--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_firewall/conditions.lib.lua	Wed Apr 03 16:11:20 2013 +0100
@@ -0,0 +1,94 @@
+local condition_handlers = {};
+
+local jid = require "util.jid";
+
+-- Return a code string for a condition that checks whether the contents
+-- of variable with the name 'name' matches any of the values in the
+-- comma/space/pipe delimited list 'values'.
+local function compile_comparison_list(name, values)
+	local conditions = {};
+	for value in values:gmatch("[^%s,|]+") do
+		table.insert(conditions, ("%s == %q"):format(name, value));
+	end
+	return table.concat(conditions, " or ");
+end
+
+function condition_handlers.KIND(kind)
+	return compile_comparison_list("name", kind), { "name" };
+end
+
+local wildcard_equivs = { ["*"] = ".*", ["?"] = "." };
+
+local function compile_jid_match_part(part, match)
+	if not match then
+		return part.." == nil"
+	end
+	local pattern = match:match("<(.*)>");
+	-- TODO: Support Lua pattern matching (main issue syntax... << >>?)
+	if pattern then
+		if pattern ~= "*" then
+			return ("%s:match(%q)"):format(part, pattern:gsub(".", wildcard_equivs));
+		end
+	else
+		return ("%s == %q"):format(part, match);
+	end
+end
+
+local function compile_jid_match(which, match_jid)
+	local match_node, match_host, match_resource = jid.split(match_jid);
+	local conditions = {
+		compile_jid_match_part(which.."_node", match_node);
+		compile_jid_match_part(which.."_host", match_host);
+		match_resource and compile_jid_match_part(which.."_resource", match_resource) or nil;
+	};
+	return table.concat(conditions, " and ");
+end
+
+function condition_handlers.TO(to)
+	return compile_jid_match("to", to), { "split_to" };
+end
+
+function condition_handlers.FROM(from)
+	return compile_jid_match("from", from), { "split_from" };
+end
+
+function condition_handlers.TYPE(type)
+	return compile_comparison_list("type", type), { "type" };
+end
+
+function condition_handlers.ENTERING(zone)
+	return ("(zones[%q] and (zones[%q][to_host] or "
+		.."zones[%q][to] or "
+		.."zones[%q][bare_to]))"
+		)
+		:format(zone, zone, zone, zone), { "split_to", "bare_to" };
+end
+
+function condition_handlers.LEAVING(zone)
+	return ("zones[%q] and (zones[%q][from_host] or "
+		.."(zones[%q][from] or "
+		.."zones[%q][bare_from]))")
+		:format(zone, zone, zone, zone), { "split_from", "bare_from" };
+end
+
+function condition_handlers.PAYLOAD(payload_ns)
+	return ("stanza:get_child(nil, %q)"):format(payload_ns);
+end
+
+function condition_handlers.FROM_GROUP(group_name)
+	return ("group_contains(%q, bare_from)"):format(group_name), { "group_contains", "bare_from" };
+end
+
+function condition_handlers.TO_GROUP(group_name)
+	return ("group_contains(%q, bare_to)"):format(group_name), { "group_contains", "bare_to" };
+end
+
+function condition_handlers.FROM_ADMIN_OF(host)
+	return ("is_admin(bare_from, %s)"):format(host ~= "*" and host or nil), { "is_admin", "bare_from" };
+end
+
+function condition_handlers.TO_ADMIN_OF(host)
+	return ("is_admin(bare_to, %s)"):format(host ~= "*" and host or nil), { "is_admin", "bare_to" };
+end
+
+return condition_handlers;