#!@PMODULES_HOME@/bin/bash
#

#set -o nounset
# we have to unset CDPATH, otherwise 'cd' prints the directoy!
unset CDPATH

# used inside output text only
declare -r  CMD='module'

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

source "${libdir}/libpmodules.bash"

declare -r  version='@PMODULES_VERSION@'
declare -r  modulecmd="${bindir}/modulecmd.tcl"

declare -rx TCL_LIBRARY="${libdir}/tcl8.6"

# required by pre 0.99.3 modulefiles
declare -rx PSI_LIBMODULES="${TCL_LIBRARY}/libmodules.tcl"

# :FIXME: this is not save, if a component contains spaces.
declare -ra modulepath=( ${MODULEPATH//:/ } )

declare verbosity_lvl=${PMODULES_VERBOSITY:-'verbose'}

shopt -s nullglob
declare -a Groups='()'
declare -A HierarchyDepths='()'

save_env() {
	local s=''
	while (( $# > 0 )); do
		s+="$( typeset -p $1 );"
		shift
	done
	echo export PMODULES_ENV=$( "${PMODULES_HOME}/bin/base64" --wrap=0 <<< "$s" )	
}

export_env() {
	local s=''
	while (( $# > 0 )); do
		echo -n "export $1=${!1};"
		shift
	done
}

trap 'save_env Groups HierarchyDepths UsedReleases PMODULES_DEFAULT_GROUPS PMODULES_DEFINED_RELEASES PMODULES_DEFAULT_RELEASES' EXIT

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

usage() {
	print_version
	echo "
USAGE:
        module [ switches ] [ subcommand ] [subcommand-args ]

SWITCHES:
        -h|-H|-?|--help         this usage info
        -V|--version            modules version & configuration options

SUBCOMMANDS:
        + add|load [switches ]  modulefile [modulefile ...]
        + rm|unload             modulefile [modulefile ...]
        + switch|swap           [modulefile1] modulefile2
        + display|show          modulefile [modulefile ...]
        + avail [ switches ]    [modulefile [modulefile ...]]
        + search [ switches ]   [ args ]
        + use [ switches ]      [dir|group|release ...]
        + unuse                 dir|group|release [dir|group|release ...]
        + refresh
        + purge
        + list [ switches ]
        + clear
        + help                  [modulefile|subcommand]
        + whatis                [modulefile [modulefile ...]]
        + apropos|keyword       string
        + initadd               modulefile [modulefile ...]
        + initprepend           modulefile [modulefile ...]
        + initrm                modulefile [modulefile ...]
        + initswitch            modulefile1 modulefile2
        + initlist
        + initclear
" 1>&2
	die 1
}

subcommand_help_add() {
	echo "
USAGE:
        module add     modulefile...
        module load    modulefile...
                Load modulefile(s) into the shell environment. Loading a
		'group-head' will extend the MODULEPATH. E.g.: loading a 
		compiler makes additional modules like openmpi and libraries
		compiled with this compiler available.
" 1>&2
	die 1
}

subcommand_help_load() {
	subcommand_help_add
}

subcommand_help_rm() {
	echo "
USAGE:
        module rm      modulefile...
        moudle unload  modulefile...
                Remove modulefile(s) from the shell environment. Removing
		a 'group-head' will also unload all modules belonging to
		this group.
" 1>&2
	die 1
}

subcommand_help_unload() {
	subcommand_help_rm
}

subcommand_help_switch() {
	echo "
USAGE:
        module switch  [modulefile1] modulefile2
        module swap    [modulefile1] modulefile2
		Switch loaded modulefile1 with modulefile2. If modulefile1
		is not specified, then it is assumed to be the currently
		loaded module with the same root name as modulefile2.
" 1>&2
	die 1
}

subcommand_help_swap() {
	subcommand_help_switch
}

subcommand_help_display() {
	echo "
USAGE:
        module display modulefile...
        module show    modulefile...
		Display information about one or more modulefiles.  The
		display sub-command will list the full path of the
		modulefile(s) and all (or most) of the environment changes
		the modulefile(s) will make if loaded.  It will not display
		any environment changes found within conditional statements.
" 1>&2
	die 1
}

subcommand_help_show() {
	subcommand_help_display
}

subcommand_help_apropos() {
	echo "
USAGE:
        module apropos string
        module keyword string	Seeks through the 'whatis' informations of all modulefiles for
		the specified string.  All module-whatis informations matching
		the string will be displayed.
		
" 1>&2
	die 1
}

subcommand_help_keyword() {
	subcommand_help_apropos
}


subcommand_help_avail() {
	echo "
USAGE:
        module avail string
		List all available modulefiles in the current MODULEPATH. If
		an argument is given, then each directory in the MODULEPATH
		is searched for modulefiles whose pathname match the argument.

		This command does *not* display all installed modules on the
		system. Only *loadable* modules are listed.  The list of 
		available modules may change either by loading other modules,
		e.g. a compiler, or with the sub-command 'use'.
" 1>&2
	die 1
}

subcommand_help_search() {
	echo "
USAGE:
        module search [switches] string...
		Search installed modules. If an argument is given, search
		for modules whose name match the argument.

SWITCHES: 
        --no-header
		Suppress output of a header.

