#!/bin/sh

set -e

exit0() {
	echo "$1"
	exit 0
}

exit1() {
# FIXME: pass error messages via stderr (not stdout)
#	echo >&2 "Error: $1"
	[ -z "$1" ] || echo "$1"
	exit 1
}

vardir="/var/lib/kannel/hello"
findobjects() {
	set -e
	type="$1"; [ -n "$type" ] || return1 "Internal error (findobjects: empty type)!"; shift
	limit="$@"
	regex="$(echo  "$limit" | perl -ne '/^\/(.+)\/$/ and print $1')"
	args="$(echo  "$limit" | perl -ne 's/.*?([a-z0-9]+).*?/ $1/g and print')"
	[ -d "$vardir/$type" ] || exit0
	if [ -z "$*" ]; then
		cd "$vardir/$type" && find -mindepth 1 -maxdepth 1 -type d -printf '%f\n'
	elif [ -n "$regex" ]; then
		cd "$vardir/$type" && find -mindepth 1 -maxdepth 1 -type d -regex "$regex"
	elif [ -n $args ]; then
		args_multiline="$(echo "$args" | perl -pe 's/[[:space:]]+/\n/g')"
		cd "$vardir/$type" && ! find -mindepth 1 -maxdepth 1 -type d -printf '%f\n' \
			| grep -Fx "$args_multiline" || true
	else
		exit1 "Internal error (findobjects: illegal limit)!"
	fi
}
finditems() {
	set -e
	type="$1"; [ -n "$type" ] || exit1 "Internal error (finditems: empty type)!"; shift
	name="$1"; [ -n "$name" ] || exit1 "Internal error (finditems: empty name)!"; shift
	limit="$@"
	regex="$(echo  "$limit" | perl -ne '/^\/(.+)\/$/ and print $1')"
	args="$(echo  "$limit" | perl -ne 's/.*?([a-z0-9]+).*?/ $1/g and print')"
	dir="$type/$name"
	[ -d "$vardir/$dir" ] || exit0
	if [ -z "$*" ]; then
		cd "$vardir/$dir" && find -mindepth 1 -maxdepth 1 -type f -printf '%f\n'
	elif [ -n "$regex" ]; then
		cd "$vardir/$dir" && find -mindepth 1 -maxdepth 1 -type f -regex "$regex"
	elif [ -n $args ]; then
		args_multiline="$(echo "$args" | perl -pe 's/[[:space:]]+/\n/g')"
		cd "$vardir/$dir" && ! find -mindepth 1 -maxdepth 1 -type f -printf '%f\n' \
			| grep -Fx "$args_multiline" || true
	else
		exit1 "Internal error (finditems: illegal limit)!"
	fi
}
getitem() {
	set -e
	type="$1"; [ -n "$type" ] || exit1 "Internal error (getitem: empty type)!"; shift
	name="$1"; [ -n "$name" ] || exit1 "Internal error (getitem: empty name)!"; shift
	item="$1"; [ -n "$item" ] || exit1 "Internal error (getitem: empty item)!"; shift
	file="$type/$name/$item"
	[ ! -s "$vardir/$file" ] || cat "$vardir/$file"
}
additem() {
	set -e
	type="$1"; [ -n "$type" ] || exit1 "Internal error (additem: empty type)!"; shift
	name="$1"; [ -n "$name" ] || exit1 "Internal error (additem: empty name)!"; shift
	item="$1"; [ -n "$item" ] || exit1 "Internal error (additem: empty item)!"; shift
	data="$*"; [ -n "$data" ] || exit1 "Internal error (additem: empty data)!"; shift
	data="$(echo "$data" | perl -0 -pe 's/\s+/ /g; s/^\s+//; s/\s+$//')"
	truename="$(findobjects "$type" "$name")" || exit1 "$truename"
	[ -n "$truename" ] || exit1 "No $type named \"$name\"!"
	file="$type/$truename/$item"
	[ ! -s "$vardir/$file" ] || linecount="$(grep -c . "$vardir/$file")"
	echo "$data" >> "$vardir/$file"
	chgrp --reference="$vardir" "$vardir/$file"
	echo "$data${linecount+ (on top of $linecount other values)}"
}
addobject() {
	set -e
	type="$1"; [ -n "$type" ] || exit1 "Internal error (addobject: empty type)!"; shift
	name="$1"; [ -n "$name" ] || exit1 "Internal error (addobject: empty name)!"; shift
	oldname="$(findobjects "$type" "$name")" || exit1 "$oldname"
	[ -z "$oldname" ] || exit1 "$type \"$name\" already exist!"

