#!/bin/bash

# Copyright (c) 2009, 2010, 2012 Peter Palfrader
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

set -e
set -u

MYLOGNAME="`basename "$0"`[$$]"
BASEDIR="/home/staticsync/static-master"
COMPONENTLIST=/etc/static-components.conf

usage() {
	echo "local Usage: $0 <host>"
	echo "via ssh orig command:"
	echo "                      rsync <stuff>"
	echo "                      static-master-update-component <component>"
}

one_more_arg() {
	if [ "$#" -lt 1 ]; then
		usage >&2
		exit 1
	fi
}

info() {
	logger -p daemon.info -t "$MYLOGNAME" "$1"
}

croak() {
	logger -s -p daemon.warn -t "$MYLOGNAME" "$1"
	exit 1
}

lock() {
  local fd="$1"; shift
  local path="$1"; shift
  local exclusive="$1"; shift

  eval "exec $fd< '$path'"

  if [ "$exclusive" -gt 0 ]; then
    locktype="-e"
  else
    locktype="-s"
  fi

  if ! flock "$locktype" "$fd"; then
    echo >&2 "$0: Cannot acquire lock on $base (flock $locktype failed) - Very bad, we should have waited!"
    exit 1
  fi
}

do_rsync() {
	local remote_host="$1"; shift

	local args="--server --sender -vlHtrze.iLsf --safe-links ."
	if [ "$*" = "$args -new-/" ] || [ "$*" = "$args ./-new-/" ] ; then
		local path="$BASEDIR/current-push"
		info "serving $remote_host with $path"
		rsync $args "$path/."
	elif [ "$*" = "$args . -live-/" ] || [ "$*" = "$args . ./-live-/" ] ; then
		local path="$BASEDIR/current-live"
		info "host $remote_host wants $path, acquiring lock"
		lock 200 "$path" 0
		rsync $args "$path/."
	else
		info "NOT allowed for $remote_host: rsync $*"
		echo >&2 "This rsync command ($@) not allowed."
		exit 1
	fi
}

do_update_component() {
	local remote_host="$1"; shift

	one_more_arg "$@"
	component="$1"
	shift

	hit="$(awk -v component="$component" -v host="$remote_host" '$1 == component && $2 == host {print $3; exit}' "$COMPONENTLIST")"
	if [ -n "$hit" ]; then
		exec static-master-update-component "$component"
		echo >&2 "Exec failed"
		croak "exec failed"
	else
		info "Not whitelisted: $remote_host update $component"
		echo >&2 "Not whitelisted: $remote_host update $component"
		exit 1
	fi
}


if [ "${1:-}" = "-h" ] || [ "${1:-}" = "--help" ]; then
	usage
	exit 0
fi

one_more_arg "$@"
remote_host="$1"
shift


# check/parse remote command line
if [ -z "${SSH_ORIGINAL_COMMAND:-}" ] ; then
	croak "Did not find SSH_ORIGINAL_COMMAND"
fi
set "dummy" ${SSH_ORIGINAL_COMMAND}
shift

info "host $remote_host called with $*"

one_more_arg "$@"
action="$1"
shift

case "$action" in
	rsync)
		do_rsync "$remote_host" "$@"
		;;
	static-master-update-component)
		do_update_component "$remote_host" "$@"
		;;
	*)
		croak "Invalid operation '$action'"
		;;
esac