network.lua

local ColyseusClient = require "colyseus.client"

local client
local room

-- {"8dh34=fg" = "/gameobject1"}
local players_gameobjects = {}

-- ---------------
-- LOCAL FUNCTIONS
-- ---------------

-- support function, Lua does not support natively non-linear tables length
local function get_table_length(t)
	local count = 0
	for _ in pairs(t) do
		count = count + 1
	end
	return count
end

local function register_messages()
	--#IF HEADLESS
	-- -----------------------------------------------
	-- *AUTHORITY* COLYSEUS MESSAGES CALLBACK
	-- these are only executed in the server authority
	-- -----------------------------------------------
	room.state.players:on_add(function(player, session_id)
		-- spawn a player, if session_id match, it's always not controllable because here we are in the game server
		local player_gameobject_id = nil;

		if not player["is_authority"] then
			-- spawn a gameobject as long as it's not the authority
			player_gameobject_id = factory.create("/spawner#factory", vmath.vector3(480, 320, 0), vmath.quat(), { controllable = false })
		end

		if player_gameobject_id then
			players_gameobjects[session_id] = player_gameobject_id
		end
	end)

	room.state.players:on_remove(function(player, session_id)
		local goid_to_remove = players_gameobjects[session_id]

		if goid_to_remove then
			go.delete(goid_to_remove)
			players_gameobjects[session_id] = nil
		end
	end)

	-- Listen for changes in the colyseus state - AUTHORITY
	room.state.players:on_change(function(value, index)
		if value and get_table_length(players_gameobjects) > 0 then
			-- send a message to the correct player script, to indicate that
			-- it needs to move
			local session_id = value.session_id
			local moving_x = value.moving_x
			local moving_y = value.moving_y

			if players_gameobjects[session_id] then
				msg.post(hash(players_gameobjects[session_id]).."#player", "moving", { moving_x = moving_x, moving_y = moving_y })
			end
		end
	end)
	--#ELSE
	-- -------------------------------------------
	-- *GAME CLIENT* COLYSEUS MESSAGES CALLBACK
	-- these are only executed in the game clients
	-- -------------------------------------------
	room.state.players:on_add(function(player, session_id)
		-- spawn a player, if session_id match, it needs to be controllable because it's me.
		local player_gameobject_id = nil;
		local pos = {
			x = player.position.x,
			y = player.position.y
		}

		if session_id == room["sessionId"] then
			player_gameobject_id = factory.create("/spawner#factory", vmath.vector3(pos.x, pos.y, 0), vmath.quat(), { controllable = true })
		else
			if not player["is_authority"] then
				-- we don't want to spawn a player for the authority
				player_gameobject_id = factory.create("/spawner#factory", vmath.vector3(pos.x, pos.y, 0), vmath.quat(), { controllable = false })
				go.set(player_gameobject_id, "position", vmath.vector3(player.position.x, player.position.y, 0))
			end
		end

		if player_gameobject_id then
			players_gameobjects[session_id] = player_gameobject_id
		end
	end)

	room.state.players:on_remove(function(player, session_id)
		local goid_to_remove = players_gameobjects[session_id]

		if goid_to_remove then
			go.delete(goid_to_remove)
			players_gameobjects[session_id] = nil
		end
	end)

	-- Listen for changes in the colyseus state - GAME CLIENT
	room.state.players:on_change(function(value, index)
		-- state has changed, we must update the player velocity
		if value and get_table_length(players_gameobjects) > 0 then
			-- send a message to the correct player script, to indicate that
			-- it needs to move
			local session_id = value.session_id
			local x = value.linear_velocity.x
			local y = value.linear_velocity.y

			if players_gameobjects[session_id] then
				go.set(hash(players_gameobjects[session_id]).."#collisionobject", "linear_velocity", vmath.vector3(x, y, 0))
				go.set(hash(players_gameobjects[session_id]), "position", vmath.vector3(value.position.x, value.position.y, 0))
			end
		end
	end)
	--#ENDIF
end

local function join()
	client = ColyseusClient.new("ws://localhost:2567")

	client:join_or_create("my_room", {}, function(err, _room)
		if err then
			print("Join error")
			pprint(err)
			return
		end

		print("Successfully joined room")
		room = _room

		register_messages()
	end)
end

-- ------------
-- DEFOLD HOOKS
-- ------------

function init(self)
	--#IF HEADLESS
	join()
	--#ENDIF
end

function on_message(self, message_id, message, sender)
	-- -------------------
	-- CONNECTION MESSAGES
	-- -------------------

	if message_id == hash("join") then
		join()
	end

	if message_id == hash("disconnect") then
		if room then
			for _session_id, _goid in pairs(players_gameobjects) do
				go.delete(_goid)
			end

			players_gameobjects = {}
			room:leave()
			print("Room left")
		end
	end

	-- -----------------------
	-- VELOCITY UPDATE MESSAGE
	-- -----------------------

	if message_id == hash("linear_velocity") then
		if get_table_length(players_gameobjects) then
			local session_id = nil

			for _session_id, _goid in pairs(players_gameobjects) do
				if hash(_goid) == hash(message.goid) then
					session_id = _session_id
				end
			end

			room:send("linear_velocity", {
				linear_velocity = {
					x = message.linear_velocity.x,
					y = message.linear_velocity.y
				},
				position = {
					x = message.position.x,
					y = message.position.y
				},
				moving_x = message.moving_x,
				moving_y = message.moving_y,
				session_id = session_id
			})
		end
	end

	-- ------------------
	-- KEY PRESS MESSAGES
	-- ------------------
	
	if message_id == hash("pressed_up") then
		if room then
			room:send("pressed_up")
		end
	end

	if message_id == hash("released_up") then
		if room then
			room:send("released_up")
		end
	end

	if message_id == hash("pressed_down") then
		if room then
			room:send("pressed_down")
		end
	end

	if message_id == hash("released_down") then
		if room then
			room:send("released_down")
		end
	end

	if message_id == hash("pressed_right") then
		if room then
			room:send("pressed_right")
		end
	end

	if message_id == hash("released_right") then
		if room then
			room:send("released_right")
		end
	end

	if message_id == hash("pressed_left") then
		if room then
			room:send("pressed_left")
		end
	end

	if message_id == hash("released_left") then
		if room then
			room:send("released_left")
		end
	end
end