        --release=RELEASE
		Search for modules within this release. You can specify this
		switch multiple times.  Without this switch, the used releases
		will be searched.

        -a|--all-releases
		Search within all releases.
		
        --with=STRING
		Search for modules compiled with modules matching string. The
		command

		module search --with=gcc/4.8.3

		lists all modules in the hierarchy compiled with gcc 4.8.3.
" 1>&2
	die 1
}

subcommand_help_use() {
	echo "
USAGE:
        module use [-a|--append|-p|--prepend] [directory|group|release...]
		Without arguments this sub-command displays information about
		the module search path, used families and releases. You can
		use this sub-command to get a list of available families and
		releases.

		With a directory as argument, this directory will either be
		prepended or appended to the module search path. The default
		is to prepend the directory.

		With a group as argument, the modules in this group will 
		be made available.

		With a release as argument, this modules with this release
		will be made available.

SWITCHES:
        -a | --append -p | --prepend )
                Append/prepend agrument to module search path or list of to be
                searched releases.
" 1>&2
	die 1
}

subcommand_help_unuse() {
	echo "
unuse directory|group|release...
		Remove the given directory, group or release from the search
		path.
" 1>&2
	die 1
}
subcommand_help_update() {
	echo "
USAGE:
        module update
                Attempt  to  reload  all  loaded  modulefiles.
" 1>&2
	die 1
}

subcommand_help_refresh() {
	echo "
USAGE:
        module refresh
                Force a refresh of all non-persistent components of currently
		loaded modules.  This should be used on derived shells where
		aliases need to be reinitialized but the environment variables
		have already been set by the currently loaded modules.
" 1>&2
	die 1
}

subcommand_help_purge() {
	echo "
USAGE:
        module purge
		Unload all loaded modulefiles.
" 1>&2
	die 1
}

subcommand_help_list() {
	echo "
USAGE:
        module list
		List loaded modules.
" 1>&2
	die 1
}

subcommand_help_clear() {
	echo "
USAGE:
        module clear
		Force the Modules package to believe that no modules are
		currently loaded.
" 1>&2
	die 1
}

subcommand_help_whatis() {
	echo "
USAGE:
        module whatis [modulefile...]
                Display the information set up by the module-whatis commands
		inside the specified modulefile(s). If no modulefile is
		specified, all 'whatis' lines will be shown.
" 1>&2
	die 1
}

subcommand_help_initadd() {
	echo "
USAGE:
        module initadd	modulefile...
		Add modulefile(s) to the shell's initialization file in the
		user's home directory.  The startup files checked (in order)
		are:

                    csh -   .modules, .cshrc(.ext), .csh_variables, and
                            .login(.ext)
                    tcsh -  .modules, .tcshrc, .cshrc(.ext), .csh_variables,
                            and .login(.ext)
                    (k)sh - .modules, .profile(.ext), and .kshenv(.ext)
                    bash -  .modules, .bash_profile, .bash_login,
                            .profile(.ext) and .bashrc(.ext)
                    zsh -   .modules, .zcshrc(.ext), .zshenv(.ext), and
                            .zlogin(.ext)

                If a 'module load' line is found in any of these files, the
                modulefile(s) is(are) appended to any existing list of 
                modulefiles.  The 'module load' line must be located in at
                least one of the files listed above for any of the 'init'
                sub-commands to work properly.  If the 'module load' line
                line is found in multiple shell initialization files, all
		of the lines are changed.
" 1>&2
	die 1
}

subcommand_help_initprepend() {
	echo "
USAGE:
        module initprepend modulefile...
		Does the same as initadd but prepends the given modules to
		the beginning of the list.
" 1>&2
	die 1
}

subcommand_help_initrm() {
	echo "
USAGE:
        module initrm modulefile...
		Remove modulefile(s) from the shell's initialization files.
" 1>&2
	die 1
}

subcommand_help_initswitch() {
	echo "
USAGE:
        module initswitch modulefile1 modulefile2
		Switch modulefile1 with modulefile2 in the shell's initialization files.
" 1>&2
	die 1
}

subcommand_help_initlist() {
	echo "
USAGE:
        module initlist
		List all of the modulefiles loaded from the shell's initialization file.
" 1>&2
	die 1
}

subcommand_help_initclear() {
	echo "
USAGE:
	module initclear
		Clear all of the modulefiles from the shell's initialization files.
" 1>&2
	die 1
}

#
# get release of module
# Note:
# - the release of a modulefile outside ${PMODULES_ROOT} is 'stable'
# - the release of a modulefile inside ${PMODULES_ROOT} without a 
#   coresponding release file is 'unstable'
#
# Args:
# 	$1: absolute modulefile name
#
get_release() {
	local -r modulefile=$1

	# is modulefile outside ${PMODULES_ROOT}?
	if [[ ! ${modulefile} =~ ${PMODULES_ROOT} ]]; then
		echo 'stable'
		return 0
	fi

	# we are inside ${PMODULES_ROOT}
	local -r releasefile="${modulefile%/*}/.release-${modulefile##*/}"
	if [[ -r ${releasefile} ]]; then
		# read releasefile, remove empty lines, spaces etc
		local -r data=$( < "${releasefile}" )
		echo ${data}
	else	
		echo 'unstable'
	fi
	return 0
}

