class_name StageSpawner
extends RefCounted
## StageSpawner - Registry-driven factory for the Sandbox Stage Builder (Phase 2).
##
## A spawn registry maps an id to a terrain/prop/stickman template. Adding a new
## spawnable type only requires appending a registry entry - no hard-coded match
## statements on ids. Reuses TerrainUtils, PropUtils and StickmanFactory.

# ---------------------------------------------------------------------------
# Preloaded dependencies (resolved directly, independent of the global class
# registry, so this script compiles even when the editor's class cache is stale)
# ---------------------------------------------------------------------------

const TERRAIN_UTILS := preload("res://scripts/terrain_utils.gd")
const PROP_UTILS := preload("res://scripts/prop_utils.gd")
const PROP_BLOCK := preload("res://scripts/prop_block.gd")
const STICKMAN_FACTORY := preload("res://scripts/stickman_factory.gd")

# ---------------------------------------------------------------------------
# Constants
# ---------------------------------------------------------------------------

## Default stickman asset (the only complete, upright figure).
const DEFAULT_STICKMAN_PATH := "res://stickmen/test.stk"

## The rig's feet rest ~385 px below its root (hips), so placing the root 385 px
## above the cursor puts the feet on it.
const STICKMAN_FOOT_OFFSET := Vector2(0.0, -385.0)

const TERRAIN_GRID_SIZE: float = 16.0

# ---------------------------------------------------------------------------
# State
# ---------------------------------------------------------------------------

var _world: Node2D
var _registry: Array[Dictionary] = []
var _stickman_data: Dictionary = {}

# ---------------------------------------------------------------------------
# Lifecycle
# ---------------------------------------------------------------------------

func _init(world: Node2D) -> void:
	_world = world
	_stickman_data = STICKMAN_FACTORY.load_stk(DEFAULT_STICKMAN_PATH)
	if _stickman_data.is_empty():
		push_warning("StageSpawner: failed to load default stickman '%s'." % DEFAULT_STICKMAN_PATH)
	_build_registry()

# ---------------------------------------------------------------------------
# Public API
# ---------------------------------------------------------------------------

func get_spawnable_ids() -> Array[String]:
	var ids: Array[String] = []
	for entry: Dictionary in _registry:
		ids.append(String(entry["id"]))
	return ids


func get_label(id: String) -> String:
	var entry := _find_entry(id)
	return String(entry.get("label", id)) if not entry.is_empty() else id


func get_spawn_offset(id: String) -> Vector2:
	var entry := _find_entry(id)
	if entry.is_empty():
		return Vector2.ZERO
	return entry.get("spawn_offset", Vector2.ZERO)


## Spawn the registry type at `world_position`; returns null + push_warning on
## an unknown id.
func spawn(id: String, world_position: Vector2) -> Node2D:
	var entry := _find_entry(id)
	if entry.is_empty():
		push_warning("StageSpawner: unknown spawn id '%s'." % id)
		return null
	var offset: Vector2 = entry.get("spawn_offset", Vector2.ZERO)
	var pos := world_position + offset
	match String(entry.get("kind", "")):
		"terrain":
			return _spawn_terrain(entry, pos)
		"prop":
			return _spawn_prop(entry, pos)
		"stickman":
			return _spawn_stickman(pos)
		_:
			push_warning("StageSpawner: unknown spawn kind '%s'." % entry.get("kind", ""))
			return null


## World-space AABB for a spawnable node: union of the Polygon2D child's world
## points; for a stickman rig, union of its mounted `Body/*` shape geometry; a
## point rect otherwise.
static func get_world_aabb(node: Node2D) -> Rect2:
	if node == null or not is_instance_valid(node):
		return Rect2()
	var poly := node.get_node_or_null(NodePath("Polygon2D")) as Polygon2D
	if poly != null and not poly.polygon.is_empty():
		var rect := Rect2(node.to_global(poly.polygon[0]), Vector2.ZERO)
		for p: Vector2 in poly.polygon:
			rect = rect.expand(node.to_global(p))
		return rect
	var body := node.get_node_or_null(NodePath("Body")) as Node2D
	if body != null:
		var acc := { "min_x": INF, "min_y": INF, "max_x": -INF, "max_y": -INF }
		_collect_visual_points(body, acc)
		if acc["min_x"] <= acc["max_x"]:
			return Rect2(Vector2(acc["min_x"], acc["min_y"]), Vector2(acc["max_x"] - acc["min_x"], acc["max_y"] - acc["min_y"]))
	if node.get_node_or_null(NodePath("Skeleton2D")) != null:
		return node.global_transform * Rect2(Vector2(-120.0, -1000.0), Vector2(240.0, 1000.0))
	return Rect2(node.global_position, Vector2.ZERO)


static func _collect_visual_points(node: Node, acc: Dictionary) -> void:
	if node is Line2D:
		for p: Vector2 in (node as Line2D).points:
			_accumulate((node as Line2D).to_global(p), acc)
	elif node is Polygon2D:
		for p: Vector2 in (node as Polygon2D).polygon:
			_accumulate((node as Polygon2D).to_global(p), acc)
	for child: Node in node.get_children():
		_collect_visual_points(child, acc)


static func _accumulate(p: Vector2, acc: Dictionary) -> void:
	acc["min_x"] = minf(acc["min_x"], p.x)
	acc["min_y"] = minf(acc["min_y"], p.y)
	acc["max_x"] = maxf(acc["max_x"], p.x)
	acc["max_y"] = maxf(acc["max_y"], p.y)

