#!/usr/bin/env ruby

###########################################################
# Notice of Public Domain Status
###########################################################
# The author, Ari Johnson, hereby relinquishes any copyright privileges
# to the content of this file.  It is hereby placed in the public domain
# free of any copyright restrictions.
###########################################################

###########################################################
# Configuration
###########################################################
# You will have to set these to match your system.  Note
# that this script will figure out which database, user,
# and password to use but it cannot figure out what query
# to use in listing all your mailboxes.
###########################################################

$postconf = '/usr/sbin/postconf'
$mailfilter = 'mailreaver.crm'
$crmdir = '/var/mail/crm/'
$query = 'SELECT mailbox, uid, gid FROM account_view'

require 'dbi'

###########################################################
# Utility functions
###########################################################

def postconf(parameter)
  return `#{$postconf} #{parameter}`.sub(/^[^=]*\s*=\s*(.*)$/, '\1').strip
end

def find_map(path)
  method, path = path.split(':', 2)
  if method == 'proxy'
    method, path = path.split(':', 2)
  end
  if ! path
    path = method
    method = postconf('default_database_type')
  end
  return method, path
end

def each_account
  mbmeth, mbpath = find_map($mailbox_maps)
  uidmeth, uidpath = find_map($uid_maps)
  gidmeth, gidpath = find_map($gid_maps)

  if mbmeth != 'pgsql' or uidmeth != 'pgsql' or gidmeth != 'pgsql'
    $stderr.puts("designed only for postgres")
    exit 1
  end

  mbparm = read_map_file(mbpath)
  uidparm = read_map_file(uidpath)
  gidparm = read_map_file(gidpath)

  dbh = DBI.connect("DBI:Pg:#{mbparm['dbname']}:#{mbparm['hosts']}", mbparm['user'], mbparm['password'])

  count = 0
  dbh.select_all($query) do |row|
    count += 1
    yield row['mailbox'], row['uid'], row['gid']
  end

  return count
end

def read_map_file(path)
  lines = IO.readlines(path)
  if ! lines
    $stderr.puts("could not read file #{path}")
    exit 1
  end

  retval = Hash.new

  lines.each do |line|
    line.scan(/^([^=]*)\s*=\s*(.*)$/) do |parameter, value|
      if parameter and value
        retval[parameter.strip] = value.strip
      end
    end
  end

  return retval
end

def process_spam(mailbox, uid, gid)
  fork do
    begin
      Process.egid = gid
      Process.euid = uid

      Dir.chdir($mailbox_base)
      Dir.chdir(mailbox)

      spam_new = Dir.new(".Spam/new")
      spam_cur = Dir.new(".Spam/cur")
      fneg_new = Dir.new(".Spam.False Negatives/new")
      fneg_cur = Dir.new(".Spam.False Negatives/cur")
      fpos_new = Dir.new(".Spam.False Positives/new")
      fpos_cur = Dir.new(".Spam.False Positives/cur")

      if ! spam_new or ! spam_cur or ! fneg_new or ! fneg_cur or ! fpos_new or ! fpos_cur
        return
      end

      fneg_new.each do |file|
        if File.ftype(".Spam.False Negatives/new/#{file}") == "file"
          learn_spam(".Spam.False Negatives/new/#{file}")
          File.rename(".Spam.False Negatives/new/#{file}", ".Spam/new/#{file}")
        end
      end

      fneg_cur.each do |file|
        if File.ftype(".Spam.False Negatives/cur/#{file}") == "file"
          learn_spam(".Spam.False Negatives/cur/#{file}")
          File.rename(".Spam.False Negatives/cur/#{file}", ".Spam/new/#{file}")
        end
      end

      fpos_new.each do |file|
        if File.ftype(".Spam.False Positives/new/#{file}") == "file"
          learn_nonspam(".Spam.False Positives/new/#{file}")
          File.rename(".Spam.False Positives/new/#{file}", "new/#{file}")
        end
      end

      fpos_cur.each do |file|
        if File.ftype(".Spam.False Positives/cur/#{file}") == "file"
          learn_nonspam(".Spam.False Positives/cur/#{file}")
          File.rename(".Spam.False Positives/cur/#{file}", "new/#{file}")
        end
      end
    rescue Exception
    end
  end

  Process.wait
end

def learn_spam(message)
  `crm -u #{$crmdir} #{$mailfilter} --spam < '#{message}'`.strip
end

def learn_nonspam(message)
  `crm -u #{$crmdir} #{$mailfilter} --good < '#{message}'`.strip
end

###########################################################
# Main processing code
###########################################################

# Load in the necessary postfix configuration
$mailbox_base = postconf('virtual_mailbox_base')
$mailbox_maps = postconf('virtual_mailbox_maps')
$uid_maps = postconf('virtual_uid_maps')
$gid_maps = postconf('virtual_gid_maps')

each_account do |mailbox, uid, gid|
  process_spam(mailbox, uid, gid)
end