC"),
                    vec![channel.clone()], topic.clone(), MsgType::Irc),
            &NAMES(ref ch, ref target) =>
                Message::format(None, Borrowed("NAMES"),
                    vec![Owned(ch.connect(","))], target.clone(), MsgType::Irc),
            &LIST(ref ch, ref target) =>
                Message::format(None, Borrowed("LIST"),
                    vec![Owned(ch.connect(","))], target.clone(), MsgType::Irc),
            &INVITE(ref nick, ref channel) =>
                Message::format(None, Borrowed("INVITE"),
                    vec![nick.clone()], Some(channel.clone()), MsgType::Irc),
            &KICK(ref ch, ref users, ref comment) =>
                Message::format(None, Borrowed("KICK"),
                    vec![Owned(ch.connect(",")), Owned(users.connect(","))],
                    comment.clone(), MsgType::Irc),
            &PRIVMSG(ref target, ref msg) =>
                Message::format(None, Borrowed("PRIVMSG"),
                    vec![target.clone()], Some(msg.clone()), MsgType::Irc),
            &NOTICE(ref target, ref text) =>
                Message::format(None, Borrowed("NOTICE"),
                    vec![target.clone()], Some(text.clone()), MsgType::Irc),
            &MOTD(ref target) =>
                Message::format(None, Borrowed("MOTD"), vec![], target.clone(), MsgType::Irc),
            &LUSERS(ref lu) =>
                Message::format(None, Borrowed("LUSERS"),
                    lu.as_ref().map(|&(ref mask, _)| vec![mask.clone()]).unwrap_or(vec![]),
                    lu.as_ref().and_then(|&(_, ref target)| target.clone()), MsgType::Irc),
            &VERSION(ref target) =>
                Message::format(None, Borrowed("VERSION"), vec![], target.clone(), MsgType::Irc),
            &STATS(ref st) =>
                Message::format(None, Borrowed("STATS"),
                    st.as_ref().map(|&(ref query, _)| vec![query.clone()]).unwrap_or(vec![]),
                    st.as_ref().and_then(|&(_, ref target)| target.clone()), MsgType::Irc),
            &LINKS(ref l) =>
                Message::format(None, Borrowed("LINKS"),
                    l.as_ref().map(|&(ref remote, ref mask)| if remote.is_some() {
                    vec![remote.clone().unwrap(), mask.clone()] } else { vec![mask.clone()] }).unwrap_or(vec![]),
                    None, MsgType::Irc),
            &TIME(ref target) =>
                Message::format(None, Borrowed("TIME"), vec![], target.clone(), MsgType::Irc),
            &CONNECT(ref server, ref port, ref remote) =>
                Message::format(None, Borrowed("CONNECT"),
                    vec![server.clone(), Owned(format!("{}", port))], remote.clone(), MsgType::Irc),
            &TRACE(ref target) =>
                Message::format(None, Borrowed("TRACE"), vec![], target.clone(), MsgType::Irc),
            &ADMIN(ref target) =>
                Message::format(None, Borrowed("ADMIN"), vec![], target.clone(), MsgType::Irc),
            &INFO(ref target) =>
                Message::format(None, Borrowed("INFO"), vec![], target.clone(), MsgType::Irc),
            &SERVLIST(ref sl) =>
                Message::format(None, Borrowed("SERVLIST"),
                    sl.as_ref().map(|&(ref mask, ref target)| target.as_ref()
                    .map(|t| vec![mask.clone(), t.clone()])
                    .unwrap_or_else(|| vec![mask.clone()]))
                    .unwrap_or(vec![]), None, MsgType::Irc),
            &SQUERY(ref name, ref text) =>
                Message::format(None, Borrowed("SQUERY"),
                    vec![name.clone()], Some(text.clone()), MsgType::Irc),
            &WHO(ref mask, o) =>
                Message::format(None, Borrowed("WHO"),
                    match (mask, o) {
                        (&Some(ref m), true) => vec![m.clone(), Borrowed("o")],
                        (&Some(ref m), false) => vec![m.clone()],
                        (&None, _) => vec![]
                    }, None, MsgType::Irc),
            &WHOIS(ref target,  ref masks) =>
                Message::format(None, Borrowed("WHOIS"),
                    target.as_ref().map(|t| vec![t.clone(), Owned(masks.connect(","))])
                    .unwrap_or_else(|| vec![Owned(masks.connect(","))]), None, MsgType::Irc),
            &WHOWAS(ref nick, ref count) =>
                Message::format(None, Borrowed("WHOWAS"), match count {
                        &Some((ref c, Some(ref t))) => vec![Owned(nick.connect(",")), c.clone(), t.clone()],
                        &Some((ref c, None)) => vec![Owned(nick.connect(",")), c.clone()],
