-- BALL: energy ball that flies around, can bounce and activate stuff
-- rnd 2016:

minetest.register_entity("basic_machines:ball",{
	timer = 0, 
	lifetime = 20, -- how long it exists before disappearing
	energy = 1, -- if negative it will deactivate stuff
	owner = "",
	origin = {x=0,y=0,z=0},
	hp_max = 1,
	visual="sprite",
	visual_size={x=.50,y=.50},
	collisionbox = {0,0,0,0,0,0},
	physical=false,
	--textures={"basic_machines_ball"},
		on_punch=function(self, puncher, time_from_last_punch, tool_capabilities, dir) -- ball is punched
			
		end,
	on_activate = function(self, staticdata)
		self.object:set_properties({textures={"basic_machines_ball.png"}})
		self.object:setvelocity({x=0,y=0,z=0})
		self.timer = 0;self.owner = "";
		self.origin = self.object:getpos();
	end,
	
	on_step = function(self, dtime)
		self.timer=self.timer+dtime
		if self.timer>self.lifetime then 
			self.object:remove() 
			return 
		end
		
		local pos=self.object:getpos()
		
		local origin = self.origin;
		local r = 20;
		if math.abs(pos.x-origin.x)>r or math.abs(pos.y-origin.y)>r or math.abs(pos.z-origin.z)>r then -- remove if it goes too far
			self.object:remove() 
			return 
		end
		
		local nodename = minetest.get_node(pos).name;
		local walkable = false;
		if nodename ~= "air" then 
			walkable = minetest.registered_nodes[nodename].walkable;
		end

		if walkable then -- we hit a node
			--minetest.chat_send_all(" hit node at " .. minetest.pos_to_string(pos))
			
			if minetest.is_protected(pos,self.owner) then return end
			local node = minetest.get_node(pos);
			local table = minetest.registered_nodes[node.name];
			if table and table.mesecons and table.mesecons.effector then
				local effector = table.mesecons.effector;
				if self.energy>0 then
					if not effector.action_on then return end
					effector.action_on(pos,node,16); 
				elseif self.energy<0 then
					if not effector.action_off then return end
					effector.action_off(pos,node,16); 
				end
				self.object:remove() 
			else -- bounce
				local v = self.object:getvelocity();
				local opos = {x=math.modf(pos.x),y=math.modf(pos.y), z=math.modf(pos.z)}; -- obstacle
				
				opos.x=math.abs(pos.x-opos.x);
				opos.y=math.abs(pos.y-opos.y);
				opos.z=math.abs(pos.z-opos.z);
				local maxo = math.max(opos.x,opos.y,opos.z);
				--minetest.chat_send_all(minetest.pos_to_string(opos))
				if opos.x == maxo then
					v.x=-v.x
				elseif opos.y == maxo then
					v.y=-v.y
				else
					v.z=-v.z				
				end
				self.object:setvelocity(v);
				if maxo<0.25 then self.object:remove() end -- too deep inside block, just remove
			end
			
			return
		end
	end,
})


minetest.register_node("basic_machines:ball_spawner", {
	description = "Spawns energy ball one block above",
	tiles = {"basic_machines_ball.png"},
	groups = {oddly_breakable_by_hand=2,mesecon_effector_on = 1},
	drawtype = "liquid",
	walkable = false,
	alpha = 150,
	sounds = default.node_sound_wood_defaults(),
	after_place_node = function(pos, placer)
		local meta = minetest.env:get_meta(pos)
		meta:set_string("owner", placer:get_player_name()); 
	end,

	mesecons = {effector = {
		action_on = function (pos, node,ttl) 
			if ttl<0 then return end
			local obj = minetest.add_entity({x=pos.x,y=pos.y,z=pos.z}, "basic_machines:ball");
			local luaent = obj:get_luaentity();
			luaent.energy = 1;
		end,
		
		action_off = function (pos, node,ttl) 
			if ttl<0 then return end
			local obj = minetest.add_entity({x=pos.x,y=pos.y,z=pos.z}, "basic_machines:ball");
			local luaent = obj:get_luaentity();
			luaent.energy = -1;
			obj:set_properties({textures={"basic_machines_ball.png^[colorize:blue:120"}})
		end
		}
	},
})


minetest.register_craft({
	output = "basic_machines:ball_spawner",
	recipe = {
		{"basic_machines:power_cell"},
		{"basic_machines:keypad"}
	}
})