@tool
extends Node3D
# Лес одним MultiMesh: одна отрисовка на все деревья, удобно для веба.

@export var tree_scene: PackedScene:
	set(v):
		tree_scene = v
		_queue_rebuild()
@export var count := 60:
	set(v):
		count = v
		_queue_rebuild()
@export var area_radius := 220.0           # Радиус леса вокруг центра
@export var spawn_clear_radius := 12.0     # Свободная зона вокруг старта
@export var building_clear_radius := 14.0  # Свободная зона вокруг построек
@export var path_clear_radius := 7.0       # Свободная зона вокруг пути камня
@export var scale_range := Vector2(1.3, 2.0)
@export var seed_value := 1:
	set(v):
		seed_value = v
		_queue_rebuild()
@export var visible_distance := 160.0      # Дальше — деревья не рисуются
@export var trunk_radius := 1.4            # Коллизия ствола (до масштабирования)
@export var trunk_height := 9.0
@export var cast_shadows := false          # Тени от 150 деревьев тяжелы для веба

func _ready() -> void:
	_rebuild()

func _queue_rebuild() -> void:
	if is_node_ready():
		_rebuild.call_deferred()

func _rebuild() -> void:
	if tree_scene == null:
		return
	for n in ["Trees", "TrunkColliders"]:
		var old := get_node_or_null(n)
		if old:
			remove_child(old)
			old.queue_free()
	var inst := tree_scene.instantiate()
	var mi := _find_mesh(inst)
	if mi == null:
		push_error("forest: в tree_scene нет MeshInstance3D")
		return
	var mesh := mi.mesh
	var base := mi.transform  # смещение меша внутри glb

	var keep_out := _collect_keep_out()
	var rng := RandomNumberGenerator.new()
	rng.seed = seed_value

	var xforms: Array[Transform3D] = []
	var tries := 0
	while xforms.size() < count and tries < count * 30:
		tries += 1
		var p := Vector2.from_angle(rng.randf() * TAU) * sqrt(rng.randf()) * area_radius
		if p.length() < spawn_clear_radius or _blocked(p, keep_out):
			continue
		var s := rng.randf_range(scale_range.x, scale_range.y)
		var b := Basis(Vector3.UP, rng.randf() * TAU).scaled(Vector3(s, s * rng.randf_range(0.9, 1.15), s))
		xforms.append(Transform3D(b, Vector3(p.x, 0.0, p.y)) * base)

	var mm := MultiMesh.new()
	mm.transform_format = MultiMesh.TRANSFORM_3D
	mm.mesh = mesh
	mm.instance_count = xforms.size()
	for i in xforms.size():
		mm.set_instance_transform(i, xforms[i])

	var mmi := MultiMeshInstance3D.new()
	mmi.name = "Trees"
	mmi.multimesh = mm
	mmi.cast_shadow = GeometryInstance3D.SHADOW_CASTING_SETTING_ON if cast_shadows else GeometryInstance3D.SHADOW_CASTING_SETTING_OFF
	mmi.visibility_range_end = visible_distance
	mmi.visibility_range_end_margin = 20.0
	mmi.visibility_range_fade_mode = GeometryInstance3D.VISIBILITY_RANGE_FADE_DISABLED
	mmi.custom_aabb = AABB(Vector3(-area_radius - 20, -5, -area_radius - 20), Vector3(area_radius * 2 + 40, 60, area_radius * 2 + 40))
	add_child(mmi)
	inst.free()
	if not Engine.is_editor_hint():
		_add_colliders(xforms)

# Мультимеш коллизий не даёт — ставим по цилиндру на ствол каждого дерева
func _add_colliders(xforms: Array[Transform3D]) -> void:
	var body := StaticBody3D.new()
	body.name = "TrunkColliders"
	add_child(body)
	for t in xforms:
		var s := t.basis.get_scale()
		var shape := CylinderShape3D.new()
		shape.radius = trunk_radius * s.x
		shape.height = trunk_height * s.y
		var cs := CollisionShape3D.new()
		cs.shape = shape
		cs.position = Vector3(t.origin.x, t.origin.y + shape.height * 0.5, t.origin.z)
		body.add_child(cs)

func _find_mesh(n: Node) -> MeshInstance3D:
	if n is MeshInstance3D:
		return n
	for c in n.get_children():
		var r := _find_mesh(c)
		if r:
			return r
	return null

# Круги (x, z, радиус), куда деревья ставить нельзя
func _collect_keep_out() -> Array[Vector3]:
	var out: Array[Vector3] = []
	var arch := get_node_or_null("../Architecture")
	if arch:
		for c in arch.get_children():
			if c is Path3D:
				for pt in c.curve.get_baked_points():
					var g: Vector3 = c.to_global(pt)
					out.append(Vector3(g.x, g.z, path_clear_radius))
			elif c is Node3D:
				out.append(Vector3(c.global_position.x, c.global_position.z, building_clear_radius))
	return out

func _blocked(p: Vector2, keep_out: Array[Vector3]) -> bool:
	for k in keep_out:
		if p.distance_squared_to(Vector2(k.x, k.y)) < k.z * k.z:
			return true
	return false