#! /bin/sh
#
# Get a directory name as input and convert all mail files inside
# to mbox format
#
# NOTE: processing of subdirectories not yet implemented correctly:
#       all mails in subfolders are put into the same mbox
#       (it would be better if an mbox file will be generated for
#       each subfolder)
# NOTE: calculation of message date in case of 'From:' doesn't recognise
#       time zones
#
# History:
# Feb 06 2001 Joerg Reinhardt
# - first edition
# Feb 07 2001 Joerg Reinhardt
# - added usage output
# Feb 12 2001 Joerg Reinhardt
# - mails not containing a 'From:' field but an 'X-From-Line:' or a
#   'Reply-To:' field are now recognised and also processed (e.g. put into
#   the mbox file); this works fine for all my mails
# - added progress information
# - warning about corrupt files is now written to stderr

# check for argument or help argument respectively
if [[ ($1 == "") ||
    ($1 == "-h") ||
    ($1 == "--help") ||
    ($1 == "-help") ]]; then
    echo "Usage: "$0" <Xfmail-mail-directory>";
fi;

# check if parameter is a directory
if [[ -d $1 ]]; then
# set target filename
    dirname=`echo $1 | awk '{while(substr($0,length($0),1)=="/"){$0=substr($0,1,length($0)-1);}print $0;}'`;
    mboxfile=$dirname'.mbox';

# check if directory is empty
    if [[ `find $dirname -type f` == "" ]]; then
	echo $dirname": directory empty."
	exit 1;
    fi;

# prevent automatic overwriting of target
    if [[ -e $mboxfile ]]; then \
	dialogtext="Write file "$mboxfile"?";
	if dialog --yesno "$dialogtext" 10 60; then
	    clear;
	    rm -vf $mboxfile;
	else
	    clear; exit 1;
	fi;
    fi;

    echo "writing xfmail mail directory '$1' to '$mboxfile'.";


# collect files inside Xfmail mail-directory and produce MBOX format
# target file
    for i in `find $1/* -type f`; do
# output progress information
	echo -n -e \\r"                                                                               "
	echo -n -e \\rprocessing $i
# look for senders email address in the order
# 'From:'
# 'X-From-Line:'
# 'Reply-To:'
	shortfromflag='true';
	fromline=`grep 'From:' $i`;
# parse 'From:' field
	from=`echo $fromline | awk 'BEGIN{FS="<";}{if($0~/</) {pos=index($2,">");if(pos!=0) {print substr($2,1,pos-1);}} else {pos=index($0,":");print substr($0,pos+1);}}'`;
	if [[ $from == "" ]]; then
	    shortfromflag='false';
	    fromline=`grep 'X-From-Line:' $i`;
	    from=`echo $fromline | awk 'BEGIN{FS="Line:";}{print $2;}'`;
	    if [[ $from == "" ]]; then
		shortfromflag='true';
		fromline=`grep 'Reply-To:' $i`;
# parse 'Reply-To:' field
		from=`echo $fromline | awk 'BEGIN{FS="<";}{if($0~/</) {pos=index($2,">");if(pos!=0) {print substr($2,1,pos-1);}} else {pos=index($0,":");print substr($0,pos+1);}}'`;
		if [[ $from == "" ]]; then
		    echo;
		    echo "WARNING: "$i": no 'From:' nor 'X-From-Line:' nor 'Reply-To:' field found." >&2;
		    continue;
		fi;
	    fi;
	fi;
	if [[ $shortfromflag == "true" ]]; then
# parse date field
	    dateline=`grep 'Date:' $i`;
	    if [[ $dateline == "" ]]; then
# set dummy date if no date field found
		dateline="Date: Thu, 01 Jan 1970 00:00:00 +0000 (GMT)";
	    fi;
	    weekday=`echo $dateline | awk '{gsub(/,/,"",$2);print $2;}'`;
	    day=`echo $dateline | awk '{print $3;}'`;
	    month=`echo $dateline | awk '{print $4;}'`;
	    year=`echo $dateline | awk '{print $5;}'`;
	    time=`echo $dateline | awk '{print $6;}'`;
	    diffGMT=`echo $dateline | awk '{print $7;}'`;
	    timezone=`echo $dateline | awk '{print $8;}'`;

# output MBOX mail header
	    echo "From " $from $weekday $month $day $time $year >> $mboxfile;
	else
# output long MBOX mail header found in 'X-From-Line:' field
	    echo $from >> $mboxfile;
	fi;

# output mail itself
	cat $i >> $mboxfile;
    done;
    echo;
else
    echo $1": not a directory.";
fi;