#!@PMODULES_HOME@/bin/bash

shopt -s expand_aliases

declare -r bindir=$(cd $(dirname "$0") && pwd -P)

get_options() {
	"${bindir}/getopt" "$@"
}

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=<dst>
                Initialize a new minimal Pmodule environment.
"
}
     
log() {
        local -ri fd=$1
        local -r fmt="$2\n"
        shift 2
        printf -- "$fmt" "$@" >> /dev/fd/$fd
}

info() {
        log 2 "$1\n" "${@:2}"
}

error() {
        log 2 "$1\n" "${@:2}"
}

debug() {
        [[ ${PSI_DEBUG} ]] || return 0
        log 2 "$@"
}

die() {
        local -ri ec=$1
        shift
        local cout
        if (( ec == 0)); then
                cout='1'
        else
                cout='2'
        fi      
        if [[ -n $@ ]]; then
                local -r fmt=$1
                shift
                log $cout "$fmt" "$@"
        fi
        exit $ec
}

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() {
	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
}

subcommand_init() {
	local src=''
	local target_dirs=()
	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_dirs+=( "$1" )
				;;
		esac
		shift
	done
	(( ${#target_dirs[@]} != 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=$(id -u)
	if (( euid == 0 )); then
		[[ -n "$ENV_USER" ]] || die 1 "Error: --user parameter is required!"
		id -u "$ENV_USER" > /dev/null 2>&1 || die 1 "Error: Unable to retrieve user id of user '$ENV_USER'"
	else
		[[ -z "$ENV_USER" ]] || die 1 "Error: --user option is only allowed if running as root!"
	fi

	[[ -n "${PSI_PREFIX}" ]] &&
	    [[ -n "${PSI_CONFIG_DIR}" ]] &&
	    [[ -n "${PSI_MODULES_ROOT}" ]] &&
	    [[ -n "${PSI_TEMPLATES_DIR}" ]] &&
	    [[ -n "${PMODULES_HOME}" ]] &&
	    [[ -n "${PMODULES_VERSION}" ]] || die 1 "
Error: the module environment you are going to use as source has not been
initialized properly!"

	[[ -d "${PSI_PREFIX}" ]] &&
	    [[ -d "${PSI_PREFIX}/${PSI_CONFIG_DIR}" ]] &&
	    [[ -d "${PSI_PREFIX}/${PSI_MODULES_ROOT}" ]] &&
	    [[ -d "${PSI_PREFIX}/${PSI_TEMPLATES_DIR}" ]] &&
	    [[ -d "${PMODULES_HOME}" ]] || die 1 "
Error: the module environment '$PSI_PREFIX' has not been initialized properly!"

	echo "
Attempting to create a minimal module environment from the
environment at '${PSI_PREFIX}'
"

	function init_pmodules_environment() {
		local -r target_dir=$1
		local src=''
		local dst=''
		echo "Initializing target directory '${target_dir}' ..."
		if [[ -d "${target_dir}" ]]  && [[ ${force} == no ]]; then
		    echo "Warning: ${target_dir} already exists."
		    read -p "Do you really want to re-run the initialization? (y/N) " ans
		    case ${ans} in
			    y|Y )
				    :
				    ;;
			    * )
				    exit 1
				    ;;
		    esac
		fi

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

		src="${PSI_PREFIX}/${PSI_CONFIG_DIR}/"
		dst="${target_dir}/${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="${PSI_PREFIX}/${PSI_TEMPLATES_DIR}/"
		dst="${target_dir}/${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
		
		src="${PMODULES_HOME}/"
		dst="${target_dir}/${PMODULES_HOME#$PSI_PREFIX/}/"
		echo "Synching Pmodules software from '${src}' to '${dst}'..."
		$DRY mkdir -p "${dst}" || die 1 "Error: creating target directory failed!"
		$DRY rsync --recursive --links --perms --delete \
		     "${src}" "${dst}" || die 1 "Error: synch operation failed!"
		echo
		
		src="${PSI_PREFIX}/${PSI_MODULES_ROOT}/Tools/Pmodules"
		dst="${target_dir}/${PSI_MODULES_ROOT}/Tools/Pmodules"
		echo "Setting up modulefile for Pmodules in '${dst}'..."
		$DRY mkdir -p "${dst}" || die 1 "Error: make directory failed!"
		$DRY ln -fs "../../../${PSI_TEMPLATES_DIR}/Tools/Pmodules/modulefile" \
		     "${dst}/${PMODULES_VERSION}" || die 1 "Error: setting sym-link failed!"
		$DRY cp "${src}/.release-${PMODULES_VERSION}" "${dst}" || die 1 "Error: setting release failed!"
		echo
		
		if [[ -n "${ENV_USER}" ]]; then
	            echo "Changing user of new module environment to '${ENV_USER}'..."
		    $DRY chown -R "${ENV_USER}" "${target_dir}" || die 1 "Error: changing owner failed!"
		    echo
		fi
		echo "New minimal module environment created at '${target_dir}'."
		echo "To use this environment, execute"
		echo "   ln -s ${target_dir} /opt/psi as root (delete the /opt/psi link if it already exists)"
		echo "   source ${target_dir}/$PSI_CONFIG_DIR/profile.bash"
	}

	umask 022
	for target_dir in "${target_dirs[@]}"; do
		init_pmodules_environment "${target_dir}"
	done

}

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|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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