#!/bin/bash
# vi: fdm=marker

##################
# Constants {{{1 #
##################

PROG_NAME=$(basename $0)
VERSION=1.5
YES=yes

# Set grep command
if [ -z "$MAKE_VERSIONS_GREP" ] ; then
	MAKE_VERSIONS_GREP=grep
fi

# Set sed command
if [ -z "$MAKE_VERSIONS_SED" ] ; then
	MAKE_VERSIONS_SED=sed
fi

# Set Dockerfile path
if [ -z "$MAKE_VERSIONS_DOCKERFILE" ] ; then
	MAKE_VERSIONS_DOCKERFILE=Dockerfile
fi

#########################
# Global variables {{{1 #
#########################

DEBUG=0
TAGPREFIX=
BRANCHTAG=
OUTPUT_FILE=PhenoMeNal_Versions.txt

###################
# Print help {{{1 #
###################

function print_help {
	echo "Usage: $PROG_NAME [options]"
	echo
	echo "   -b, --branch-tag           Use git branch for building container tag prefix. If branch is \"develop\", container tag prefix will be prefixed with \"dev_\"."
	echo "   -g, --debug                Debug mode."
	echo "   -h, --help                 Print this help message."
	echo "   -t, --tag-prefix           Output container tag prefix."
	echo "   -v, --version              Print version."
	echo
	echo "Environment variables:"
	echo "   MAKE_VERSIONS_DOCKERFILE   Set a custom Dockerfile path. By default Dockerfile is supposed to be inside the working directory."
	echo "   MAKE_VERSIONS_GREP         Set custom grep command to use."
	echo "   MAKE_VERSIONS_SED          Set custom sed command to use."
}

############
# Msg {{{1 #
############

function msg {

	local tag=$1
	shift
	local code_level=1
	is_numeric=$(echo $1 | grep '^[0-9]*$')
	if [ -n "$is_numeric" ] ; then
		code_level=$1
		shift
	fi
	local msg=$1

	# Check tag
	if [ -z "$tag" -o \( "$tag" != INFO -a "$tag" != DEBUG -a "$tag" != ERROR \) ] ; then
		echo "ERROR: Unvalid message tag \"$tag\"." >&2
		exit 999
	fi

	# Print message
	[ "$tag" = DEBUG -a "$DEBUG" -lt "$code_level" ] || echo "$tag: $msg" >&2

	# Exit
	[ $tag = ERROR ] && exit $code_level

	return 0
}

##################
# Read args {{{1 #
##################

function read_args {

	local args="$*" # save arguments for debugging purpose
	
	# Read options
	while true ; do
		shift_count=1
		case $1 in
			-b|--branch-tag)        BRANCHTAG=$YES ;;
			-g|--debug)             DEBUG=$((DEBUG + 1)) ;;
			-h|--help)              print_help ; exit 0 ;;
			-t|--tag-prefix)        TAGPREFIX=$YES ;;
			-v|--version)           echo $VERSION ; exit 0 ;;
			-|--|--*)               msg ERROR "Illegal option $1." ;;
			-?)                     msg ERROR "Unknown option $1." ;;
			-[^-]*) split_opt=$(echo $1 | sed 's/^-//' | sed 's/\([a-zA-Z]\)/ -\1/g') ; set -- $1$split_opt "${@:2}" ;;
			*) break
		esac
		shift $shift_count
	done
	shift $((OPTIND - 1))

	# Read remaining arguments
	[ $# -eq 0 ] || msg ERROR "No remaining argument is allowed."

	# Debug
	msg DEBUG 1 "Arguments are : $args"
}

#########################
# Extract versions {{{1 #
#########################

function extract_versions {

	local versions=()
	local TOOL_VERSION_names="TOOL_VERSION software.version"
	local CONTAINER_VERSION_names="CONTAINER_VERSION version"

	# Loop on all version variables
	for version_var in TOOL_VERSION CONTAINER_VERSION ; do

		msg DEBUG 2 "Looking for variable $version_var..."
		var_names=${version_var}_names
		for version_var_name in ${!var_names} ; do

			msg DEBUG 2 "Trying variable name $version_var_name..."

			# Look for lines containing version definition
			for cmd in 'ENV' LABEL ; do

				msg DEBUG 2 "Trying command $cmd..."

				line=$($MAKE_VERSIONS_GREP "^[[:space:]]*$cmd[[:space:]]*$version_var_name" $MAKE_VERSIONS_DOCKERFILE)
				[ -n "$line" ] && break
			done

			# Leave as soon as we've found a match
			[ -n "$line" ] && break
		done

		msg DEBUG 2 "Found line \"$line\" for variable $version_var."

		# Check we've found something
		[ -n "$line" ] || msg ERROR "Cannot find definition of $version_var inside $MAKE_VERSIONS_DOCKERFILE file."

		# Replace with right variable name
		line=$(echo $line | $MAKE_VERSIONS_SED -e "s/$version_var_name/$version_var/")
		msg DEBUG 2 "Replaced variable name: \"$line\"."

		# Extract definition of version variable
		version_def=$(echo $line | $MAKE_VERSIONS_SED -e "s/^.*[[:space:]]*\($version_var\)[[:space:]]*=[[:space:]]*\(.*\)$/\1=\2/")
		msg DEBUG "New version variable definition: $version_def"

		# Add definiton to array
		versions+=($version_def)
	done

	# Output versions
	printf "%s\n" "${versions[@]}" >$OUTPUT_FILE

	# Add tag prefix
	if [ -n "$TAGPREFIX" ] ; then

		# Load written file
		msg DEBUG "Sourcing written file \"$OUTPUT_FILE\"..."
		source $OUTPUT_FILE
		msg DEBUG "TOOL_VERSION=$TOOL_VERSION"
		msg DEBUG "CONTAINER_VERSION=$CONTAINER_VERSION"

		# Get git branch
		if [ -n "$BRANCHTAG" ] ; then
			msg DEBUG "Looking for git branch..."
			git=$(which git)
			if [ -n "$git" ] ; then
				msg DEBUG "Found git as \"$git\"."
				branch=$(git status | grep "On branch" | sed 's/^On branch //')
				msg DEBUG "Current git branch is \"$branch\"."
				if [ "$branch" = develop ] ; then
					BRANCH_PREFIX=dev_
					msg DEBUG "Adding prefix \"$BRANCH_PREFIX\" to tag."
				fi
				if [[ $branch == release* ]] ; then
					BRANCH_PREFIX=rc_
					msg DEBUG "Adding prefix \"$BRANCH_PREFIX\" to tag."
				fi
			fi
		fi

		# Append tag prefix definition to the file
		local VERSION_TAG="${BRANCH_PREFIX}v${TOOL_VERSION}_cv${CONTAINER_VERSION}"
	 	echo "CONTAINER_TAG_PREFIX=$VERSION_TAG" >>$OUTPUT_FILE
		msg DEBUG "CONTAINER_TAG_PREFIX=$VERSION_TAG"
	fi
}

#############
# MAIN {{{1 #
#############

# Read arguments
read_args "$@"

# Test presence of Dockerfile
[ -f "$MAKE_VERSIONS_DOCKERFILE" ] || msg ERROR "No \"$MAKE_VERSIONS_DOCKERFILE\" file !"

# Extract versions
extract_versions