extends Node3D
## mtgodot-poc — M0' harness.
##
## Builds the minimal scene the plan asks for (orbit camera + DirectionalLight3D
## with shadows + WorldEnvironment/sky + placeholder cube + an empty Metin2Model),
## then reports whether the GDExtension loaded.
##
## M1 will replace the cube with Metin2Model.load_gr2(...) output.

const ORBIT_SPEED := 0.01
const ZOOM_STEP := 0.3
const PITCH_LIMIT := 1.45

var _cam: Camera3D
var _yaw := 0.6
var _pitch := 0.45
var _dist := 4.0
var _target := Vector3(0.0, 1.0, 0.0)
var _dragging := false


func _ready() -> void:
	_build_environment()
	_build_sun()
	_build_camera()
	_build_placeholder()
	_probe_extension()
	print("[mtgodot] M0' harness ready — drag: orbit, wheel: zoom, F2: screenshot")
	# Batch capture: MTGODOT_AUTOSHOT=/abs/path.png godot --path project
	var autoshot := OS.get_environment("MTGODOT_AUTOSHOT")
	if autoshot != "":
		await get_tree().create_timer(0.8).timeout
		var img := get_viewport().get_texture().get_image()
		img.save_png(autoshot)
		print("[mtgodot] autoshot -> ", autoshot)
		get_tree().quit()


func _build_environment() -> void:
	var we := WorldEnvironment.new()
	var env := Environment.new()
	var sky := Sky.new()
	sky.sky_material = ProceduralSkyMaterial.new()
	env.background_mode = Environment.BG_SKY
	env.sky = sky
	env.ambient_light_source = Environment.AMBIENT_SOURCE_SKY
	env.tonemap_mode = Environment.TONE_MAPPER_FILMIC
	we.environment = env
	add_child(we)


func _build_sun() -> void:
	var sun := DirectionalLight3D.new()
	sun.rotation_degrees = Vector3(-45.0, -35.0, 0.0)
	sun.shadow_enabled = true
	add_child(sun)


func _build_camera() -> void:
	_cam = Camera3D.new()
	_cam.current = true
	_cam.fov = 55.0
	add_child(_cam)
	_update_camera()


func _build_placeholder() -> void:
	var cube := MeshInstance3D.new()
	cube.name = "Placeholder"
	cube.mesh = BoxMesh.new()
	cube.position = _target
	add_child(cube)


func _probe_extension() -> void:
	if not ClassDB.class_exists("Metin2Model"):
		push_error("[mtgodot] Metin2Model NOT registered — GDExtension failed to load")
		return
	var m := ClassDB.instantiate("Metin2Model") as Node3D
	m.name = "Metin2Model"
	add_child(m)
	print("[mtgodot] Metin2Model registered OK — ", m.call("libgr2_info"))
	# Optional: point MTGODOT_PROBE_GR2 at a real .gr2 to exercise libgr2 end to end.
	var probe := OS.get_environment("MTGODOT_PROBE_GR2")
	if probe != "":
		print("[mtgodot] probe_gr2(", probe, ") -> ", m.call("probe_gr2", probe))


func _update_camera() -> void:
	var offset := Vector3(
		cos(_pitch) * sin(_yaw),
		sin(_pitch),
		cos(_pitch) * cos(_yaw)) * _dist
	_cam.position = _target + offset
	_cam.look_at(_target, Vector3.UP)


func _unhandled_input(event: InputEvent) -> void:
	if event is InputEventMouseButton:
		var mb := event as InputEventMouseButton
		match mb.button_index:
			MOUSE_BUTTON_LEFT:
				_dragging = mb.pressed
			MOUSE_BUTTON_WHEEL_UP:
				_dist = maxf(0.5, _dist - ZOOM_STEP)
				_update_camera()
			MOUSE_BUTTON_WHEEL_DOWN:
				_dist = minf(50.0, _dist + ZOOM_STEP)
				_update_camera()
	elif event is InputEventMouseMotion and _dragging:
		var mm := event as InputEventMouseMotion
		_yaw -= mm.relative.x * ORBIT_SPEED
		_pitch = clampf(_pitch + mm.relative.y * ORBIT_SPEED, -PITCH_LIMIT, PITCH_LIMIT)
		_update_camera()
	elif event is InputEventKey:
		var k := event as InputEventKey
		if k.pressed and k.keycode == KEY_F2:
			_screenshot()


func _screenshot() -> void:
	var img := get_viewport().get_texture().get_image()
	var path := "user://shot_%d.png" % Time.get_ticks_msec()
	img.save_png(path)
	print("[mtgodot] screenshot -> ", ProjectSettings.globalize_path(path))