#!/usr/bin/env ruby

# Some info:
# - correctly handles charset/encoding in Subject
# - correctly handles various from formats
# - correctly strips message to 160 (bit less, though) chars, if requested
# - correctly(?) strips quoted lines and replied/forwarded parts
# - incorrectly handles content of message - doesn't attempt to fix/recognize
#   multiparts, content encodings, content charsets
#   This is serious bug. But I'm not going to implement whole MIME module
#   now, just to fix it. Maybe later.

$conf = Hash.new

#----------------=[ Config section

# Recipient of the announce?
$conf['to'] = 'to@example.com'

# Prefix before 'from' address
$conf['from'] = 'B'

# Envelope sender
$conf['fromeml'] = 'from@example.com'

# Flag file to disable sms sending
$conf['flagfile'] = '/home/wejn/.no.nmsms'

# Don't limit sms to 160 chars
$conf['unlimited'] = false

# Path to recoding program
$conf['recodeby'] = '/home/wejn/bin/cconv'

# Path to sending program
#$conf['sendby'] = "/var/qmail/bin/qmail-inject -h -f%%FROM%%"
$conf['sendby'] = "/usr/sbin/sendmail -t -f%%FROM%%"

#----------------=[ End of config section

# Commandline parsing
def usage
	puts <<EOF
Usage: #{$0} [option...]
Options:
--to ADDR          -t  ADDR Address where to send the SMS
--from ADDR        -f  ADDR Sender's address of the message
--from-prefix PFX  -p  PFX  Prefix to use before the sms address
--help             -h  This help message
EOF
end

begin
	require 'getoptlong'
	parser = GetoptLong.new
	parser.set_options(
		["--to", "-t", GetoptLong::REQUIRED_ARGUMENT],
		["--from", "-f", GetoptLong::REQUIRED_ARGUMENT],
		["--from-prefix", "-p", GetoptLong::REQUIRED_ARGUMENT],
		["--help", "-h", GetoptLong::NO_ARGUMENT])
	parser.each_option { |name, arg|
		case name
		when "--help"
			usage
			exit 0
		when "--to"
			$conf['to'] = arg
		when "--from"
			$conf['fromeml'] = arg
		when "--from-prefix"
			$conf['from'] = arg
		else
			raise RuntimeError, "blaf"
		end
	}
rescue
	exit 1
end
unless ARGV.size.zero?
	$stderr.puts "Extra parameters at commandline, abort!"
	exit 1
end
# End of it

# --
# Setup initial values
# --
$body = false
$from = nil
$subject = nil
$send = false
$content = ""
$contentadd = true

# --
# Read the mail
# --
ARGF.each { |x|
	# Determine if it's body part
	$body = true if $body == false && x =~ /^$/

	# Body part? Add to content if not too long and not quoted
	# and not part of original/forwarded message
	if $body
		if $content.length < 1000 && $contentadd && x !~ /^\s*[>:]/
			$contentadd = false if x =~ /^---?\s*$/
			if x =~ /^-*\s*Forwarded\s*mess.*-*\s*$/ ||
					x =~ /^-*\s*Original\s*Message\s*-/ ||
					x =~ /^On\s*.*\s*wrote:\s*$/
				$contentadd = false
				next
			end
			$content += x
		end
		next
	end

	# Non body part here ... find from and subject
	x.chomp!
	case x
		when /^From:/; $from = x.sub(/^From:\s*/, '') if $from.nil?
		when /^Subject:/; $subject = x.sub(/^Subject:\s*/, '') if $subject.nil?
	end
}

# --
# Perform some parsing
# --

# Get email from: 'email (name)' format
$from.sub!(/^([^@]*@[^@ ]*)\s*\(.*\)\s*$/, '\1')

# Get email from: 'name <email>' format
$from.sub!(/^[^<]*<([^@]*@[^@]*)>\s*$/, '\1')

# Parse && recode subject -- this should be MIME compatible
if $subject =~ /=\?[^?]*\?.\?.*\?=/
	def wTranslate(x)
		x = x.gsub!(/(^=\?|\?=$)/, '')
		x = x.split("?", -1)
		case x[1].downcase
			when 'q'; x[2] = x[2].gsub(/_/, ' ').unpack('M')[0]
			when 'b'; x[2] = x[2].unpack('m')[0]
		end
		case x[0].downcase
			#when 'windows-1252'; ie = '1252'
			when 'windows-1250'; ie = '1250'
			when 'iso-8859-2'; ie = 'il2'
			when 'iso-8859-1'; ie = 'il2' # glitch, i know
			else; ie = nil
		end
		x[2] = `#{$conf['recodeby']} #{ie} ascii '#{x[2]}'` unless ie.nil?
		x[2].chomp
	end
	$subject.gsub!(/=\?.*?\?=/) { |x| wTranslate(x) }
end

# --
# Determine whether we will sending it
# --
case $from
	when /^mailer-daemon@/i; $send = false
	when /^postmaster@/i; $send = false
	else; $send = true
end

$send = false if test ?f, $conf['flagfile']

# --
# Send it ...
# --
if $send
	open("|#{$conf['sendby'].gsub(/%%FROM%%/, $conf['fromeml'])}", 'w') { |x|
		$bsent = 12 # Magic, don't change ('trash' chars we can't get rid of)
		realfrom = "#{$conf['from']}=#$from"
		x.puts("From: #{realfrom}")
		$bsent += realfrom.length
		x.puts("To: #{$conf['to']}")
		x.puts("\n")
		tosend = "#$subject;#$content"
		tosend = tosend[Range.new(0, 160 - $bsent)] unless $conf['unlimited']
		x.puts(tosend)
	}
end

# --
# Be happy now
# --
exit 0

# vim: set ft=ruby ts=4 sw=4 :