#!/bin/sh
#
# Purpose {{{
# This script will create homedir for members of an LDAP group
#   1. Get members list from LDAP group given as argument
# …
#
# 2021-11-19
# }}}
# Vars {{{
readonly PROGNAME=$(basename "${0}")
readonly PROGDIR=$(readlink -m $(dirname "${0}"))
readonly ARGS="${*}"
readonly NBARGS="${#}"
[ -z "${DEBUG}" ] && DEBUG=1
## Export DEBUG for sub-script
export DEBUG

# Default values for some vars
readonly LDAP_GROUP_BASE_DEFAULT="ou=grouper,dc=univ-rennes1,dc=fr"
readonly LDAP_SERVER_DEFAULT="ldap://ldap.univ-rennes1.fr"
if [ -f /etc/nslcd.conf ]; then
	readonly LDAP_PASSWD_CMD_DEFAULT=$(sed -n 's/\(^bindpw \)\(.*\)/\2/p' /etc/nslcd.conf)
	readonly LDAP_USER_CMD_DEFAULT=$(sed -n 's/\(^binddn \)\(.*\)/\2/p' /etc/nslcd.conf)
fi
readonly HOME_BASE_DEFAULT="/home"

## Colors
readonly PURPLE='\033[1;35m'
readonly RED='\033[0;31m'
readonly RESET='\033[0m'
readonly COLOR_DEBUG="${PURPLE}"
# }}}
usage() {                                                       # {{{

	cat <<- EOF
usage: $PROGNAME [-b|-d|-g|-h|-p|-s|-u]

Create homedir for members of the given LDAP group.

EXAMPLES :
    - Create homedir for members of "ldap:group:my_group"
        ${PROGNAME} --group "ldap:group:my_group"

    - Use default SSSD user for ldap requests
        ${PROGNAME} --user-cmd "sed -n 's/\(^ldap_default_bind_dn = \)\(.*\)/\2/p' /etc/sssd/sssd.conf"

OPTIONS :
    -b,--base LDAP_BASE
        Set different LDAP base (default: ${LDAP_GROUP_BASE_DEFAULT}).

    -d,--debug
        Enable debug messages.

    -g,--group LDAP_GROUP_CN
        Required.
        LDAP group to parse in order to get the list of homedir to create
        to create.

    -h,--home,--home-base
        Base directory to use for user's home directory
        (default: ${HOME_BASE_DEFAULT}).

    --help
        Print this help message.

    -p,--password,--password-cmd "sed -n … /etc/…"
        Command to get LDAP bind password from a file (by default,
        works with NSLCD − /etc/nslcd.conf).

    -s,--server ldap://ldap.domain.tld
        LDAP url to use for ldapsearch request
        (default: ${LDAP_SERVER_DEFAULT}).

    -u,--user,--user-cmd "sed -n … /etc/…"
        Command to get LDAP bind user from a file (by default,
        works with NSLCD − /etc/nslcd.conf).

	EOF

}
# }}}
debug_message() {                                               # {{{

	local_message="${1}"

	## Print message if DEBUG is enable (=0)
	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6b\e[m\n' "DEBUG − ${PROGNAME} : ${local_message}"

	return 0
}
# }}}
error_message() {                                               # {{{

	local_error_message="${1}"
	local_error_code="${2}"

	## Print error message
	printf '%b\n' "ERROR − ${PROGNAME} : ${RED}${local_error_message}${RESET}"

	exit "${local_error_code:=66}"
}
# }}}
define_vars() {                                                 # {{{

	# If ldap_group_cn wasn't defined (argument) {{{
	if [ -z "${ldap_group_cn}" ]; then
		## Keep it empty
		ldap_group_cn=""
	fi
	# }}}
	# If ldap_group_base wasn't defined (argument) {{{
	if [ -z "${ldap_group_base}" ]; then
		## Use default value
		ldap_group_base="${LDAP_GROUP_BASE_DEFAULT}"
	fi
	# }}}
	# If ldap_server wasn't defined (argument) {{{
	if [ -z "${ldap_server}" ]; then
		## Use default value
		ldap_server="${LDAP_SERVER_DEFAULT}"
	fi
	# }}}
	# If ldap_passwd wasn't defined (argument) {{{
	if [ -z "${ldap_passwd}" ]; then
		## Use default command
		ldap_passwd="${LDAP_PASSWD_CMD_DEFAULT}"
		debug_message "Use default command to get LDAP password."
	fi
	# }}}
	# If ldap_user wasn't defined (argument) {{{
	if [ -z "${ldap_user}" ]; then
		## Use default command
		ldap_user="${LDAP_USER_CMD_DEFAULT}"
		debug_message "Use default command to get LDAP user."
	fi
	# }}}
	# If home_base wasn't defined (argument) {{{
	if [ -z "${home_base}" ]; then
		## Use default value
		home_base="${HOME_BASE_DEFAULT}"
	fi
	# }}}

