--[[ $%BEGINLICENSE%$
 Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.

 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License as
 published by the Free Software Foundation; version 2 of the
 License.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 02110-1301  USA

 $%ENDLICENSE%$ --]]

function packet_auth(fields)
	fields = fields or { }
	return "\010" ..             -- proto version
		(fields.version or "5.0.45-proxy") .. -- version
		"\000" ..             -- term-null
		"\001\000\000\000" .. -- thread-id
		"\065\065\065\065" ..
		"\065\065\065\065" .. -- challenge - part I
		"\000" ..             -- filler
		"\001\130" ..         -- server cap (long pass, 4.1 proto)
		"\008" ..             -- charset
		"\002\000" ..         -- status
		("\000"):rep(13) ..   -- filler
		"\065\065\065\065"..
		"\065\065\065\065"..
		"\065\065\065\065"..
		"\000"                -- challenge - part II
end

function connect_server()
	-- emulate a server
	proxy.response = {
		type = proxy.MYSQLD_PACKET_RAW,
		packets = {
			packet_auth()
		}
	}
	return proxy.PROXY_SEND_RESULT
end

function read_query( packet )
	if packet:byte() ~= proxy.COM_QUERY then 
		proxy.response = { type = proxy.MYSQLD_PACKET_OK }
		return proxy.PROXY_SEND_RESULT
	end

	if packet:sub(2) == "SELECT NULL" then
		proxy.response = { 
			type = proxy.MYSQLD_PACKET_OK,
			resultset = {
				fields = { { name = "NULL" } },
				rows = {
					{ nil }
				}
			}
		}
	end
	
	return proxy.PROXY_SEND_RESULT
end