: ${PMODULES_DEFINED_RELEASES:=':unstable:stable:deprecated:'}

is_release() {
	[[ ${PMODULES_DEFINED_RELEASES} =~ :$1: ]]
}

is_used_release() {
	[[ ":${UsedReleases}:" =~ :$1: ]]
}

declare used_groups=":${PMODULES_USED_GROUPS}:"

is_used_group() {
	[[ ${used_groups} =~ :$1: ]]
}

module_is_loaded() {
	[[ :${LOADEDMODULES}: =~ :$1: ]]
}

#
# check shebang
# $1: file name to test
is_modulefile() {
	local -r fname=$1
	local shebang
	[[ -r ${fname} ]] || return 1
	read -n 11 shebang < "${fname}"
	[[ "${shebang}" == "#%Module1.0" ]]
}

subcommand_generic0() {
	local -r subcommand=$1
	shift
	local opts=''
	opts=$(get_options -- '' "$@") || subcommand_help_${subcommand}
	eval set --  "${opts}"
	while (( $# > 0 )); do
		case $1 in
			-- )
				shift
				;;
			* )
				die 3 "${CMD} ${subcommand}: illegal argument -- $1"
				;;
		esac
	done
	"${modulecmd}" "${shell}" "${subcommand}"
}

subcommand_generic1() {
	local -r subcommand=$1
	shift
	local opts=''
	opts=$(get_options -- '' "$@") || subcommand_help_${subcommand}
	eval set --  "${opts}"
	local args=()
	while (( $# > 0 )); do
		case $1 in
			-- )
					;;
			* )
				if (( ${#args[@]} == 0 )); then
				        args+=( "$1" )
				else
					die 3 "${CMD} ${subcommand}: only one argument allowed"
				fi
				;;
		esac
		shift
	done
	if (( ${#args[@]} == 0 )); then
	        die 3 "${CMD} ${subcommand}: missing argument"
	fi
	"${modulecmd}" "${shell}" "${subcommand}" "${args[@]}"
}

subcommand_generic1plus() {
	local -r subcommand=$1
	shift
	local opts=''
	opts=$(get_options -- '' "$@") || subcommand_help_${subcommand}
	eval set --  "${opts}"
	local args=()
	while (( $# > 0 )); do
		case $1 in
			-- )
				;;
			* )
				args+=( "$1" )
				;;
		esac
		shift
	done
	if (( ${#args[@]} == 0 )); then
	        die 3 "${CMD} ${subcommand}: missing argument"
	fi
	"${modulecmd}" "${shell}" "${subcommand}" "${args[@]}"
}

subcommand_generic1or2() {
	local -r subcommand=$1
	shift
	local opts=''
	opts=$(get_options -- '' "$@") || subcommand_help_${subcommand}
	eval set --  "${opts}"
	local args=()
	while (( $# > 0 )); do
		case $1 in
			-- )
				;;
			* )
				if (( ${#args[@]} > 2 )); then
					die 3 "${CMD} ${subcommand}: only one or two arguments are allowed"
				fi
				args+=( "$1" )
				;;
		esac
		shift
	done
	if (( ${#args[@]} == 0 )); then
	        die 3 "${CMD} ${subcommand}: missing argument"
	fi
	"${modulecmd}" "${shell}" "${subcommand}" "${args[@]}"
}

#
# load [-fsvw] <module>
# 
# $1: module to load
#
subcommand_load() {
	local release='undef'
	local moduledir=''
	local m=''

	#
	# Test whether a given module can be loaded according to the 
	# accepted releases.
	#
	# Notes:
	#	The variable 'release' in function 'subcommand_load()' will be set.
	#	The release of a modulefile outsite our hierarchy is 'stable'.
	#
	# $1: absolute name of modulefile
	#
	is_loadable() {
		release=$( get_release "$1" )			
		[[ :${UsedReleases}: =~ ${release} ]] && return 0
		return 1
	}

	#
	# Test whether a given module is available.
	# Possible cases:
	# - absolute file- or link-name in- or outside our hierarchy
	# - relative file- or link-name in- or outside out hierarchy
	# - full module name in- or outside our hierarchy
	# - module name without version in- or outside our hierarchy
	# - directory in- or outsite our hierarchy (not supported by modulecmd.tcl!)
	#
	# arguments:
	# 	$1: module name or file
	#
	# possible return values:
	# 	0: is a loadable module
	# 	1: nothing found
	# 	2: wrong shebang
	# 	3: has unused release
	#	4: inside our hierarchy but not loadable
	#
	# Notes:
	#	The variable 'release' in function 'subcommand_load()' will be set.
	#	The variable 'm' in function 'subcommand_load()' may be set.
	#
	is_available() {
		local  m=$1

		# handle the case of an absolute or relative file- or link-name
		if [[ -f ${m} ]]; then
			if [[ "${m:0:1}" != "/" ]]; then
				# convert to absolte path if relative
				m=$(get_abspath "${m}")
			fi
			is_modulefile "${m}" || return 2
			is_loadable "${m}"   || return 3
			if [[ "${m}" =~ "${PMODULES_ROOT}" ]]; then
				for dir in "${modulepath[@]}"; do
					[[ "${m}" =~ "${dir}" ]] && return 0
				done
				return 4
			else
				return 0
			fi
		fi

