#!/bin/sh
#
# Purpose {{{
# This script will try to get the list of directories that doesn't
# have a owner known from the system
#   1. …
# …
#
# 2022-03-28
# }}}
# 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

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

	cat <<- HELP
usage: $PROGNAME [-d|-h]

Try to give a description…

EXAMPLES :
    - Check the directories of the current place :
        ${PROGNAME}

OPTIONS :
    --debug
        Enable debug messages.

    -h,--help
        Print this help message.

HELP

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

	local_debug_message="${1}"

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

	unset local_debug_message

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

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

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

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

	## If path_to_check wasn't defined (argument) {{{
	if [ -z "${path_to_check}" ]; then
		## Use default value
		readonly path_to_check=$(pwd)
	fi
	## }}}

	## Temp file vars {{{
	full_dir_list_path="/tmp/${PROGNAME}.full.list"
	true > "${full_dir_list_path}"
	unknow_dir_list_path="/tmp/${PROGNAME}.unkwon.list"
	true > "${unknow_dir_list_path}"
	## }}}
}
# }}}
is_file_empty() {                                               # {{{

	local_file="${1}"

	## File is empty by default
	return_is_file_empty="0"

	## Check if the file is empty
	if [ ! -s "${local_file}" ]; then
		return_is_file_empty="0"
		debug_message "is_file_empty − \
The file ${RED}${local_file}${COLOR_DEBUG} is empty or doesn't exists."
	else
		return_is_file_empty="1"
		debug_message "is_file_empty − \
The file ${RED}${local_file}${COLOR_DEBUG} exists and has a size greater than zero."
	fi

	return "${return_is_file_empty}"

}
# }}}
get_dir_list() {                                                # {{{

	## Return False by default
	return_get_dir_list="1"

	## Get directories and exclude hidden
	if command find "${path_to_check}" -mindepth 1 -maxdepth 1 -type d -not -iname '.*' -printf '%f\n' \
		> "${full_dir_list_path}"; then
		debug_message "get_dir_list − \
${RED}${path_to_check}${COLOR_DEBUG} directories list successfully created (see ${full_dir_list_path} file)."
		return_get_dir_list="0"
	else
		debug_message "get_dir_list − \
Error in ${RED}find${COLOR_DEBUG} command for ${path_to_check} directory."
		return_get_dir_list="1"
	fi

	return "${return_get_dir_list}"
}
# }}}

main() {                                                        # {{{

	## Define all vars
	define_vars

	## Get the list of all directories {{{
	get_dir_list
	## }}}
	## Verify if directories list is empty {{{
	### And EXIT with error message
	is_file_empty "${full_dir_list_path}" \
		&& error_message "The directories list of ${path_to_check} is empty (${full_dir_list_path} file)." 10
	## }}}

	## Parse directories list {{{
	while IFS= read -r dir; do
		### Get owner information {{{
		debug_message "while loop - Try to get ${RED}${dir}${COLOR_DEBUG} owner information."
		dir_owner_name="$(stat -c "%U" "${path_to_check}/${dir}" \
			|| error_message "Can't stat ${path_to_check}/${dir} directory." 20)"
		### }}}
		### If owner is UNKNOWN {{{
		if [ "${dir_owner_name}" = "UNKNOWN" ]; then
			debug_message "while loop - Owner of ${path_to_check}/${dir} directory is no longer available on this system (${RED}${dir_owner_name}${COLOR_DEBUG})."
			### Add this directory to specific list
			printf '%b\n' "${path_to_check}/${dir}" >> "${unknow_dir_list_path}"
		### }}}
		### If owner is known from the system {{{
		else
			debug_message "while loop - Owner of ${path_to_check}/${dir} directory is ${RED}${dir_owner_name}${COLOR_DEBUG}, skip this directory."
		fi
		### }}}
	done < "${full_dir_list_path}"
	## }}}

	## Clean temp file {{{
	### full_dir_list_path if DEBUG is NOT enable
	[ ! "${DEBUG}" -eq "0" ] && rm --force -- "${full_dir_list_path}"
	## }}}

	## If unknow_dir_list_path doesn't contains anything {{{
	## Exit with success
	is_file_empty "${unknow_dir_list_path}" \
		&& debug_message "${path_to_check} doesn't contains any directory with unknown owner." \
		&& exit 0
	## }}}

	## If some directories without owner are presents {{{
	debug_message "${RED}${path_to_check}${COLOR_DEBUG} seems to contain some directories without owners. Please check the content of ${unknow_dir_list_path} file."
	## }}}

}
# }}}

# 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 "${1}" in
		--debug )                             ## debug
			DEBUG=0
			;;
		-h|--help )                           ## help
			usage
			## Exit after help informations
			exit 0
			;;
		-d|--dir|--directory )                ## Define path_to_check with given arg
			## Move to the next argument
			shift
			## Define var
			readonly path_to_check="${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 0