poppy-client/shared/networkFormat.lua

table.unpack = table.unpack or unpack
string.pack = function(...) return love.data.pack("string", ...) end
string.unpack = love.data.unpack
string.packsize = string.packsize or love.data.getPackedSize

-- Lua data types: nil, boolean, number, string, function, userdata, thread, and table.
-- Not representable here: function, userdata, thread.
format = {
--[[ Poppy specific
 0x81 = "remoteCall",
-- lua specific
 0x02 = "shortString",
 0x03 = "longString",
 0x04 = "nil",
 0x05 = "true",
 0x06 = "false",
 0x07 = "number",
-- love2d/poppy specific
 0x48 = "colorAlpha",
 0x49 = "color"]]--
}
format.decodeFunction = function(encoded, index)
	local nameLength, index = string.unpack("<I1", encoded, index)
	local name, index = string.unpack("<c".. nameLength, encoded, index)
	if name == "init" then DEBUG = true end
	local argNumber, index = string.unpack("<I1", encoded, index)
	local clientID, index = string.unpack("<I2", encoded, index)
	local arguments = {}
	for i = 1, argNumber do
		local argtype = ""
		argType, index = string.unpack("<I1", encoded, index)
		if argType == 0x02 then
			local stringLength, nwString
			stringLength, index = string.unpack("<I1", encoded, index)
			nwString, index = string.unpack("<c"..stringLength, encoded, index)
			arguments[i] = nwString
		elseif argType == 0x03 then
			local stringLength, nwString
			stringLength, index = string.unpack("<I2", encoded, index)
			nwString, index = string.unpack("<c"..stringLength, encoded, index)
			arguments[i] = string
		elseif argType == 0x04 then
			arguments[i] = nil
		elseif argType == 0x05 then
			arguments[i] = true
		elseif argType == 0x06 then
			arguments[i] = false
		elseif argType == 0x07 then
			local number
			number, index = string.unpack("<n", encoded, index)
			arguments[i] = number
		elseif argType == 0x48 then
			local color = {}
			color[1], color[2], color[3], color[4], index = string.unpack("<ffff", encoded, index)
			arguments[i] = color
		elseif argType == 0x49 then
			local color = {nwType = "color"}
			color[1], color[2], color[3], index = string.unpack("<fff", encoded, index)
			arguments[i] = color
		else
			error("failed to decode argument " .. i .. " index is at " ..index.. " len is " .. encoded:len() .. "value is " .. argType)
		end
	end
	return name, clientID, arguments
end



format.encodeFunction = function(name, clientID, ...)
	assert(name and clientID)
	-- Format
	-- byte1 0x81 to indicate a function
	-- byte2 length of the name of the function
	-- byte3-byteN name of the function
	-- byteN+1 number of arguments to the function
	-- byteN+2 type of argument
	-- byteN+3-byteM argument specific syntax
	-- byteM+1 type of next argument
	-- and so on
	local encoded = "\x81"
	encoded = encoded .. string.pack("<I1", name:len())
	encoded = encoded  .. name .. string.pack("<I1", select("#", ...))
	-- can't use ipairs, it does stop on nil
	-- can't use pairs, it ignores nil :D
	encoded = encoded .. string.pack("<I2", clientID)
	local args = { ... }
	for i=1, select("#", ...) do
		local value = args[i]
		if type(value) == "function" or  type(value) ==  "CFunction" or type(value) == "userdata"
			or type(value) == "thread" then
			error("unencodeable data passed! of type: " .. type(value))
		elseif type(value) == "nil" then
			encoded = encoded .. "\x04"
		elseif type(value) == "boolean" then
			if value then
				encoded = encoded .. "\x05"
			else
				encoded = encoded .. "\x06"
			end
		elseif type(value) == "string" then
			if value:len() > 255 then
				encoded = encoded .. "\x03" .. string.pack("<I2", value:len()) .. value
			else
				encoded = encoded .. "\x02" .. string.pack("<I1", value:len()) .. value
			end
		elseif type(value) == "number" then
			encoded = encoded .. "\x07" .. string.pack("<n", value)
		elseif type(value) == "table" then
			if value.nwType == "color" and #value == 3 then
				encoded = encoded .. "\x49" .. string.pack("<fff",  value[1], value[2], value[3])
			elseif value.nwType == "color" and #value == 4 then
				encoded = encoded .. "\x48" ..
					string.pack("<ffff", value[1], value[2], value[3], value[4])
			else
				error("Got table but don't know how to encode it")
			end
		else
			error("unimplemented type for encoding!")
		end
	end

	return encoded
end


function format.testEncoder()
	local testCases = {
		Jeremeeeey = { true, true, nil, false, 69, "Jeremy stop that >:(" },
		buildBlocks = { 32, 32, 64, 64, "longHashValueISwear" },
		colorWorld = { {nwType = "color", 0.4, 0.4, 0.4 }, {nwType = "color", 0.4, 0.4, 0.4, 0.5}},
		slangvariants = { "oy mate", "how ya doing", "sup brooo", "heya", "hey there ma dude" }
	}
	print("Running encoder tests...")
	
	for name, value in pairs(testCases) do
		local encoded = format.encodeFunction(name, 3, table.unpack(value))
		local name, _, decodedArgs = format.decodeFunction(encoded)
		
		local sucess = true
		for iter= 1, #value do
			local var = value[iter]
			if var ~= decodedArgs[iter] and not type(var) == table then
				sucess = false
			end
		end
		if sucess then
			print(name .. " suceeded!")
		else
			print(name .. " failed.")
		end
	end
end

return format