class_name Movement_StateReceiver
extends Node

## Movement component 
# attempts to interact with movement of the scene root without knowing what
# it is. It can be perhaps a static body or kinematicbody 
# it doesn't actually move a node, that's what the state machine does
# but it does keep track of velocity
# I can't give it an actor node or a direct reference. 
# It can use a number of detection components to help inform decisions.

export var debug_component: bool = false

onready var current_state = StateAnimatedActor.new()
onready var parent: KinematicBody2D = get_parent()

export var callable_state_machine :NodePath
var request_state_change: FuncRef

onready var desired_movement_vector: Vector2 = Vector2(0,0)

# Since animactor state machine can actually view properties from this type
# I'm thinking about moving the velocity tracker in here instead of player.
var velocity = Vector2(0,0)
var foo_velocity = preload("res://src/classes/velocity_calculations.gd").new()

#Removing Probably not used
#var sim_velocity = Vector2(0,0)
var physics_delta:float
var process_delta:float

var modifier: StateModifierMovement

#Removing Probably not used
#var attack_function: FuncRef

const UP = -1.0
const DOWN = 1.0
const LEFT = -1.0
const RIGHT = 1.0

func _ready():
	foo_velocity.debug = true

	## FuncRef to request state machine change state
	request_state_change = funcref(get_node(callable_state_machine), 'change_to_known_state')
	## Connect signal to get alerted of state change
	get_node(callable_state_machine).connect("state_changed", self,"_on_state_change")
	## Get notified when modifiers updated
	get_node(callable_state_machine).connect("modifiers_updated",self,"_on_modifiers_updated")
	## A reference to the current state machine state
	current_state = get_node(callable_state_machine).current_state
	## A reference to the state machine merged modifiers
	#modifier = get_node(callable_state_machine).merged_animation_state_modifiers
	
############
## These get called by the parent
############
func process_physics(delta):
	physics_delta = delta
	if has_method('_state_process_physics_' + current_state.name):
		call('_state_process_physics_' + current_state.name)
#	else:
#		move_actor_as_desired()

# more likely needed for Players
func process_physics_input(delta):
	physics_delta = delta
	if has_method('_state_process_physics_input_' + current_state.name):
		call('_state_process_physics_input_' + current_state.name)

# More likely needed for NPCs
func process(delta):
	process_delta = delta
	if has_method('_state_process_' + current_state.name):
		call('_state_process_' + current_state.name)

# For event based input polling (Hadouken?)
func process_unhandled_input(event: InputEvent):
	# Reset desired movement vector
	desired_movement_vector = Vector2(0,0)
	if has_method('_state_process_input_' + current_state.name):
			call('_state_process_input_' + current_state.name)

############

############
## A Series of helper functions
############
func go_up():
	desired_movement_vector.y = UP
func go_down():
	desired_movement_vector.y = DOWN
func go_left():
	desired_movement_vector.x = LEFT
func go_right():
	desired_movement_vector.x = RIGHT
func stop():
	desired_movement_vector = Vector2(0,0)

# Return the desired direction of movement for the character
# in the range [-1, 1], where positive values indicate a desire
# to move to the right and negative values to the left.
func get_movement_direction() -> float:
	return desired_movement_vector.x

# Return a boolean indicating if the character wants to jump
func wants_jump() -> bool:
	return false

# Return a boolean indicating if the character wants to attack
func wants_shoot() -> bool:	
	return false

# Return a boolean indicating if the character wants to dash
func wants_dash() -> bool:	
	return false

func wants_roll() -> bool:	
	return false

func wants_climb() -> bool:	
	return false
############

func get_climb_shape_location() -> Vector2:
	return Vector2(-1,-1)

func _on_state_change(old_state_name:String, new_state :State):
	###### State machine
	if new_state is StateAnimatedActor: #Testing this. Update: It works
		## Confirmed that I do neet to update the current_state with the passed state.
		current_state = new_state
		if has_method('_on_state_change_' + current_state.name):
			call('_on_state_change_' + current_state.name)
	else:
		push_warning("Received non animated Actor state.")
	#current_state = new_state

func _on_modifiers_updated(_modifier_type :int, _modifier_action :int, _merged_modifier :StateModifier):
	## Get reference (subscribe) to the merged modifier for movement
	if _merged_modifier is StateModifierMovement:
		print("Registered Modifier Movement: ", _merged_modifier.horizontal_speed)
		modifier = _merged_modifier

func apply_state_modifier(movement_parameters :MovementParameters) -> MovementParameters:
	if modifier and modifier.is_active:
		if (current_state.is_grounded and modifier.only_grounded): # Should we skip
			movement_parameters.apply_state_modifier(modifier)
	
