#define SPECIAL 0
#define CONTACT_GENERAL 1
#define CONTACT_HANDS 2
#define CONTACT_FEET 3
#define AIRBORNE 4

/*

IMPORTANT NOTE: Please delete the diseases by using cure() proc or del() instruction.
Diseases are referenced in global list, so simply setting mob or obj vars
to null does not delete the object itself. Thank you.

*/


/datum/disease
	var/name = "No disease"
	var/stage = 1 //all diseases start at stage 1
	var/max_stages = 0.0
	var/cure = null
	var/cure_id = null// reagent.id or list containing them
	var/cure_list = null // allows for multiple possible cure combinations
	var/cure_chance = 8//chance for the cure to do its job
	var/spread = null //spread type description
	var/spread_type = AIRBORNE
	var/contagious_period = 0//the disease stage when it can be spread
	var/list/affected_species = list()
	var/mob/living/carbon/affected_mob = null //the mob which is affected by disease.
	var/holder = null //the atom containing the disease (mob or obj)
	var/carrier = 0.0 //there will be a small chance that the person will be a carrier
	var/curable = 1 //can this disease be cured? (By itself...)
	var/list/strain_data = list() //This is passed on to infectees
	var/stage_prob = 5		// probability of advancing to next stage, default 5% per check
	var/agent = "some microbes"//name of the disease agent
	var/permeability_mod = 1//permeability modifier coefficient.
	var/desc = null//description. Leave it null and this disease won't show in med records.
	var/severity = null//severity descr
	var/longevity = 250//time in "ticks" the virus stays in inanimate object (blood stains, corpses, etc). In syringes, bottles and beakers it stays infinitely.

/datum/disease/proc/stage_act()
	var/cure_present = has_cure()
	//world << "[cure_present]"

	if(carrier&&!cure_present)
		//world << "[affected_mob] is carrier"
		return

	spread = (cure_present?"Remissive":initial(spread))

	if(stage > max_stages)
		stage = max_stages
	if(prob(stage_prob) && stage != max_stages && !cure_present) //now the disease shouldn't get back up to stage 4 in no time
		stage++
	if(stage != 1 && (prob(1) || (cure_present && prob(cure_chance))))
		stage--
	else if(stage <= 1 && ((prob(1) && src.curable) || (cure_present && prob(cure_chance))))
//		world << "Cured as stage act"
		src.cure()
		return
	return

/datum/disease/proc/has_cure()//check if affected_mob has required reagents.
	if(!cure_id) return 0
	var/result = 1
	if(cure_list == list(cure_id))
		if(istype(cure_id, /list))
			for(var/C_id in cure_id)
				if(!affected_mob.reagents.has_reagent(C_id))
					result = 0
		else if(!affected_mob.reagents.has_reagent(cure_id))
			result = 0
	else
		for(var/C_list in cure_list)
			if(istype(C_list, /list))
				for(var/C_id in cure_id)
					if(!affected_mob.reagents.has_reagent(C_id))
						result = 0
			else if(!affected_mob.reagents.has_reagent(C_list))
				result = 0

	return result


/mob/proc/contract_disease(var/datum/disease/virus, var/skip_this = 0, var/force_species_check=1)
//	world << "Contract_disease called by [src] with virus [virus]"
	if(src.stat >=2) return


	if(force_species_check)
		var/fail = 1
		for(var/name in virus.affected_species)
			var/mob_type = text2path("/mob/living/carbon/[lowertext(name)]")
			if(mob_type && istype(src, mob_type))
				fail = 0
				break
		if(fail) return

	if(skip_this == 1)//be wary, it replaces the current disease...
		if(src.virus)
			src.virus.cure(0)
		src.virus = new virus.type
		src.virus.affected_mob = src
		src.virus.strain_data = virus.strain_data.Copy()
		src.virus.holder = src
		if(prob(5))
			src.virus.carrier = 1
		return

	if(src.virus) return

	if(virus.type in src.resistances)
		if(prob(99.9)) return
		src.resistances.Remove(virus.type)//the resistance is futile


/*
	var/list/clothing_areas	= list()
	var/list/covers = list(UPPER_TORSO,LOWER_TORSO,LEGS,FEET,ARMS,HANDS)
	for(var/Covers in covers)
		clothing_areas[Covers] = list()

	for(var/obj/item/clothing/Clothing in src)
		if(Clothing)
			for(var/Covers in covers)
				if(Clothing&Covers)
					clothing_areas[Covers] += Clothing

*/
	if(prob(15/virus.permeability_mod)) return //the power of immunity compels this disease!

	var/obj/item/clothing/Cl = null
	var/passed = 1

	//chances to target this zone
	var/head_ch
	var/body_ch
	var/hands_ch
	var/feet_ch

	switch(virus.spread_type)
		if(CONTACT_HANDS)
			head_ch = 0
			body_ch = 0
			hands_ch = 100
			feet_ch = 0
		if(CONTACT_FEET)
			head_ch = 0
			body_ch = 0
			hands_ch = 0
			feet_ch = 100
		else
			head_ch = 100
			body_ch = 100
			hands_ch = 25
			feet_ch = 25


	var/target_zone = pick(head_ch;1,body_ch;2,hands_ch;3,feet_ch;4)//1 - head, 2 - body, 3 - hands, 4- feet

