Group = {}

FFI.cdef[[
	struct Port;
	struct Net {
		bool state;
		bool fxstate;
		bool in_queue;
		int updatetick;
		int internal_ref;
		int state_num;
		int num_in_ports_update;
		struct Port* in_ports_update[1];
	};
]]

function Group.new(self)
	local o = {
		state = false,
		fxstate = false,
		updatetick = 0,
		wires = {},
		out_ports = {},
		in_ports = {},
		in_ports_update = {},
		
		state_num = 0,
		in_queue = false,
	
		nwires = 0,
		nout_ports = 0,
		nin_ports = 0,
	}
	setmetatable(o, self)
	self.__index = self
	return o
end

function Group.getsize(self)
	return self.nwires + self.nout_ports + self.nin_ports
end

function Group.addwire(self, wire)
	if Wire.getgroup(wire) ~= self then
		if Wire.getgroup(wire) ~= nil then
			Group.mergewith(self, Wire.getgroup(wire))
		else
			self.wires[wire] = wire
			self.nwires = self.nwires + 1
			
			Wire.setgroup(wire, self)
			Wire.update(wire)
			Simulation.queuegroup(GSim, self)
		end
	end
end

function Group.removewire(self, wire)
	Wire.setgroup(wire, nil)
	self.wires[wire] = nil
	
	local sim = GSim
	
	for k, wire in pairs(self.wires) do
		Wire.setgroup(wire, nil)
	end
	
	for k, port in pairs(self.out_ports) do
		Port.setgroup(port, nil)
	end
	
	for k, port in pairs(self.in_ports) do
		Port.setgroup(port, nil)
	end
	
	for k, wire in pairs(self.wires) do
		Simulation.connectwire(sim, wire)
	end
	
	for k, port in pairs(self.out_ports) do
		Simulation.connectport(sim, port)
	end
	
	for k, port in pairs(self.in_ports) do
		Simulation.connectport(sim, port)
	end
	
	self.wires = {}
	self.out_ports = {}
	self.in_ports = {}
	
	self.nwires = 0
	self.nout_ports = 0
	self.nin_ports = 0
	
	Simulation.dequeuegroup(GSim, self)
end

function Group.addport(self, port)
	if port.group~=nil then error("port already has group") end
	port.group = self
	
	if port.type == PortTypes.output then
		if self.out_ports[port] then error("port already in group") end
		
		self.out_ports[port] = port
		self.nout_ports = self.nout_ports + 1
		if Port.getstate(port) then
			self.state_num = self.state_num + 1
		end
		
		Simulation.queuegroup(GSim, self)
		
	elseif port.type == PortTypes.input then
		if self.in_ports[port] then error("port already in group") end
		
		self.in_ports[port] = port
		self.nin_ports = self.nin_ports + 1
		if port.causeupdate then
			self.in_ports_update[port] = port
		end
		
		Simulation.queuegate(GSim, Port.getgate(port))
		
	end
end

function Group.removeport(self, port)
	if port.group~=self then error("port does not have group") end
	port.group = nil
	
	if port.type == PortTypes.output then
		if not self.out_ports[port] then error("port not in group") end
		self.out_ports[port] = nil
		self.nout_ports = self.nout_ports - 1
		
		if Port.getstate(port) then
			self.state_num = self.state_num - 1
		end
		
		Simulation.queuegroup(GSim, self)
		
	elseif port.type == PortTypes.input then
		if not self.in_ports[port] then error("port not in group") end
		
		self.in_ports[port] = nil
		self.nin_ports = self.nin_ports - 1
		if port.causeupdate then
			self.in_ports_update[port] = nil
		end
		
		Simulation.queuegate(GSim, Port.getgate(port))
	end
end

function Group.mergewith(self, group)
	if Group.getsize(self) >= Group.getsize(group) then
		Group.mergeinto(group, self)
		return self
	else
		Group.mergeinto(self, group)
		return group
	end
end

function Group.mergeinto(self, group)
	for k, wire in pairs(self.wires) do
		Wire.setgroup(wire, nil)
		Group.addwire(group, wire)
	end

	for k, port in pairs(self.out_ports) do
		Port.setgroup(port, nil)
		Group.addport(group, port)
	end

	for k, port in pairs(self.in_ports) do
		Port.setgroup(port, nil)
		Group.addport(group, port)
	end
	
	self.wires = {}
	self.out_ports = {}
	self.in_ports = {}

	self.nwires = 0
	self.nout_ports = 0
	self.nin_ports = 0
	
	Simulation.dequeuegroup(GSim, self)
end

function Group.setstate(self, state)
	if state ~= self.state then
		local sim = GSim
		
		self.state = state
		self.updatetick = sim.currenttick
		
		for k, port in pairs(self.in_ports_update) do
			Simulation.queuegate(sim, Port.getgate(port))
		end
		
		Simulation.queuegroupfx(sim, self)
	end
end

function Group.update(group)
	Group.setstate(group, group.state_num>0)
end