package Buff
import public BuffObjEditing
import public DamageEvent
import LinkedListModule
import Squares
import TextTagEntity
import ClosureTimers
import LinkedList
import ErrorHandling
import UnitIndexer
import Frentity
import ClosureEvents

/*
 * Use Frentity Buffs for your custom buff needs.
 * 1. Create your buff object using `createDummyBuffObject`.
 * 2. Create a class for your buff that extends one of the preset buffs.
 * 3. Apply the buff via `new YourBuff().apply(target)`
 *
 * Buffs have 2 lifecycle hooks:
 *
 * 	function onApply()
 *	function onEnd()
 *
 * and api for attack/defense modifiers.
 *
 *	function attackModifier()
 *	function defenseModifier()
*/

public constant BUFF_ANIM_PERIOD = 0.25
LinkedList<Buff> array buffMap

public function unit.hasBuffs() returns boolean
	return buffMap[this.getIndex()] != null

public function unit.addBuff(Buff buffObj)
	if buffObj == null or this == null
		error("Cannot add null buff or null target")
	if not this.hasBuffs()
		buffMap[this.getIndex()] = new LinkedList<Buff>()..add(buffObj)
	else
		buffMap[this.getIndex()].add(buffObj)

public function unit.hasBuff(int buffTypeId) returns boolean
	return this.getBuff(buffTypeId) != null

public function unit.getBuff(int buffTypeId) returns Buff
	if this.hasBuffs()
		for b in this.getBuffs()
			if b.typeId == buffTypeId
				return b
	return null


public function unit.removeBuff(Buff bff)
	if this.hasBuffs()
		let itr = this.getBuffs().iterator()
		for b from itr
			if b == bff
				itr.remove().terminate()
		itr.close()

public function unit.removeBuffById(int typeId)
	if this.hasBuffs()
		let itr = this.getBuffs().iterator()
		for b from itr
			if b.typeId == typeId
				itr.remove().terminate()
		itr.close()

public function unit.getBuffs() returns LinkedList<Buff>
	return buffMap[this.getIndex()]

public function unit.clearBuffs()
	let buffs = this.getBuffs()
	if buffs != null
		for bff in buffs
			bff.terminate()
		destroy buffs
		buffMap[this.getIndex()] = null

public function unit.transferBuffs(unit otherEntity)
	if otherEntity == null
		error("Target Entity may not be null")
	if this == null
		error("Origin Entity may not be null")
	let buffs = this.getBuffs()

	if buffs == null or buffs.size() == 0
		return

	for bff in buffs
		if not bff.done
			bff.apply(otherEntity)
	destroy buffs
	buffMap[this.getIndex()] = null

public abstract class Buff
	use LinkedListModule

	unit target = null
	real duration
	buffTuple buffData
	var done = false

	construct(real duration, buffTuple buffData)
		this.duration = duration
		this.buffData = buffData

	abstract function apply(unit target)

	function onApply()

	function attackModifier()

	function defenseModifier()

	function onEnd()

	function update()
		if duration <= 0.
			terminate()
		else
			duration -= BUFF_ANIM_PERIOD

	function refresh()
		refresh(false)

	function refresh(boolean forceRefresh)
		if not target.hasAbility(buffData.abilId) or forceRefresh
			target.addAbility(buffData.abilId)

	function terminate()
		if not done
			done = true
			onEnd()
			destroy this

	ondestroy
		if target != null
			this.target.removeAbility(this.buffData.buffId)
			target.removeBuff(this)
			target.removeAbility(buffData.abilId)
		target = null

init
	// Call attack and defense modifiers of buffs
	DamageEvent.addListener() ->
		let def = GetTriggerUnit()
		let att = GetEventDamageSource()
		if DISABLE_TEAMATTACK and (def.getOwner().isAllyOf(att.getOwner()) or def.getOwner() == att.getOwner())
			// Falsify teamattacks
			if DamageEvent.getAmount() > 0.5
				DamageEvent.setAmount(0)
				if SHOW_SQUARE
					new TextTagEntity(def.getPos().toVec3(), vec3(GetRandomReal(-2,2),GetRandomReal(-2,2),GetRandomReal(8,10)), getSquare(), 10, .8,
						colorA(GetRandomInt(150,250),GetRandomInt(125,150),GetRandomInt(125,150), 255))
		else
			if att.hasBuffs()
				for bff in att.getBuffs()
					if not bff.done
						bff.attackModifier()

			if def.hasBuffs()
				for bff in def.getBuffs()
					if not bff.done
						bff.defenseModifier()

	// Update the buff display on unit upgrade
	EventListener.add(EVENT_PLAYER_UNIT_UPGRADE_FINISH) ->
		let upg = GetTriggerUnit()
		if upg.getIndex() > 0
			doAfter(0.01) ->
				if upg.hasBuffs()
					for bff in upg.getBuffs()
						bff.refresh(true)

	// Remove buffs when a unit dies and all other triggers fired.
	EventListener.add(EVENT_PLAYER_UNIT_DEATH) ->
		let u = GetTriggerUnit()
		u.clearBuffs()