/*
This object is contained within zone/var/connections. It's generated whenever two turfs from different zones are linked.
Indirect connections will not merge the two zones after they reach equilibrium.
*/
#define CONNECTION_DIRECT   2
#define CONNECTION_INDIRECT 1
#define CONNECTION_CLOSED   0


connection
	var
		turf/simulated //The turfs involved in the connection.
			A
			B
		zone
			zone_A
			zone_B
		ref_A
		ref_B
		indirect = CONNECTION_DIRECT //If the connection is purely indirect, the zones should not join.
		last_updated //The tick at which this was last updated.
		no_zone_count = 0

	New(turf/T,turf/O)
		A = T
		B = O
		if(A.zone && B.zone)
			if(!A.zone.connections) A.zone.connections = list()
			A.zone.connections += src
			zone_A = A.zone
			ref_A = "\ref[A]"

			if(!B.zone.connections) B.zone.connections = list()
			B.zone.connections += src
			zone_B = B.zone
			ref_B = "\ref[B]"

			if(ref_A in air_master.turfs_with_connections)
				var/list/connections = air_master.turfs_with_connections[ref_A]
				connections.Add(src)
			else
				air_master.turfs_with_connections[ref_A] = list(src)

			if(ref_B in air_master.turfs_with_connections)
				var/list/connections = air_master.turfs_with_connections[ref_B]
				connections.Add(src)
			else
				air_master.turfs_with_connections[ref_B] = list(src)

			if(A.CanPass(null, B, 0, 0))

				if(!A.zone.connected_zones)
					A.zone.connected_zones = list()
				if(!B.zone.connected_zones)
					B.zone.connected_zones = list()

				if(B.zone in A.zone.connected_zones)
					A.zone.connected_zones[B.zone]++
				else
					A.zone.connected_zones += B.zone
					A.zone.connected_zones[B.zone] = 1

				if(A.zone in B.zone.connected_zones)
					B.zone.connected_zones[A.zone]++
				else
					B.zone.connected_zones += A.zone
					B.zone.connected_zones[A.zone] = 1

			else
				indirect = CONNECTION_CLOSED


				if(!A.zone.closed_connection_zones)
					A.zone.closed_connection_zones = list()
				if(B.zone in A.zone.closed_connection_zones)
					A.zone.closed_connection_zones[B.zone]++
				else
					A.zone.closed_connection_zones += B.zone
					A.zone.closed_connection_zones[B.zone] = 1

				if(!B.zone.closed_connection_zones)
					B.zone.closed_connection_zones = list()
				if(A.zone in B.zone.closed_connection_zones)
					B.zone.closed_connection_zones[A.zone]++
				else
					B.zone.closed_connection_zones += A.zone
					B.zone.closed_connection_zones[A.zone] = 1

			if(A.HasDoor(B) || B.HasDoor(A))
				indirect = CONNECTION_INDIRECT
		else
			world.log << "Attempted to create connection object for non-zone tiles: [T] -> [O]"
			del(src)

	Del()
		if(ref_B in air_master.turfs_with_connections)
			var/list/connections = air_master.turfs_with_connections[ref_B]
			connections.Remove(src)

		if(ref_A in air_master.turfs_with_connections)
			var/list/connections = air_master.turfs_with_connections[ref_A]
			connections.Remove(src)

		if(A)
			if(A.zone && A.zone.connections)
				A.zone.connections.Remove(src)
				if(!A.zone.connections.len)
					del A.zone.connections
		if(B)
			if(B.zone && B.zone.connections)
				B.zone.connections.Remove(src)
				if(!B.zone.connections.len)
					del B.zone.connections
		if(zone_A)
			if(zone_A && zone_A.connections)
				zone_A.connections.Remove(src)
				if(!zone_A.connections.len)
					del zone_A.connections
		if(zone_B)
			if(zone_B && zone_B.connections)
				zone_B.connections.Remove(src)
				if(!zone_B.connections.len)
					del zone_B.connections

