#!/bin/sh

set -e

# make data writable both from kannel and designated shell accounts
umask 0007

vardir=/var/lib/kannel/hello
sbindir=/usr/local/sbin

exit0() {
	[ -n "$1" ] && echo "$1"
	exit 0
}
exit1() {
	[ -z "$1" ] || echo "Error: $1" || echo "Internal error!"
	response="${1+Error: $1}${-Internal error!}"
# FIXME: pass error messages via stderr (not stdout)
#	echo >&2 "$response"
	echo "$response"
	exit 1
}

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 $linecount other values)}"
	[ ! -s "$vardir/$file" ] || linecount="$(grep -c . "$vardir/$file")"
	echo "$data" > "$vardir/$file"
#	chgrp --reference="$vardir" "$vardir/$file"
	echo "$data"
}
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
	fallback="$1"; [ -n "$fallback" ] || exit1 "Internal error (addobject: empty fallback)!"; shift
	[ -z "$*" ] || exit1 "Internal error (addobject: too many options)!"
	case "$fallback" in
		keep|replace|fail) :;;
		*) exit1 "Internal error (addobject: unknown fallback)!";;
	esac

#	if [ -e "$vardir/$type/$name" ]; then
	oldname="$(findobjects "$type" "$name")" || exit1 "$oldname"
	if [ -n "$oldname" ]; then
		case "$fallback" in
		  keep)
			action="kept"
			;;
		  replace)
			delopbject "$type" "$oldname"
			;;
# TODO		  rename)
# TODO			renameopbject "$type" "$oldname"
# TODO			;;
		  fail)
			exit1 "Adding $type failed ($name already exists)!"
			;;
		esac
	else
		mkdir -p "$vardir/$type/$name"
#		chgrp -R --reference="$vardir" "$vardir/$type"
	fi
}

cmd="$1"; shift
case "$cmd" in
  add|create)
	type="$1"; [ -n "$type" ] || exit1 "Internal error (empty type)!"; shift
	name="$1"; [ -n "$name" ] || exit1 "Internal error (empty name)!"; shift
	oldname="$(findobjects "$type" "$name")" || exit1 "$oldname"

