#!@PMODULES_HOME@/bin/bash

shopt -s expand_aliases

declare -r bindir=$(cd $(dirname "$0") && pwd)
declare -r libdir=$(cd "${bindir}/../lib" && pwd)

source "${libdir}/libpmodules.bash"

print_version() {
	echo "
Pmodules ${version} using Tcl Environment Modules @MODULES_VERSION@
Copyright GNU GPL v2
" 1>&2
}

usage() {
	local -r prog=$(basename $0)
	print_version
	echo "
Usage: ${prog} [ switches ] [ subcommand ] [subcommand-args ]

Switches:
        --dry-run     do nothing
        --force       force overwrite

Available SubCommands and Args:
        init [--src=<src>] [--user=<user>] <dst>
                Initialize a new minimal Pmodule environment.

        install <module> [--with=<dep>...]
                Install matching modules
"
}
     

declare force='no'
declare dry_run='no'
declare DRY=''
declare subcommand=''
declare sargs=()

subcommand_help_init() {
	echo "
init [--src=<src>] [--user=<user>] <dst>
                Initialize a new minimal Pmodule environment in directory
                <dst>. The <user> parameter must only be present if
                 ${prog} is executed as root.
" 1>&2
}

subcommand_help_install() {
	echo "
install <module>... [--with=<dep>...] [--release=<release>...] [--src=<src>]
                Install matching modules
" 1>&2
}

subcommand_help() {
	if [[ $# == 0 ]]; then
	        usage
	elif typeset -F subcommand_help_$1 > /dev/null 2>&1 ; then
	        # help for sub-command
		subcommand_help_$1
	else
		usage
	fi
}

#
# Derive the relative module installation path
# from the relative modulefile path
#
# $1: relative module file path
#
get_module_prefix() {
	local -a comp=( ${1//\// } )    # split rel.path into components
	local path="${comp[0]}"		# result path
	local -i i
	for ((i=1; i<${#comp[@]}; i+=2)); do
		path+="/${comp[$((-i-1))]}/${comp[$((-i))]}"
	done
	echo "${path}"
}

#
# Derive the relative module release file path
# from the relative module file path
#
# $1: relative module file path
#
get_releasefile_name() {
	echo "$(dirname "$1")/.release-$(basename "$1")"
}

#
# Sync a module from one Pmodules environment to another:
# - sync module installation
# - sync modulefile
# - sync release file
#
# $1: relative modulefile path
# $2: source prefix of Pmodule environment
# $3: target prefix of Pmodule environment
#
sync_module() {
	local -r rel_modulefile=$1
	local -r src_prefix=$2
	local -r target_prefix=$3

	local -r rel_module_prefix=$( get_module_prefix "${rel_modulefile}" )
	local -r rel_releasefile=$( get_releasefile_name "${rel_modulefile}" )

	if [[ ! -d "${target_prefix}/${rel_module_prefix}" ]] || [[ "${force}" == 'yes' ]]; then
		$DRY mkdir -p "${target_prefix}/${rel_module_prefix}" || return $?
		$DRY rsync --links --perms --recursive --delete \
		      "${src_prefix}/${rel_module_prefix}/" \
		      "${target_prefix}/${rel_module_prefix}/" || return $?
	fi
	local -r src_modulefile="${src_prefix}/${PSI_MODULES_ROOT}/${rel_modulefile}"
	local -r src_releasefile="${src_prefix}/${PSI_MODULES_ROOT}/${rel_releasefile}"
	local -r target_modulefile="${target_prefix}/${PSI_MODULES_ROOT}/${rel_modulefile}"
	local -r target_releasefile="${target_prefix}/${PSI_MODULES_ROOT}/${rel_releasefile}"