		if(indirect != CONNECTION_CLOSED)
			if(A && A.zone)
				if(B && B.zone)
					if(B.zone in A.zone.connected_zones)
						if(A.zone.connected_zones[B.zone] > 1)
							A.zone.connected_zones[B.zone]--
						else
							A.zone.connected_zones -= B.zone
					if(A.zone.connected_zones && !A.zone.connected_zones.len)
						A.zone.connected_zones = null
				if( zone_B && (!B.zone || zone_B != B.zone) )
					if(zone_B in A.zone.connected_zones)
						if(A.zone.connected_zones[zone_B] > 1)
							A.zone.connected_zones[zone_B]--
						else
							A.zone.connected_zones -= zone_B
					if(A.zone.connected_zones && !A.zone.connected_zones.len)
						A.zone.connected_zones = null
			if(zone_A && (!A.zone || zone_A != A.zone))
				if(B && B.zone)
					if(B.zone in zone_A.connected_zones)
						if(zone_A.connected_zones[B.zone] > 1)
							zone_A.connected_zones[B.zone]--
						else
							zone_A.connected_zones -= B.zone
					if(zone_A.connected_zones && !zone_A.connected_zones.len)
						zone_A.connected_zones = null
				if( zone_B && (!B.zone || zone_B != B.zone) )
					if(zone_B in zone_A.connected_zones)
						if(zone_A.connected_zones[zone_B] > 1)
							zone_A.connected_zones[zone_B]--
						else
							zone_A.connected_zones -= zone_B
					if(zone_A.connected_zones && !zone_A.connected_zones.len)
						zone_A.connected_zones = null
			if(B && B.zone)
				if(A && A.zone)
					if(A.zone in B.zone.connected_zones)
						if(B.zone.connected_zones[A.zone] > 1)
							B.zone.connected_zones[A.zone]--
						else
							B.zone.connected_zones -= A.zone
					if(B.zone.connected_zones && !B.zone.connected_zones.len)
						B.zone.connected_zones = null
				if( zone_A && (!A.zone || zone_A != A.zone) )
					if(zone_A in B.zone.connected_zones)
						if(B.zone.connected_zones[zone_A] > 1)
							B.zone.connected_zones[zone_A]--
						else
							B.zone.connected_zones -= zone_A
					if(B.zone.connected_zones && !B.zone.connected_zones.len)
						B.zone.connected_zones = null
			if(zone_B && (!B.zone || zone_B != B.zone))
				if(A && A.zone)
					if(A.zone in zone_B.connected_zones)
						if(zone_B.connected_zones[A.zone] > 1)
							zone_B.connected_zones[A.zone]--
						else
							zone_B.connected_zones -= A.zone
					if(zone_B.connected_zones && !zone_B.connected_zones.len)
						zone_B.connected_zones = null
				if( zone_A && (!A.zone || zone_A != A.zone) )
					if(zone_A in zone_B.connected_zones)
						if(zone_B.connected_zones[zone_A] > 1)
							zone_B.connected_zones[zone_A]--
						else
							zone_B.connected_zones -= zone_A
					if(zone_B.connected_zones && !zone_B.connected_zones.len)
						zone_B.connected_zones = null
		else
			if(A && A.zone)
				if(B && B.zone)
					if(B.zone in A.zone.closed_connection_zones)
						if(A.zone.closed_connection_zones[B.zone] > 1)
							A.zone.closed_connection_zones[B.zone]--
						else
							A.zone.closed_connection_zones -= B.zone
					if(A.zone.closed_connection_zones && !A.zone.closed_connection_zones.len)
						A.zone.closed_connection_zones = null
				if( zone_B && (!B.zone || zone_B != B.zone) )
					if(zone_B in A.zone.closed_connection_zones)
						if(A.zone.closed_connection_zones[zone_B] > 1)
							A.zone.closed_connection_zones[zone_B]--
						else
							A.zone.closed_connection_zones -= zone_B
					if(A.zone.closed_connection_zones && !A.zone.closed_connection_zones.len)
						A.zone.closed_connection_zones = null
			if(zone_A && (!A.zone || zone_A != A.zone))
				if(B && B.zone)
					if(B.zone in zone_A.closed_connection_zones)
						if(zone_A.closed_connection_zones[B.zone] > 1)
							zone_A.closed_connection_zones[B.zone]--
						else
							zone_A.closed_connection_zones -= B.zone
					if(zone_A.closed_connection_zones && !zone_A.closed_connection_zones.len)
						zone_A.closed_connection_zones = null
				if( zone_B && (!B.zone || zone_B != B.zone) )
					if(zone_B in zone_A.closed_connection_zones)
						if(zone_A.closed_connection_zones[zone_B] > 1)
							zone_A.closed_connection_zones[zone_B]--
						else
							zone_A.closed_connection_zones -= zone_B
					if(zone_A.closed_connection_zones && !zone_A.closed_connection_zones.len)
						zone_A.closed_connection_zones = null
			if(B && B.zone)
				if(A && A.zone)
					if(A.zone in B.zone.closed_connection_zones)
						if(B.zone.closed_connection_zones[A.zone] > 1)
							B.zone.closed_connection_zones[A.zone]--
						else
							B.zone.closed_connection_zones -= A.zone
					if(B.zone.closed_connection_zones && !B.zone.closed_connection_zones.len)
						B.zone.closed_connection_zones = null
				if( zone_A && (!A.zone || zone_A != A.zone) )
					if(zone_A in B.zone.closed_connection_zones)
						if(B.zone.closed_connection_zones[zone_A] > 1)
							B.zone.closed_connection_zones[zone_A]--
						else
							B.zone.closed_connection_zones -= zone_A
					if(B.zone.closed_connection_zones && !B.zone.closed_connection_zones.len)
						B.zone.closed_connection_zones = null
			if(zone_B && (!B.zone || zone_B != B.zone))
				if(A && A.zone)
					if(A.zone in zone_B.closed_connection_zones)
						if(zone_B.closed_connection_zones[A.zone] > 1)
							zone_B.closed_connection_zones[A.zone]--
						else
							zone_B.closed_connection_zones -= A.zone
					if(zone_B.closed_connection_zones && !zone_B.closed_connection_zones.len)
						zone_B.closed_connection_zones = null
				if( zone_A && (!A.zone || zone_A != A.zone) )
					if(zone_A in zone_B.closed_connection_zones)
						if(zone_B.closed_connection_zones[zone_A] > 1)
							zone_B.closed_connection_zones[zone_A]--
						else
							zone_B.closed_connection_zones -= zone_A
					if(zone_B.closed_connection_zones && !zone_B.closed_connection_zones.len)
						zone_B.closed_connection_zones = null
		. = ..()

