#!/bin/bash
AUTO=0

# Check env for any default settings, command line options will override these.
if [ -z "$PULL_MTA" ]; then
    PULL_MTA="sendmail"
fi

# Prevent environment leakage to these vars.
unset TO
unset CC

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
  -g           Use git-send-email to send mail instead of sendmail
  -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 "aghp:t:" OPT; do
    case $OPT in
        a)
            AUTO=1
            ;;
        g)
            PULL_MTA="git"
            ;;
        h)
            usage
            exit 0
            ;;
        p)
            PDIR=${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
    case "$PULL_MTA" in
        git)
            export IFS=$','
            GIT_TO=$(for R in $TO; do echo -n "--to='$R' "; done)
            GIT_CC=$(for R in $CC; do echo -n "--cc='$R' "; done)
            unset IFS
            for PATCH in $PDIR/*patch; do
                # We harvest the emails manually, so force git not to.
                eval "git send-email $GIT_TO $GIT_CC --no-chain-reply-to --suppress-cc=all $PATCH"
                if [ $? -eq 1 ]; then
                    ERROR=1
                fi
            done
            ;;
        sendmail)
            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 $CC has
                # proven to be an exercise in futility.
                #
                # Use tail to remove the email envelope from git or formail as
                # msmtp (sendmail) would choke on them.
                #
                # Modify the patch date for sequential delivery, but retain the
                # original date as "Old-Date".
                DATE=$(date +"%a, %d %b %Y %k:%M:%S %z")
                cat $PATCH | formail -I "To: $TO" -I "CC: $CC" -i "Date: $DATE" | tail -n +2 | sendmail -t
                if [ $? -eq 1 ]; then
                    ERROR=1
                fi
            done
            ;;
        *)
            echo "ERROR: unknown MTA: $PULL_MTA"
            usage
            exit 1
            ;;
    esac

    if [ $ERROR -eq 1 ]; then
        echo "ERROR: Failed to send one or more messages. Check your MTA log for details."
    fi
else
    echo "Send aborted."
fi