// Involves cooperating with other ai_holders.
/datum/ai_holder
	var/cooperative = FALSE						// If true, asks allies to help when fighting something.
	var/call_distance = 5	//CHOMPEdit - 14 is way too egreigous					// How far away calls for help will go for.
	var/last_helpask_time = 0					// world.time when a mob asked for help.
	var/list/faction_friends = list()			// List of all mobs inside the faction with ai_holders that have cooperate on, to call for help without using range().
												// Note that this is only used for sending calls out. Receiving calls doesn't care about this list, only if the mob is in the faction.
												// This means the AI could respond to a player's call for help, if a way to do so was implemented.

	// These vars don't do anything currently. They did before but an optimization made them nonfunctional.
	// It was probably worth it.
	var/call_players = FALSE					// (Currently nonfunctional) If true, players get notified of an allied mob calling for help.
	var/called_player_message = "needs help!"	// (Currently nonfunctional) Part of a message used when above var is true. Full message is "\The [holder] [called_player_message]"

/datum/ai_holder/New(new_holder)
	..()
	if(cooperative)
		build_faction_friends()

/datum/ai_holder/Destroy()
	if(faction_friends)
		if(faction_friends.len) //This list is shared amongst the faction
			faction_friends -= src
	return ..()

// Handles everything about that list.
// Call on initialization or if something weird happened like the mob switched factions.
/datum/ai_holder/proc/build_faction_friends()
	if(faction_friends.len) // Already have a list.
		// Assume we're moving to a new faction.
		faction_friends -= src   // Get us out of the current list shared by everyone else.
		faction_friends = list() // Then make our list empty and unshared in case we become a loner.

	// Find another AI-controlled mob in the same faction if possible.
	var/mob/living/first_friend
	for(var/mob/living/L in living_mob_list)
		if(L.faction == holder.faction && L.ai_holder)
			first_friend = L
			break

	if(first_friend) // Joining an already established faction.
		faction_friends = first_friend.ai_holder.faction_friends
		faction_friends |= holder
	else // We're the 'founder' (first and/or only member) of this faction.
		faction_friends |= holder

// Requests help in combat from other mobs possessing ai_holders.
/datum/ai_holder/proc/request_help()
	ai_log("request_help() : Entering.", AI_LOG_DEBUG)
	if(!cooperative || ((world.time - last_helpask_time) < 10 SECONDS))
		return

	ai_log("request_help() : Asking for help.", AI_LOG_INFO)
	last_helpask_time = world.time

//	for(var/mob/living/L in range(call_distance, holder))
	for(var/mob/living/L in faction_friends)
		if(L == holder) // Lets not call ourselves.
			continue
		if(holder.z != L.z) // On seperate z-level.
			continue
		if(get_dist(L, holder) > call_distance) // Too far to 'hear' the call for help.
			continue

		if(holder.IIsAlly(L))
			// This will currently never run sadly, until faction_friends is made to accept players too.
			// That might be for the best since I can imagine it getting spammy in a big fight.
			if(L.client && call_players) // Dealing with a player.
				ai_log("request_help() : Asking [L] (Player) for help.", AI_LOG_INFO)
				to_chat(L, "<span class='critical'>\The [holder] [called_player_message]</span>")

			else if(L.ai_holder) // Dealing with an AI.
				ai_log("request_help() : Asking [L] (AI) for help.", AI_LOG_INFO)
				L.ai_holder.help_requested(holder)

	ai_log("request_help() : Exiting.", AI_LOG_DEBUG)

// What allies receive when someone else is calling for help.1
/datum/ai_holder/proc/help_requested(mob/living/friend)
	ai_log("help_requested() : Entering.", AI_LOG_DEBUG)
	if(stance == STANCE_SLEEP)
		ai_log("help_requested() : Help requested by [friend] but we are asleep.", AI_LOG_INFO)
		return
	if(!cooperative)
		ai_log("help_requested() : Help requested by [friend] but we're not cooperative.", AI_LOG_INFO)
		return
	if(stance in STANCES_COMBAT)
		ai_log("help_requested() : Help requested by [friend] but we are busy fighting something else.", AI_LOG_INFO)
		return
	if(!can_act())
		ai_log("help_requested() : Help requested by [friend] but cannot act (stunned or dead).", AI_LOG_INFO)
		return
	if(!holder.IIsAlly(friend)) // Extra sanity.
		ai_log("help_requested() : Help requested by [friend] but we hate them.", AI_LOG_INFO)
		return
	var/their_target = friend?.ai_holder?.target
	if(their_target) // They have a target and aren't just shouting for no reason
		if(!can_attack(their_target, vision_required = FALSE))
			ai_log("help_requested() : Help requested by [friend] but we don't want to fight their target.", AI_LOG_INFO)
			return
		if(get_dist(holder, friend) <= follow_distance)
			ai_log("help_requested() : Help requested by [friend] but we're already here.", AI_LOG_INFO)
			return
		if(get_dist(holder, friend) <= vision_range) // Within our sight.
			ai_log("help_requested() : Help requested by [friend], and within target sharing range.", AI_LOG_INFO)
			last_conflict_time = world.time // So we attack immediately and not threaten.
			give_target(their_target, urgent = TRUE) // This will set us to the appropiate stance.
			ai_log("help_requested() : Given target [target] by [friend]. Exiting", AI_LOG_DEBUG)
			return

	// Otherwise they're outside our sight, lack a target, or aren't AI controlled, but within call range.
	// So assuming we're AI controlled, we'll go to them and see whats wrong.
	ai_log("help_requested() : Help requested by [friend], going to go to friend.", AI_LOG_INFO)
	if(their_target)
		add_attacker(their_target) // We won't wait and 'warn' them while they're stabbing our ally
	set_follow(friend, 10 SECONDS)
	ai_log("help_requested() : Exiting.", AI_LOG_DEBUG)