[MIRROR] Turf slip component [NEEDS TESTING] (#11730)

Co-authored-by: Will <7099514+Willburd@users.noreply.github.com>
Co-authored-by: Cameron Lennox <killer65311@gmail.com>

code/datums/components/turfslip.dm

@@ -0,0 +1,91 @@
+/datum/component/turfslip
+	var/mob/living/owner
+	var/slip_dist = TURFSLIP_WET
+	var/dirtslip = FALSE
+
+/datum/component/turfslip/Initialize()
+	if (!isliving(parent))
+		return COMPONENT_INCOMPATIBLE
+	owner = parent
+	RegisterSignal(owner, COMSIG_MOVABLE_MOVED, PROC_REF(move_react))
+
+/datum/component/turfslip/proc/start_slip(var/turf/simulated/start, var/is_dirt)
+	var/slip_stun = 6
+	var/floor_type = "wet"
+	var/already_slipping = (slip_dist > 1)
+
+	// Handle dirt slipping
+	dirtslip = is_dirt
+	if(dirtslip)
+		slip_stun = 10
+		if(start.dirt > 50)
+			floor_type = "dirty"
+		else if(start.is_outdoors())
+			floor_type = "uneven"
+
+	// Proper sliding behavior
+	switch(start.wet)
+		if(TURFSLIP_LUBE)
+			floor_type = "slippery"
+			slip_dist = 99 //Skill issue.
+			slip_stun = 10
+			dirtslip = FALSE
+		if(TURFSLIP_ICE)
+			floor_type = "icy"
+			slip_stun = 4
+			slip_dist = rand(1,3)
+			dirtslip = FALSE
+
+	// Only start the slip timer if we are not already sliding
+	if(!already_slipping)
+		owner.slip("the [floor_type] floor", slip_stun)
+		addtimer(CALLBACK(src, PROC_REF(next_slip)), 1)
+
+/datum/component/turfslip/proc/move_react(atom/source, atom/oldloc, direction, forced, list/old_locs, momentum_change)
+	SIGNAL_HANDLER
+
+	// Can the mob slip?
+	if(QDELETED(owner) || isbelly(owner.loc))
+		qdel(src)
+		return
+
+	// Can the turf be slipped on?
+	var/turf/simulated/ground = get_turf(owner)
+	if(!ground || !ground.check_slipping(owner,dirtslip))
+		qdel(src)
+		return
+
+	addtimer(CALLBACK(src, PROC_REF(next_slip)), 1)
+
+/datum/component/turfslip/proc/next_slip()
+	// check tile for next slip
+	if(!step(owner, owner.dir) || dirtslip) // done sliding, failed to move, dirt also only slips once
+		qdel(src)
+		return
+	// Kill the slip if it's over
+	if(!--slip_dist)
+		qdel(src)
+		return
+
+/datum/component/turfslip/Destroy(force = FALSE)
+	UnregisterSignal(owner, COMSIG_MOVABLE_MOVED)
+	owner.inertia_dir = 0
+	owner = null
+	slip_dist = 0
+	. = ..()
+
+
+////////////////////////////////////////////////////////////////////////////////////////
+// Helper proc
+////////////////////////////////////////////////////////////////////////////////////////
+/turf/proc/check_slipping(var/mob/living/M)
+	return FALSE
+
+/turf/simulated/check_slipping(var/mob/living/M,var/dirtslip)
+	if(M.buckled)
+		return FALSE
+	if(!wet && !(dirtslip && (dirt > 50 || is_outdoors() == OUTDOORS_YES)))
+		return FALSE
+	if(wet == TURFSLIP_WET && M.m_intent == I_WALK)
+		return FALSE
+	return TRUE