		# check whether $m is in our modulepath
		for dir in "${modulepath[@]}"; do
			if [[ -d ${dir}/$1 ]]; then
				# module specified without version, like 'hdf5'
				while read fname; do
					is_modulefile "${fname}" || return 2
					if is_loadable "${fname}"; then
						moduledir="${dir}"
						return 0
					fi
				done < <(find "${dir}/$1" -mindepth 1 -maxdepth 1 -type l -o -type f  \! -name ".*")
			else
				# module specified with name/version, like 'hdf5/1.8.14'
				[[ -f ${dir}/$1 ]] || continue
 				[[ -r ${dir}/$1 ]] || continue
				is_modulefile "${dir}/$1" || return 2
		        	if is_loadable "${dir}/$1"; then
					moduledir="${dir}"
					return 0
				fi
			fi
		done
		return 1
	}

	#
	# output load 'hints'
	#
	# Note:
	#	The variable 'm' from the parent function will be used
	#	but not changed.
	#
	# Args:
	#	none
	output_load_hints() {
		local -ra rels=( ${PMODULES_DEFINED_RELEASES//:/ } )
		for rel in "${rels[@]}"; do
			eval $( subcommand_use "${rel}" )
			if is_available "${m}"; then
				info "${m}: is ${rel}! If you want to load this module, run"
				info "\tmodule use ${rel}"
				info "before running"
				info  "\tmodule load ${m}"
				exit 42
			fi
		done
		local something_found='no'
		local -a output=()
		local -a release=()
		local -a loadable=()
		local -i i=0
		local -i n=0
		while read -a line; do
			output[n]="module load ${line[@]:3} ${line[0]}"
			release[n]=${line[1]}
			if [[ ":${UsedReleases}:" =~ "${release[n]}" ]]; then
				loadable[n]='yes'
			else
				loadable[n]='no'
			fi
			n+=1
		done < <(subcommand_search  "${m}" -a --no-header 2>&1)
		info "${CMD} load: module unavailable -- ${m}"
		if (( n > 0 )); then
			info "\nBut the following modules chain(s) are available in the hierarchy:"
			for ((i=n-1; i >=0; i--)); do
				if [[ "${loadable[i]}" == "no" ]]; then
 				        info "${output[i]}\t# ${release[i]}"
				else
					info "${output[i]}"
				fi
			done
		fi
	}

	local opts
	opts=$(get_options -o fsvw -l force -l silent -l verbose -l warn -- "$@") || \
	    subcommand_help_load
	eval set --  "${opts}"
	local args=()
	opts=''
	while (($# > 0)); do
		case $1 in
			-f | --force )
				opts+=' -f'
				;;
			-s | --silent )
				verbosity_lvl='silent'
				;;
			-v | --verbose )
				verbosity_lvl='verbose'
				;;
			-w | --warn )
				verbosity_lvl='warn'
				;;
			-- )
				;;
			* )
				args+=( $1 )
				;;
			esac
			shift
	done
	if (( ${#args[@]} == 0 )); then
		die 2 "${CMD} load: No module specified."
	fi
	for m in "${args[@]}"; do		
		if is_available "${m}"; then
		        if [[ ${verbosity_lvl} != silent ]] && [[ ${release} != stable ]]; then
			        info "Warning: the ${release} module '${m}' has been loaded."
			fi
			"${modulecmd}" "${shell}" ${opts} load "${m}"
		else
			if [[ ${verbosity_lvl} == 'verbose' ]]; then
			        output_load_hints
			else
				die 3 "${CMD} load: module unavailable -- ${m}"
			fi
		fi
	done
}

#
# unload <module>
#
subcommand_unload() {
	# :FIXME: add dependency tests: don't unload if module is required be
	#	  another module
	while (( $# > 0 )); do
		subcommand_generic1 unload "$1"
		shift
	done
}

#
# swap <module> [<module>]
#
subcommand_swap() {
	subcommand_generic1or2 swap "$@"
}

#
# show <module>
#
subcommand_show() {
	while (( $# > 0 )); do
		subcommand_generic1 show "$1"
		shift
	done
}

#
# get all available modules in given directory.
# return list like
#	modulename1 release1 modulename2 release2 ...
#
get_available_modules() {
	local -r dir=$1
	local -r module=$2
	local -r use_releases=${3:-${UsedReleases}}
	local -a mods=()
	while read mod; do
		local release=$( get_release "${dir}/${mod}" )

		if [[ :${use_releases}: =~ :${release}: ]]; then
		        mods+=( "${mod}" ${release} )
		fi
	done < <(MODULEPATH="${dir}" "${modulecmd}" bash -t avail "${module}" 2>&1 | tail -n +2)
	echo "${mods[@]}"
}

#
# avail [-hlt] [<module-pattern>...]
#
subcommand_avail() {
	# use this variable in the output functions
	local -a mods=()
	local dir=''
	
