vgstation13/code/ZAS/ZAS_Turfs.dm

/atom/var/pressure_resistance = ONE_ATMOSPHERE

/turf/var/zone/zone

/turf/assume_air(datum/gas_mixture/giver) //use this for machines to adjust air
	qdel(giver)
	giver = null
	return 0

/turf/return_air()
	//Create gas mixture to hold data for passing
	var/datum/gas_mixture/GM = new

	GM.oxygen = oxygen
	GM.carbon_dioxide = carbon_dioxide
	GM.nitrogen = nitrogen
	GM.toxins = toxins

	GM.temperature = temperature
	GM.update_values()

	return GM

// For new turfs
/turf/proc/copy_air_from(var/turf/T)
	oxygen = T.oxygen
	carbon_dioxide = T.carbon_dioxide
	nitrogen = T.nitrogen
	toxins = T.toxins

	temperature = T.temperature

/turf/remove_air(amount as num)
	var/datum/gas_mixture/GM = new

	var/sum = oxygen + carbon_dioxide + nitrogen + toxins
	if(sum>0)
		GM.oxygen = (oxygen/sum)*amount
		GM.carbon_dioxide = (carbon_dioxide/sum)*amount
		GM.nitrogen = (nitrogen/sum)*amount
		GM.toxins = (toxins/sum)*amount

	GM.temperature = temperature
	GM.update_values()

	return GM

/turf/simulated/var/current_graphic = null
/turf/simulated/var/tmp/datum/gas_mixture/air
/turf/simulated/var/tmp/processing = 1
/turf/simulated/var/tmp/air_check_directions = 0 //Do not modify this, just add turf to air_master.tiles_to_update
/turf/simulated/var/tmp/obj/fire/active_hotspot
/turf/simulated/var/tmp/was_icy=0

/turf/simulated/proc/update_visuals()
	overlays = 0

	if(decals.len)
		overlays += decals

	var/siding_icon_state = return_siding_icon_state()
	if(siding_icon_state)
		overlays += image('icons/turf/floors.dmi',siding_icon_state)

	// ONLY USED IF ZAS_SETTINGS SAYS SO.
	var/datum/gas_mixture/model = return_air()
	if(model.graphics & GRAPHICS_COLD)
		// Only make a few tiles ice at a time.
		if(!was_icy) // && prob(10))
			wet=3 // Custom ice
			was_icy=1

		// Only display ice on tiles that are actually icy.
		if(was_icy)
			var/o=""
			//if(is_plating())
			//	o="snowfloor_s"
			//else
			if(is_plasteel_floor())
				o="snowfloor"
			if(o!="")
				overlays += image('icons/turf/overlays.dmi',o)
	else
		// ALWAYS unset wet and icy.
		wet=0
		was_icy=0

		// 10% chance of becoming wet on thawing
		if(prob(10) && was_icy)
			wet = 1
			if(wet_overlay)
				overlays -= wet_overlay
				wet_overlay = null
			wet_overlay = image('icons/effects/water.dmi',src,"wet_floor")
			overlays += wet_overlay

			spawn(800)
				if (!istype(src)) return
				if(wet >= 2) return
				wet = 0
				if(wet_overlay)
					overlays -= wet_overlay
					wet_overlay = null

	if(model.graphics & GRAPHICS_PLASMA)
		overlays.Add(plmaster)

	if(model.graphics & GRAPHICS_N2O)
		overlays.Add(slmaster)

	//if(model.graphics & GRAPHICS_REAGENTS)
	//	overlays.Add(slmaster/*rlmaster*/)


/turf/simulated/New()
	..()

	if(!blocks_air)
		air = new

		air.oxygen = oxygen
		air.carbon_dioxide = carbon_dioxide
		air.nitrogen = nitrogen
		air.toxins = toxins

		air.temperature = temperature
		air.update_values()

		if(air_master)
			air_master.tiles_to_update.Add(src)

	else
		if(air_master)
			for(var/direction in cardinal)
				var/turf/simulated/floor/target = get_step(src,direction)
				if(istype(target))
					air_master.tiles_to_update |= target

/turf/simulated/Destroy()
	if(active_hotspot)
		qdel(active_hotspot)
		active_hotspot = null
	if(blocks_air)
		for(var/direction in list(NORTH, SOUTH, EAST, WEST))
			var/turf/simulated/tile = get_step(src,direction)
			if(istype(tile) && !tile.blocks_air)
				air_master.tiles_to_update.Add(tile)
	..()

