extends Area2D
## Scrap drop — the positioning reward gradient (canon 2026-08-07:
## kills drop scrap physically; collecting it gates in-run card
## levels). Drifts to the mech inside the magnet radius, collected on
## contact, fades out if ignored. Constructed in code, no scene.

var value := 1
var magnet_radius := 70.0
var drift_speed := 150.0
var lifetime := 20.0

var _t := 0.0
var _sprite: Sprite2D


func _ready() -> void:
	add_to_group("salvage")
	collision_layer = 0
	collision_mask = 2
	monitorable = false
	var cs := CollisionShape2D.new()
	var sh := CircleShape2D.new()
	sh.radius = 6.0
	cs.shape = sh
	add_child(cs)
	# Runtime load, not preload — resilient to a stale import cache.
	_sprite = Sprite2D.new()
	_sprite.texture = load("res://assets/sprites_ph/scrap_ph.png")
	add_child(_sprite)
	body_entered.connect(_on_body_entered)


func _physics_process(delta: float) -> void:
	_t += delta
	if _t >= lifetime:
		queue_free()
		return
	var mech := get_tree().get_first_node_in_group("mech") as Node2D
	if mech != null and global_position.distance_to(mech.global_position) <= magnet_radius:
		global_position = global_position.move_toward(mech.global_position, drift_speed * delta)
	# Fade the sprite out over the last 3s of life.
	if _t >= lifetime - 3.0 and _sprite != null:
		_sprite.modulate.a = clampf((lifetime - _t) / 3.0, 0.0, 1.0)


func _on_body_entered(body: Node) -> void:
	if body.is_in_group("mech"):
		var hand := get_tree().get_first_node_in_group("hand")
		if hand != null:
			hand.add_salvage(value)
		queue_free()