	# get number of columns of terminal
	cols=$(tput cols)

	output_header() {
		local caption=${dir/${PMODULES_ROOT}\/}
		local caption=${caption/\/${PMODULES_MODULEFILES_DIR}/: }
		local caption=${caption/: \//: }
		let i=($cols-${#caption})/2-2
		printf -- "%0.s-" $(seq 1 $i) 1>&2
		printf -- " %s " "${caption}" 1>&2
		printf -- "%0.s-" $(seq 1 $i) 1>&2
		printf -- "\n" 1>&2
	}

	terse_output() {
		output_header
		for (( i=0; i<${#mods[@]}; i+=2 )); do
			local mod=${mods[i]}
			local release=${mods[i+1]}
			case $release in
				stable )
					out=''
					;;
				* )
					out="${release}"
					;;
			esac
			printf "%-20s\t%s\n" "${mod}" "${out}" 1>&2
		done
		info ""
	}

	#
	# :FIXME: for the time being, this is the same as terse_output!
	long_output() {
		output_header
		for (( i=0; i<${#mods[@]}; i+=2 )); do
			local mod=${mods[i]}
			local release=${mods[i+1]}
			case $release in
				stable )
					out=''
					;;
				* )
					out=${release}
					;;
			esac
			printf "%-20s\t%s\n" "${mod}" "${out}" 1>&2
		done
		info ""
	}

	human_readable_output() {
		output_header

		local -i column=$cols
		local -i colsize=16
		for ((i=0; i<${#mods[@]}; i+=2)); do
			if [[ ${verbosity_lvl} == 'verbose' ]]; then
			        local  release=${mods[i+1]}
			        case ${mods[i+1]} in
					stable )
						mod=${mods[i]}
						;;
					* )
						mod="${mods[i]}(${release:0:1})"
						;;
				esac
			else
				mod=${mods[i]}
			fi
			local -i len=${#mod}
			local -i span=$(( len / 16 + 1 ))
			local -i colsize=$(( span * 16 ))
			if (( column+len >= cols )); then
			        printf -- "\n" 1>&2
				column=0
			fi
			if (( column+colsize < cols )); then
			        fmt="%-${colsize}s"
			else
				fmt="%-s"
			fi
			printf "${fmt}" "${mod}" 1>&2
			column+=colsize
		done
		printf -- "\n\n" 1>&2
	}
	local opts=''
	opts=$(get_options -o hlt -l human -l long -l terse -- "$@") || subcommand_help_avail
	eval set --  "${opts}"
	local pattern=()
	local output_function=''
	local opts=''
	while (($# > 0)); do
		case $1 in
			-h | --human )
				[[ -z ${opts} ]] || \
				    die 1 "${CMD} list: you cannot set both options: '$1' and '${opts}'."
				opts=$1
				output_function='human_readable_output'
				;;
			-l | --long )
				[[ -z ${opts} ]] || \
				    die 1 "${CMD} list: you cannot set both options: '$1' and '${opts}'."
				opts=$1
				output_function='long_output'
				;;
			-t | --terse )
				[[ -z ${opts} ]] || \
				    die 1 "${CMD} list: you cannot set both options: '$1' and '${opts}'."
				opts=$1
				output_function='terse_output'
				;;
			-- )
				;;
			* )
				pattern+=( "$1" )
				;;
		esac
		shift
	done
	output_function=${output_function:-human_readable_output}
	if (( ${#pattern[@]} == 0 )); then
	        pattern+=( '' )
	fi
	for string in "${pattern[@]}"; do
		for dir in "${modulepath[@]}"; do
			mods=( $( get_available_modules "${dir}" "${string}" ) )
			[[ ${#mods[@]} == 0 ]] && continue

			${output_function}
		done
	done
}

# get available groups
# $1: root of modulefile hierarchy
#
get_groups () {
	local -r root="$1"
	{
		cd "${root}" 
		for f in [A-Z]*; do
			Groups+=( $f )
		done
	};
}

#
# $1: root of modulefile hierarchy
get_hierarchy_depth () {
	local -r root="$1"
	{
		cd "${root}"
		local _group
		for _group in "${Groups[@]}"; do
			local  tmp=$(find "${_group}/modulefiles" -depth -type f -o -type l | head -1)
			local -a tmp2=( ${tmp//\// } )
			local depth=${#tmp2[@]}
			let depth-=4
			HierarchyDepths[$_group]=${depth} 
		done
	};
}

#
# use [-a|--append|-p|--prepend] [directory|group|release...]
#
subcommand_use() {
	if (( ${#Groups[@]} == 0 )); then
	        get_groups "${PMODULES_ROOT}"
		get_hierarchy_depth "${PMODULES_ROOT}"
	fi
	print_info() {
		local f
		local r
		info "Used groups:"
		for f in ${used_groups//:/ }; do
			info "\t${f}"
		done
		info "\nUnused groups:"
		local _group
		for _group in "${Groups[@]}"; do
			local -i depth=${HierarchyDepths[${_group}]}
			if ! is_used_group "${_group}" && (( depth == 0 )); then
			    info "\t${_group}"
			fi
		done
		
		info "\nUsed releases:"
		for r in ${UsedReleases//:/ }; do
			info "\t${r}"
		done
		info "\nUnused releases:"
		for r in ${PMODULES_DEFINED_RELEASES//:/ }; do
			if ! is_used_release $r; then
				info "\t${r}"
			fi
		done

