#! /usr/bin/ruby

DOMAINNAME = "oku.edu.mie-u.ac.jp"
COUNTDIR   = "/var/oml/"

def incr_count(countfile)
  c = 0
  begin
    File.open(countfile, "r+") do |f|
      f.flock(File::LOCK_EX)
      x = f.read(4)
      c = ((x[0] * 256 + x[1]) * 256 + x[2]) * 256 + x[3] + 1
      x[0] = (c >> 24) & 255
      x[1] = (c >> 16) & 255
      x[2] = (c >>  8) & 255
      x[3] =  c        & 255
      f.rewind
      f.write(x[0..3])
      f.flock(File::LOCK_UN)
    end
  rescue
    File.open(countfile, "w") do |f|
      f.flock(File::LOCK_EX)
      f.write("\000\000\000\001")
      c = 1
      f.flock(File::LOCK_UN)
    end
  end
  return c
end

def getheader
  $buf = gets() if $buf == nil
  if $buf == nil or $buf =~ /\A[\r\n]*\z/
    return nil
  end
  line = $buf
  $buf = gets()
  while $buf =~ /\A[ \t]/
    line += $buf
    $buf = gets()
  end
  return line
end  

opt = Hash.new  # command-line options
while ARGV[0] =~ /^-(.)$/
  ARGV.shift
  opt[$1] = true
end

mlname = ARGV[0];  ARGV.shift
distfile = ARGV[0];  ARGV.shift
distname = ARGV[0];  ARGV.shift

exit if mlname == nil

distname = "dist-" + mlname if distname == nil

subjectregexp = Regexp.new('\Asubject\:\s*(re\:\s*)*(\[' + mlname + '(:\d+)?\]\s*)?(.*)\z',
                           Regexp::IGNORECASE | Regexp::MULTILINE)

header = ""
subject = "\n"
envfrom = nil
fromlist = nil

while line = getheader
  if line =~ /\Afrom\s+((\S*).*)\z/mi
    header += "X-Envelope-From: #{$1}"
    envfrom = $2
  elsif line =~ /\Afrom:(.*)\z/mi
    fromlist = $1
    if opt['f']
      header += "From: #{mlname}@#{DOMAINNAME}\n"
      header += "X-" + line
    else
      header += line
    end
  elsif line =~ /\Adisposition-notification-to:(.*)\z/mi
    # do nothing
  elsif !opt['r'] and line =~ /\Areply-to:(.*)\z/mi
    header += "X-" + line
  elsif line =~ subjectregexp
    subject = $4
  else
    header += line
  end
end

if !fromlist
  ok = false
elsif fromlist =~ /viagra/i  # 例
  ok = false
elsif distfile
  ok = false
  if opt['e'] and envfrom
    lowerfromlist = envfrom.downcase
  else
    lowerfromlist = fromlist.downcase
  end
  File.foreach(distfile) do |line|
    if line =~ /^\#\-\s*(\S*)/
      ok = false if lowerfromlist.include?($1.downcase)
    elsif line =~ /^\#?\s*(\S*)\s*\(.*?\)\s*$/
      ok = true if lowerfromlist.include?($1.downcase)
    elsif line =~ /^\#?\s*(\S*)/
      ok = true if lowerfromlist.include?($1.downcase)
    end
  end
else
  ok = true
end

if ok
  count = incr_count("#{COUNTDIR}#{mlname}.cnt")
  if opt['f']
    header += "Subject: "  # 携帯でSubject:が長いと読みにくいということなので
  elsif opt['c']
    header += "Subject: [#{mlname}] "
  else
    header += sprintf("Subject: [%s:%04d] ", mlname, count)
  end
else
  header += sprintf("Subject: Undelivered: [%s] ", mlname)
end

header += subject
header += "Reply-To: #{mlname}@#{DOMAINNAME}\n" if !opt['r']
header += "Errors-To: #{mlname}-admin@#{DOMAINNAME}\n"

if ok
  pipe = "|/usr/sbin/sendmail -oi -f #{mlname}-admin #{distname}"
else
  pipe = "|/usr/sbin/sendmail -oi -f #{mlname}-admin #{mlname}-admin"
end

open(pipe, "w") do |p|
  p.print header
  p.print "\n"
  while line = gets
    p.print line
  end
end