#!/bin/sh

USAGE=$(cat <<-END
Usage: $(basename "$0") [-h|--help] [-o|--output-dir PATH] -- generate Scylla version and build information files.

Options:
  -h|--help show this help message.
  -o|--output-dir PATH specify destination path at which the version files are to be created.

By default, the script will attempt to parse 'version' file
in the current directory, which should contain a string of
'\$version-\$release' form.

Otherwise, it will call 'git log' on the source tree (the
directory, which contains the script) to obtain current
commit hash and use it for building the version and release
strings.

The script assumes that it's called from the Scylla source
tree.

The files created are:
  SCYLLA-VERSION-FILE
  SCYLLA-RELEASE-FILE
  SCYLLA-PRODUCT-FILE

By default, these files are created in the 'build'
subdirectory under the directory containing the script.
The destination directory can be overriden by
using '-o PATH' option.
END
)

while [[ $# -gt 0 ]]; do
	opt="$1"
	case $opt in
		-h|--help)
			echo "$USAGE"
			exit 0
			;;
		-o|--output-dir)
			OUTPUT_DIR="$2"
			shift
			shift
			;;
		*)
			echo "Unexpected argument found: $1"
			echo
			echo "$USAGE"
			exit 1
			;;
	esac
done

SCRIPT_DIR="$(dirname "$0")"

if [ -z "$OUTPUT_DIR" ]; then
	OUTPUT_DIR="$SCRIPT_DIR/build"
fi

# Default scylla product/version tags
PRODUCT=scylla
VERSION=5.1.dev

if test -f version
then
	SCYLLA_VERSION=$(cat version | awk -F'-' '{print $1}')
	SCYLLA_RELEASE=$(cat version | awk -F'-' '{print $2}')
else
	DATE=$(date --utc +%Y%m%d)
	GIT_COMMIT=$(git -C "$SCRIPT_DIR" log --pretty=format:'%h' -n 1 --abbrev=12)
	SCYLLA_VERSION=$VERSION
	# For custom package builds, replace "0" with "counter.your_name",
	# where counter starts at 1 and increments for successive versions.
	# This ensures that the package manager will select your custom
	# package over the standard release.
	SCYLLA_BUILD=0
	SCYLLA_RELEASE=$SCYLLA_BUILD.$DATE.$GIT_COMMIT
fi

if [ -f "$OUTPUT_DIR/SCYLLA-RELEASE-FILE" ]; then
	GIT_COMMIT_FILE=$(cat "$OUTPUT_DIR/SCYLLA-RELEASE-FILE" |cut -d . -f 3)
	if [ "$GIT_COMMIT" = "$GIT_COMMIT_FILE" ]; then
		exit 0
	fi
fi

echo "$SCYLLA_VERSION-$SCYLLA_RELEASE"
mkdir -p "$OUTPUT_DIR"
echo "$SCYLLA_VERSION" > "$OUTPUT_DIR/SCYLLA-VERSION-FILE"
echo "$SCYLLA_RELEASE" > "$OUTPUT_DIR/SCYLLA-RELEASE-FILE"
echo "$PRODUCT" > "$OUTPUT_DIR/SCYLLA-PRODUCT-FILE"