#!/bin/bash
AUTO=0

usage()
{
cat <<EOM
Usage: $(basename $0) [-h] [-a] [[-t email]...] -p pull-dir 
  -t email     Explicitly add email to the recipients
  -a           Automatically harvest recipients from "*-by: email" lines
               in the patches in the pull-dir
  -p pull-dir  Directory containing summary and patch files
EOM
}

# Collect To and CC addresses from the patch files if they exist
# $1: Which header to add the recipients to, "TO" or "CC"
# $2: The regex to match and strip from the line with email addresses
harvest_recipients()
{
    TO_CC=$1
    REGX=$2
    export IFS=$',\n'
    for PATCH in $PDIR/*.patch; do
        # Grab To addresses
        for EMAIL in $(sed '/^---$/q' $PATCH | grep -e "$REGX" | sed "s/$REGX//"); do
            if [ "$TO_CC" == "TO" ] && [ "${TO/$EMAIL/}" == "$TO" ] && [ -n "$EMAIL" ]; then
                if [ -z "$TO" ]; then TO=$EMAIL; else TO="$TO,$EMAIL"; fi
            elif [ "$TO_CC" == "CC" ] && [ "${CC/$EMAIL/}" == "$CC" ] && [ -n "$EMAIL" ]; then
                if [ -z "$CC" ]; then CC=$EMAIL; else CC="$CC,$EMAIL"; fi
            fi
        done
    done
    unset IFS
}


# Parse and verify arguments
while getopts "ahp:t:" OPT; do
    case $OPT in
        a)
            AUTO=1
            ;;
        h)
            usage
            exit 0
            ;;
        p)
            PDIR=${OPTARG%/}
            if [ ! -d $PDIR ]; then
                echo "ERROR: pull-dir \"$PDIR\" does not exist."
                usage
                exit 1
            fi
            ;;
        t)
            if [ -n "$TO" ]; then
                TO="$TO,$OPTARG"
            else
                TO="$OPTARG"
            fi
            ;;
    esac
done

if [ -z "$PDIR" ]; then
    echo "ERROR: you must specify a pull-dir."
    usage
    exit 1
fi


# Verify the cover letter is complete and free of tokens
CL="$PDIR/0000-cover-letter.patch"
for TOKEN in SUBJECT BLURB; do
    grep -q "*** $TOKEN HERE ***" "$CL"
    if [ $? -eq 0 ]; then
        echo "ERROR: Please edit $CL and try again (Look for '*** $TOKEN HERE ***')."
        exit 1
    fi
done


# Harvest emails from the generated patches and populate the TO and CC variables
# In addition to To and CC headers/lines, the common Signed-off-by, Tested-by,
# etc. (*-by) will be added to CC.
if [ $AUTO -eq 1 ]; then
    harvest_recipients TO "^[Tt][Oo]: *"
    harvest_recipients CC "^[Cc][Cc]: *"
    harvest_recipients CC "^.*-[Bb][Yy]: *"
fi

if [ -z "$TO" ] && [ -z "$CC" ]; then
    echo "ERROR: you have not specified any recipients."
    usage
    exit 1
fi


# Generate report for the user and require confirmation before sending
cat <<EOM
The following patches:
$(for PATCH in $PDIR/*.patch; do echo "    $PATCH"; done)

will be sent to the following recipients:
    To: $TO
    CC: $CC

EOM
echo "Continue? [y/N] "
read cont

if [ "$cont" == "y" ] || [ "$cont" == "Y" ]; then
    ERROR=0
    for PATCH in $PDIR/*patch; do
        # Insert To and CC headers via formail to keep them separate and
        # appending them to the sendmail command as -- $TO $CC has proven
        # to be an exercise in futility.
        # 
        # Use tail to remove the email envelope from git or formail as
        # msmtp (sendmail) would choke on them.
        cat $PATCH | formail -I "To: $TO" -I "CC: $CC" | tail -n +2 | sendmail -t
        if [ $? -eq 1 ]; then
            ERROR=1
        fi
    done
    if [ $ERROR -eq 1 ]; then
        echo "ERROR: sendmail failed to send one or more messages. Check your"
        echo "       sendmail log for details."
    fi
else
    echo "Send aborted."
fi