#! /usr/bin/tclsh
#
#    send stdin to an XOS server,
#    echo the XOS reply from that socket to stdout
#    then exit.
#
#    usage:
#	echo "gtos_start_move detector_z 100" | xos_exchange.tcl host count keytext timeout
#
#

# read command line
set host [lindex $argv 0]
set lines [lindex $argv 1]
set keytext [subst -nocommands -novariables [lindex $argv 2]]
set timeout [lindex $argv 3]

# impose defaults
set port 14242
if { "$timeout" == ""} { set timeout 30 }
if { "$keytext" == ""} { set keytext "\n" }
if { "$lines" == ""} { set lines -1}
if { "$port" == ""}  { set port 14242 }
if { "$host" == ""}  { set host localhost }


# alternate interpretations of the command line
if { ! [string is digit $lines] } {
    set lines -1
}

# initialize common variables
set status "normal"
set cmplen [string length $keytext]
set window [expr $cmplen - 1]


# open the first socket connection (usually to get the new port)
set sock [socket $host $port]
fconfigure $sock -buffering none -translation binary -blocking 1
set message [read $sock 200]
set message [string range $message 0 [string first "\0" $message]]
close $sock
scan [string range $message [expr [string wordend $message 0]+1] end] "%d" port

# open the second socket connection (on the listening port we were given by the first)
#puts "listening $host server is on $port"
set sock [socket $host $port]
fconfigure $sock -buffering none -translation binary -blocking 1

# claim to be a gui (what else are we going to be?)
set tosend "gtos_client_is_gui"
#append tosend "\0"
while {[string length $tosend] < 200} {append tosend " "}
puts -nonewline $sock $tosend
#puts "connected"

fconfigure stdin -buffering line -translation lf
#fconfigure stdout -translation binary -blocking 0
#-translation {auto auto}

# check for failed connection


# now define procedures for handling this

proc bgerror { code } {
    global sock
    puts stderr "bgerror: $code"
    set status "bgerror"
    flush $sock
    close $sock
    exit 2
}

proc timeout {} {
    global timeout
#    puts stderr "idle"
    after [expr int( $timeout * 1000 ) ] {
#	puts stderr "timeout"
	set status "timeout"
    }
}

# send everything from stdin to the remote socket as an XOS message
proc send_request {sock} {
    global status

    # cancel this procedure when there is no more input
    if { [eof stdin] } {
	fileevent $sock writable ""
	rename send_request ""
	return
    }

    # postpone timeout if there is input to process
    after cancel [after info]
    after idle timeout

    # read data from std input and send it to the remote computer as a 200-byte asciiz string
    set tosend [gets stdin]
#    append tosend "\0"
    if {! [string length $tosend]} return
    while {[string length $tosend] < 200} {append tosend " "}
    puts -nonewline $sock $tosend
#    puts stderr "sending: |$tosend|"
}

proc read_reply {sock} {
    # almost everything is global (xos_exchange will only use one socket)
    global lines reply cmplen window keytext status
    
    # postpone timeout if there is input to process
    after cancel [after info]
    after idle timeout
    
    # echo "real" text of reply to std output
    set message [read $sock 200]
#    append reply "$string"
#    if{ [string length $reply] < 200 } return

    set message [string range $message 0 [expr [string first "\0" $message]-1]]

    # print out the character
    if { [catch {puts "$message"} foo] } {
	# must be a broken pipe
	#puts stderr "broken pipe "
	set status "broken pipe"
	return
    }

    # count down the number of "lines" read (keytexts "seen")
    if { [string match "*$keytext*" "$message"] } {
	incr lines -1
    }

    # check for completed read
    if { $lines == 0} {
	set status "normal"
	return
    }

    # check for broken socket
    if { [eof $sock] } {
	#puts stderr "socket broken by remote host "
	set status "closed"
	return
    }
}

fileevent $sock readable [list read_reply $sock]
fileevent $sock writable [list send_request $sock]
after idle timeout
vwait status

# close up
flush $sock
close $sock
if {$status != "normal"} {
#    puts stderr "$status"
    exit 9
}
exit