# ---------------------------------------------------------------------------
# Registry
# ---------------------------------------------------------------------------

func _build_registry() -> void:
	_registry = [
		{
			"id": "ground", "label": "Ground", "kind": "terrain",
			"points": PackedVector2Array([Vector2(-100, -16), Vector2(100, -16), Vector2(100, 16), Vector2(-100, 16)]),
			"fill": Color(0.25, 0.55, 0.25), "outline": Color(0.05, 0.10, 0.05), "width": 2.0,
			"spawn_offset": Vector2.ZERO,
		},
		{
			"id": "ramp", "label": "Ramp", "kind": "terrain",
			"points": PackedVector2Array([Vector2(-96, 32), Vector2(96, -96), Vector2(96, -32), Vector2(-96, 96)]),
			"fill": Color(0.30, 0.50, 0.30), "outline": Color(0.05, 0.10, 0.05), "width": 2.0,
			"spawn_offset": Vector2.ZERO,
		},
		{
			"id": "step", "label": "Step", "kind": "terrain",
			"points": PackedVector2Array([
				Vector2(-128, 128), Vector2(128, 128), Vector2(128, -128), Vector2(64, -128),
				Vector2(64, -64), Vector2(0, -64), Vector2(0, 0), Vector2(-64, 0),
				Vector2(-64, 64), Vector2(-128, 64),
			]),
			"fill": Color(0.30, 0.50, 0.30), "outline": Color(0.05, 0.10, 0.05), "width": 2.0,
			"spawn_offset": Vector2.ZERO,
		},
		{
			"id": "crate", "label": "Crate", "kind": "prop",
			"payload": PROP_UTILS.create_box(), "preset": PROP_BLOCK.MaterialPreset.WOOD,
			"spawn_offset": Vector2.ZERO,
		},
		{
			"id": "ball", "label": "Ball", "kind": "prop",
			"payload": PROP_UTILS.create_ball(), "preset": PROP_BLOCK.MaterialPreset.RUBBER,
			"spawn_offset": Vector2.ZERO,
		},
		{
			"id": "stickman", "label": "Stickman", "kind": "stickman",
			"spawn_offset": STICKMAN_FOOT_OFFSET,
		},
	]


func _find_entry(id: String) -> Dictionary:
	for entry: Dictionary in _registry:
		if String(entry.get("id", "")) == id:
			return entry
	return {}

# ---------------------------------------------------------------------------
# Spawn helpers
# ---------------------------------------------------------------------------

## Center the terrain template on its local origin so the block rotates about
## its own center, then place the block at the cursor.
func _spawn_terrain(entry: Dictionary, world_position: Vector2) -> TerrainBlock:
	var template: PackedVector2Array = entry["points"]
	var center := _points_center(template)
	var centered := PackedVector2Array()
	for p: Vector2 in template:
		centered.append(p - center)
	var block: TerrainBlock = TERRAIN_UTILS.spawn_block(
		_world,
		centered,
		TERRAIN_GRID_SIZE,
		entry.get("fill", TERRAIN_UTILS.DEFAULT_FILL_COLOR),
		entry.get("outline", TERRAIN_UTILS.DEFAULT_OUTLINE_COLOR),
		float(entry.get("width", 2.0))
	)
	block.position = world_position
	return block


func _spawn_prop(entry: Dictionary, world_position: Vector2) -> PropBlock:
	var payload: Dictionary = entry["payload"]
	var preset: int = int(entry.get("preset", PROP_BLOCK.MaterialPreset.WOOD))
	return PROP_UTILS.spawn_prop(_world, world_position, payload, preset, Vector2.ZERO)


func _spawn_stickman(world_position: Vector2) -> StickmanRig:
	if _stickman_data.is_empty():
		push_warning("StageSpawner: no stickman data loaded; check '%s'." % DEFAULT_STICKMAN_PATH)
		return null
	var rig: StickmanRig = STICKMAN_FACTORY.spawn_from_data(_stickman_data)
	if rig == null:
		push_warning("StageSpawner: failed to spawn stickman.")
		return null
	rig.position = world_position
	_world.add_child(rig)
	return rig


static func _points_center(pts: PackedVector2Array) -> Vector2:
	if pts.is_empty():
		return Vector2.ZERO
	var sum := Vector2.ZERO
	for p: Vector2 in pts:
		sum += p
	return sum / float(pts.size())