# Global maildrop filter file

# Uncomment this line to make maildrop default to ~/Maildir for
# delivery- this is where courier-imap (amongst others) will look.
#DEFAULT="$HOME/Maildir"
SHELL="/bin/bash"
SENDMAIL="/opt/cropswap/sendmail.sh"
SUBUNSUB="/opt/cropswap/subunsub.sh"
DEBUGMAIL="/opt/cropswap/debug.sh"
MAILBOT="/usr/bin/mailbot"
SIGNUPRESP="/opt/cropswap/signup.eml"
SUBSCRIBERESP="/opt/cropswap/subunsub.eml"

#
# Uncomment to debug
#SENDMAIL="/opt/cropswap/debug.sh"
#MAILBOT="/opt/cropswap/debug.sh"
#

POSTMASTER="postmaster@localhost"
POSTMASTERREGEX=escape($POSTMASTER)

# bi-directional group
# From subscribed member -> other subscribed members
MEMBERGROUP="cropswap-members@shandan.one"
MEMBERGROUPREGEX=escape($MEMBERGROUP)

# uni-directional group
# From anyone -> organizers
# From organizers -> subscribed members
ORGANIZERGROUP="cropswap@shandan.one"
ORGANIZERGROUPREGEX=escape($ORGANIZERGROUP)

SUFFIX=0

FORWARD=0
SUBSCRIBE=""
CONTINUE=0
TOPOSTMASTER=0
TOORGANIZER=0
TOMEMBER=0
TO=""

UNHANDLED=5
BADREQUEST=4
UNREGISTERED=3
UNSUBSCRIBED=2
FATAL=1

foreach /^(To|Cc):.*/
{
   ADDR=getaddr($MATCH)
   foreach (tolower $ADDR) =~ /^$POSTMASTER$/
   {
      if (/^X\-GROUP:\s*$ORGANIZERGROUPREGEX\s*$/)
      {
         TOORGANIZER=1
      }
      if (/^X\-GROUP:\s*$MEMBERGROUPREGEX\s*$/)
      {
         TOORGANIZER=1
      }
      CONTINUE=1
      TOPOSTMASTER=1
   }
   foreach (tolower $ADDR) =~ /^$ORGANIZERGROUPREGEX$/
   {
      TOORGANIZER=1
      CONTINUE=1
   }
   foreach (tolower $ADDR) =~ /^$MEMBERGROUPREGEX$/
   {
      TOMEMBER=1
      CONTINUE=1
   }
   foreach /^(To|Cc):\s+(.*)\s+\<$ORGANIZERGROUPREGEX\>$/
   {
      TOALIAS=$MATCH2
   }
   foreach /^(To|Cc):\s+(.*)\s+\<$MEMBERGROUPREGEX\>$/
   {
      TOALIAS=$MATCH2
   }
}

if (!$CONTINUE)
{
   EXITCODE=$UNHANDLED
   exit
}

if ($TOMEMBER && $TOORGANIZER)
{
   cc "|$DEBUGMAIL multiplemembergroupset"
   EXITCODE=$BADREQUEST
   exit
}

if ($TOMEMBER)
{
   MAILGROUP=$MEMBERGROUP
   SUBJECT="Crop Swap Member"
}
elsif ($TOORGANIZER)
{
   MAILGROUP=$ORGANIZERGROUP
   SUBJECT="Crop Swap Notice"
}
else
{
   cc "|$DEBUGMAIL nomembergroupset"
   EXITCODE=$FATAL
   exit
}
LISTDIR="/var/mail/maildrop/$MAILGROUP"
MLIST="$LISTDIR/mlist"
SLIST="$LISTDIR/slist"


if ($TOPOSTMASTER)
{
   if (/^Subject:\s*\[SIGNUP\]\s*$/)
   {
      if (/^X-MEMBER-ALIAS:\s*(.*)\s*$/)
      {
         gdbmopen($MLIST, "W")
         ALIAS=$MATCH1
         KEY=$ALIAS
         EXISTS=gdbmfetch($KEY)
         while ($EXISTS ne "" && $EXISTS ne tolower($FROM))
         {
            SUFFIX=($SUFFIX + 1)
            KEY="$ALIAS $SUFFIX"
            EXISTS=gdbmfetch($KEY)
         }
         if (gdbmstore(tolower($FROM), $KEY) == 0 && gdbmstore($KEY, tolower($FROM)) == 0)
         {
            gdbmclose
            to "|$MAILBOT -N -t $SIGNUPRESP -A 'From: $MAILGROUP' -f$FROM /usr/bin/sendmail $FROM"
         }
         else
         {
            gdbmclose
            EXITCODE=$FATAL
            exit
         }
      }
      EXITCODE=$BADREQUEST
      # No response to unregistered users
      exit
   }
   EXITCODE=$UNHANDLED
   # No response to unregistered users
   exit
}

gdbmopen($MLIST, "R")
ALIAS=gdbmfetch(tolower($FROM))
if ($ALIAS eq "")
{
    gdbmclose
    if ($TOORGANIZER)
    {
       #
       # TODO: test this works at all
       FROM=$FROM
       REPLYTO=$FROM
       SLIST="$LISTDIR/alist"
       to "!"
    }
    EXITCODE=$UNREGISTERED
    exit
}
gdbmclose


#
# REGISTERED USERS ONLY
#
if (/^Subject:\s*\[(SUBSCRIBE|UNSUBSCRIBE)\]\s*$/)
{
   SUBSCRIBE=$MATCH1
}

if ($SUBSCRIBE ne "")
{
   gdbmopen($SLIST, "W")
   if (gdbmstore(tolower($FROM), $SUBSCRIBE) == 0)
   {
      gdbmclose
      system "$SUBUNSUB '$SUBSCRIBE' '$ALIAS' '$FROM'"
      to "|$MAILBOT -N -t $SUBSCRIBERESP -A 'From: $MAILGROUP' -f$FROM /usr/sbin/sendmail $FROM"
   }
   else
   {
      gdbmclose
      EXITCODE=$FATAL
      exit
   }
}


gdbmopen($SLIST, "R")
FORWARD=(gdbmfetch(tolower($FROM)) eq "SUBSCRIBE")
gdbmclose


if (!$FORWARD)
{
   EXITCODE=$UNSUBSCRIBED
   exit
}

#
# SUBSCRIBED USERS
#
NOFORWARD=$FROM
if ($TOMEMBER)
{
   FROM=$ALIAS
   gdbmopen($MLIST, "R")
   TO=gdbmfetch($TOALIAS)
   gdbmclose
   to "!"
}

MLIST="$LISTDIR/alist"
gdbmopen($MLIST, "R")
ORGANIZER=gdbmfetch(tolower($FROM))
gdbmclose

if ($ORGANIZER eq "")
{
   SLIST="$LISTDIR/alist"
   to "!"
}

#
# ORGANIZERS ONLY
#
FROM=$ORGANIZER
MLIST="$LISTDIR/mlist"
gdbmopen($MLIST, "R")
TO=gdbmfetch($TOALIAS)
gdbmclose
to "!"