_lustre_cmds()
{
	local cmd="$1"
	local sub="$2"

	# "--list-command" prints commands in columns and truncates long ones
	"$cmd" "$sub" --non-existent-option |
		sed -e 1d -e '$d' -e 's/"//g' -e /=/d -e /exit/d -e /quit/d
}

_lustre_long_opts()
{
	local cmd="$1"
	local sub="$2"
	local subsub="$3"

	# strip off usage message decoration and leave long opts
	if [[ -n "$subsub" ]]; then
		"$cmd" "$sub" help "$subsub" |& grep -owE -- '--[-a-zA-Z0]*'
	else
		"$cmd" help "$sub" |& sed -e 1d | grep -owE -- '--[-a-zA-Z0]*'
	fi
	# several commands take the same options as setstripe, except --delete
	case "$sub$subsub" in
	migrate|mirrorcreate|mirrorextend)
		_lustre_long_opts "$cmd" setstripe | grep -v -- --delete
	esac
}

_lustre_short_opts()
{
	local cmd="$1"
	local sub="$2"
	local subsub="$3"

	# strip off usage message decoration and leave short opts
	if [[ -n "$subsub" ]]; then
		"$cmd" "$sub" help "$subsub" |& grep -owE -- '-[-a-zA-Z0]'
	else
		"$cmd" help "$sub" |& grep -owE -- '-[-a-zA-Z0]'
	fi
	# several commands take the same options as setstripe, except -d
	case "$sub$subsub" in
	migrate|mirrorextend|mirrorextend)
		_lustre_short_opts "$cmd" setstripe | grep -v -- -d
	esac
}

_lustre_comp_flags()
{
	local cmd=$1
	local flags

	flags=$("$cmd" help find |& tr "<>[],}" " " |
		grep -- '--component-flags {' | cut -d\{ -f2)
	if [[ -z "$flags" ]]; then
		local version=($("$cmd" --version))

		case "${version[1]}" in
		2.13*) flags="init stale prefer offline nosync extension";;
		2.12*|2.11*) flags="init stale prefer offline nosync";;
		*) flags="init";;
		esac
	fi
	echo $flags
}

_lustre_mountpoints()
{
	findmnt --list -t lustre -n -o TARGET
}

_lustre_mount_fsnames()
{
	local mountpoint

	# FIXME: will fail if newlines in $mountpoint, why would anyone do that?
	_lustre_mountpoints | while read mountpoint; do
		lfs getname -n "$mountpoint" 2> /dev/null
	done
}

_lustre_devices()
{
	lctl device_list | awk '{ print $4 }'
}

_lustre_fsnames()
{
	local mountpoint="${1:-'.'}"

	local fsname=$(lfs getname -n "$mountpoint" 2>/dev/null)

	[[ -n "$fsname" ]] && echo "$fsname" || _lustre_mount_fsnames
}

_lustre_layouts()
{
	"$cmd" help find |& tr "[]," " " | grep -- --layout | sed "s/.*-L //"
}

_lustre_mdts()
{
	lfs mdts $1 | grep _UUID | sed -e "s/[0-9]*: //" -e "s/_UUID.*//"
}

_lustre_osts()
{
	lfs osts $1 | grep _UUID | sed -e "s/[0-9]*: //" -e "s/_UUID.*//"
}

_lustre_pools()
{
	if [[ -d "$1" ]]; then
		"$cmd" pool_list $1 2> /dev/null | grep -v "[Pp]ools from" |
			cut -d. -f2
		return 0
	fi

	for fsname in $(_lustre_fsnames $1); do
		"$cmd" pool_list $fsname 2> /dev/null | grep -v "[Pp]ools from"
	done
}

_lfs()
{
	local cur prev words cword
	local mountpoint cmd sub find_opts

	COMPREPLY=()
	# allow different versions of bash_completion to work
	if declare -F _init_completion > /dev/null; then
		# this provides more functionality, but is only in v2.x
		_init_completion || return
	else
		# this is compatible with both v1.3 and v2.x
		_get_comp_words_by_ref cur prev words cword
	fi

	cmd="${words[0]}"
	sub="${words[1]}"
	[[ "$sub" == "mirror" || "$sub" == "pcc" ]] && subsub="${words[2]}"
	if [[ "$cword" == "1" || "$prev" == "help" ]]; then
		COMPREPLY+=($(compgen -W '$(_lustre_cmds "$cmd")' -- "$cur"))
		return 0
	fi

	case "$cur" in
	--*)
		COMPREPLY+=($(compgen -W '$(_lustre_long_opts "$cmd" "$sub" "$subsub")' -- "$cur"))
		return 0
		;;
	-*)
		# lfs find allows "-longopt" for compatibility with find(1)
		[[ "$sub" == "find" ]] && find_opts=$(_lustre_long_opts "$cmd" find)
		COMPREPLY+=($(compgen -W '$(_lustre_short_opts "$cmd" "$sub" "$subsub") ${find_opts//--/-}' -- "$cur"))
		return 0
		;;
	esac