		info "\nAdditonal directories in MODULEPATH:"
		let n=0
		for (( i=0; i<${#modulepath[@]}; i++)); do
			if [[ ! ${modulepath[i]} =~ ${PMODULES_ROOT} ]]; then
			        info "\t${modulepath[i]}"
			        let n+=1
			fi
		done
		if (( n == 0 )); then
		        info "\tnone"
		fi
		info "\n"
	}

	use () {
		
		local dirs_to_add=()
		local subcommand_switches=''
		while (( $# > 0)); do
			arg=$1
			# if is release
			# ...
			# elif is group
			# ...
			# elif matches modulepath root
			# ...
			# elif is directory
			# ...
			local modulefiles_dir="${PMODULES_ROOT}/${arg}/${PMODULES_MODULEFILES_DIR}"
			if [[ ${arg} == -a ]] || [[ ${arg} == --append ]]; then
			        subcommand_switches='--append'
			elif [[ ${arg} == -p ]] || [[ ${arg} == --prepend ]]; then
			        subcommand_switches=''
			elif is_release "${arg}"; then
			        # releases are always *appended*
			        append_path UsedReleases "${arg}"
			elif [[ ! ${arg} =~ */* ]] && [[ -d ${modulefiles_dir} ]]; then
				if (( ${HierarchyDepths[$arg]} != 0 )); then
					die 3 "${CMD} ${0##_}: cannot add group ${arg} to module path"
				fi
				append_path PMODULES_USED_GROUPS "${arg}"
			       	dirs_to_add+=( ${modulefiles_dir} )
			elif [[ ${arg} =~ ^${PMODULES_ROOT} ]]; then
				die 3 "${CMD} ${0##_}: illegal directory: ${arg}"
			elif [[ -d ${arg} ]]; then
			        local normalized_dir=$(cd "${arg}" && pwd)
				dirs_to_add+=( ${normalized_dir} )
			elif [[ ${arg} =~ "-*" ]]; then
				die 3 "${CMD} ${0##_}: illegal switch: ${arg}"
			else
				die 3 "${CMD} ${0##_}: neither a directory, release or group: ${arg}"
			fi
			shift
		done
		echo "export PMODULES_USED_GROUPS=${PMODULES_USED_GROUPS}"
		[[ ${#dirs_to_add[@]} == 0 ]] && return

		for dir in "${dirs_to_add[@]}"; do
			subcommand_generic1 use ${subcommand_switches} "${dir}"
		done
	}
	
	if [[ $# == 0 ]]; then
	        print_info
	else
		use "$@"
	fi
}

#
# unuse directory|group|release...
#
subcommand_unuse() {
	local opts=''
	opts=$(get_options -- '' "$@") || subcommand_help_unuse
	eval set --  "${opts}"
	local dirs_to_remove=()
	while (( $# > 0)); do
		if [[ "$1" == "--" ]]; then
		        shift
			continue
		fi
		arg=$1
		# if is release
		# ...
		# elif is group
		# ...
		# elif matches modulepath root
		# ...
		# elif is directory
		# ...
		local modulefiles_dir="${PMODULES_ROOT}/${arg}/${PMODULES_MODULEFILES_DIR}"
		if is_release "${arg}"; then
			remove_path UsedReleases "${arg}"
		elif [[ ! ${arg} =~ */* ]] &&  [[ -d ${modulefiles_dir} ]]; then
			if (( ${HierarchyDepths[$arg]} != 0 )); then
				die 3 "${CMD} ${0##_}: cannot remove group ${arg} from module path"
			fi
			remove_path PMODULES_USED_GROUPS "${arg}"
			dirs_to_remove+=( ${modulefiles_dir} )
		elif [[ -d ${arg} ]]; then
			local normalized_dir=$(cd "${arg}" && pwd)
			dirs_to_remove+=( ${normalized_dir} )
		elif [[ ${arg} =~ ^${PMODULES_ROOT} ]]; then
			die 3 "${CMD} ${0##_}: illegal directory: ${arg}"
		elif [[ ${arg} =~ "-*" ]]; then
		        die 3 "${CMD} ${0##*_}: illegal option: ${arg}"
		else
			die 3 "${CMD} ${0##*_}: not a directory: ${arg}"
		fi
		shift
	done
	echo "export PMODULES_USED_GROUPS=${PMODULES_USED_GROUPS}"
	[[ ${#dirs_to_remove[@]} == 0 ]] && return
	for dir in "${dirs_to_remove[@]}"; do
		subcommand_generic1 unuse "${dir}"
	done
}

#
# update
#
# :FIXME: either compile Modules with --enable-beginenv or remove the sub-command
#
subcommand_update() {
	subcommand_generic0 update "$@"
}

