#!/bin/sh
# \
exec expect "$0" ${1+"$@"}

# Name: tknewsbiff
# Author: Don Libes
# Version: 1.2b
# Written: January 1, 1994

# Description: When unread news appears in your favorite groups, pop up
# a little window describing which newsgroups and how many articles.
# Go away when articles are no longer unread.
# Optionally, run a UNIX program (to play a sound, read news, etc.)

# Default config file in ~/.tknewsbiff[-host]

# These two procedures are needed because Tk provides no command to undo
# the "wm unmap" command.  You must remember whether it was iconic or not.
# PUBLIC
proc unmapwindow {} {
	global _window_open

	switch [wm state .] \
	iconic {
		set _window_open 0
	} normal {
		set _window_open 1
	}
	wm withdraw .
}
unmapwindow
# window state starts out as "iconic" before it is mapped, Tk bug?
# make sure that when we map it, it will be open (i.e., "normal")
set _window_open 1

# PUBLIC
proc mapwindow {} {
	global _window_open

	if {$_window_open} {
		wm deiconify .
	} else {
		wm iconify .
	}
}

proc _abort {msg} {
	global argv0

	puts "$argv0: $msg"
	exit 1
}

if {[info exists env(DOTDIR)]} {
	set home $env(DOTDIR)
} else {
	set home [glob ~]
}

set delay		  60
set width		  27
set height		  10
set _default_config_file  $home/.tknewsbiff
set _config_file	  $_default_config_file
set _default_server	  news
set server		  $_default_server
set server_timeout	  60

log_user 0

listbox .list -yscroll ".scrollbar set" -font "*-m-*" -setgrid 1
scrollbar .scrollbar -command ".list yview" -relief raised
.list config -highlightthickness 0 -border 0
.scrollbar config -highlightthickness 0
pack .scrollbar -side left -fill y
pack .list -side left -fill both -expand 1

while {[llength $argv]>0} {
	set arg [lindex $argv 0]

	if {[file readable $arg]} {
		if {0==[string compare active [file tail $arg]]} {
			set active_file $arg
			set argv [lrange $argv 1 end]
		} else {
			# must be a config file
			set _config_file $arg
			set argv [lrange $argv 1 end]
		}
	} elseif {[file readable $_config_file-$arg]} {
		# maybe it's a hostname suffix for a newsrc file?
		set _config_file $_default_config_file-$arg
		set argv [lrange $argv 1 end]
	} else {
		# maybe it's just a hostname for regular newsrc file?
		set server $arg
		set argv [lrange $argv 1 end]
	}
}

proc _read_config_file {} {
	global _config_file argv0 watch_list ignore_list

	# remove previous user-provided proc in case user simply
	# deleted it from config file
	proc user {} {}

	set watch_list {}
	set ignore_list {}

	if {[file exists $_config_file]} {
		# uplevel allows user to set global variables
		if {[catch {uplevel source $_config_file} msg]} {
			_abort "error reading $_config_file\n$msg"
		}
	}

	if {[llength $watch_list]==0} {
		watch *
	}
}

# PUBLIC
proc watch {args} {
	global watch_list

	lappend watch_list $args
}

# PUBLIC
proc ignore {ng} {
	global ignore_list

	lappend ignore_list $ng
}

# get time and server
_read_config_file

# if user didn't set newsrc, try ~/.newsrc-server convention.
# if that fails, fall back to just plain ~/.newsrc
if {![info exists newsrc]} {
	set newsrc $home/.newsrc-$server
	if {![file readable $newsrc]} {
		set newsrc $home/.newsrc
		if {![file readable $newsrc]} {
			_abort "cannot tell what newgroups you read
found neither $home/.newsrc-$server nor $home/.newsrc"
		}
	}
}

# PRIVATE
proc _read_newsrc {} {
	global db newsrc

	if {[catch {set file [open $newsrc]} msg]} {
		_abort $msg
	}
	while {-1 != [gets $file buf]} {
		if {[regexp "!" $buf]} continue
		if {[regexp "(\[^:]*):.*\[-, ](\[0-9]+)" $buf dummy ng seen]} {
			set db($ng,seen) $seen
		}
		# only way 2nd regexp can fail is on lines
		# that have a : but no number
	}
	close $file
}

proc _unknown_host {} {
	global server _default_server

	if {0==[string compare $_default_server $server]} {
		puts "tknewsbiff: default server <$server> is not known"
	} else {
		puts "tknewsbiff: server <$server> is not known"
	}

	puts "Give tknewsbiff an argument - either the name of your news server
or active file.  I.e.,

	tknewsbiff news.nist.gov
	tknewsbiff /usr/news/lib/active

If you have a correctly defined configuration file (.tknewsbiff),
an argument is not required.  See the man page for more info."
	exit 1
}

