extends Node3D

const MISSION_POINTS := [
	{
		"title": "Rejoignez la balise de navigation",
		"position": Vector3(0.0, -22.0, -58.0),
		"color": Color("5ddcff"),
		"radius": 8.0,
	},
	{
		"title": "Descendez au-delà de 60 m et inspectez la balise",
		"position": Vector3(38.0, -66.0, -128.0),
		"color": Color("ffbd59"),
		"radius": 4.0,
	},
	{
		"title": "Revenez dans la zone de récupération",
		"position": Vector3(0.0, -12.0, 12.0),
		"color": Color("7af0a5"),
		"radius": 8.0,
	},
]

var _submarine: SubmarineController
var _hud: PocHud
var _alarm_player: AlarmPlayer
var _mission_index := 0
var _mission_markers: Array[Node3D] = []
var _mission_guide_groups: Array[Node3D] = []
var _terminal := false
var _elapsed_time := 0.0


func _ready() -> void:
	_ensure_input_actions()
	_build_environment()
	_build_course()

	_hud = PocHud.new()
	add_child(_hud)

	_alarm_player = AlarmPlayer.new()
	add_child(_alarm_player)

	_submarine = SubmarineController.new()
	_submarine.name = "Submarine"
	_submarine.position = Vector3(0.0, -12.0, 12.0)
	_submarine.mission_origin = _submarine.position
	_submarine.telemetry_updated.connect(_on_telemetry_updated)
	_submarine.loss_triggered.connect(_on_loss_triggered)
	_submarine.abandon_progress_changed.connect(_hud.set_ejection_progress)
	add_child(_submarine)

	_update_mission_marker_visibility()
	_hud.set_objective(MISSION_POINTS[0]["title"])


func _process(delta: float) -> void:
	if _terminal:
		return

	_elapsed_time += delta
	var target: Vector3 = MISSION_POINTS[_mission_index]["position"]
	var distance := _submarine.global_position.distance_to(target)
	_hud.set_objective(MISSION_POINTS[_mission_index]["title"], distance)

	if distance <= float(MISSION_POINTS[_mission_index]["radius"]):
		_mission_index += 1
		if _mission_index >= MISSION_POINTS.size():
			_complete_course()
		else:
			_update_mission_marker_visibility()


func _unhandled_input(event: InputEvent) -> void:
	if event.is_action_pressed("debug_critical") and not _terminal:
		_submarine.force_critical_state()
	if _terminal and event.is_action_pressed("restart_poc"):
		get_tree().reload_current_scene()


func _on_telemetry_updated(snapshot: Dictionary) -> void:
	if _hud == null:
		return
	_hud.update_telemetry(snapshot)
	_alarm_player.update_alerts(
		get_process_delta_time(),
		[
			int(snapshot["oxygen_alert"]),
			int(snapshot["battery_alert"]),
			int(snapshot["hull_alert"]),
			int(snapshot["depth_alert"]),
		]
	)


func _on_loss_triggered(reason: StringName) -> void:
	_terminal = true
	_alarm_player.reset()
	var message: String = {
		&"hull_failure": "La coque a cédé sous la pression ou après un impact.",
		&"oxygen_depleted": "L’oxygène est épuisé. La capsule a été récupérée.",
		&"manual_ejection": "Vous avez abandonné volontairement le véhicule.",
	}.get(reason, "Le véhicule a été perdu.")
	_hud.show_terminal("SOUS-MARIN PERDU", message)


func _complete_course() -> void:
	_terminal = true
	_submarine.controls_enabled = false
	Input.mouse_mode = Input.MOUSE_MODE_VISIBLE
	_alarm_player.reset()
	_hud.show_terminal(
		"PARCOURS TERMINÉ",
		"Temps : %02d:%02d\nOxygène, propulsion, pression et retour ont été exercés."
		% [int(_elapsed_time) / 60, int(_elapsed_time) % 60]
	)


func _update_mission_marker_visibility() -> void:
	for marker_index in _mission_markers.size():
		_mission_markers[marker_index].visible = marker_index == _mission_index
	for guide_index in _mission_guide_groups.size():
		_mission_guide_groups[guide_index].visible = guide_index == _mission_index


func _build_environment() -> void:
	var world_environment := WorldEnvironment.new()
	var environment := Environment.new()
	environment.background_mode = Environment.BG_COLOR
	environment.background_color = Color("031823")
	environment.ambient_light_source = Environment.AMBIENT_SOURCE_COLOR
	environment.ambient_light_color = Color("2b6575")
	environment.ambient_light_energy = 0.46
	environment.fog_enabled = true
	environment.fog_light_color = Color("174553")
	environment.fog_light_energy = 0.52
	environment.fog_density = 0.013
	environment.fog_height = -5.0
	environment.fog_height_density = 0.03
	world_environment.environment = environment
	add_child(world_environment)

