source: code/branches/tutorial/data/tcl/irk/lib/irkconnect.tcl @ 10973

# irkconnect.tcl:
#
# This file provides the IRK commands to connect to remote servers
# as well as some attendant utility procedures:

namespace eval ::irk {

    # The "connect" procedure returns a token
    # for the connection to this server.
    #
    # symsrv            The symbolic name of the server to connect to.
    # nick              The nick name to use.
    # user              The user name to use.
    # pass              The password to use. 
    # disp              The command dispatcher expression to use.

    proc connect {{symsrv ""} {nick ""} {user ""} {pass ""} {disp ""}} {
        variable state

        # Auto initialize the list of connections. We do this so that
        # the list is not reset each time the irk.tcl file is sourced.

        if {![info exists state(connections)]} {
            set state(connections) {}
        }

        # Try to convert the symbolic server name to a
        # server description. This may throw an error,
        # we propagate it.

        set servdesc [locate $symsrv]

        # If the nickname is not specified, there must be
        # a nick setting in the state array; use that

        if {![string compare $nick ""]} {
            if {![info exists state(-$symsrv,nick)]} {
                error "No nick given or set in global state"
            }
            set nick $state(-$symsrv,nick)
        }

        # If a global nick is not set, save this nick for use
        # as a global nick.

        if {![info exists state(-$symsrv,nick)]} {
            set state(-$symsrv,nick) $nick
        }

        # If user is not supplied, see if there is a global
        # user registered in the IRK package state. If not,
        # invent a user.

        if {![string compare $user ""]} {
            if {[info exists state(-$symsrv,user)]} {
                set user $state(-$symsrv,user)
            } else {
                set user $nick
                set state(-$symsrv,user) $user
            }
        }

        # If a password is not supplied, see if there is a global
        # one registered. If so, use that. Otherwise, do not
        # use a password.

        if {![string compare $pass ""]} {
            if {[info exists state(-$symsrv,pass)]} {
                set pass $state(-$symsrv,pass)
            }
        }

        # If a dispatcher expression is not supplied, there must be a
        # global dispatcher expression in the state array, and use that.

        if {![string compare $disp ""]} {
            if {![info exists state(dispatcher)]} {
                error "ERROR: o dispatch given or found in global state"
            }
            set disp $state(dispatcher)
        }

        # Try to connect to the given server.

        set h [lindex $servdesc 0]
        set p [randselect [lindex $servdesc 1]]

        set s [opensocket $h $p]

        # The socket is line buffered and consumed by the
        # supplied consumer

        fconfigure $s -translation auto -buffering line
        fileevent $s readable [list ::irk::consumer $s]


        # Identify ourselves to the IRK server: If a password is given
        # send that first. Then send the nick name and user name.

        if {[string compare $pass ""]} {
            puts $s "PASS $pass"
        }

        puts $s "NICK $nick"
        puts $s "USER $user $h $h :$user"

        # Make a connection token:

        set contok [contok $s $symsrv]

        # Save the state for this new connection

        lappend state(connections) $contok

        set state($contok,port) $p
        set state($contok,host) $h
        set state($contok,symsrv) $symsrv
        set state($contok,nick) $nick
        set state($contok,user) $user
        set state($contok,pass) $pass
        set state($contok,disp) $disp

        # Set up some default behavior for the connection:

        setupDefaultActions $contok $nick

        # Collect information about who the server thinks we are

        puts $s "WHOIS $nick"

        # Finally return the token for this connection:

        return $contok
    }

    # This procedure makes an easy to remember connection token. It takes
    # the symbolic server's name and appends _<n> to it, where n is an
    # integer starting at 0 and monotonically increasing for every new
    # connection to that server.
    #
    # Once it figures out what the connection token is going to be,
    # it associates it with the given socket so it can be used.

    proc contok {sock symsrv} {
        variable state

        # Compute the symbolic name for this connection:

        if {![info exists state($symsrv,counter)]} {
            set state($symsrv,counter) 0
        }
        set contok ${symsrv}_$state($symsrv,counter)
        incr state($symsrv,counter)

        # Associate the symbolic name with the socket:

        set state($contok,socket) $sock
        set state($sock,contok) $contok

        return $contok
    }

    # The locate procedure tries to convert the symbolic name for
    # a connection to a server/port specification.

    proc locate {s} {
        variable symsrv
        variable state

        # If the caller specified "" as the name of the server, select
        # a random one from the list of known servers.

        if {![string compare $s ""]} {
            set s [randselect $state(servers)]
        }

        # Now see if the requested server exists:

        if {![info exists symsrv($s)]} {
            error \
                "Could not find a match for symbolic IRK server name \"$s\""
        }

        # It does, return the server specification:

        return $symsrv($s)
    }

    # opensocket connects to the requested server and port, either
    # directly or through a SOCKS5 proxy.

    proc opensocket {server port} {
        variable state

        if {[info exists state(-socksproxy)] \
                && [info exists state(-socksport)]} {
            set sock [socket $state(-socksproxy) $state(-socksport)]
            return [::socks::init $sock $server $port]
        }

        return [socket $server $port]
    }

    # The disconnect procedure disconnects from a given connection
    # identified by its symbolic name, and cleans up state associated
    # with the connection.

    proc disconnect {contok} {
        variable state

        if {[catch {set s $state($contok,socket)} err]} {
            error "ERROR: $contok: No such IRC connection"
        }

        # Send a QUIT message.

        if {[info exists state(quitmsg)]} {
            set q ":$state($contok,nick) $state(quitmsg)"
        } else {
            set q ":$state($contok,nick) quit"
        }
        puts $s "QUIT $q"

        # Try to close the connection with the server.

        catch {close $s}

        # And clean up all state associated with this connection:

        array unset state $contok,*
        
        # Remove this connection from the list of active connections:

        set i [lsearch $state(connections) $s]
        set state(connections) [lreplace $state(connections) $i $i]

        return ""
    }
}