	case "$sub" in
	check)
		[[ -n "$cur" ]] && return 0
		COMPREPLY+=($(compgen -W '$("$cmd" help check |& grep usage |
					    sed -e "s/[<>|]/ /g" \
					        -e "s/.*check //")' -- "$cur"))
		return 0
		;;
	df)
		mapfile -t COMPREPLY < <(
			_lustre_mountpoints | grep -- "^$cur" | sed 's/ /\\ /g'
		)
		return 0
		;;
	find)
		[[ -d "${words[2]}" ]] && mountpoint="${words[2]}"
		case "${prev/--/-}" in
		-component-flags|-comp-flags)
			# FIXME: this should allow a comma-separated list
			COMPREPLY+=($(compgen -W '$(_lustre_comp_flags)' -- "$cur"))
			return 0
			;;
		-g|-group)
			COMPREPLY+=($(compgen -g -- "$cur"))
			return 0
			;;
		-L|-layout)
			COMPREPLY+=($(compgen -W '$(_lustre_layouts)' -- "$cur"))
			return 0
			;;
		-m|-mdt)
			# FIXME: this should allow a comma-separated list
			COMPREPLY+=($(compgen -W '$(_lustre_mdts "$mountpoint")' -- "$cur"))
			return 0
			;;
		-O|-ost)
			# FIXME: this should allow a comma-separated list
			COMPREPLY+=($(compgen -W '$(_lustre_osts "$mountpoint")' -- "$cur"))
			return 0
			;;
		-pool)
			COMPREPLY+=($(compgen -W '$(_lustre_pools "$mountpoint")' -- "$cur"))
			return 0
			;;
		-t|-type)
			COMPREPLY+=($(compgen -W 'b c d f l p s' -- "$cur"))
			return 0
			;;
		-u|-user)
			COMPREPLY+=($(compgen -u -- "$cur"))
			return 0
			;;
		esac
		if [ -z "$mountpoint" ]; then
			mapfile -t COMPREPLY < <(
				_lustre_mountpoints | grep -- "^$cur" |
					sed -e 's/ /\\ /g'
			)
			return 0
		fi
		;;
	mirror)
		if [[ "$prev" == "$sub" ]]; then
			COMPREPLY+=($(compgen -W '$(_lustre_cmds "$cmd" "$sub")' -- "$cur"))
			return 0
		fi
		;;
	pcc)
		if [[ "$prev" == "$sub" ]]; then
			COMPREPLY+=($(compgen -W '$(_lustre_cmds "$cmd" "$sub")' -- "$cur"))
			return 0
		fi
		;;
	pool_list)
		COMPREPLY+=($(compgen -W '$(_lustre_fsnames
					    _lustre_pools)' -- "$cur"))
		return 0
		;;
	setstripe)
		case "$prev" in
		--component-flags|--comp-flags)
			# only subset allowed, easier to list than exclude for now
			# COMPREPLY+=($(compgen -W '$(_lustre_comp_flags)' -- "$cur"))
			# FIXME: this should allow a comma-separated list
			COMPREPLY+=($(compgen -W 'nosync prefer' -- "$cur"))
			return 0
			;;
		-p|--pool)
			COMPREPLY+=($(compgen -W '$(_lustre_pools)' -- "$cur"))
			return 0
			;;
		esac
		;;
	esac

	_filedir
	return 0
} &&
complete -F _lfs lfs

_lctl()
{
	local cur prev words cword

	COMPREPLY=()
	# allow different versions of bash_completion to work
	if declare -F _init_completion > /dev/null; then
		# this provides more functionality, but is only in v2.x
		_init_completion || return
	else
		# this is compatible with both v1.3 and v2.x
		_get_comp_words_by_ref cur prev words cword
	fi

	cmd="${words[0]}"
	sub="${words[1]}"
	[[ "$sub" == "--device" && $cword -ge 4 ]] && sub="${words[3]}"

	if [[ "$cword" == "1" || "$prev" == "help" ]]; then
		COMPREPLY+=($(compgen -W '$(_lustre_cmds "$cmd")' -- "$cur"))
		return 0
	fi

	case "$cur" in
	--*)
		COMPREPLY+=($(compgen -W '$(_lustre_long_opts "$cmd" "$sub")' -- "$cur"))
		return 0
		;;
	-*)
		COMPREPLY+=($(compgen -W '$(_lustre_short_opts "$cmd" "$sub")' -- "$cur"))
		return 0
		;;
	esac

	case "$sub" in
	--device)
		if [[ "$cword" == "2" ]]; then
			COMPREPLY+=($(compgen -W '$(_lustre_devices)' -- "$cur"))
		elif [[ "$cword" == "3" ]]; then
			COMPREPLY+=($(compgen -W '$(_lustre_cmds "$cmd")' -- "$cur"))
		fi
		return 0
		;;
	get_param|list_param|set_param)
		local filter="s/=$//"
		[[ "$sub" == "set_param" ]] && filter="/[^=/]$/d"
		mapfile -t COMPREPLY < <(
		    "$cmd" list_param -F "${cur#[\"\']}*" 2>/dev/null |
		    sed -e "$filter" -e 's#/$#.#' \
			-e "s#^${cur//\*/[^.]*}#$cur#"
		)
		compopt -o nospace

		return 0
		;;
	pcc)
		if [[ "$prev" == "$sub" ]]; then
			COMPREPLY+=($(compgen -W '$(_lustre_cmds "$cmd" "$sub")' -- "$cur"))
			return 0
		fi
		;;
	pool_list)
		if [[ "$cword" == "2" ]]; then
			COMPREPLY+=($(compgen -W '$(_lustre_mountpoints
						    _lustre_fsnames
						    _lustre_pools)' -- "$cur"))
			return 0
		fi
		;;
	pool_destroy)
		if [[ "$cword" == "2" ]]; then
			COMPREPLY+=($(compgen -W '$(_lustre_pools)' -- "$cur"))
			return 0
		fi
		return 0
		;;
	pool_add|pool_remove)
		if [[ "$cword" == "2" ]]; then
			COMPREPLY+=($(compgen -W '$(_lustre_pools)' -- "$cur"))
			return 0
		elif [[ "$cword" == "3" ]]; then
			COMPREPLY+=($(compgen -W '$(_lustre_osts)' -- "$cur"))
			return 0
		fi
		return 0
		;;
	esac
} &&
complete -F _lctl lctl