#!/bin/bash
ODIR=pull-$$
RELATIVE_TO="master"
COMMIT_ID="HEAD"
PULL_URL="git://git.openembedded.org/openembedded-core-contrib"
WEB_URL_PREFIX="http://git.openembedded.org/cgit.cgi/openembedded-core-contrib/log/?h="
PREFIX="PATCH"

usage() {
CMD=$(basename $0)
cat <<EOM
Usage: $CMD [-h] [-o output_dir] [-m msg_body_file] [-s subject] [-r relative_to] [-i commit_id] -b contrib_branch
  -h                  Display this help message
  -o output_dir       Specify the output directory for the messages (default: pull-PID)
  -m msg_body_file    The file containing a blurb to be inserted into the summary email
  -r relative_to      Starting commit (default: master)
  -i commit_id        Ending commit (default: HEAD)
  -b contrib_branch   Branch-name in the $PULL_URL
  -s subject          The subject to be inserted into the summary email
  -p prefix           Use [prefix N/M] instead of [PATCH N/M] as the subject prefix

 Examples:
   $CMD -b nitin/basic
   $CMD -r distro/master -i nitin/distro -b nitin/distro
   $CMD -r master -i misc -b nitin/misc -o pull-misc
   $CMD -p "RFC PATCH" -b nitin/experimental
EOM
}

# Parse and validate arguments
while getopts "b:hi:m:o:r:s:p:" OPT; do
    case $OPT in
    b)
        CONTRIB_BRANCH="$OPTARG"
        ;;
    h)
        usage
        exit 0
        ;;
    i)
        COMMIT_ID="$OPTARG"
        ;;
    m)
        BODY="$OPTARG"
        if [ ! -e "$BODY" ]; then
            echo "ERROR: Body file does not exist"
            exit 1
        fi
        ;;
    o)
        ODIR="$OPTARG"
        ;;
    p)
        PREFIX="$OPTARG"
        ;;
    r)
        RELATIVE_TO="$OPTARG"
        ;;
    s)
        SUBJECT="$OPTARG"
        ;;
    esac
done

if [ -z "$CONTRIB_BRANCH" ]; then
    usage
    exit 1
fi


# Perform a sanity test on the web URL. Issue a warning if it is not
# accessible, but do not abort as users may want to run offline.
WEB_URL="$WEB_URL_PREFIX$CONTRIB_BRANCH"
wget -q $WEB_URL -O /dev/null
if [ $? -ne 0 ]; then
    echo "WARNING: Branch '$CONTRIB_BRANCH' was not found on the contrib git tree."
    echo "         Please check your contrib-branch parameter before sending."
    echo ""
fi

if [ -e $ODIR ]; then
	echo "ERROR: output directory $ODIR exists."
	exit 1
fi
mkdir $ODIR


# Generate the patches and cover letter
git format-patch -M --subject-prefix="$PREFIX" -n -o $ODIR --thread=shallow --cover-letter $RELATIVE_TO..$COMMIT_ID > /dev/null


# Customize the cover letter
CL="$ODIR/0000-cover-letter.patch"
(cat <<EOM

Pull URL: $PULL_URL
  Branch: $CONTRIB_BRANCH
  Browse: $WEB_URL

Thanks,
    $(git config user.name) <$(git config user.email)>
---

EOM
) | sed -i "/BLURB HERE/ r /dev/stdin" "$CL"

# If the user specified a message body, insert it into the cover letter and
# remove the BLURB token.
if [ -n "$BODY" ]; then
    sed -i "/BLURB HERE/ r $BODY" "$CL"
    sed -i "/BLURB HERE/ d" "$CL"
fi

# If the user specified a subject, replace the SUBJECT token with it.
if [ -n "$SUBJECT" ]; then
    sed -i -e "s/\*\*\* SUBJECT HERE \*\*\*/$SUBJECT/" "$CL"
fi


# Generate report for user
cat <<EOM
The following patches have been prepared:
$(for PATCH in $(ls $ODIR/*); do echo "    $PATCH"; done)

Review their content, especially the summary mail:
    $CL

When you are satisfied, you can send them with:
    send-pull-request -a -p $ODIR
EOM