# read active file
# PRIVATE
proc _read_active {} {
	global db server active_list active_file
	upvar #0 server_timeout timeout

	set active_list {}

	if {[info exists active_file]} {
		spawn -open [open $active_file]
	} else {
		spawn telnet $server nntp
		expect {
			"20*\n" {
				# should get 200 or 201
			} "NNTP server*\n" {
				puts "tknewsbiff: unexpected response from server:"
				puts "$expect_out(buffer)"
				return 1
			} "unknown host" {
				_unknown_host
			} timeout {
				close
				wait
				return 1
			} eof {
				# loadav too high probably
				wait
				return 1
			}
		}
		exp_send "list\r"
		expect "list\r\n"	;# ignore echo of "list" command
		expect -re "215\[^\n]*\n" ;# skip "Newsgroups in form" line
	}
	
	expect {
		-re "(\[^ ]*) 0*(\[^ ]+) \[^\n]*\n" {
			set ng $expect_out(1,string)
			set hi $expect_out(2,string)
			lappend active_list $ng
			set db($ng,hi) $hi
			exp_continue
		}
		".\r\n" close
		".\r\r\n" close
		timeout close
		eof
	}

	wait
	return 0
}

# test in various ways for good newsgroups
# return 1 if good, 0 if not good
# PRIVATE
proc _isgood {ng threshold} {
	global db seen_list ignore_list

	# skip if we don't subscribe to it
	if {![info exists db($ng,seen)]} {return 0}

	# skip if the threshold isn't exceeded
	if {$db($ng,hi) - $db($ng,seen) < $threshold} {return 0}

	# skip if it matches an ignore command
	foreach igpat $ignore_list {
		if {[string match $igpat $ng]} {return 0}
	}

	# skip if we've seen it before
	if {[lsearch -exact $seen_list $ng]!=-1} {return 0}

	# passed all tests, so remember that we've seen it
	lappend seen_list $ng
	return 1
}

# return 1 if not seen on previous turn
# PRIVATE
proc _isnew {ng} {
	global previous_seen_list

	if {[lsearch -exact $previous_seen_list $ng]==-1} {
		return 1
	} else {
		return 0
	}
}

# schedule display of newsgroup in global variable "newsgroup"
# PUBLIC
proc display {} {
	global display_list newsgroup

	lappend display_list $newsgroup
}

# PRIVATE
proc _update_ngs {} {
	global watch_list active_list newsgroup

	foreach watch $watch_list {
		set threshold 1
		set display display
		set new {}

		set ngpat [lindex $watch 0]
		set watch [lrange $watch 1 end]

		while {[llength $watch] > 0} {
			switch -- [lindex $watch 0] \
			-threshold {
				set threshold [lindex $watch 1]
				set watch [lrange $watch 2 end]
			} -display {
				set display [lindex $watch 1]
				set watch [lrange $watch 2 end]
			} -new {
				set new [lindex $watch 1]
				set watch [lrange $watch 2 end]
			} default {
				_abort "watch: expecting -threshold -display or -new but found: [lindex $watch 0]"
			}
		}

		foreach ng $active_list {
			if {[string match $ngpat $ng]} {
				if {[_isgood $ng $threshold]} {
					if {[llength $display]} {
						set newsgroup $ng
						uplevel $display
					}
					if {[_isnew $ng]} {
						if {[llength $new]} {
							set newsgroup $ng
							uplevel $new
						}
					}
				}
			}
		}
	}
}

# initialize display

set min_reasonable_width 8

wm minsize . $min_reasonable_width 1
wm maxsize . 999 999
if {0 == [info exists active_file] && 
    0 != [string compare $server $_default_server]} {
	wm title . "news@$server"
	wm iconname . "news@$server"
}