	## Temp file vars {{{
	readonly ldap_user_list_path="/tmp/${PROGNAME}.ldap.user.list"
	readonly ldap_previous_user_list_path="/tmp/.${PROGNAME}.previous.ldap.user.list"
	## }}}
}
# }}}

is_var_empty() {                                                # {{{

	## Return False by default
	return_var_empty="1"
	## Total number of variables to test
	local_total_var="${#}"

	loop_count_var_empty="0"

	## While it remains a variable to test
	while [ "${local_total_var}" -gt "${loop_count_var_empty}" ]; do
		debug_message "is_var_empty − \
Test var: ${1}."
		### Test if this is empty and set return value to True
		[ -z "${1}" ] && return_var_empty="0"

		### Increase the number of tested variables
		loop_count_var_empty=$((loop_count_var_empty+1))

		### Shift to the next variable
		shift
	done

	return "${return_var_empty}"

}
# }}}
is_var_empty_silent() {                                         # {{{

	## Return False by default
	return_var_empty_silent="1"
	## Total number of variables to test
	local_total_var="${#}"

	loop_count_var_empty_silent="0"

	## While it remains a variable to test
	while [ "${local_total_var}" -gt "${loop_count_var_empty_silent}" ]; do
		### Test if this is empty and set return value to True
		[ -z "${1}" ] && return_var_empty_silent="0"

		### Increase the number of tested variables
		loop_count_var_empty_silent=$((loop_count_var_empty_silent+1))

		### Shift to the next variable
		shift
	done

	return "${return_var_empty_silent}"

}
# }}}
is_command_available() {                                        # {{{

	local_command_available_cmd="${1}"

	## Return False by default
	return_command_available="1"

	if [ "$(command -v ${local_command_available_cmd})" ]; then
		debug_message "is_command_available − \
${RED}${local_command_available_cmd}${COLOR_DEBUG} seems present on this host."
		return_command_available="0"
	else
		debug_message "is_command_available − \
${RED}${local_command_available_cmd}${COLOR_DEBUG} is not available on this host."
		return_command_available="1"
	fi

	return "${return_command_available}"

}
# }}}
is_directory_absent() {                                         # {{{

	local_directory_absent="${1}"

	## Directory doesn't exists by default
	return_is_directory_absent="0"

	### Check if the directory exists
	# shellcheck disable=SC2086
	if test -d "${local_directory_absent}"; then
		return_is_directory_absent="1"
		debug_message "is_directory_absent − \
The directory ${RED}${local_directory_absent}${COLOR_DEBUG} exists."
	else
		return_is_directory_absent="0"
		debug_message "is_directory_absent − \
The directory ${RED}${local_directory_absent}${COLOR_DEBUG} doesn't exist."
	fi

	return "${return_is_directory_absent}"

}
# }}}
get_ldap_user_list() {                                          # {{{

	## Return False by default
	return_get_ldap_user_list="1"

	debug_message "get_ldap_user_list − \
Create or empty ${RED}${ldap_user_list_path}${COLOR_DEBUG} file to store user list of ${RED}${ldap_group_cn}${COLOR_DEBUG} LDAP group."
	true > "${ldap_user_list_path}"

	if command ldapsearch -ZZ -D "${ldap_user}" -w "${ldap_passwd}" -H "${ldap_server}" -s one -b "${ldap_group_base}" "(cn=${ldap_group_cn})" member \
	| sed -n 's/\(^member: uid=\)\(.*\)\(,ou=.*\)/\2/p' \
	| sort > "${ldap_user_list_path}"; then
		if [ -s "${ldap_user_list_path}" ]; then
			debug_message "get_ldap_user_list − \
${RED}${ldap_group_cn}${COLOR_DEBUG} users list successfully created (see ${ldap_user_list_path} file)."
			command chmod 0400 -- "${ldap_user_list_path}"
			return_get_ldap_user_list="0"
		else
			debug_message "get_ldap_user_list − \
Error, the users list of ${ldap_group_cn} is empty (${ldap_user_list_path} file)."
			return_get_ldap_user_list="1"
		fi
	else
		debug_message "get_ldap_user_list − \
Error in ${RED}ldapsearch${COLOR_DEBUG} command for ${ldap_group_cn} LDAP group."
		return_get_ldap_user_list="1"
	fi

	return "${return_get_ldap_user_list}"

}
# }}}
is_file_present() {                                             # {{{

	local_file_present="${1}"

	## File doesn't exist by default
	return_is_file_present="1"

	### Check if the file exists
	# shellcheck disable=SC2086
	if find ${local_file_present} > /dev/null 2>&1; then
		return_is_file_present="0"
		debug_message "is_file_present − \
The file ${RED}${local_file_present}${COLOR_DEBUG} exists."
	else
		return_is_file_present="1"
		debug_message "is_file_present − \
The file ${RED}${local_file_present}${COLOR_DEBUG} doesn't exist."
	fi

	return "${return_is_file_present}"

}
# }}}
is_file_similar() {                                             # {{{

	local_similar_file_one="${1}"
	local_similar_file_two="${2}"

