extends Node
class_name ReedCameraAnchorController

const _CONSTANTS = preload("res://addons/reedcamera/_data/CameraSystemConst.gd")
## =========================
## Private
## =========================
var _anchors: Array[CameraAnchor] = []
var _current_anchor: CameraAnchor
var _current_position := Vector2.ZERO
var _tween: Tween

## =========================
## Config
## =========================
@export var enabled := true
@export var move_duration := 0.4
@export var ease_type := Tween.EASE_OUT
@export var trans_type := Tween.TRANS_CUBIC

## =========================
## Runtime State
## =========================

#var _current_position: Vector2
var _target_position: Vector2
#var _tween: Tween
var _has_target := false

## =========================
## Lifecycle
## =========================

func _ready() -> void:
	var sys := Engine.get_singleton(_CONSTANTS.CAMERA_SYSTEM_NAME)
	if not sys:
		return

	_anchors = sys.get_all_anchors()

	sys.anchor_registered.connect(_on_anchor_added)
	sys.anchor_unregistered.connect(_on_anchor_removed)

	_evaluate()

func _on_anchor_added(anchor: CameraAnchor) -> void:
	_anchors.append(anchor)
	_evaluate()

func _on_anchor_removed(anchor: CameraAnchor) -> void:
	_anchors.erase(anchor)
	if _current_anchor == anchor:
		_current_anchor = null
	_evaluate()

func _evaluate() -> void:
	var winner := _pick_best_anchor()
	if winner == _current_anchor:
		return

	_switch_to(winner)

func _pick_best_anchor() -> CameraAnchor:
	var best: CameraAnchor
	var best_p := -INF

	for a in _anchors:
		if not a.enabled:
			continue
		if a.priority > best_p:
			best = a
			best_p = a.priority

	return best

func _switch_to(anchor: CameraAnchor) -> void:
	if not anchor:
		return

	_current_anchor = anchor
	var target := anchor.global_position

	if _tween and _tween.is_running():
		_tween.kill()

	if not anchor.use_blend or anchor.blend_time <= 0.0:
		_current_position = target
		return

	_tween = get_tree().create_tween()
	_tween.set_trans(Tween.TRANS_CUBIC)
	_tween.set_ease(Tween.EASE_OUT)
	_tween.tween_property(self, "_current_position", target, anchor.blend_time)

## =========================
## CameraPointer Interface
## =========================
func get_base_position() -> Vector2:
	return _current_position