package Collider
import Fx
import TimedLoop
import LinkedList

constant real DEFAULT_COLLISION_SIZE  	=   50.0 // These are defaults, on one hand you can change them
constant real DEFAULT_MAX_SPEED	   		= 1500.0 // on the other hand, if a spell relies on the defaults
constant real DEFAULT_EXPIRATION_TIME 	=	5.0  // changing them would make the behavior vary...


public enum Angle
	NO_MOVEMENT
	HOMING_UNIT
	HOMING_POINT
	ROTATING

public abstract class Collider
	use TimedLoop
	Fx fx

	real expirationTime 	= DEFAULT_EXPIRATION_TIME
	real speed		  		= 0.0
	real acceleration  		= 0.0
	real maxSpeed	   		= DEFAULT_MAX_SPEED
	real minSpeed	   		= 0.0
	real angleSpeed	 		= 0.0
	real collisionSize 		= DEFAULT_COLLISION_SIZE

	private boolean silent = false
	private LinkedList<int> seenIds = new LinkedList<int>()

	private boolean dead = false

	private Angle angleMode = Angle.NO_MOVEMENT

	private unit homingTargetUnit = null
	private vec2 homingTarget

	construct( vec2 pos, angle dir, string _fxPath )
		fx = new Fx( pos, dir )
		startTimedLoop()

	abstract function onUnitHit( unit hitTarget )

	abstract function loopControl()

	function setDirection( angle v )
		fx.setXYAngle( v )

	function setTarget( unit u )
		if u == null
			angleMode = Angle.NO_MOVEMENT
		else
			angleMode = Angle.HOMING_UNIT

		homingTargetUnit = u

	function setTarget( vec2 target )
		angleMode = Angle.HOMING_POINT
		homingTarget = target

	function forgetTarget()
		angleMode = Angle.NO_MOVEMENT

	function isRotating() returns boolean
		return angleMode == Angle.ROTATING

	function setRotating( boolean val )
		if val
			angleMode = Angle.ROTATING
		else if angleMode == Angle.ROTATING
			angleMode = Angle.NO_MOVEMENT

	override function onTimedLoop()
		expirationTime -= ANIMATION_PERIOD
		if dead or expirationTime <= 0.0
			destroy this
		else
			let anglexy = angleBetweenCoords(fx.getPos2().x, fx.getPos2().y, homingTarget.x, homingTarget.y)
			var df1 = (anglexy - fx.getXYAngle()).radians()
			var df2 = (PI2 + anglexy.radians()) - fx.getXYAngle().radians()
			var ns = angleSpeed
			if ns != 0.0
				if angleMode == Angle.HOMING_UNIT
					if ( GetUnitTypeId(homingTargetUnit) == 0 ) or IsUnitType( homingTargetUnit, UNIT_TYPE_DEAD )
						angleMode = Angle.NO_MOVEMENT
						homingTargetUnit = null
					else
						homingTarget = homingTargetUnit.getPos()

				if not angleMode == Angle.ROTATING and angleMode != Angle.NO_MOVEMENT
					if ns <= 0.
						ns = -ns

					if df1 <= 0
						if df2 <= 0
							if df2 >= df1
								df1 = df2
						else
							if -df1 >= df2
								df1 = df2
					else
						if df2 <= 0
							if -df2 <= df1
								df1 = df2
						else
							if df2 <= df1
								df1 = df2
					if df1 <= 0
						if -df1 >= ns
							ns = -ns
						else
							ns = df1
					else
						if df1 <= ns
							ns = df1
					var d = fx.getXYAngle().radians()
					d += ns
					if d >= PI2
						d -= PI2
					else if d < 0
						d += PI2

					fx.setXYAngle(angle(d))


			ns = speed + acceleration * ANIMATION_PERIOD
			if ns < minSpeed
				ns = minSpeed
			else if ns > maxSpeed
				ns = maxSpeed

			let dt = ((speed + ns) /2) * ANIMATION_PERIOD
			speed = ns
			let newP = vec2( fx.getX()+dt*fx.getXYAngle().cos(), fx.getY()+dt*fx.getXYAngle().sin())
			fx.setXY(newP)

			GroupEnumUnitsInRange( ENUM_GROUP, newP.x, newP.y, collisionSize + MAX_COLLISION_SIZE, null)
			let itr = ENUM_GROUP.iterator()
			for u from itr
				if not IsUnitType(u, UNIT_TYPE_DEAD)  and not(dead) and (GetUnitTypeId(u) != DUMMY_UNIT_ID) and IsUnitInRangeXY(u, newP.x, newP.y, collisionSize)
					if not seenIds.contains(u.getHandleId() )
						onUnitHit(u)
			itr.close()
			ENUM_GROUP.clear()

			if not dead
				loopControl()

	function terminate()
		dead = true

	function hiddenDestroy()
		silent = true
		dead = true

	ondestroy
		destroy seenIds
		if silent
			fx.hiddenDestroy()
		else
			destroy fx

		stopTimedLoop()