#
# refresh
#
subcommand_refresh() {
	subcommand_generic0 refresh "$@"
}

#
# purge
#
subcommand_purge() {
	subcommand_generic0 purge "$@"
}

#
# list [-hlt]
#
subcommand_list() {
	local opts=''
	opts=$(get_options -o hlt -l human -l long -l terse -- "$@") || subcommand_help_list
	eval set --  "${opts}"
	local opts=''
	while (( $# > 0 )); do
		case $1 in
			-h | --human )
				[[ -z ${opts} ]] || \
				    die 1 "${CMD} list: you cannot set both options: '$1' and '${opts}'."
				opts='-h'
				;;
			-l | --long )
				[[ -z ${opts} ]] || \
				    die 1 "${CMD} list: you cannot set both options: '$1' and '${opts}'."
				opts='-l'
				;;
			-t | --terse )
				[[ -z ${opts} ]] || \
				    die 1 "${CMD} list: you cannot set both options: '$1' and '${opts}'."
				opts='-t'
				;;
			-- )
				;;
			* )
				die 1 "${CMD} list: invalid argument -- $1"
				;;
		esac
		shift
	done
	"${modulecmd}" "${shell}" list "${opts}"
}

pmodules_init() {
	source "${PMODULES_ROOT}/${PMODULES_CONFIG_DIR}/environment.bash"

	declare -g LOADEDMODULES=''
	declare -g PMODULES_USED_GROUPS=''
	declare -g MODULEPATH=''
	declare -g _LMFILES_=''
	for group in ${PMODULES_DEFAULT_GROUPS}; do
		append_path MODULEPATH "${PMODULES_ROOT}/${group}/${PMODULES_MODULEFILES_DIR}"
		append_path PMODULES_USED_GROUPS "${group}"
	done
	declare -ag Groups='()'
	declare -Ag HierarchyDepths='()'
	declare -g  UsedReleases=''
	for r in ${PMODULES_DEFAULT_RELEASES//:/ }; do
		append_path UsedReleases "${r}"
	done

}

#
# clear
#
subcommand_clear() {
	local opts=''
	opts=$(get_options -- '' "$@") || subcommand_help_${subcommand}
	eval set --  "${opts}"
	while (( $# > 0 )); do
		case $1 in
			-- )
				shift
				;;
			* )
				die 3 "${CMD} ${subcommand}: illegal argument -- $1"
				;;
		esac
	done
	pmodules_init
	export_env LOADEDMODULES PMODULES_USED_GROUPS MODULEPATH _LMFILES_
}

#
# search [switches] [STRING...]
#
subcommand_search() {
	local modules=()
	local with_modules='//'
	local src_prefix=''
	local _print_header='yes'
	local _print_modulefiles='no'
	local use_releases=':'
	local -r fmt="%-20s %-10s %-12s %-s\n"

	# no args
	print_header() {
		printf '\n' 1>&1
		printf "${fmt}" "Module" "Release" "Group" "Requires" 1>&2
		printf -- '-%.0s' {1..60} 1>&2
		printf '\n' 1>&2
	}

	# args:
	# $1: module name pattern
	search () {
		local -r module=$1
		# we must write temporary results to a file for sorting
		local -r tmpfile=$( mktemp /tmp/$(basename $0).XXXXXX ) \
		    || die 1 "Oops: unable to create tmp file!"
		local _group
		# loop over all groups
		for _group in "${Groups[@]}"; do
			local depth=${HierarchyDepths[${_group}]}
			# get all potential directories of group with module-files 
			local mpaths=( $(find \
					     "${src_prefix}/${_group}/modulefiles" \
					     -type d \
					     -mindepth ${depth} -maxdepth ${depth} \
					     2>/dev/null))
			local mpath
			for mpath in "${mpaths[@]}"; do
				# get dependencies encoded in directory name
				local p="${mpath/${src_prefix}}"
				p=( ${p//\// } )
				local deps=()
				local -i i
				for ((i=2; i < ${#p[@]}; i+=2)); do
					deps+=( ${p[i]}/${p[i+1]} )
				done
				local requires=${deps[@]}

				# get and print all available modules in $mpath
				# with respect to the requested releases
				local mods=( $( get_available_modules \
						    "${mpath}" \
						    "${module}" \
						    "${use_releases}" ) )
				[[ ${#mods[@]} == 0 ]] && continue
				for (( i=0; i<${#mods[@]}; i+=2 )); do
					printf "${fmt}" ${mods[i]} "${mods[i+1]}" \
					       ${_group} "${requires}" >> "${tmpfile}"
				done
			done
		done
		if [[ "${_print_modulefiles}" == "no" ]]; then
			sort -k 1,1 -k 4,4 -k 5,5 "${tmpfile}" | awk "${with_modules}" 1>&2
		else
			while read -a line; do
				# group first
				local out="${line[2]}/"
				# add directory of modulefiles
				out+="${PMODULES_MODULEFILES_DIR}/"
				for d in "${line[@]:3}"; do
					out+="$d/"
				done
				out+="${line[0]}"
				info "${out}"
			done < <(sort -k 1,1 -k 4,4 -k 5,5 "${tmpfile}" | awk "${with_modules}")
		fi
		rm -f "${tmpfile}"
	}

	opts=$(get_options -o 'ahH?' \
			   -l help \
			   -l no-header \
			   -l print-modulefiles \
			   -l release: \
			   -l with: \
			   -l all-releases \
			   -l src: \
			   --  "$@") || subcommand_help_${0##*_}
	eval set --  "${opts}"
	
	while (( $# > 0 )); do
		case $1 in
			--no-header )
				_print_header='no'
				;;
			--print-modulefiles )
				_print_modulefiles='yes'
				_print_header='no'
				;;
			--release )
				is_release "$2" || \
				    die 1 "${CMD} search: illegal release name -- $2"
				use_releases+="$2:"
				shift
				;;
			--with )
				if [[ -z $2 ]] || [[ "$2" =~ "-*" ]]; then
				        die 1 "${CMD} search: with what?"
				fi
				with_modules+=" && / ${2//\//\\/}/"
				shift
				;;
			-a | --all-releases )
				use_releases="${PMODULES_DEFINED_RELEASES}"
				;;
			--src )
				src_prefix=$2
				check_pmodules_directories "${src_prefix}"
				
				shift
				;;
			-\? | -h | -H | --help )
				usage
				;;
			-- )
				;;
			* )
				modules+=( "$1" )
				;;
		esac
		shift
	done
	if [[ -z "${src_prefix}" ]]; then
	        src_prefix="${PMODULES_ROOT}"
	fi
	
	if [[ "${use_releases}" == ":" ]]; then
                use_releases=":${UsedReleases}:"
	fi
	