	if [[ -e "${src_modulefile}" ]] || [[ -e "${src_releasefile}" ]]; then
	        local dir=$( dirname "${target_modulefile}" )
		$DRY mkdir -p "${dir}" || return $?
	fi
	if [[ -e "${src_modulefile}" ]]; then
	        $DRY rsync --links --perms --recursive \
		     "${src_modulefile}" "${target_modulefile}" || return $?
	fi
	if [[ -e "${src_releasefile}" ]]; then
	        $DRY rsync --links --perms --recursive \
		     "${src_releasefile}" "${target_releasefile}" || return $?
	fi
}

subcommand_init() {
	local src=''
	local target_prefixes=()
	local user=''
	local opts=''
	opts=$(get_options -o h -l src: -l user: -l help -- "$@")
	if [[ $? != 0 ]]; then
		subcommand_help_init
		exit 1
	fi
	eval set --  "${opts}"
	while (($# > 0)); do
		case $1 in 
			--src )
				src=$2
				shift
				;;
			--user )
				user=$2
				shift
				;;
			-- )
				:
				;;
			-* | -h | --help )
				echo "$1: illegal option" 1>&2
				subcommand_help_init
				exit 1
				;;
			* )
				target_prefixes+=( "$1" )
				;;
		esac
		shift
	done
	(( ${#target_prefixes[@]} != 0 )) || die 1 "Error: no target directory specified!"

	if [[ -n "${src}" ]]; then
		[[ -d "${src}" ]] || die 1 "Error: ${src}: source directory does not exist!"
		[[ -r "${src}/config/profile.bash" ]] || \
		    die 1 "Error: ${src}: shell profile does not exist or is not readable!"
		source "${src}/config/profile.bash"
	fi
	local -i euid=$(id -u)
	if (( euid == 0 )); then
	        [[ -n "${user}" ]] || \
		    die 1 "Error: --user parameter is required!"
		id -u "${user}" > /dev/null 2>&1 || \
		    die 1 "Error: Unable to retrieve user id of user '${user}'"
	else
		[[ -z "${user}" ]] || \
		    die 1 "Error: --user option is only allowed if running as root!"
	fi
	
	check_pmodules_env || die 1 "Giving up ..."
	
	echo "
Attempting to create a minimal module environment from the
environment at '${PSI_PREFIX}'
"

	init_pmodules_environment() {
		local -r src_prefix="${PSI_PREFIX}"
		local -r target_prefix=$1
		local src=''
		local dst=''
		echo "Initializing target directory '${target_prefix}' ..."
		echo
		if [[ -d "${target_prefix}" ]]  && [[ ${force} == no ]]; then
			echo "Warning: ${target_prefix} already exists."
			get_YN_answer "Do you really want to re-run the initialization? (y/N) " || \
				      die 1 "Abort ..."
		fi

		echo "Creating target directory '${target_prefix}'..."
		$DRY mkdir -p "${target_prefix}" || die 1 "Error: make directory failed!"
		echo

		src="${src_prefix}/${PSI_CONFIG_DIR}/"
		dst="${target_prefix}/${PSI_CONFIG_DIR}/"
		echo "Synching configuration from '${src}' to '${dst}'..."
		$DRY rsync --recursive --links --perms --delete \
		     "${src}" "${dst}" || die 1 "Error: synch operation failed!"
		echo
		
		src="${src_prefix}/${PSI_TEMPLATES_DIR}/"
		dst="${target_prefix}/${PSI_TEMPLATES_DIR}/"
		echo "Synching template files from '${src}' to '${dst}'..."
		$DRY rsync --recursive --links --perms --delete \
		     "${src}" "${dst}" || die 1 "Error: synch operation failed!"
		echo

		dst="${target_prefix}/${PSI_MODULES_ROOT}/"
		echo "Creating root directory '${dst}' for module hierarchy ..."
		$DRY mkdir -p "${dst}"
		echo

		echo "Syncing Pmodules ..."
		sync_module "Tools/Pmodules/${PMODULES_VERSION}" \
			    "${src_prefix}" \
			    "${target_prefix}" || die 1 "Error: sync Pmodules failed!"
		echo