                        &None => vec![Owned(nick.connect(","))]
                    }, None, MsgType::Irc),
            &PING(ref s1, ref s2) =>
                Message::format(None, Borrowed("PING"), vec![s1.clone()], s2.clone(), MsgType::Irc),
            &PONG(ref s1, ref s2) =>
                Message::format(None, Borrowed("PONG"), vec![s1.clone()], s2.clone(), MsgType::Irc),
                        /*&Command::PING(ref server1, ref server2) => {
                let mut c = Vec::new();
                c.push(server1.clone());
                if let &Some(ref s) = server2 { c.push(s.clone()) }
                Message::format(None, "PING", c, None, MsgType::Irc)
            },
            &Command::PONG(ref server1, ref server2) => {
                let mut c = Vec::new();
                c.push(server1.clone());
                if let &Some(ref s) = server2 { c.push(s.clone()) }
                Message::format(None, "PONG", c, None, MsgType::Irc)
            },*/
            _ => unimplemented!()
        }
    }

/*    pub fn to_static(&self) -> Command<'static> {
        use self::Command::*;
        match self {
            &PASS(ref pw) => PASS(pw.to_owned().clone()),
            /*&NICK(ref nick) =>
                Message::format(None, Borrowed("NICK"), vec![], Some(nick.clone()), MsgType::Irc),
            &USER(ref user, ref mode, ref unused, ref realname) =>
                Message::format(None, Borrowed("USER"),
                    vec![user.clone(), mode.clone(), unused.clone()],
                    Some(realname.clone()), MsgType::Irc),
            &OPER(ref name, ref pw) =>
                Message::format(None, Borrowed("OPER"),
                    vec![name.clone(), pw.clone()], None, MsgType::Irc),
            &UMODE(ref mode) =>
                Message::format(None, Borrowed("MODE"), vec![], Some(mode.clone()), MsgType::Irc),
            &SERVICE(ref nick, ref reserved, ref distribution, ref type_, ref reserved2, ref info) =>
                Message::format(None, Borrowed("SERVICE"),
                    vec![nick.clone(), reserved.clone(), distribution.clone(),
                    type_.clone(), reserved2.clone()], Some(info.clone()), MsgType::Irc),
            &QUIT(ref msg) =>
                Message::format(None, Borrowed("QUIT"), vec![], msg.clone(), MsgType::Irc),
            &SQUIT(ref server, ref comment) =>
                Message::format(None, Borrowed("SQUIT"),
                    vec![server.clone()], Some(comment.clone()), MsgType::Irc),
            &JOIN(ref ch, ref pw) =>
                Message::format(None, Borrowed("JOIN"),
                    vec![Owned(ch.connect(",")), Owned(pw.connect(","))], None, MsgType::Irc),
            &PART(ref ch, ref reason) =>
                Message::format(None, Borrowed("PART"),
                    vec![Owned(ch.connect(","))], reason.clone(), MsgType::Irc),
            &MODE(ref channel, ref modes) =>
                // Screw this, folding will have to do.
                Message::format(None, Borrowed("MODE"),
                    modes.iter().fold(vec![channel.clone()], |mut v, &(ref a, ref b)| {
                        v.push(a.clone());
                        v.push(b.clone());
                        v
                    }), None, MsgType::Irc),
            &TOPIC(ref channel, ref topic) =>
                Message::format(None, Borrowed("TOPIC"),
                    vec![channel.clone()], topic.clone(), MsgType::Irc),
            &NAMES(ref ch, ref target) =>
                Message::format(None, Borrowed("NAMES"),
                    vec![Owned(ch.connect(","))], target.clone(), MsgType::Irc),
            &LIST(ref ch, ref target) =>
                Message::format(None, Borrowed("LIST"),
                    vec![Owned(ch.connect(","))], target.clone(), MsgType::Irc),
            &INVITE(ref nick, ref channel) =>
                Message::format(None, Borrowed("INVITE"),
                    vec![nick.clone()], Some(channel.clone()), MsgType::Irc),
            &KICK(ref ch, ref users, ref comment) =>
                Message::format(None, Borrowed("KICK"),
                    vec![Owned(ch.connect(",")), Owned(users.connect(","))],
                    comment.clone(), MsgType::Irc),
            &PRIVMSG(ref target, ref msg) =>
                Message::format(None, Borrowed("PRIVMSG"),
                    vec![target.clone()], Some(msg.clone()), MsgType::Irc),
            &NOTICE(ref target, ref text) =>
                Message::format(None, Borrowed("NOTICE"),
                    vec![target.clone()], Some(text.clone()), MsgType::Irc),