	return movement_parameters


## Passed in acceleration, vel, etc is applied to whatever
## the parent is. If Kinematic then move_and_slide, otherwise manually adjusted
func apply_movement_to_parent( _velocity :Vector2) -> void:
	var snap = Vector2.DOWN * 8
	## Disable snap when trying to jump (hacky?)
	if _velocity.y < -8:
		snap = Vector2.ZERO
	if parent is KinematicBody2D:
		foo_velocity.velocity = parent.move_and_slide_with_snap(_velocity, snap , Vector2.UP, true)

enum RANGE_PLACEMENT {
	BEFORE_RANGE = -1,
	WITHIN_RANGE = 0,
	PAST_RANGE = 1
}

## Side effects for these variables
# velocity - doesn't change but uses it to set base calculations
# accepts the state to determine movement, the deltatime, and an optional direction 
# Update: Actually should just return movement in PPS
##

## Could these be datatypes or a class? Sure
var _h_impulse_applied :bool = false
var _h_impulse_speed_tracking :Vector2
var _v_impulse_applied :bool = false
var _v_impulse_speed_tracking :Vector2

func new_move_actor_as_desired(_delta :float,
		_state :StateAnimatedActor,
		_movement_override_normal := Vector2(0,0),
		_velocity_override := Vector2(0,0)) -> Vector2:
	
	var calc_velocity = Vector2.ZERO
	if _velocity_override.x != 0.0:
		calc_velocity.x = _velocity_override.x
	else:
		calc_velocity.x = velocity.x
	if _velocity_override.y != 0.0:
		calc_velocity.y = _velocity_override.y
	else:
		calc_velocity.y = velocity.y

	var calc_acceleration = Vector2.ZERO
	var calc_inertia :Vector2
	#calc_inertia.x = abs(calc_velocity.x)
	## We're now toing to preserve inertia direction
	calc_inertia.x = calc_velocity.x
	calc_inertia.y = calc_velocity.y
	
	var calc_inertial_dir = Vector2(sign(calc_velocity.x),sign(calc_velocity.y))
	#var calc_friction :Vector2 = Vector2.ZERO

	## Determine movement direction
	# If there is an inertia direction from existing velocity and 
	# no desired movement we'll continue to travel in that direction.
	##
	## If an override has been passed (we're ignoring input direction
	var move_direction = Vector2.ZERO
	if _movement_override_normal != Vector2.ZERO:
		move_direction = resolve_move_direction(calc_inertia, _movement_override_normal)
	else:
		move_direction = resolve_move_direction(calc_inertia, desired_movement_vector)
	
	var modifier_indicator := ''
	var movement_parameters :MovementParameters = _state.get_movement_parameters()


	## Inertia only applies if there is a difference between the 
	# base move speed and a derived move speed. This makes it so all you
	# have to do is provide a move speed and that is the speed we will travel.
	# but if a modifier applies, or an accelleration is given.
	# an entirely differant process occurs.
	# h_speed.x can be thought of as impulse speed. While h_speed.y
	# is the destination speed. 
	# We move towards h_speed.y at the acceleration rate
	##
	var h_speed = resolve_h_speed(movement_parameters)
	var v_speed = resolve_v_speed(movement_parameters)
	## Speed will now be expected to move in the direction of travel
	h_speed *= move_direction.x
	v_speed *= move_direction.y
	
	## Now determine placement of current velocity to speed range
	var h_range_placement = placement_to_speed_range(calc_velocity.x, h_speed)
	var v_range_placement = placement_to_speed_range(calc_velocity.y, v_speed)

	## We don't want to be able to scoot our impulse speed to cheat the movement
	# Any non zero speed that goes opposite to our inertial direction
	# should only be allowed once. 
	## Reset the impulse when back in range
	# may also want to reset when hspeed is static
	if (h_range_placement == RANGE_PLACEMENT.WITHIN_RANGE and 
			_h_impulse_applied == true	):
		print("resetting H impulse")
		_h_impulse_applied = false
	if (v_range_placement == RANGE_PLACEMENT.WITHIN_RANGE and 
			_v_impulse_applied == true	):
		print("resetting V impulse")
		_v_impulse_applied = false

	## Acceleration is always postive because we use the 
	# move toward functions.
	calc_acceleration.x = abs(resolve_h_acceleration(movement_parameters, move_direction.x))

