#!/bin/sh
#
# fake-mhsend   -- pretend to be the MH send program
#
#   Pretend to be the MH send program and collect the out going mail.
# Which is passed to the filter script given in your ".mh_profile" to
# edit/filter (EG: append signature) that mail, before it is forwarded
# on to the real send program.
# 
# NOTE: this program does not in itself do anthing to the mail, just 
# allows you to write your own simple outgoing mail filter program.
# It is completely controled by the .mh_profile and sould only require
# editing if the filter has special requirements (eg: was -mime option
# given).
#
# The mail filter used should allow one option [-v] for verbose!
#
# My own filter reads the outgoing mail for special markers to select
# specific signatures from a signature archive, or just pick one at
# random. It also adds a X-Face to the mail and in the future possibily
# allow mime encoding for my voice or other such wonders.
# 
# Anthony Thyssen       19 March 1998       <anthony@cit.gu.edu.au>
#
# ------------
# 
# To use this wrapper "fake-mhsend" is added to your ".mh_profile" with
#     sendproc:     fake-mhsend
#     mail-filter:  {mail filter program you want to use}
#     realsend:     send
#     fake-mhsend:  {send option you like}
#     send:
#
# These options are in order
#    sendproc:     Tell MH to use this program for sending mail (in your PATH)
#    mail-filter:  The mail filter    (Usage:  filter [-v] [file])
#                  you want this program to filter outgoing mail through.
#                  EG: append signature, add X-Face etc...
#    realsend:     What program is the real MH send command to use
#    fake-mhsend:  Options to this program (to pass to real send program)
#    send:         MUST BE EMPTY!
#            Ensure send has NO internal user options, any such options
#            should be added to "fake-mhsend" or unexpected results could
#            occur. Particularly with options like ``-push''.
#
# WARNING: ExMH user must re-read the .mh_profile for it to take effect.
#
# This program is of medium complexity and assumes the following call
# structure, but should work with any send options....
#  * From ``What Now?'' sends arguments are (file is last item)
#       send  {draftfilepath}
#  * From ExMH the sendmail call is
#       send  -draftf +drafts -draftm {mesgnum}
#  
# ---------------------------
# --- defaults and programs ---
# Discover where this shell script program resides
# This is a standard ritual for my shell scripts.
# currently the only thing of importance is PROGNAME for reading
# mh_profile options for this program correctly.
ORIGDIR=`pwd`                          # original directory (builtin)
PROGNAME=`type $0 | awk '{print $3}'`  # search for executable on path
PROGDIR=`dirname $PROGNAME`            # extract directory of program
PROGNAME=`basename $PROGNAME`          # base name of program (for options)
cd $PROGDIR                            # go to that directory
PROGDIR=`pwd`                          # remove any symbolic link parts
cd $ORIGDIR                            # return to where we were

mailfilter=`mhparam mail-filter`       # mail filter to use
realsend=`mhparam realsend`            # user selected send program
[ ! "$realsend" ] && realsend=send     # default send program


# --- Read the complex send arguments ---
# This was extracted from the "send" source! Arrrgghhh...

# prepend the ".mh_profile" options for this program
# NOTE: the -- is required for some shells for thsi set to work properly
# but with other shells it is included into argument list so we check.
set -$- -- `mhparam $PROGNAME` "$@"
[ "X$1" = "X--" ] && shift

# The major arguments and options
sendargs=""
draft=""
draftf=""
draftm=""

while [ $# -gt 0 ]; do
  arg="$1"; shift
  case "$arg" in
    #
    # just pass on these options (no option argument)
    -debug | -draft | -encrypt | -noencrypt | -nofilter | \
    -format | -noformat | -forw* | -noforw* | -mime | -nomime | \
    -msgid | -nomsgid | -uniq* | -nouniq* | -watch | -nowatch | \
    -mail | -saml | -send | -soml | -snoop \
    ) # just pass on these options
      sendargs="$sendargs $arg"
      ;;
    #
    # just pass on these options (one option argument)
    -alias | -filter | -width | -client | -server \
    ) # pass on these options with single argument
      sendargs="$sendargs $arg $1";  shift
      ;;
    #
    # these arguments we have to worry about especially
    -draftf* )    draftf="$1"                     # what draft folder
                  sendargs="$sendargs $arg $1"; shift ;;
    -draftm* )    draftm="$1"                     # message in draft folder
                  sendargs="$sendargs $arg $1"; shift ;;
    -nodraftf* )  draftf=""                       # cancel any draft folder
                  sendargs="$sendargs $arg" ;;
    -help)        NOFILTER=true                   # don't filter mail!
                  sendargs="$sendargs $arg" ;;
    -verbose )    VERBOSE=true                    # be verbose
                  sendargs="$sendargs $arg" ;;
    -noverbose )  VERBOSE=''                      # do NOT be verbose
                  sendargs="$sendargs $arg" ;;
    # Backgrounding send cound stuff up this script unless we handly it
    -push )       BACKGROUND=true ;;              # note, but do not pass 
    -nopush )     BACKGROUND="" ;;                # turn it off again
    # 
    #  What is left?
    #
    -*) echo >&2 "ERROR: fake-mhsend: unknown option \"$arg\" -- ABORTING"
        exit 1 ;;
    *)  draft="$arg"    # Presumably the draft file number (don't auto pass)
        # This is the item we most want, and take all this trouble to find!
        # it is also probably the last item and we will force it to be last.
        # Lets make sure that it is the last item!
  esac
done

# force non background processing
# NOTE draft argument should be empty if -draftf method is used!
sendargs="$sendargs -nopush $draft"

if [ "$draft" -a "$draftf" ]; then
  echo >&2 "ERROR: fake-mhsend: Both conficting options! -- ABORTING"
  exit 1
fi
if [ "$draftf" -a -z "$draftm" ]; then
  echo >&2 "ERROR: fake-mhsend: Missing -draftm option! -- ABORTING"
  exit 1
fi
if [ -z "$draft" -a "$draftf" -a "$draftm" ]; then
  draft="`mhpath $draftf $draftm`"
fi
if [ ! -f "$draft" ]; then
  echo >&2 "ERROR: Unable to location draft mail \"$draft\""
  exit 1;
fi

# ------- Do the Real Work ---------

if [ "$NOFILTER" ]; then
  [ "$VERBOSE" ] &&
       echo >&2 "Fake-mhsend: no filter -- just passing mail through"
  exec $realsend $sendargs ${BACKGROUND:+'&'}
  exit 0
fi

# main job as a proceedure to allow us to background it
filter_send() {
  [ "$VERBOSE" ] && echo "Filtering Mail : $mailfilter"
  # Move original mail to a backup and replace it with the filtered version.
  cp -p $draft $draft.orig      # copy so original permissions are retained
  $mailfilter ${VERBOSE:+'-v'} $draft.orig > $draft
  if [ ! -s $draft ]; then
    echo >&2 "Mail filter failed"
    exit 1
  fi

  [ "$VERBOSE" ] && echo "Mailing Filtered Mail to \"$realsend\""
  $realsend $sendargs
  
  if [ -f $draft ]; then     # IS draft file still present?
    [ "$VERBOSE" ] && echo "Clean up after Mailing -- restoring original"
    mv $draft.orig $draft    # THEN return original unfiltered draft!
    #rm -f $draft.orig       # alturnative just remove original
  else
    [ "$VERBOSE" ] && echo "Clean up after Mailing -- removing original"
    rm -f $draft.orig        # filtered mail was removed -- remove original
  fi
}

# Do the job -- background it if required
#filter_send ${BACKGROUND:+'&'}
( filter_send & ) &

# ------------