Move species trait logic to living-level

code/datums/traits/traits.dm

@@ -16,45 +16,62 @@
 /mob/living/proc/GetTraits()
 	SHOULD_NOT_SLEEP(TRUE)
 	RETURN_TYPE(/list)
-	return traits
-
-/mob/living/carbon/human/GetTraits()
-	if(traits)
-		return traits
-	return species.traits
+	var/decl/species/our_species = get_species()
+	return traits || our_species?.traits
 
 /mob/living/proc/SetTrait(trait_type, trait_level)
 	SHOULD_NOT_SLEEP(TRUE)
+	var/decl/species/our_species = get_species()
 	var/decl/trait/T = GET_DECL(trait_type)
 	if(!T.validate_level(trait_level))
 		return FALSE
 
-	LAZYSET(traits, trait_type, trait_level)
-	return TRUE
-
-/mob/living/carbon/human/SetTrait(trait_type, trait_level)
-	var/decl/trait/T = GET_DECL(trait_type)
-	if(!T.validate_level(trait_level))
-		return FALSE
-
-	if(!traits) // If traits haven't been setup before, check if we need to do so now
-		var/species_level = species.traits[trait_type]
+	if(our_species && !traits) // If species traits haven't been setup before, check if we need to do so now
+		var/species_level = our_species.traits[trait_type]
 		if(species_level == trait_level) // Matched the default species trait level, ignore
 			return TRUE
-		traits = species.traits.Copy() // The setup is to simply copy the species list of traits
+		traits = our_species.traits.Copy() // The setup is to simply copy the species list of traits
 
-	return ..(trait_type, trait_level)
-
-/mob/living/proc/RemoveTrait(trait_type)
-	LAZYREMOVE(traits, trait_type)
-
-/mob/living/carbon/human/RemoveTrait(trait_type)
-	// If traits haven't been setup, but we're trying to remove a trait that exists on the species then setup traits
-	if(!traits && (trait_type in species.traits))
-		traits = species.traits.Copy()
+	LAZYSET(traits, trait_type, trait_level)
+	return TRUE
 
-	..(trait_type) // Could go through the trouble of nulling the traits list if it's again equal to the species list but eh
-	traits = traits || list() // But we do ensure that humans don't null their traits list, to avoid copying from species again
+/mob/living/proc/RemoveTrait(trait_type, canonize = TRUE)
+	var/decl/species/our_species = get_species()
+	// If traits haven't been set up, but we're trying to remove a trait that exists on the species then set up traits
+	if(!traits && LAZYISIN(our_species?.traits, trait_type))
+		traits = our_species.traits.Copy()
+	if(LAZYLEN(traits))
+		LAZYREMOVE(traits, trait_type)
+	// Check if we can just default back to species traits.
+	if(canonize)
+		CanonizeTraits()
+
+/// Removes a trait unless it exists on the species.
+/// If it does exist on the species, we reset it to the species' trait level.
+/mob/living/proc/RemoveExtrinsicTrait(trait_type)
+	var/decl/species/our_species = get_species()
+	if(!LAZYACCESS(our_species?.traits, trait_type))
+		RemoveTrait(trait_type)
+	else if(our_species?.traits[trait_type] != GetTraitLevel(trait_type))
+		SetTrait(trait_type, our_species?.traits[trait_type])
+
+/// Sets the traits list to null if it's identical to the species list.
+/// Returns TRUE if the list was reset and FALSE otherwise.
+/mob/living/proc/CanonizeTraits()
+	if(!traits) // Already in canonical form.
+		return FALSE
+	var/decl/species/our_species = get_species()
+	if(!our_species) // Doesn't apply without a species.
+		return FALSE
+	var/list/missing_traits = traits ^ our_species?.traits
+	var/list/matched_traits = traits & our_species?.traits
+	if(LAZYLEN(missing_traits))
+		return FALSE
+	for(var/trait in matched_traits) // inside this loop we know our_species exists and has traits
+		if(traits[trait] != our_species.traits[trait])
+			return FALSE
+	traits = null
+	return TRUE
 
 /decl/trait
 	abstract_type = /decl/trait