/turf/simulated/copy_air_from(var/turf/T)
	//if(istype(T,/turf/simulated))
	//	var/turf/simulated/ST=T
	//	air=ST.air
	air=T.return_air()

/turf/simulated/assume_air(datum/gas_mixture/giver)
	if(!giver)	return 0
	if(zone && zone.air && !iscatwalk(src))
		zone.air.merge(giver)
		return 1
	else
		return ..()

/turf/simulated/return_air()
	if(zone)
		return zone.air
	else if(air)
		return air

	else
		return ..()

/turf/simulated/remove_air(amount as num)
	if(zone)
		var/datum/gas_mixture/removed = null
		removed = zone.air.remove(amount)
		if(zone.air.check_tile_graphic())
			update_visuals(zone.air)
		return removed
	else if(air)
		var/datum/gas_mixture/removed = null
		removed = air.remove(amount)

		if(air.check_tile_graphic())
			update_visuals(air)
		return removed

	else
		return ..()

/turf/simulated/proc/update_air_properties()
	if(iscatwalk(src))
		return ..()
	var/air_directions_archived = air_check_directions
	air_check_directions = 0

	for(var/direction in cardinal)
		if(ZAirPass(get_step(src,direction)))
			air_check_directions |= direction

	if(!zone && !blocks_air) //No zone, but not a wall.
		for(var/direction in DoorDirections) //Check door directions first.
			if(air_check_directions&direction)
				var/turf/simulated/T = get_step(src,direction)
				if(!istype(T) || iscatwalk(T))
					continue
				if(T.zone)
					T.zone.AddTurf(src)
					break
		if(!zone) //Still no zone
			for(var/direction in CounterDoorDirections) //Check the others second.
				if(air_check_directions&direction)
					var/turf/simulated/T = get_step(src,direction)
					if(!istype(T) || iscatwalk(T))
						continue
					if(T.zone)
						T.zone.AddTurf(src)
						break
		if(!zone) //No zone found, new zone!
			new/zone(src)
		if(!zone) //Still no zone, the floodfill determined it is not part of a larger zone.  Force a zone on it.
			new/zone(list(src))

	//Check pass sanity of the connections.
	if("\ref[src]" in air_master.turfs_with_connections)
		for(var/connection/C in air_master.turfs_with_connections["\ref[src]"])
			air_master.connections_to_check |= C

	if(zone && istype(zone.air) && !zone.rebuild)
		if(zone.air.check_tile_graphic())
			update_visuals(zone.air)
		for(var/direction in cardinal)
			var/turf/T = get_step(src,direction)
			if(!istype(T))
				continue

			//I can connect to air in this direction
			if(air_check_directions&direction)

				//If either block air, we must look to see if the adjacent turfs need rebuilt.
				if(!CanPass(null, T, 0, 0))

					//Target blocks air
					if(!T.CanPass(null, T, 0, 0))
						var/turf/NT = get_step(T, direction)

						//If that turf is in my zone still, rebuild.
						if(istype(NT,/turf/simulated) && !iscatwalk(NT) && NT in zone.contents)
							zone.rebuild = 1

						//If that is an unsimulated tile in my zone, see if we need to rebuild or just remove.
						else if(istype(NT) && NT in zone.unsimulated_tiles)
							var/consider_rebuild = 0
							for(var/d in cardinal)
								var/turf/UT = get_step(NT,d)
								if(istype(UT, /turf/simulated) && UT.zone == zone && UT.CanPass(null, NT, 0, 0)) //If we find a neighboring tile that is in the same zone, check if we need to rebuild
									consider_rebuild = 1
									break
							if(consider_rebuild)
								zone.rebuild = 1 //Gotta check if we need to rebuild, dammit
							else
								zone.RemoveTurf(NT) //Not adjacent to anything, and unsimulated.  Goodbye~

						//To make a closed connection through closed door.
						ZConnect(T, src)

					//If I block air.
					else if(T.zone && !T.zone.rebuild)
						var/turf/NT = get_step(src, reverse_direction(direction))

						//If I am splitting a zone, rebuild.
						if(istype(NT,/turf/simulated) && !iscatwalk(NT) && (NT in T.zone.contents || (NT.zone && T in NT.zone.contents)))
							T.zone.rebuild = 1