	case "$type" in
	  default)
		case "$name" in
		    session|prefix)
			item="$name"
			data="$1"
			;;
		    *)
			exit1 "unknown default \"$1\""
			;;
		esac
		str=$(addobject "$type" "$name" keep) || exit1 "$str"
		str=$(additem "$type" "$name" "$item" "$data") || exit1 "$str"
		response="Added $type $name $data"
		;;
	  user)
		session="$(getitem "default" "session" "session")" || exit1 "Internal error: $session"
		[ -z "$session" ] || session_group="$(getitem "session" "$session" "group")" || exit1 "Internal error: $session_group"
		plural=
		for chunk in $@; do
			case $chunk in
			  +[[:digit:]]*)
				[ -z "$phone" ] || exit1 "Too many phone numbers (use only a single number, e.g. 40843136 or +4540843136)!"
				phone="$chunk"
				;;
			  [[:digit:]][[:digit:]][[:digit:]][[:digit:]]*)
				[ -z "$phone" ] || exit1 "Too many phone numbers (use only a single number, e.g. 40843136 or +4540843136)!"
				[ -z "$session" ] || prefix="$(getitem "session" "$session" "prefix")" || exit1 "Internal error: $prefix"
				[ -n "$prefix" ] || exit1 "Missing prefix (use international phone numbering, e.g. +4540843136${session+, or add default prefix to session $session})!"
				# TODO: optionally validate $phone_min and $phone_max
				phone="$prefix$chunk"
				;;
			  [[:alpha:]][[:alnum:]]*)
				[ -z "$groups" ] || plural=true
				groups="${groups+$groups }$chunk"
				;;
			  *)
				exit1 "Internal error (unknown user item \"$1\")!"
				;;
			esac
		done
		response="Added $type $name"
		fallback=fail
		if [ -z "$oldname" ]; then
			[ -n "$phone" ] || exit1 "Missing phone number (required)!"
		else
			[ -n "$phone$groups" ] || exit1 "No items to update (include one or more of phone number and groups)!"
			fallback=keep
			response="Updated $type $name"
		fi
		str=$(addobject "$type" "$name" "$fallback") || exit1 "$str"
		[ -z "$phone" ] || dummy="$(additem "$type" "$name" "phone" "$phone")"
# TODO: distinguish session group from included ones (i.e. mention explicitly if added)
		[ -z "$session_group" ] || groups="$session_group $groups"
		for group in $groups; do
# TODO: strip existing, duplicate and session groups, and mention stripping in response
			dummy="$(additem "$type" "$name" "group" "$group")"
		done
		if [ -n "$phone" ]; then
			if [ -n "$groups" ]; then
				response="$response with phone $phone and group${plural+s} $groups"
			else
				response="$response with phone $phone"
			fi
		elif [ -n "$groups" ]; then
			response="$response with group${plural+s} $groups"
		fi
		;;
	  group)
		for chunk in $@; do
			case $chunk in
			  [[:alpha:]][[:alnum:]]*)
				[ -z "$session" ] || exit1 "Too many sessions (a group can be only in a single session)!"
				session="$chunk"
				;;
			  *)
				exit1 "Internal error (unknown group item \"$1\")!"
				;;
			esac
		done
		response="Added $type $name"
		fallback=fail
		if [ -n "$oldname" ]; then
			[ -n "$session" ] || exit1 "Group already exists (and no session name to update was included)!"
			fallback=keep
			response="Updated $type $name"
		fi
		str=$(addobject "$type" "$name" "$fallback") || exit1 "$str"
		[ -z "$session" ] || dummy="$(additem "$type" "$name" "session" "$session")"
		[ -z "$session" ] || response="$response with session $session"
		;;
	  session)
		for chunk in $@; do
			case $chunk in
			  +[[:digit:]]*)
				[ -z "$prefix" ] || exit1 "Too many country prefixes (use only one, e.g. +45)!"
				prefix="$chunk"
				;;
			  [[:alpha:]][[:alnum:]]*)
				[ -z "$group" ] || exit1 "Too many default groups (use only one)!"
# FIXME: fail if group does not exist
				group="$chunk"
				;;
			  *)
				exit1 "Internal error (unknown session item \"$1\")!"
				;;
			esac
		done
# TODO: distinguish default prefix from included one (i.e. mention explicitly if added)
		[ -n "$prefix" ] || prefix="$(getitem "default" "prefix" "prefix")" || exit1 "Internal error: $prefix"
		response="Added $type $name"
		fallback=fail
		if [ -n "$oldname" ]; then
			[ -n "$prefix$group" ] || exit1 "Session already exists (and no default group or country prefix to add/update was included)!"
			fallback=keep
			response="Updated $type $name"
		fi
		str=$(addobject "$type" "$name" "$fallback") || exit1 "$str"
		[ -z "$prefix" ] || dummy="$(additem "$type" "$name" "prefix" "$prefix")"
		[ -z "$group" ] || dummy="$(additem "$type" "$name" "group" "$group")"
		if [ -n "$prefix" ]; then
			if [ -n "$group" ]; then
				response="$response with default country prefix $prefix and default group $group"
			else
				response="$response with default country prefix $prefix"
			fi
		elif [ -n "$group" ]; then
			response="$response with default group $group"
		fi
		;;
	  *)
		exit1 "Cannot add \"$1\" (try \"/help\" to see supported commands)!"
		;;
	esac
	exit0 "$response"
	;;
  del|delete|remove)
	case "$1" in
	  default|user|group|session)
		type="$1"; shift
		name="$1"; [ -n "$name" ] || exit1 "Internal error (empty name)!"; shift
		[ -z "$*" ] || exit1 "Internal error (too many options)!"
		oldname="$(findobjects "$type" "$name")" || exit1 "Internal error${oldname+: $oldname}"
		[ -n "$oldname" ] || exit1 "No $type named \"$name\"!"
		items="$(finditems "$type" "$name")" || exit1 "Internal error${items+: $items}"
# TODO: find user by phone number
		for item in $items; do
			rm "$vardir/$type/$name/$item" || exit1 "Internal error during $type $name item removal!"
		done
# FIXME: remove items of other objects referencing this object
		rmdir "$vardir/$type/$name" || exit1 "Internal error during $type $name object removal!"
		exit0 "Deleted $type: $name."
		;;
	  *)
		exit1 "Cannot delete \"$1\" (try \"/help\" to see supported commands)!"
		;;
	esac
	;;
  list|show|view)
	case "$1" in
	  default|user|group|session)
		type="$1"; shift
		response="$(listobject "$type" "$@")" || exit1 "Failed listing $type${response+: $response}"
		exit0 "Listing $type: $response."
		;;
	  *)
		exit1 "Cannot list \"$1\" (try \"/help\" to see supported commands)!"
		;;
	esac
	;;
  help)
	cat <<EOF
Admin commands:
/add user NICK [+PREFIX]NUMBER [GROUP ...]
/add group GROUP [USER ...]
/add session SESSION [PREFIX] [GROUP]
/add default prefix|session VALUE
/del user NICK|NUMBER
/del group GROUP
/del session SESSION
/del default prefix|session
EOF
	exit 0
	;;
  status)
	response="$($sbindir/localshowkannelstatus)"
	exit0 "$response"
	;;
  *)
	exit1 "unknown command \"$cmd\"!"
	;;
esac