	proc/Cleanup()
		if(!A || !B)
			//world.log << "Connection removed: [A] or [B] missing entirely."
			del src
		if(A.zone == B.zone)
			//world.log << "Connection removed: Zones now merged."
			del src
		if(ref_A != "\ref[A]" || ref_B != "\ref[B]")
			del src
		if((A.zone && A.zone != zone_A) || (B.zone && B.zone != zone_B))
			Sanitize()
		if(!A.zone || !B.zone)
			no_zone_count++
			if(no_zone_count >= 5)
				//world.log << "Connection removed: [A] or [B] missing a zone."
				del src
			return 0
		return 1

	proc/CheckPassSanity()
		Cleanup()
		if(A.zone && B.zone)
			if(A.ZAirPass(B))
				var/door_pass = A.CanPass(null,B,1.5,1)
				if(door_pass || A.CanPass(null,B,0,0))
					if(indirect == CONNECTION_CLOSED)
						//ADJUST FOR CAN CONNECT
						if(!A.zone.connected_zones)
							A.zone.connected_zones = list()
						if(B.zone in A.zone.connected_zones)
							A.zone.connected_zones[B.zone]++
						else
							A.zone.connected_zones += B.zone
							A.zone.connected_zones[B.zone] = 1

						if(!B.zone.connected_zones)
							B.zone.connected_zones = list()
						if(A.zone in B.zone.connected_zones)
							B.zone.connected_zones[A.zone]++
						else
							B.zone.connected_zones += A.zone
							B.zone.connected_zones[A.zone] = 1

						if(A.zone.closed_connection_zones)
							if(A.zone.closed_connection_zones[B.zone] > 1)
								A.zone.closed_connection_zones[B.zone]--
							else
								A.zone.closed_connection_zones.Remove(B.zone)
						if(A.zone.closed_connection_zones && !A.zone.closed_connection_zones.len)
							A.zone.closed_connection_zones = null

						if(B.zone.closed_connection_zones)
							if(B.zone.closed_connection_zones[A.zone] > 1)
								B.zone.closed_connection_zones[A.zone]--
							else
								B.zone.closed_connection_zones.Remove(A.zone)

						if(B.zone.closed_connection_zones && !B.zone.closed_connection_zones.len)
							B.zone.closed_connection_zones = null

					if(door_pass)
						indirect = CONNECTION_DIRECT
					else if(!door_pass)
						indirect = CONNECTION_INDIRECT

				else if(indirect > CONNECTION_CLOSED)
					indirect = CONNECTION_CLOSED

					//ADJUST FOR CANNOT CONNECT
					if(A.zone.connected_zones)
						if(A.zone.connected_zones[B.zone] > 1)
							A.zone.connected_zones[B.zone]--
						else
							A.zone.connected_zones.Remove(B.zone)
					if(A.zone.connected_zones && !A.zone.connected_zones.len)
						A.zone.connected_zones = null

					if(B.zone.connected_zones)
						if(B.zone.connected_zones[A.zone] > 1)
							B.zone.connected_zones[A.zone]--
						else
							B.zone.connected_zones.Remove(A.zone)

					if(B.zone.connected_zones && !B.zone.connected_zones.len)
						B.zone.connected_zones = null