	case "$type" in
	    user)
		session="$(findobjects "session" "default")" || exit1 "$truename"
		[ -z "$session" ] || phone_ccc="$(finditems "session" "$session" "phone_ccc")" || exit1 "$phone_ccc"
		for chunk in $@; do
		  case $chunk in
		    +[[:digit:]]*)
			[ -z "$phone" ] || exit1 "Multiple phone numbers (use only a single number, e.g. 40843136 or +4540843136)!"
			phone_ccc="$chunk"
			;;
		    [[:digit:]][[:digit:]][[:digit:]][[:digit:]]*)
			[ -n "$phone_ccc" ] || [ -n "$phone_ccc_default" ] || exit1 "Unknown country calling code (use international phone numbering, e.g. +4540843136)!"
			[ -z "$phone" ] || exit1 "Multiple phone numbers (use only a single number, e.g. 40843136 or +4540843136)!"
			# TODO: optionally validate $phone_min and $phone_max
			phone="$phone_ccc$chunk"
			;;
		    [[:alpha:]][[:alnum:]]*)
			[ -z "$nick" ] || exit1 "Multiple nick names (use only a single nick name)!"
			nick="$chunk"
			;;
		    *)
			exit1 "Internal error (additems: unknown item)!"
			;;
		  esac
		done
		[ -n "$phone" ] || exit1 "Missing phone number (use a single full number, e.g. 40843136 or +4540843136)!"
		[ -n "$nick" ] || exit1 "Missing nick name!"
		;;
	esac

	mkdir -p "$vardir/$type/$name"
	chgrp --reference="$vardir" "$vardir/$type/$name"
	case "$type" in
	    user)
		additem "$type" "$name" "nick" "$nick"
		additem "$type" "$name" "phone" "$phone"
		details="with nick and phone number"
		;;
	esac

	echo "$name${details+: ($details)}"
}
delobject() {
	set -e
	type="$1"; [ -n "$type" ] || exit1 "Internal error (delobject: empty type)!"; shift
	name="$1"; [ -n "$name" ] || exit1 "Internal error (delobject: empty name)!"; shift
	oldname="$(findobjects "$type" "$name")" || exit1 "$oldname"
	[ -n "$oldname" ] || exit1 "No $type named \"$name\"!"
	items="$(finditems "$type" "$name")" || exit1 "$items"
	for item in $items; do
		rm "$vardir/$type/$name/$item" || exit1 "Internal error!"
	done
	rmdir "$vardir/$type/$name" || exit1 "Internal error!"
	echo "$name"
}

cmd="$1"; shift
case "$cmd" in
  add|create)
	case "$1" in
	  user|group)
		type="$1"; shift
		response="$(addobject "$type" "$@")" || exit1 "Failed adding $type${response+: $response}"
		exit0 "Added $type: $response."
		;;
	  *)
		exit1 "Cannot add \"$1\" (try \"add user\" or \"add group\" instead)!"
		;;
	esac
	;;
  del|delete|remove)
	case "$1" in
	  user|group)
		type="$1"; shift
		response="$(delobject "$type" "$@")" || exit1 "Failed deleting $type${response+: $response}"
		exit0 "Deleted $type: $response."
		;;
	  *)
		exit1 "Cannot delete \"$1\" (try \"del user\" or \"del group\" instead)!"
		;;
	esac
	;;
  list|show|view)
	case "$1" in
	  user|group)
		type="$1"; shift
		response="$(listobject "$type" "$@")" || exit1 "Failed listing $type${response+: $response}"
		exit0 "Listing $type: $response."
		;;
	  *)
		exit1 "Cannot list \"$1\" (try \"list user\" or \"list group\" instead)!"
		;;
	esac
	;;
  status)
	msg="$(/usr/local/sbin/localshowkannelstatus)"
	exit0 "$msg"
	;;
  *)
	exit1 "unknown command \"$cmd\"!"
	;;
esac