						//If NT is unsimulated, parse if I should remove it or rebuild.
						else if(istype(NT) && NT in T.zone.unsimulated_tiles)
							var/consider_rebuild = 0
							for(var/d in cardinal)
								var/turf/UT = get_step(NT,d)
								if(istype(UT, /turf/simulated) && UT.zone == T.zone && UT.CanPass(null, NT, 0, 0)) //If we find a neighboring tile that is in the same zone, check if we need to rebuild
									consider_rebuild = 1
									break

							//Needs rebuilt.
							if(consider_rebuild)
								T.zone.rebuild = 1

							//Not adjacent to anything, and unsimulated.  Goodbye~
							else
								T.zone.RemoveTurf(NT)

				else
					//Produce connection through open door.
					ZConnect(src,T)

			//Something like a wall was built, changing the geometry.
			else if(air_directions_archived&direction)
				var/turf/NT = get_step(T, direction)

				//If the tile is in our own zone, and we cannot connect to it, better rebuild.
				if(istype(NT,/turf/simulated) && !iscatwalk(NT) && NT in zone.contents)
					zone.rebuild = 1

				//Parse if we need to remove the tile, or rebuild the zone.
				else if(istype(NT) && NT in zone.unsimulated_tiles)
					var/consider_rebuild = 0

					//Loop through all neighboring turfs to see if we should remove the turf or just rebuild.
					for(var/d in cardinal)
						var/turf/UT = get_step(NT,d)

						//If we find a neighboring tile that is in the same zone, rebuild
						if(istype(UT, /turf/simulated) && UT.zone == zone && UT.CanPass(null, NT, 0, 0))
							consider_rebuild = 1
							break

					//The unsimulated turf is adjacent to another one of our zone's turfs,
					//  better rebuild to be sure we didn't get cut in twain
					if(consider_rebuild)
						zone.rebuild = 1

					//Not adjacent to anything, and unsimulated.  Goodbye~
					else
						zone.RemoveTurf(NT)

	if(air_check_directions)
		processing = 1
	else
		processing = 0
	return 1

/turf/proc/HasDoor(turf/O)
	//Checks for the presence of doors, used for zone spreading and connection.
	//A positive numerical argument checks only for closed doors.
	//Another turf as an argument checks for windoors between here and there.
	for(var/obj/machinery/door/D in src)
		if(isnum(O) && O)
			if(!D.density) continue
		if(istype(D,/obj/machinery/door/window))
			if(!istype(O))
				continue
			if(D.dir == get_dir(D,O))
				return 1
		else
			return 1

/turf/proc/ZCanPass(turf/simulated/T, var/include_space = 0)
	//Fairly standard pass checks for turfs, objects and directional windows. Also stops at the edge of space.
	if(!istype(T))
		return 0

	if(!istype(T) && !include_space)
		return 0
	else
		if(T.blocks_air||blocks_air)
			return 0

		for(var/obj/obstacle in src)
			if(istype(obstacle, /obj/machinery/door) && !obstacle:air_properties_vary_with_direction)
				continue
			if(!obstacle.CanPass(null, T, 1.5, 1))
				return 0

		for(var/obj/obstacle in T)
			if(istype(obstacle, /obj/machinery/door) && !obstacle:air_properties_vary_with_direction)
				continue
			if(!obstacle.CanPass(null, src, 1.5, 1))
				return 0

		return 1

/turf/proc/ZAirPass(turf/T)
	//Fairly standard pass checks for turfs, objects and directional windows.
	if(!istype(T))
		return 0

	if(T.blocks_air||blocks_air)
		return 0

	for(var/obj/obstacle in src)
		if(istype(obstacle, /obj/machinery/door) && !obstacle:air_properties_vary_with_direction)
			continue
		if(!obstacle.CanPass(null, T, 0, 0))
			return 0

	for(var/obj/obstacle in T)
		if(istype(obstacle, /obj/machinery/door) && !obstacle:air_properties_vary_with_direction)
			continue
		if(!obstacle.CanPass(null, src, 0, 0))
			return 0

	return 1

/*UNUSED
/turf/proc/check_connections()
	//Checks for new connections that can be made.
	for(var/d in cardinal)
		var/turf/simulated/T = get_step(src,d)
		if(istype(T) && ( !T.zone || !T.CanPass(0,src,0,0) ) )
			continue
		if(T.zone != zone)
			ZConnect(src,T)

/turf/proc/check_for_space()
	//Checks for space around the turf.
	for(var/d in cardinal)
		var/turf/T = get_step(src,d)
		if(istype(T,/turf/space) && T.CanPass(0,src,0,0))
			zone.AddSpace(T)
			*/