extends SceneTree
## Adaptive preview selection, placement/commit behavior, and per-finish CPU costs.

const RENDERER := preload("res://scripts/stage/scenery/stage_surface_renderer.gd")
const CONTROLLER := preload("res://scripts/editors/stage/stage_scenery_controller.gd")

class TimedWall extends StageWallPanel:
	var draw_times_usec: Array[int] = []

	func _draw() -> void:
		var started: int = Time.get_ticks_usec()
		super._draw()
		draw_times_usec.append(Time.get_ticks_usec() - started)

class TimedGround extends StageBackgroundGround:
	var draw_times_usec: Array[int] = []

	func _draw() -> void:
		var started: int = Time.get_ticks_usec()
		super._draw()
		draw_times_usec.append(Time.get_ticks_usec() - started)

class SlowWall extends StageWallPanel:
	var inject_delay: bool = true

	func get_surface_draw_origin_world() -> Vector2:
		if inject_delay:
			OS.delay_usec(PREVIEW_DRAW_BUDGET_USEC + 1000)
		return super.get_surface_draw_origin_world()

var _failures: Array[String] = []


func _initialize() -> void:
	call_deferred("_run")


func _run() -> void:
	root.size = Vector2i(2560, 1440)
	for finish: StringName in RENDERER.WALL_FINISHES + RENDERER.BACKGROUND_FINISHES:
		_expect(not RENDERER.needs_light_preview(finish, Vector2(16.0, 16.0)), "tiny %s keeps its detail" % finish)
		_expect(not RENDERER.needs_light_preview(finish, Vector2.ZERO), "invisible %s has no preview work" % finish)
		_test_placement(finish)
		await _benchmark_finish(finish)
	for finish: StringName in [&"finish_wall_brick", &"finish_wall_wood", &"finish_background_grass", &"finish_background_carpet"]:
		_expect(RENDERER.needs_light_preview(finish, Vector2(2400.0, 1320.0)), "large %s reduces detail automatically" % finish)
	_expect(not RENDERER.needs_light_preview(&"finish_wall_paint", Vector2(100000.0, 100000.0)), "paint stays detailed at any size")
	_expect(not RENDERER.needs_light_preview(&"finish_background_concrete", Vector2(2400.0, 1320.0)), "ordinary concrete slab patterns stay detailed")
	_expect(RENDERER.needs_light_preview(&"finish_background_concrete", Vector2(24000.0, 13200.0)), "very large concrete patterns can also simplify")
	_expect(RENDERER.needs_light_preview(&"finish_wall_wood", Vector2(240.0, 132.0), Vector2(10.0, 10.0)), "work estimate accounts for motif scale")
	await _test_runtime_fallback()
	if _failures.is_empty():
		print("PASS: adaptive scenery surface previews")
	else:
		for failure: String in _failures:
			push_error("FAIL: " + failure)
	quit(0 if _failures.is_empty() else 1)


func _test_placement(finish: StringName) -> void:
	var world := Node2D.new()
	var ghosts := Node2D.new()
	var controller := CONTROLLER.new() as StageSceneryController
	root.add_child(world)
	root.add_child(ghosts)
	root.add_child(controller)
	controller.configure(world, ghosts, null)
	var wall: bool = RENDERER.is_wall_finish(finish)
	var tint: Color = RENDERER.default_tint(finish)
	var start := Vector2(-300.0, -150.0)
	if wall:
		controller.begin_wall(finish, start, tint)
	else:
		controller.begin_background_ground(finish, start, tint)
	var ghost: StageRectSurface = ghosts.get_child(0) as StageRectSurface
	_expect(ghost.interactive_preview, "%s placement opts into adaptive rendering" % finish)
	var press := InputEventMouseButton.new()
	press.button_index = MOUSE_BUTTON_LEFT
	press.pressed = true
	controller.handle_mouse_button(press, start, false)
	controller.handle_mouse_motion(Vector2(2100.0, 1170.0))
	var bounds: Rect2 = ghost.global_transform * ghost.get_local_bounds()
	var release := InputEventMouseButton.new()
	release.button_index = MOUSE_BUTTON_LEFT
	controller.handle_mouse_button(release, Vector2(2100.0, 1170.0), false)
	_expect(world.get_child_count() == 1, "%s commits one surface" % finish)
	var placed: StageRectSurface = world.get_child(0) as StageRectSurface
	_expect(not placed.interactive_preview, "%s commit uses full detail" % finish)
	_expect(placed.finish_id == finish and placed.tint == tint, "%s preserves finish and tint" % finish)
	_expect(bounds.is_equal_approx(placed.global_transform * placed.get_local_bounds()), "%s preserves preview bounds" % finish)
	controller.exit_tool()
	world.free()
	ghosts.free()
	controller.free()


func _benchmark_finish(finish: StringName) -> void:
	var sample: StageRectSurface = TimedWall.new() if RENDERER.is_wall_finish(finish) else TimedGround.new()
	sample.position = Vector2(1280.0, 720.0)
	sample.interactive_preview = true
	sample.configure(Vector2(2400.0, 1320.0), finish, RENDERER.default_tint(finish))
	root.add_child(sample)
	await process_frame
	await process_frame
	var preview_usec: float = await _measure_redraws(sample)
	sample.interactive_preview = false
	await process_frame
	await process_frame
	var full_usec: float = await _measure_redraws(sample)
	print("%s CPU redraw: adaptive=%.2f ms, full=%.2f ms" % [finish, preview_usec / 1000.0, full_usec / 1000.0])
	sample.free()


func _measure_redraws(sample: StageRectSurface) -> float:
	var timings: Array[int] = sample.get("draw_times_usec")
	timings.clear()
	for _iteration: int in 3:
		sample.queue_redraw()
		await process_frame
		await process_frame
	_expect(not timings.is_empty(), "surface draws during benchmark")
	var total: float = 0.0
	for elapsed: int in timings:
		total += float(elapsed)
	return total / maxf(1.0, float(timings.size()))


func _test_runtime_fallback() -> void:
	var sample := SlowWall.new()
	sample.position = Vector2(100.0, 100.0)
	sample.interactive_preview = true
	sample.configure(Vector2(16.0, 16.0), &"finish_wall_wood", Color.WHITE)
	root.add_child(sample)
	await process_frame
	await process_frame
	_expect(sample.get("_preview_over_budget"), "measured slow redraw enables the fallback even for a small panel")
	sample.inject_delay = false
	sample.configure(Vector2(20.0, 20.0), sample.finish_id, sample.tint)
	await process_frame
	await process_frame
	_expect(sample.get("_preview_over_budget"), "fallback stays stable during the current placement session")
	sample.interactive_preview = false
	_expect(not sample.get("_preview_over_budget"), "leaving preview resets the timing fallback")
	sample.free()


func _expect(condition: bool, message: String) -> void:
	if not condition:
		_failures.append(message)