	## We are always moving from h_speed.x towards y at a given rate
	## if we have a difference of speed and an acceleration
	##TODO: The Min Max could be augmented to just be h_speed.x and prevent the sliding.
	if h_speed.x != h_speed.y and calc_acceleration.x != 0.0:
		var direction_accel :float = calc_acceleration.x * _delta #* move_direction.x
		if h_speed.x > h_speed.y:
			direction_accel *= -1
		match h_range_placement:
			RANGE_PLACEMENT.BEFORE_RANGE:
				## Also apply impulse here
				if _h_impulse_applied == false:
					calc_inertia.x += h_speed.x
					_h_impulse_applied = true
					#impulse_applied_dir = move_direction.x
				calc_inertia.x = clamp(calc_inertia.x + direction_accel,
										min(calc_inertia.x, h_speed.y),
										max(calc_inertia.x, h_speed.y))
			RANGE_PLACEMENT.WITHIN_RANGE:
				## If we're within the range but our speed has just changed
				if _h_impulse_applied == false and _h_impulse_speed_tracking != h_speed:
					## Set inertia to starting speed, we're already in range
					calc_inertia.x = h_speed.x
					_h_impulse_applied = true
				calc_inertia.x = clamp(calc_inertia.x + direction_accel,
										min(h_speed.x, h_speed.y),
										max(h_speed.x, h_speed.y))
			RANGE_PLACEMENT.PAST_RANGE:
				calc_inertia.x = clamp(calc_inertia.x - direction_accel, # Friction
										min(calc_inertia.x, h_speed.y),
										max(calc_inertia.x, h_speed.y))
		
			
	elif calc_inertia.x != 0.0 and calc_acceleration.x != 0.0: ## We still have inertia but no difference in movement
		if h_speed.x < h_speed.y:
			h_speed.x = clamp(h_speed.x,0.0,h_speed.y)

		## Move back towards the base speed
		calc_inertia.x = move_toward(calc_inertia.x, h_speed.x, calc_acceleration.x * _delta)

	else:
		## inertia is just base speed
		calc_inertia.x = h_speed.x
		calc_inertial_dir.x = 0.0 # sign(calc_inertia.x) 

	## Another idea, just return the calculated velocity in PPS	
	## For now, y component of velocity is just gravity
	if v_speed.x != v_speed.y: ## For now gravity is just the default acceleration
		var direction_accel :float = movement_parameters.gravity * _delta #* move_direction.x
		if v_speed.x > v_speed.y:
			direction_accel *= -1
		match v_range_placement:
			RANGE_PLACEMENT.BEFORE_RANGE:
				## Also apply impulse here
				if _v_impulse_applied == false:
					calc_inertia.y += v_speed.x
					_v_impulse_applied = true
					#impulse_applied_dir = move_direction.x
				calc_inertia.y = clamp(calc_inertia.y + direction_accel,
										min(calc_inertia.x, v_speed.y),
										max(calc_inertia.x, v_speed.y))
			RANGE_PLACEMENT.WITHIN_RANGE:
				## If we're within the range but our speed has just changed
				if _v_impulse_applied == false and _v_impulse_speed_tracking != v_speed:
					## Set inertia to starting speed, we're already in range
					calc_inertia.y = v_speed.x
					_v_impulse_applied = true
				calc_inertia.y = clamp(calc_inertia.y + direction_accel,
										min(v_speed.x, v_speed.y),
										max(v_speed.x, v_speed.y))
			RANGE_PLACEMENT.PAST_RANGE:
				calc_inertia.y = clamp(calc_inertia.y - direction_accel, # Friction
										min(calc_inertia.y, v_speed.y),
										max(calc_inertia.y, v_speed.y))

	else:
		## The previous vertical movement methods
		calc_inertia.y += movement_parameters.gravity * _delta

	## Track or last speed for in range impulses
	_h_impulse_speed_tracking = h_speed
	_v_impulse_speed_tracking = v_speed

	calc_velocity.y = calc_inertia.y
	calc_velocity.x = calc_inertia.x
	
	if debug_component:
		UiManager.debug_text =	( #"H_Speed x Dir: " + str(h_speed) + str('duh') +
			modifier_indicator + "H_Speed  Fm:{0} To:{1}".format({"0":"%5.2f" % h_speed.x, "1":"%5.2f" % h_speed.y}) + 
			"\nV_Speed  Fm:{0} To:{1}".format({"0":"%5.2f" % v_speed.x, "1":"%5.2f" % v_speed.y}) + 
			"\nSpeedRange   :   {0}, {1}".format({"0":"%5.2f" % h_range_placement, "1":"%5.2f" % v_range_placement}) +
			"\nVelocity_Calc:   {0}, {1}".format({"0":"%5.2f" % calc_velocity.x, "1":"%5.2f" % calc_velocity.y}) +
			"\nInertia_Calc:   {0}, {1}".format({"0":"%5.2f" % calc_inertia.x, "1":"%5.2f" % calc_inertia.y}) +
			"\nVelocity_Real:   {0}, {1}".format({"0":"%5.2f" % velocity.x, "1":"%5.2f" % velocity.y}) +
			#"\nFriction:   {0}, {1}".format({"0":"%5.2f" % calc_friction.x, "1":"%5.2f" % calc_friction.y}) +
			"\nAccelCalc   :   {0}, {1}".format({"0":"%5.2f" % calc_acceleration.x, "1":"%5.2f" % calc_acceleration.y}) +
			# h_range_placement
			#"\nLength: " + str(velocity.length()) +
			"\nMoveDir: {0}, {1}".format({"0":"%4.1f" % move_direction.x, "1":"%4.1f" % move_direction.y})
			)
		