	if(istype(src, /mob/living/carbon/human))
		var/mob/living/carbon/human/H = src

		switch(target_zone)
			if(1)
				if(isobj(H.head))
					Cl = H.head
					passed = prob(Cl.permeability_coefficient*100*virus.permeability_mod)
//					world << "Head pass [passed]"
				if(passed && isobj(H.wear_mask))
					Cl = H.wear_mask
					passed = prob(Cl.permeability_coefficient*100*virus.permeability_mod)
//					world << "Mask pass [passed]"
			if(2)//arms and legs included
				if(isobj(H.wear_suit))
					Cl = H.wear_suit
					passed = prob(Cl.permeability_coefficient*100*virus.permeability_mod)
//					world << "Suit pass [passed]"
				if(passed && isobj(H.slot_w_uniform))
					Cl = H.slot_w_uniform
					passed = prob(Cl.permeability_coefficient*100*virus.permeability_mod)
//					world << "Uniform pass [passed]"
			if(3)
				if(isobj(H.wear_suit) && H.wear_suit.body_parts_covered&HANDS)
					Cl = H.wear_suit
					passed = prob(Cl.permeability_coefficient*100*virus.permeability_mod)
//					world << "Suit pass [passed]"

				if(passed && isobj(H.gloves))
					Cl = H.gloves
					passed = prob(Cl.permeability_coefficient*100*virus.permeability_mod)
//					world << "Gloves pass [passed]"
			if(4)
				if(isobj(H.wear_suit) && H.wear_suit.body_parts_covered&FEET)
					Cl = H.wear_suit
					passed = prob(Cl.permeability_coefficient*100*virus.permeability_mod)
//					world << "Suit pass [passed]"

				if(passed && isobj(H.shoes))
					Cl = H.shoes
					passed = prob(Cl.permeability_coefficient*100*virus.permeability_mod)
//					world << "Shoes pass [passed]"
			else
				src << "Something strange's going on, something's wrong."

			/*if("feet")
				if(H.shoes && istype(H.shoes, /obj/item/clothing/))
					Cl = H.shoes
					passed = prob(Cl.permeability_coefficient*100)
					//
					world << "Shoes pass [passed]"
			*/		//
	else if(istype(src, /mob/living/carbon/monkey))
		var/mob/living/carbon/monkey/M = src
		switch(target_zone)
			if(1)
				if(M.wear_mask && isobj(M.wear_mask))
					Cl = M.wear_mask
					passed = prob(Cl.permeability_coefficient*100+virus.permeability_mod)
					//world << "Mask pass [passed]"

	if(passed && virus.spread_type == AIRBORNE && src.internals)
		passed = (prob(50*virus.permeability_mod))

	if(passed)
//		world << "Infection in the mob [src]. YAY"


/*
	var/score = 0
	if(istype(src, /mob/living/carbon/human))
		if(src:gloves) score += 5
		if(istype(src:wear_suit, /obj/item/clothing/suit/space)) score += 10
		if(istype(src:wear_suit, /obj/item/clothing/suit/bio_suit)) score += 10
		if(istype(src:head, /obj/item/clothing/head/helmet/space)) score += 5
		if(istype(src:head, /obj/item/clothing/head/bio_hood)) score += 5
	if(src.wear_mask)
		score += 5
		if((istype(src:wear_mask, /obj/item/clothing/mask) || istype(src:wear_mask, /obj/item/clothing/mask/surgical)) && !src.internal)
			score += 5
		if(src.internal)
			score += 5
	if(score > 20)
		return
	else if(score == 20 && prob(95))
		return
	else if(score >= 15 && prob(75))
		return
	else if(score >= 10 && prob(55))
		return
	else if(score >= 5 && prob(35))
		return
	else if(prob(15))
		return
	else*/
		src.virus = new virus.type
		src.virus.strain_data = virus.strain_data.Copy()
		src.virus.affected_mob = src
		src.virus.holder = src
		if(prob(5))
			src.virus.carrier = 1
		return
	return


/datum/disease/proc/spread(var/source=null)
	//world << "Disease [src] proc spread was called from holder [source]"
	if(src.spread_type == SPECIAL)//does not spread
		return

	if(src.stage < src.contagious_period) //the disease is not contagious at this stage
		return

	if(!source)//no holder specified
		if(src.affected_mob)//no mob affected holder
			source = src.affected_mob
		else //no source and no mob affected. Rogue disease. Break
			return


	var/check_range = AIRBORNE//defaults to airborne - range 4
	if(src.spread_type != AIRBORNE)
		check_range = 0

	for(var/mob/living/carbon/M in oviewers(check_range, source))
		M.contract_disease(src)

	return


/datum/disease/proc/process()
	if(!src.holder) return
	if(prob(40))
		src.spread(holder)
	if(src.holder == src.affected_mob)
		if(affected_mob.stat < 2) //he's alive
			src.stage_act()
		else //he's dead.
			if(src.spread_type!=SPECIAL)
				src.spread_type = CONTACT_GENERAL
			src.affected_mob = null
	if(!src.affected_mob) //the virus is in inanimate obj
//		world << "[src] longevity = [src.longevity]"
		if(--src.longevity<=0)
			src.cure(0)
	return

/datum/disease/proc/cure(var/resistance=1)//if resistance = 0, the mob won't develop resistance to disease
	if(resistance && src.affected_mob && !(src.type in affected_mob.resistances))
//		world << "Setting res to [src]"
		var/type = "[src.type]"//copy the value, not create the reference to it, so when the object is deleted, the value remains.
		affected_mob.resistances += text2path(type)
//	world << "Removing [src]"
	spawn(0)
		del(src)
	return


/datum/disease/New(var/process=1)//process = 1 - adding the object to global list. List is processed by master controller.
	cure_list = list(cure_id) // to add more cures, add more vars to this list in the actual disease's New()
	if(process)					 // Viruses in list are considered active.
		active_diseases += src

/*
/datum/disease/Del()
	active_diseases.Remove(src)
*/