		dst="${target_prefix}/${PSI_CONFIG_DIR}/environment.bash"
		echo "Adding installation source '${src_prefix}' to '${dst}'..."
		sed -i .bak '/PMODULES_INSTALL_SOURCE/d' "${dst}"
		echo "declare -x PMODULES_INSTALL_SOURCE=\"${src_prefix}\"" >> "${dst}"
		echo

		if [[ -n "${user}" ]]; then
	                echo "Changing user of new module environment to '${user}'..."
                        $DRY chown -R "${user}" "${target_prefix}" || die 1 "Error: changing owner failed!"
                        echo
		fi
		echo "New minimal module environment created at '${target_prefix}'."
		echo "To use this environment, execute"
		echo "   sudo ln -fs ${target_prefix} /opt/psi"
		echo "   source /opt/psi/${PSI_CONFIG_DIR}/profile.bash"
	}

	umask 022
	for target_prefix in "${target_prefixes[@]}"; do
		init_pmodules_environment "${target_prefix}"
	done

}

subcommand_install() {
	local opts=''
	local -a with=()
	local -a releases=()
	local -a module_pattern=()
	local -r src_prefix="${PMODULES_INSTALL_SOURCE}"
	local -r target_prefix="${PSI_PREFIX}"

	opts=$(get_options -o hf -l dry-run -l force -l with: -l release: -l help -l src: -- "$@")
	if [[ $? != 0 ]]; then
		subcommand_help_install
		exit 1
	fi
	eval set --  "${opts}"
	while (($# > 0)); do
		case $1 in
			--dry-run )
				DRY='echo'
				;;
			--force | -f )
				force='yes'
				;;
			--release )
				releases+=( "$2" )
				shift
				;;
			--src )
				src_prefix="$2"
				shift
				;;
			--with )
				with+=( "$2" )
				shift
				;;
			-- )
				:
				;;
			-h | --help )
				subcommand_help_install
				exit 1
				;;
			-* )
				echo "$1: illegal option" 1>&2
				subcommand_help_init
				exit 1
				;;
			* )
				module_pattern+=( "$1" )
				;;
		esac
		shift
	done
	local -A modules_to_install
	local -i n=0
	while read rel_modulefile; do
		modules_to_install["${rel_modulefile}"]+='.'
		let n+=1
	done < <(${PMODULES_HOME}/bin/modulecmd bash search \
				 "${module_pattern[@]}" \
				 "${with[@]/#/--with}" \
				 "${releases[@]/#/--release=}" \
				 --no-header --print-modulefiles \
				 --src="${src_prefix}" 2>&1)
	(( n == 0 )) && die 0 "Nothing to install..."
	echo -e "The following modules will be installed/updated:\n" 1>&2
	for key in "${!modules_to_install[@]}"; do
		echo "    ${key}" 1>&2
	done
	echo 1>&2
	get_YN_answer "Do you want to continue? [n] " || die 1 "Aborting..."
	echo 1>&2
	for rel_modulefile in "${!modules_to_install[@]}"; do
		if [[ -d "${target_prefix}/${rel_modulefile}" ]]; then
			echo "    Updating; ${rel_modulefile}..." 1>&2
		else
			echo "    Installing: ${rel_modulefile}..."
		fi
		sync_module "${rel_modulefile}" \
			    "${src_prefix}" \
			    "${target_prefix}"
	done
	echo -e "\nDone!\n" 1>&2
}

while (($# > 0)); do
	case $1 in
		-h | -H | -\? | --help | -help )
			usage
			exit 1
			;;
		-V | --version )
			print_version
			exit 1
			;;
		-f | --force )
			force='yes'
			;;
		--dry-run )
			dry_run='yes'
			DRY='echo'
			;;
		-* )
			echo "$1: unknown switch.\n" 1>&2
			exit 1
			;;
		init|install|help )
			subcommand="subcommand_$1"
			shift
			sargs=( $* )
			shift $#
			;;
		* )
			echo "$1: unknown sub-command" 1>&2
			exit 1
	esac
	shift
done

$subcommand "${sargs[@]}"

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