	## Files aren't similar by default doesn't exist by default
	return_is_file_similar="1"

	if diff --brief -- "${local_similar_file_one}" "${local_similar_file_two}" > /dev/null; then
		debug_message "is_file_similar − \
${local_similar_file_one} and ${local_similar_file_two} are ${RED}similar${COLOR_DEBUG}."
		return_is_file_similar="0"
	else
		debug_message "is_file_similar − \
${local_similar_file_one} and ${local_similar_file_two} are ${RED}NOT${COLOR_DEBUG} similar."
		return_is_file_similar="1"
	fi

	return "${return_is_file_similar}"
}
# }}}
main() {                                                        # {{{

	## If ldapsearch command is not available {{{
	### exit with message and error
	is_command_available "ldapsearch" \
		|| error_message "ldapsearch command doesn't seems to be available. Please install ldap-utils package." "3"
	## }}}

	## Define all vars
	define_vars

	## If ldap_group_cn is empty {{{
	### Print help message
	### AND exit with message and error
	is_var_empty "${ldap_group_cn}" \
		&& usage \
		&& error_message "Please enter a GROUP with -g|--group option." 1
	## }}}
	## If ldap_user or ldap_passwd is empty {{{
	### Print help message
	### AND exit with message and error
	is_var_empty_silent "${ldap_user}" "${ldap_passwd}" \
		&& usage \
		&& error_message "LDAP user or password is empty. Please verify your configuration or the --user-cmd|--passwd-cmd options." 2
	## }}}
	## If home_base directory doesn't exists {{{
	### AND exit with message and error
	is_directory_absent "${home_base}" \
		&& error_message "Home base directory (${home_base}) doesn't exists. Check your configuration or use -h|--home option." 3
	## }}}

	## Try to get the user list of LDAP group {{{
	### OR Exit
	get_ldap_user_list \
		|| error_message "Can't get the user list of ${ldap_group_cn} LDAP group. Please use --debug option." 4
	## }}}
	## If a previous list of users exists {{{
	### If the two lists are the same
	### Exit
	is_file_present "${ldap_previous_user_list_path}" \
		&& is_file_similar "${ldap_user_list_path}" "${ldap_previous_user_list_path}" \
		&& debug_message "main − No new user from previous run, no more actions required." \
		&& exit 0
	## }}}

	## Information message
	debug_message "Create home directory in ${RED}${home_base}${COLOR_DEBUG}, \
for all members of ${RED}${ldap_group_cn},${ldap_group_base}${COLOR_DEBUG} LDAP group \
from ${RED}${ldap_server}${COLOR_DEBUG} LDAP server ."

	## Rename user list for next run of the script
	## AND exit
	mv --force -- "${ldap_user_list_path}" "${ldap_previous_user_list_path}" \
		&& exit 0

}
# }}}

# Manage arguments                                                # {{{
# This code can't be in a function due to argument management

if [ ! "${NBARGS}" -eq "0" ]; then

	manage_arg="0"

	## If the first argument is not an option
	if ! printf -- '%s' "${1}" | grep -q -E -- "^-+";
	then
		## Print help message and exit
		printf '%b\n' "${RED}Invalid option: ${1}${RESET}"
		printf '%b\n' "---"
		usage

		exit 1
	fi

	# Parse all options (start with a "-") one by one
	while printf -- '%s' "${1}" | grep -q -E -- "^-+"; do

	case "${1}" in
		-b|--base )                           ## Define ldap_group_base
			## Move to the next argument
			shift
			## Define var
			readonly ldap_group_base="${1}"
			;;
		-d|--debug )                          ## debug
			DEBUG=0
			;;
		-g|--group )                          ## Define ldap_group_cn
			## Move to the next argument
			shift
			## Define var
			readonly ldap_group_cn="${1}"
			;;
		-h|--home|--home-base )               ## Define home_base
			## Move to the next argument
			shift
			## Define var
			readonly home_base="${1}"
			;;
		--help )                              ## help
			usage
			## Exit after help informations
			exit 0
			;;
		-p|--password|--password-cmd )        ## Define ldap_passwd
			## Move to the next argument
			shift
			## Define var
			readonly ldap_passwd="${1}"
			;;
		-s|--server)                          ## Define ldap_server
			## Move to the next argument
			shift
			## Define var
			readonly ldap_server="${1}"
			;;
		-u|--user|--user-cmd )                ## Define ldap_user
			## Move to the next argument
			shift
			## Define var
			readonly ldap_user="${1}"
			;;
		* )                                   ## unknow option
			printf '%b\n' "${RED}Invalid option: ${1}${RESET}"
			printf '%b\n' "---"
			usage
			exit 1
			;;
	esac

	debug_message "Arguments management − \
${RED}${1}${COLOR_DEBUG} option managed."

	## Move to the next argument
	shift
	manage_arg=$((manage_arg+1))

	done

	debug_message "Arguments management − \
${RED}${manage_arg}${COLOR_DEBUG} argument(s) successfully managed."
else
	debug_message "Arguments management − \
No arguments/options to manage."
fi

# }}}

main

exit 255