					//Add to the closed connections list(s)
					if(!A.zone.closed_connection_zones)
						A.zone.closed_connection_zones = list()
					if(B.zone in A.zone.closed_connection_zones)
						A.zone.closed_connection_zones[B.zone]++
					else
						A.zone.closed_connection_zones += B.zone
						A.zone.closed_connection_zones[B.zone] = 1

					if(!B.zone.closed_connection_zones)
						B.zone.closed_connection_zones = list()
					if(A.zone in B.zone.closed_connection_zones)
						B.zone.closed_connection_zones[A.zone]++
					else
						B.zone.closed_connection_zones += A.zone
						B.zone.closed_connection_zones[A.zone] = 1

			else //If I can no longer pass air, better delete
				del src

	proc/Sanitize()
		//If the zones change on connected turfs, update it.
		if(A.zone && A.zone != zone_A && B.zone && B.zone != zone_B)
			if(!A.zone || !B.zone)
				del src

			if(A.zone == zone_B && B.zone == zone_A)
				var/turf/temp = B
				B = A
				A = temp
				zone_B = B.zone
				zone_A = A.zone
				var/temp_ref = ref_A
				ref_A = ref_B
				ref_B = temp_ref
				return

			if(zone_A)
				if(zone_A.connections)
					zone_A.connections.Remove(src)
					if(!zone_A.connections.len)
						del zone_A.connections

				if(indirect != CONNECTION_CLOSED)
					if(zone_A.connected_zones)
						if(zone_A.connected_zones[zone_B] > 1)
							zone_A.connected_zones[zone_B]--
						else
							zone_A.connected_zones.Remove(zone_B)
					if(zone_A.connected_zones && !zone_A.connected_zones.len)
						zone_A.connected_zones = null

				else
					if(zone_A.closed_connection_zones)
						if(zone_A.closed_connection_zones[zone_B] > 1)
							zone_A.closed_connection_zones[zone_B]--
						else
							zone_A.closed_connection_zones.Remove(zone_B)
					if(zone_A.closed_connection_zones && !zone_A.closed_connection_zones.len)
						zone_A.closed_connection_zones = null


			if(zone_B)
				if(zone_B.connections)
					zone_B.connections.Remove(src)
					if(!zone_B.connections.len)
						del zone_B.connections

				if(indirect != CONNECTION_CLOSED)
					if(zone_B.connected_zones)
						if(zone_B.connected_zones[zone_A] > 1)
							zone_B.connected_zones[zone_A]--
						else
							zone_B.connected_zones.Remove(zone_A)
					if(zone_B.connected_zones && !zone_B.connected_zones.len)
						zone_B.connected_zones = null

				else
					if(zone_B.closed_connection_zones)
						if(zone_B.closed_connection_zones[zone_A] > 1)
							zone_B.closed_connection_zones[zone_A]--
						else
							zone_B.closed_connection_zones.Remove(zone_A)
					if(zone_B.closed_connection_zones && !zone_B.closed_connection_zones.len)
						zone_B.closed_connection_zones = null

			if(indirect != CONNECTION_CLOSED)
				if(!A.zone.connections)
					A.zone.connections = list()
				A.zone.connections |= src
				if(!B.zone.connections)
					B.zone.connections = list()
				B.zone.connections |= src

				if(!A.zone.connected_zones)
					A.zone.connected_zones = list()
				if(B.zone in A.zone.connected_zones)
					A.zone.connected_zones[B.zone]++
				else
					A.zone.connected_zones += B.zone
					A.zone.connected_zones[B.zone] = 1

				if(!B.zone.connected_zones)
					B.zone.connected_zones = list()
				if(A.zone in B.zone.connected_zones)
					B.zone.connected_zones[A.zone]++
				else
					B.zone.connected_zones += A.zone
					B.zone.connected_zones[A.zone] = 1