# PRIVATE
proc _update_window {} {
	global server display_list height width min_reasonable_width

	if {0 == [llength $display_list]} {
		unmapwindow
		return
	}

	# make height correspond to length of display_list or
	# user's requested max height, whichever is smaller
	
	if {[llength $display_list] < $height} {
		set current_height [llength $display_list]
	} else {
		set current_height $height
	}

	# force reasonable min width
	if {$width < $min_reasonable_width} {
		set width $min_reasonable_width
	}

	wm geometry . ${width}x$current_height
	wm maxsize . 999 [llength $display_list]

	_display_ngs $width

	if {[string compare [wm state .] withdrawn]==0} {
		mapwindow
	}
}

# actually write all newsgroups to the window
# PRIVATE
proc _display_ngs {width} {
	global db display_list

	set str_width [expr $width-7]

	.list delete 0 end
	foreach ng $display_list {
		.list insert end [format \
			"%-$str_width.${str_width}s %5d" $ng \
			[expr $db($ng,hi) - $db($ng,seen)]]
	}
}

# PUBLIC
proc help {} {
	catch {destroy .help}
	toplevel .help
	message .help.text -aspect 400 -text \
{tknewsbiff - written by Don Libes, NIST, 1/1/94

tknewsbiff displays newsgroups with unread articles based on your .newsrc\
and your .tknewsbiff files.\
If no articles are unread, no window is displayed.

Click mouse button 1 for this help,\
button 2 to force display to query news server immediately,\
and button 3 to remove window from screen until the next update.

Example .tknewsbiff file:}
	message .help.sample -font "*-r-normal-*-m-*" \
	-relief raised -aspect 10000 -text \
{set width	30		;# max width, defaults to 27
set height	17		;# max height, defaults to 10
set delay	120		;# in seconds, defaults to 60
set server	news.nist.gov	;# defaults to "news"
set server_timeout 60		;# in seconds, defaults to 60
set newsrc	~/.newsrc	;# defaults to ~/.newsrc
				;# after trying ~/.newsrc-$server
# Groups to watch.
watch comp.lang.tcl
watch dc.dining		-new "play yumyum"
watch nist.security	-new "exec red-alert"
watch nist.*
watch dc.general	-threshold 5
watch *.sources.*	-threshold 20
watch alt.howard-stern	-threshold 100 -new "play robin"

# Groups to ignore (but which match patterns above).
# Note: newsgroups that you don't read are ignored automatically.
ignore *.d
ignore nist.security
ignore nist.sport

# Change background color of newsgroup list
.list config -bg honeydew1

# Play a sound file
proc play {sound} {
	exec play /usr/local/lib/sounds/$sound.au
}}
	message .help.end -aspect 10000 -text \
"Other customizations are possible.  See man page for more information."

	button .help.ok -text "ok" -command {destroy .help}
	pack .help.text
	pack .help.sample
	pack .help.end -anchor w
	pack .help.ok -fill x -padx 2 -pady 2
}

spawn cat -u; set _cat_spawn_id $spawn_id
set _update_flag 0

# PUBLIC
proc update-now {} {
	global _update_flag _cat_spawn_id

	if {$_update_flag} return	;# already set, do nothing
	set _update_flag 1

	exp_send -i $_cat_spawn_id "\r"
}

bind .list <1> help
bind .list <2> update-now
bind .list <3> unmapwindow
bind .list <Configure> {
	scan [wm geometry .] "%%dx%%d" w h
	_display_ngs $w
}

# PRIVATE
proc _sleep {timeout} {	
	global _cat_spawn_id _update_flag

	set _update_flag 0

	# restore to idle cursor
	.list config -cursor ""; update

	# sleep for a little while, subject to click from "update" button
	expect -i $_cat_spawn_id -re "...."	;# two crlfs

	# change to busy cursor
	.list config -cursor watch; update
}

set previous_seen_list {}
set seen_list {}

# PRIVATE
proc _init_ngs {} {
	global display_list db
	global seen_list previous_seen_list

	set previous_seen_list $seen_list

	set display_list {}
	set seen_list {}

	catch {unset db}
}

for {} {1} {_sleep $delay} {
	_init_ngs

	_read_newsrc
	if {[_read_active]} continue
	_read_config_file

	_update_ngs
	user
	_update_window
}