	return calc_velocity

func is_out_of_range(value: float, a: float, b: float) -> bool:
	var lower = min(a, b)
	var upper = max(a, b)
	return value <= lower or value >= upper

## Determine the trend of direction and where our current speed is
# in relation to it. This should help determine the direction of
# acceleration and whether we speed up or slow down.
##
func placement_to_speed_range(speed: float, speed_range: Vector2) -> int:
	## Actually we don't care about mix or min
	#var range_start :float = min(speed_range.x, speed_range.y)
	#var range_end :float = max(speed_range.x, speed_range.y)

	## We can be at the base range to ensure impulse can happen
	## Direction <-- that way
	if speed_range.x > speed_range.y:
		if speed < speed_range.x and speed >= speed_range.y:
			return RANGE_PLACEMENT.WITHIN_RANGE
		elif speed < speed_range.y:
			return RANGE_PLACEMENT.PAST_RANGE
		else:
			return RANGE_PLACEMENT.BEFORE_RANGE
	else: ## Direction --> that way
		if speed > speed_range.x and speed <= speed_range.y:
			return RANGE_PLACEMENT.WITHIN_RANGE
		elif speed > speed_range.y:
			return RANGE_PLACEMENT.PAST_RANGE
		else:
			return RANGE_PLACEMENT.BEFORE_RANGE
	return 0




## Returns an Vector where x is MIN_SPEED and y is MAX_SPEED
func resolve_h_speed(_params :MovementParameters) -> Vector2:
	var base_speed :float = _params.base_move_speed.x
	## if a speed difference applies
	if _params.move_speed_modifier.x != 0:
		var speed_differance = base_speed + _params.move_speed_modifier.x
		
		return(Vector2(base_speed, speed_differance))
	return Vector2(base_speed,base_speed)

func resolve_v_speed(_params :MovementParameters) -> Vector2:
	var base_speed :float = _params.base_move_speed.y
	## if a speed difference applies
	if _params.move_speed_modifier.y != 0:
		var speed_differance = base_speed + _params.move_speed_modifier.y
		
		return(Vector2(base_speed, speed_differance))
	return Vector2(base_speed,base_speed)

func resolve_h_acceleration(_params :MovementParameters, _move_direction :float) -> float:
	## TODO: Adjust for jerk, determine if we're currently experiencing accel
	## if a speed difference applies
	var _acceleration :float =  0.0
	var base_speed :float = _params.base_move_speed.x
	if _params.move_speed_modifier.x != 0:
		var speed_differance = base_speed + _params.move_speed_modifier.x
		_acceleration = _params.base_move_acceleration.x + _params.move_speed_modifier_acceleration.x
		##WIP: Add part where offset acceleration only applies until the inertia equals the offset or whatever
#		if sign(_params["_base_h_move_modifier_move_acceleration"]) == -1 and  abs(_inertia.x) >= speed_differance:
#			#print("I should add the modifier acceleration maybe?")
#			_acceleration += _params["_base_h_move_modifier_move_acceleration"]
#		else:
#			print ("not yet.")
	else:
		_acceleration = _params.base_move_acceleration.x
	
	## This works but I want to try something differant.
#	if _inertia.x != 0.0 and sign(_inertia.x) != sign(_move_direction):
#		return _acceleration * -1
#	elif sign(_move_direction) != 0:
#		## If no velocity or it matches just return as is.
#		return _acceleration 

	if sign(_move_direction) != 0:
		return _acceleration

	# No accel returned unless intended
	return 0.0

func resolve_move_direction(_momentum :Vector2,
							_movement_direction :Vector2) -> Vector2:
	var horizontal_movement_direction:float
	if sign(_movement_direction.x): ## We're trying to move
		horizontal_movement_direction = sign(_movement_direction.x)
	elif sign(_momentum.x): ## We still have momentum but not trying to move
		horizontal_movement_direction = sign(_momentum.x)
	
	var vertical_movement_direction:float
	if sign(_movement_direction.y):
		vertical_movement_direction = sign(_movement_direction.y)
	elif sign(_momentum.y):
		vertical_movement_direction = sign(_momentum.y)
	
	return Vector2(horizontal_movement_direction, vertical_movement_direction)