            &MOTD(ref target) =>
                Message::format(None, Borrowed("MOTD"), vec![], target.clone(), MsgType::Irc),
            &LUSERS(ref lu) =>
                Message::format(None, Borrowed("LUSERS"),
                    lu.as_ref().map(|&(ref mask, _)| vec![mask.clone()]).unwrap_or(vec![]),
                    lu.as_ref().and_then(|&(_, ref target)| target.clone()), MsgType::Irc),
            &VERSION(ref target) =>
                Message::format(None, Borrowed("VERSION"), vec![], target.clone(), MsgType::Irc),
            &STATS(ref st) =>
                Message::format(None, Borrowed("STATS"),
                    st.as_ref().map(|&(ref query, _)| vec![query.clone()]).unwrap_or(vec![]),
                    st.as_ref().and_then(|&(_, ref target)| target.clone()), MsgType::Irc),
            &LINKS(ref l) =>
                Message::format(None, Borrowed("LINKS"),
                    l.as_ref().map(|&(ref remote, ref mask)| if remote.is_some() {
                    vec![remote.clone().unwrap(), mask.clone()] } else { vec![mask.clone()] }).unwrap_or(vec![]),
                    None, MsgType::Irc),
            &TIME(ref target) =>
                Message::format(None, Borrowed("TIME"), vec![], target.clone(), MsgType::Irc),
            &CONNECT(ref server, ref port, ref remote) =>
                Message::format(None, Borrowed("CONNECT"),
                    vec![server.clone(), Owned(format!("{}", port))], remote.clone(), MsgType::Irc),
            &TRACE(ref target) =>
                Message::format(None, Borrowed("TRACE"), vec![], target.clone(), MsgType::Irc),
            &ADMIN(ref target) =>
                Message::format(None, Borrowed("ADMIN"), vec![], target.clone(), MsgType::Irc),
            &INFO(ref target) =>
                Message::format(None, Borrowed("INFO"), vec![], target.clone(), MsgType::Irc),
            &SERVLIST(ref sl) =>
                Message::format(None, Borrowed("SERVLIST"),
                    sl.as_ref().map(|&(ref mask, ref target)| target.as_ref()
                    .map(|t| vec![mask.clone(), t.clone()])
                    .unwrap_or_else(|| vec![mask.clone()]))
                    .unwrap_or(vec![]), None, MsgType::Irc),
            &SQUERY(ref name, ref text) =>
                Message::format(None, Borrowed("SQUERY"),
                    vec![name.clone()], Some(text.clone()), MsgType::Irc),
            &WHO(ref mask, o) =>
                Message::format(None, Borrowed("WHO"),
                    match (mask, o) {
                        (&Some(ref m), true) => vec![m.clone(), Borrowed("o")],
                        (&Some(ref m), false) => vec![m.clone()],
                        (&None, _) => vec![]
                    }, None, MsgType::Irc),
            &WHOIS(ref target,  ref masks) =>
                Message::format(None, Borrowed("WHOIS"),
                    target.as_ref().map(|t| vec![t.clone(), Owned(masks.connect(","))])
                    .unwrap_or_else(|| vec![Owned(masks.connect(","))]), None, MsgType::Irc),
            &WHOWAS(ref nick, ref count) =>
                Message::format(None, Borrowed("WHOWAS"), match count {
                        &Some((ref c, Some(ref t))) => vec![Owned(nick.connect(",")), c.clone(), t.clone()],
                        &Some((ref c, None)) => vec![Owned(nick.connect(",")), c.clone()],
                        &None => vec![Owned(nick.connect(","))]
                    }, None, MsgType::Irc),
            &PING(ref s1, ref s2) =>
                Message::format(None, Borrowed("PING"), vec![s1.clone()], s2.clone(), MsgType::Irc),
            &PONG(ref s1, ref s2) =>
                Message::format(None, Borrowed("PONG"), vec![s1.clone()], s2.clone(), MsgType::Irc),
             */           /*&Command::PING(ref server1, ref server2) => {
                let mut c = Vec::new();
                c.push(server1.clone());
                if let &Some(ref s) = server2 { c.push(s.clone()) }
                Message::format(None, "PING", c, None, MsgType::Irc)
            },
            &Command::PONG(ref server1, ref server2) => {
                let mut c = Vec::new();
                c.push(server1.clone());
                if let &Some(ref s) = server2 { c.push(s.clone()) }
                Message::format(None, "PONG", c, None, MsgType::Irc)
            },*/
            _ => unimplemented!()
        }

    }*/

    //pub fn is_reply(&self) -> bool { let i = *self as uint; i >= 200 && i <= 399 }
    //pub fn is_error(&self) -> bool { let i = *self as uint; i >= 400 && i <= 599 }
}