			else

				if(!A.zone.connections)
					A.zone.connections = list()
				A.zone.connections |= src
				if(!B.zone.connections)
					B.zone.connections = list()
				B.zone.connections |= src

				if(!A.zone.closed_connection_zones)
					A.zone.closed_connection_zones = list()
				if(B.zone in A.zone.closed_connection_zones)
					A.zone.closed_connection_zones[B.zone]++
				else
					A.zone.closed_connection_zones += B.zone
					A.zone.closed_connection_zones[B.zone] = 1

				if(!B.zone.closed_connection_zones)
					B.zone.closed_connection_zones = list()
				if(A.zone in B.zone.closed_connection_zones)
					B.zone.closed_connection_zones[A.zone]++
				else
					B.zone.closed_connection_zones += A.zone
					B.zone.closed_connection_zones[A.zone] = 1

			zone_B = B.zone

			zone_A = A.zone


		else if(A.zone && A.zone != zone_A)
			if(zone_A)

				if(zone_A.connections)
					zone_A.connections.Remove(src)
					if(!zone_A.connections.len)
						del zone_A.connections
				if(!A.zone.connections)
					A.zone.connections = list()
				A.zone.connections |= src

				if(indirect != CONNECTION_CLOSED)
					if(zone_A.connected_zones)
						if(zone_A.connected_zones[zone_B] > 1)
							zone_A.connected_zones[zone_B]--
						else
							zone_A.connected_zones.Remove(zone_B)
					if(zone_A.connected_zones && !zone_A.connected_zones.len)
						zone_A.connected_zones = null

					if(!A.zone.connected_zones)
						A.zone.connected_zones = list()
					if(!(zone_B in A.zone.connected_zones))
						A.zone.connected_zones += zone_B
						A.zone.connected_zones[zone_B] = 1
					else
						A.zone.connected_zones[zone_B]++

				else
					if(zone_A.closed_connection_zones)
						if(zone_A.closed_connection_zones[zone_B] > 1)
							zone_A.closed_connection_zones[zone_B]--
						else
							zone_A.closed_connection_zones.Remove(zone_B)
					if(zone_A.closed_connection_zones && !zone_A.closed_connection_zones.len)
						zone_A.closed_connection_zones = null

					if(!A.zone.closed_connection_zones)
						A.zone.closed_connection_zones = list()
					if(!(zone_B in A.zone.closed_connection_zones))
						A.zone.closed_connection_zones += zone_B
						A.zone.closed_connection_zones[zone_B] = 1
					else
						A.zone.closed_connection_zones[zone_B]++

				zone_A = A.zone

			else
				del src

		else if(B.zone && B.zone != zone_B)
			if(zone_B)

				if(zone_B.connections)
					zone_B.connections.Remove(src)
					if(!zone_B.connections.len)
						del zone_B.connections
				if(!B.zone.connections)
					B.zone.connections = list()
				B.zone.connections |= src

				if(indirect != CONNECTION_CLOSED)
					if(zone_B.connected_zones)
						if(zone_B.connected_zones[zone_A] > 1)
							zone_B.connected_zones[zone_A]--
						else
							zone_B.connected_zones.Remove(zone_A)
					if(zone_B.connected_zones && !zone_B.connected_zones.len)
						zone_B.connected_zones = null

					if(!B.zone.connected_zones)
						B.zone.connected_zones = list()
					if(!(zone_A in B.zone.connected_zones))
						B.zone.connected_zones += zone_A
						B.zone.connected_zones[zone_A] = 1
					else
						B.zone.connected_zones[zone_A]++

				else
					if(zone_B.closed_connection_zones)
						if(zone_B.closed_connection_zones[zone_A] > 1)
							zone_B.closed_connection_zones[zone_A]--
						else
							zone_B.closed_connection_zones.Remove(zone_A)
					if(zone_B.closed_connection_zones && !zone_B.closed_connection_zones.len)
						zone_B.closed_connection_zones = null

					if(!B.zone.closed_connection_zones)
						B.zone.closed_connection_zones = list()
					if(!(zone_A in B.zone.closed_connection_zones))
						B.zone.closed_connection_zones += zone_A
						B.zone.closed_connection_zones[zone_A] = 1
					else
						B.zone.closed_connection_zones[zone_A]++

				zone_B = B.zone

			else
				del src


#undef CONNECTION_DIRECT
#undef CONNECTION_INDIRECT
#undef CONNECTION_CLOSED