#!/bin/bash
ODIR=pull-$$
RELATIVE_TO="master"
COMMIT_ID="HEAD"
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] -u remote -b branch
  -b branch           Branch name in the specified remote
  -h                  Display this help message
  -i commit_id        Ending commit (default: HEAD)
  -m msg_body_file    The file containing a blurb to be inserted into the summary email
  -o output_dir       Specify the output directory for the messages (default: pull-PID)
  -p prefix           Use [prefix N/M] instead of [PATCH N/M] as the subject prefix
  -r relative_to      Starting commit (default: master)
  -s subject          The subject to be inserted into the summary email
  -u remote           The git remote where the branch is located

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

# Parse and validate arguments
while getopts "b:hi:m:o:p:r:s:u:" OPT; do
	case $OPT in
	b)
		BRANCH="$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="$OPTARG"
		;;
	u)
		REMOTE="$OPTARG"
		REMOTE_URL=$(git config remote.$REMOTE.url)
		if [ $? -ne 0 ]; then
			echo "ERROR: git config failed to find a url for '$REMOTE'"
			exit 1
		fi

		# Rewrite known private URLs to public URLs
		# Determine the repository name for use in the WEB_URL later
		case "$REMOTE_URL" in
		ssh://git@git.pokylinux.org*)
			REMOTE_REPO=$(echo $REMOTE_URL | sed "s#.*/\(.*\)#\1#")
			REMOTE_URL=${REMOTE_URL/'ssh://git@'/'git://'}
			;;
		ssh://git@git.yoctoproject.org*)
			REMOTE_REPO=$(echo $REMOTE_URL | sed "s#.*/\(.*\)#\1#")
			REMOTE_URL=${REMOTE_URL/"ssh://git@"/"git://"}
			;;
		esac
		# The .git suffix is optional in the URL, drop in for the REPO
		REMOTE_REPO=${REMOTE_REPO%.git}
		;;
	esac
done

if [ -z "$BRANCH" ] || [ -z "$REMOTE_URL" ]; then
	usage
	exit 1
fi


# Set WEB_URL from known remotes
case "$REMOTE_URL" in
	*git.yoctoproject.org*)
		WEB_URL="http://git.yoctoproject.org/cgit.cgi/$REMOTE_REPO/log/?h=$BRANCH"
		;;
	*git.pokylinux.org*)
		WEB_URL="http://git.pokylinux.org/cgit.cgi/$REMOTE_REPO/log/?h=$BRANCH"
		;;
esac

# 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.
if [ -n "$WEB_URL" ]; then
	wget -q $WEB_URL -O /dev/null
	if [ $? -ne 0 ]; then
		echo "WARNING: Branch '$BRANCH' was not found on the contrib git tree."
		echo "         Please check your remote and branch parameter before sending."
		echo ""
	fi
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="$ODIR/0000-cover-letter.patch"
PM="$ODIR/pull-msg"
git request-pull $RELATIVE_TO $REMOTE_URL $COMMIT_ID > "$PM"
if [ $? -ne 0 ]; then
	echo "ERROR: git request-pull reported an error"
	exit 1
fi

# The cover letter already has a diffstat, remove it from the pull-msg
# before inserting it.
sed -n "0,\#$REMOTE_URL# p" "$PM" | sed -i "/BLURB HERE/ r /dev/stdin" "$CL"
rm "$PM"

# Insert the WEB_URL if there is one
if [ -n "$WEB_URL" ]; then
	echo "  $WEB_URL" | sed -i "\#$REMOTE_URL# r /dev/stdin" "$CL"
fi


# 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