Reimplement codex implant and add config option for it

Author: out-of-phaze

code/datums/config/config_types/config_game_world.dm

@@ -23,7 +23,8 @@
 		/decl/config/toggle/roundstart_level_generation,
 		/decl/config/toggle/lights_start_on,
 		/decl/config/toggle/on/cisnormativity,
-		/decl/config/enum/colored_coating_names
+		/decl/config/enum/colored_coating_names,
+		/decl/config/toggle/codex_requires_implant
 	)
 
 /decl/config/num/exterior_ambient_light
@@ -145,4 +146,8 @@
 		"none"       = CONFIG_COATING_COLOR_NONE,
 		"mixture"    = CONFIG_COATING_COLOR_MIXTURE,
 		"components" = CONFIG_COATING_COLOR_COMPONENTS
-	)
+	)
+
+/decl/config/toggle/codex_requires_implant
+	uid = "codex_requires_implant"
+	desc = "If true, humans require a codex implant to access the codex."

code/modules/client/preference_setup/loadout/lists/augmentations.dm

@@ -33,3 +33,17 @@
 
 	user.add_organ(src, organ_to_implant_into)
 	to_chat(user, SPAN_NOTICE("Your [organ_to_implant_into.name] has been replaced with \the [src]."))
+
+// Codex implant, only available if the codex is set to require it in config
+/decl/loadout_option/augmentation/codex_implant
+	name = "Codex Implant"
+	uid = "gear_augmentation_codex"
+	description = "A neural implant that provides access to the codex."
+	path = /obj/item/implant/codex
+	custom_setup_proc_arguments = list(BP_HEAD)
+	cost = 0
+
+/decl/loadout_option/augmentation/codex_implant/can_be_taken_by(mob/living/user)
+	if(!get_config_value(/decl/config/toggle/codex_requires_implant))
+		return FALSE
+	return ..()

code/modules/codex/codex_implant.dm

@@ -5,6 +5,7 @@
 /obj/item/implant/codex
 	name = "codex implant"
 	desc = "It has 'DON'T PANIC' embossed on the casing in friendly letters."
+	known = TRUE
 
 /obj/item/implant/codex/implanted(var/mob/source)
 	. = ..(source)

code/modules/codex/codex_mob.dm

@@ -11,7 +11,11 @@
 	return TRUE
 
 /mob/living/human/can_use_codex()
-	return TRUE //has_implant(/obj/item/implant/codex, functioning = TRUE)
+	if(get_config_value(/decl/config/toggle/codex_requires_implant))
+		for(var/obj/item/implant/codex/codex_implant in contents)
+			if(codex_implant.implanted && !codex_implant.malfunction)
+				return TRUE
+	return TRUE
 
 /mob/living/human/get_codex_value()
 	return "[lowertext(species.name)] (species)"