	[[ "${_print_header}" == "yes" ]] && print_header
	if [[ ${#modules[@]} == 0 ]]; then
		modules+=( '' )
	fi

	if (( ${#Groups[@]} == 0 )) || [[ ${src_prefix} != ${PMODULES_ROOT} ]]; then
	        get_groups "${src_prefix}"
		get_hierarchy_depth "${src_prefix}"
	fi
	
	for module in "${modules[@]}"; do
		search "${module}"
	done
}

#
# help [module|sub-command]
#
subcommand_help() {
	local opts=''
	opts=$(get_options -- '' "$@") || usage
	eval set --  "${opts}"
	local arg=''
	
	while (( $# > 0 )); do
		case $1 in
			-- )
				:
				;;
			* )
				[[ -z ${arg} ]] || \
				    die 1 "${CMD} help: only one argument allowed."
				arg="$1"
				;;
		esac
		shift
	done
	if [[ -z ${arg} ]]; then
	        usage
	elif typeset -F subcommand_help_${arg} > /dev/null 2>&1 ; then
	        # help for sub-command
		subcommand_help_${arg}
	else
		# :FIXME: print help of newest *available* module
		# (respecting UsedReleases)
		subcommand_generic1plus help "${arg}"
	fi
}

#
# whatis [module]
#
subcommand_whatis() {
	if (( $# == 0 )); then
	        subcommand_generic0 whatis
	else
		subcommand_generic1plus whatis "$@"
	fi
}

#
# apropos string
#
subcommand_apropos() {
	subcommand_generic1 apropos "$@"
}

#
# initadd module...
#
subcommand_initadd() {
	subcommand_generic1plus initadd "$@"
}

#
# initprepend module...
#
subcommand_initprepend() {
	subcommand_generic1plus initprepend "$@"
}

#
# initrm module...
#
subcommand_initrm() {
	subcommand_generic1plus initrm "$@"
}

#
# initswitch module1 module2
#
subcommand_initswitch() {
	subcommand_generic1or2 initswitch "$@"
}

#
# initlist
#
subcommand_initlist() {
	subcommand_generic0 initlist "$@"
}

#
# initclear
#
subcommand_initclear() {
	subcommand_generic0 initclear "$@"
}

if [[ -n ${PMODULES_ENV} ]]; then
	eval "$("${PMODULES_HOME}/bin/base64" -d <<< "${PMODULES_ENV}" 2>/dev/null)"
else
	pmodules_init
fi

case $1 in
	bash )
		declare shell="$1"
		;;
	* )
		die 1 "${CMD}: unsupported shell -- $1"
		;;
esac
shift

declare -a sargs=()
declare -a opts=()
while (( $# > 0 )); do
	case $1 in
		-H | -\? | --help | -help )
			usage
			;;
		-V | --version )
			print_version
			die 1
			;;
		-f | --force | -s | --silent | -v | --verbose | -w | --warn )
			opts+=( "$1" )
			;;
		-t | --terse | -l | --long | -h | --human )
			opts+=( $1 )
			;;
		-a | --appent | -p | --prepend )
			opts+=( "$1" )
			;;
		--debug )
			set -x
			;;
		-* )
			die 1 "$1: unknown switch."
			;;
		add|load )
			subcommand='subcommand_load'
			shift
			sargs=( "$@" )
			shift $#
			;;
		rm|unload )
			subcommand='subcommand_unload'
			shift
			sargs=( "$@" )
			shift $#
			;;
		switch|swap )
			subcommand='subcommand_swap'
			shift
			sargs=( "$@" )
			shift $#
			;;
		display|show )
			subcommand='subcommand_show'
			shift
			sargs=( "$@" )
			shift $#
			;;
		apropos|keyword )
			subcommand='subcommand_apropos'
			shift
			sargs=( "$@" )
			shift $#
			;;
		avail|search|use|unuse|update|refresh|purge|list|clear|whatis|help )
			subcommand=subcommand_$1
			shift
			if (( $# > 0 )); then
			    sargs=( "$@" )
			    shift $#
			fi
			;;
		initadd|initprepend|initrm|initswitch|initlist|initclear )
			subcommand=subcommand_$1
			shift
			sargs=( "$@" )
			shift $#
			;;
		* )
			die 1 "${CMD}: unknown sub-command -- $1"
			;;
	esac
	shift
done

$subcommand "${sargs[@]}" "${opts[@]}"

# Local Variables:
# mode: sh
# sh-basic-offset: 8
# tab-width: 8
# End: