Airlock controller fixes

Fixes airlocks opening their doors before the pumps have turned off.
Fixes airlocks getting confused if you mash buttons in quick succession.

code/game/machinery/embedded_controller/airlock_program.dm

@@ -109,9 +109,13 @@
 	var/shutdown_pump = 0
 	switch(command)
 		if("cycle_ext")
+			//only respond to these commands if the airlock isn't already doing something
+			//prevents the controller from getting confused and doing strange things
+			if(state == target_state)
 				begin_cycle_out()
 
 		if("cycle_int")
+			if(state == target_state)
 				begin_cycle_in()
 
 		if("cycle_ext_door")
@@ -122,14 +126,6 @@
 
 		if("abort")
 			stop_cycling()
-			/*
-			//dont do this. If the airlock can't get enough air to pressurize the person inside is stuck
-			state = STATE_PRESSURIZE
-			target_state = TARGET_NONE
-			memory["target_pressure"] = ONE_ATMOSPHERE
-			signalPump(tag_airpump, 1, 1, memory["target_pressure"])
-			process()
-			*/
 
 		if("force_ext")
 			toggleDoor(memory["exterior_status"], tag_exterior_door, memory["secure"], "toggle")
@@ -140,11 +136,9 @@
 		if("purge")
 			memory["purge"] = !memory["purge"]
 			if(memory["purge"])
-				toggleDoor(memory["exterior_status"], tag_exterior_door, 1, "close")
+				close_doors()
-				toggleDoor(memory["interior_status"], tag_interior_door, 1, "close")
+				state = STATE_PREPARE
-				state = STATE_DEPRESSURIZE
 				target_state = TARGET_NONE
-				signalPump(tag_airpump, 1, 0, 0)
 
 		if("secure")
 			memory["secure"] = !memory["secure"]
@@ -188,12 +182,12 @@
 				var/target_pressure = memory["target_pressure"]
 
 				if(memory["purge"])
+					//purge apparently means clearing the airlock chamber to vacuum (then refilling, handled later)
 					target_pressure = 0
+					state = STATE_DEPRESSURIZE
+					signalPump(tag_airpump, 1, 0, 0)	//send a signal to start depressurizing
 
-				if(memory["purge"])
+				else if(chamber_pressure <= target_pressure)
-					target_pressure = 0
-
-				if(chamber_pressure <= target_pressure)
 					state = STATE_PRESSURIZE
 					signalPump(tag_airpump, 1, 1, target_pressure)	//send a signal to start pressurizing
 
@@ -201,40 +195,37 @@
 					state = STATE_DEPRESSURIZE
 					signalPump(tag_airpump, 1, 0, target_pressure)	//send a signal to start depressurizing
 
-				//Check for vacuum - this is set after the pumps so the pumps are aiming for 0
+				//Make sure the airlock isn't aiming for pure vacuum - an impossibility
-				if(!memory["target_pressure"])
+				memory["target_pressure"] = max(target_pressure, ONE_ATMOSPHERE * 0.05)
-					memory["target_pressure"] = ONE_ATMOSPHERE * 0.05
 
 		if(STATE_PRESSURIZE)
 			if(memory["chamber_sensor_pressure"] >= memory["target_pressure"] * 0.95)
-				cycleDoors(target_state)
+				//not done until the pump has reported that it's off
-
-				state = STATE_IDLE
-				target_state = TARGET_NONE
-
 				if(memory["pump_status"] != "off")
 					signalPump(tag_airpump, 0)		//send a signal to stop pumping
+				else
+					cycleDoors(target_state)
+					state = STATE_IDLE
+					target_state = TARGET_NONE
 
 
 		if(STATE_DEPRESSURIZE)
+			if(memory["chamber_sensor_pressure"] <= memory["target_pressure"] * 1.05)
 				if(memory["purge"])
-				if(memory["chamber_sensor_pressure"] <= ONE_ATMOSPHERE * 0.05)
+					memory["purge"] = 0
-					state = STATE_PRESSURIZE
+					memory["target_pressure"] = memory["internal_sensor_pressure"]
-					signalPump(tag_airpump, 1, 1, memory["target_pressure"])
+					state = STATE_PREPARE
+					target_state = TARGET_NONE
 				
-
+				else if(memory["pump_status"] != "off")
-			else if(memory["chamber_sensor_pressure"] <= memory["target_pressure"] * 1.05)
+					signalPump(tag_airpump, 0)
+				else
 					cycleDoors(target_state)
-
 					state = STATE_IDLE
 					target_state = TARGET_NONE
 
-				//send a signal to stop pumping
-				if(memory["pump_status"] != "off")
-					signalPump(tag_airpump, 0)
 
-
+	memory["processing"] = (state != target_state)
-	memory["processing"] = state != target_state
 
 	return 1