#!/bin/bash

# function used by fetch-all* to download server descriptors and
# extra info documents

# Copyright (c) 2005, 2006, 2007, 2008 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.


fetch_digest() {
	local digest
	local objecttype
	local urlpart
	local pathpart
	local target
	local targetdir
	local dirserver
	local ei

	digest="$1"
	objecttype="$2"
	if [ "$objecttype" = "server-descriptor" ] ; then
		urlpart="server"
		pathpart="server-descriptor"
	elif [ "$objecttype" = "extra-info" ] ; then
		urlpart="extra"
		pathpart="extra-info"
	else
		echo "Called fetch_digest with illegal objecttype '$objecttype'" >&2
		exit 1
	fi
	target=$( echo $digest | sed -e 's#^\(.\)\(.\)#'"$pathpart"'/\1/\2/\1\2#' )
	targetdir=$( dirname $target )
	[ -d "$targetdir" ] || mkdir -p "$targetdir"
	if ! [ -e "$target" ]; then
		for dirserver in $DIRSERVERS; do
			wget -q -O "$target" http://$dirserver/tor/$urlpart/d/"$digest" || rm -f "$target"
			if [ -s "$target" ]; then
				if egrep '^opt extra-info-digest ' "$target" > /dev/null; then
					ei=$( egrep '^opt extra-info-digest ' "$target" | awk '{print $3}' | tr 'A-F' 'a-f' )
					fetch_digest "$ei" "extra-info"
				elif egrep '^extra-info-digest ' "$target" > /dev/null; then
					ei=$( egrep '^extra-info-digest ' "$target" | awk '{print $2}' | tr 'A-F' 'a-f' )
					fetch_digest "$ei" "extra-info"
				fi
				break
			else
				rm -f "$target"
			fi
		done
	fi
	#if ! [ -e "$target" ]; then
	#	echo "$objecttype $digest" >> failed
	#fi
}