extends SceneTree
## Thumbnail-Generator für die Objekt-Bibliothek (Karte t_3a998ae4).
## Rendert JEDESM Bibliotheks-Objekt einmalig als 128-px-PNG nach
## library/thumbs/<id>.png — die Bilder werden committed, der Editor lädt sie
## dann einfach aus der Datei (LibraryBrowser.load_thumb).
##
## Ausführen (braucht echtes Rendering, NICHT --headless):
##   xvfb-run -a godot4 --rendering-driver opengl3 --path . --script res://tools/gen_thumbs.gd
##   (auf Slys PC auch ohne xvfb: godot4 --rendering-driver opengl3 --path . --script ...)
##
## Exit 0 = alle Thumbnails geschrieben.

const SIZE := 128
const BG_COLOR := Color(0.16, 0.18, 0.21)

var manifest: Dictionary = {}
var ids: Array = []
var idx := -1
var settle_frames := 0
var vp: SubViewport
var mi: MeshInstance3D
var cam: Camera3D
var out_dir := ""


func _initialize() -> void:
	var parsed: Variant = JSON.parse_string(FileAccess.get_file_as_string(SvmapIO.MANIFEST_PATH))
	if parsed is Dictionary:
		manifest = parsed
	ids = (manifest.get("objects", {}) as Dictionary).keys()
	if ids.is_empty():
		push_error("gen_thumbs: Bibliothek leer — nichts zu rendern.")
		quit(1)
		return
	out_dir = ProjectSettings.globalize_path("res://library/thumbs")
	DirAccess.make_dir_recursive_absolute(out_dir)

	vp = SubViewport.new()
	vp.size = Vector2i(SIZE, SIZE)
	vp.own_world_3d = true
	vp.render_target_update_mode = SubViewport.UPDATE_ALWAYS
	root.add_child(vp)

	var env := Environment.new()
	env.background_mode = Environment.BG_COLOR
	env.background_color = BG_COLOR
	env.ambient_light_source = Environment.AMBIENT_SOURCE_COLOR
	env.ambient_light_color = Color(1, 1, 1)
	env.ambient_light_energy = 0.7
	var we := WorldEnvironment.new()
	we.environment = env
	vp.add_child(we)

	var sun := DirectionalLight3D.new()
	sun.rotation_degrees = Vector3(-55.0, 35.0, 0.0)
	sun.light_energy = 1.1
	vp.add_child(sun)

	mi = MeshInstance3D.new()
	vp.add_child(mi)
	cam = Camera3D.new()
	cam.current = true
	vp.add_child(cam)
	idx = -1   # erst im ersten _process starten — look_at braucht eingetretene Knoten


func _next() -> void:
	idx += 1
	if idx >= ids.size():
		print("GEN_THUMBS_OK: %d Thumbnails in %s" % [ids.size(), out_dir])
		quit(0)
		return
	var oid := str(ids[idx])
	var entry: Dictionary = (manifest["objects"] as Dictionary)[oid]
	var col: Dictionary = entry.get("collision", {})
	var mesh := MeshShapes.make_placeholder(str(col.get("shape", "box")), col, 1.0)
	mi.mesh = mesh
	# Kamera diagonal aufs Objekt, passend zur Mesh-Größe (Kiste nah, Turm weit).
	var aabb := mesh.get_aabb()
	var center := aabb.get_center()
	var radius := aabb.size.length() * 0.5
	var dir := Vector3(1.0, 0.65, 1.0).normalized()
	cam.position = center + dir * (radius * 2.3 + 0.3)
	cam.look_at(center, Vector3.UP)
	settle_frames = 4


func _process(_delta: float) -> bool:
	if idx < 0:
		_next()
		return false
	if settle_frames > 0:
		settle_frames -= 1
		return false
	var img := vp.get_texture().get_image()
	var oid := str(ids[idx])
	img.save_png(out_dir + "/" + oid + ".png")
	print("  thumb: %s (%dx%d)" % [oid, img.get_width(), img.get_height()])
	_next()
	return false