	var sun := DirectionalLight3D.new()
	sun.rotation_degrees = Vector3(-55.0, -28.0, 0.0)
	sun.light_color = Color("82bdc9")
	sun.light_energy = 0.35
	sun.shadow_enabled = true
	add_child(sun)

	var surface := MeshInstance3D.new()
	var surface_mesh := PlaneMesh.new()
	surface_mesh.size = Vector2(320.0, 420.0)
	surface.mesh = surface_mesh
	surface.position = Vector3(0.0, 0.0, -80.0)
	var surface_material := StandardMaterial3D.new()
	surface_material.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
	surface_material.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
	surface_material.cull_mode = BaseMaterial3D.CULL_DISABLED
	surface_material.albedo_color = Color(0.13, 0.55, 0.65, 0.13)
	surface.material_override = surface_material
	add_child(surface)

	_add_water_particles()


func _build_course() -> void:
	_add_static_box(
		"Seafloor",
		Vector3(0.0, -96.0, -80.0),
		Vector3(300.0, 10.0, 360.0),
		Color("183a3c")
	)
	_add_static_box(
		"LeftWall",
		Vector3(-75.0, -50.0, -90.0),
		Vector3(22.0, 95.0, 260.0),
		Color("24494b")
	)

	# Nearby formations make speed, distance and heading readable from the
	# cockpit before the player reaches the first mission beacon.
	var navigation_rock_specs := [
		[Vector3(-10.0, -24.0, -12.0), Vector3(10.0, 24.0, 10.0), -14.0],
		[Vector3(12.0, -30.0, -28.0), Vector3(11.0, 34.0, 12.0), 18.0],
		[Vector3(-12.0, -38.0, -42.0), Vector3(9.0, 46.0, 10.0), 8.0],
		[Vector3(11.0, -44.0, -50.0), Vector3(8.0, 52.0, 10.0), -10.0],
		[Vector3(7.0, -55.0, -73.0), Vector3(10.0, 38.0, 12.0), -16.0],
		[Vector3(25.0, -69.0, -96.0), Vector3(12.0, 45.0, 14.0), 13.0],
		[Vector3(45.0, -72.0, -112.0), Vector3(13.0, 50.0, 15.0), -9.0],
	]
	for rock_index in navigation_rock_specs.size():
		var spec: Array = navigation_rock_specs[rock_index]
		var navigation_rock := _add_static_box(
			"NavigationRock%02d" % rock_index,
			spec[0],
			spec[1],
			Color("315553") if rock_index % 2 == 0 else Color("294947")
		)
		navigation_rock.rotation_degrees.y = spec[2]
	_add_static_box(
		"RightWall",
		Vector3(75.0, -50.0, -90.0),
		Vector3(22.0, 95.0, 260.0),
		Color("24494b")
	)

	var rock_specs := [
		[Vector3(-25.0, -70.0, -78.0), Vector3(24.0, 44.0, 28.0), -18.0],
		[Vector3(28.0, -76.0, -92.0), Vector3(18.0, 34.0, 20.0), 16.0],
		[Vector3(-12.0, -83.0, -145.0), Vector3(42.0, 22.0, 30.0), 8.0],
		[Vector3(54.0, -63.0, -150.0), Vector3(20.0, 58.0, 24.0), -12.0],
	]
	for rock_index in rock_specs.size():
		var spec: Array = rock_specs[rock_index]
		var rock := _add_static_box(
			"Rock%02d" % rock_index,
			spec[0],
			spec[1],
			Color("2d5452")
		)
		rock.rotation_degrees.y = spec[2]

	for mission_data in MISSION_POINTS:
		_mission_markers.append(
			_add_beacon(mission_data["position"], mission_data["color"])
		)

	# Intermediate lights reveal the direction of the next leg without drawing
	# a HUD arrow. Each chain only appears when its objective becomes active.
	_mission_guide_groups.append(_add_guide_chain([], Color("5ddcff")))
	_mission_guide_groups.append(
		_add_guide_chain(
			[
				Vector3(8.0, -28.0, -75.0),
				Vector3(18.0, -38.0, -94.0),
				Vector3(29.0, -51.0, -112.0),
			],
			Color("ffbd59")
		)
	)
	_mission_guide_groups.append(
		_add_guide_chain(
			[
				Vector3(30.0, -55.0, -100.0),
				Vector3(23.0, -44.0, -72.0),
				Vector3(15.0, -34.0, -44.0),
				Vector3(8.0, -23.0, -16.0),
			],
			Color("7af0a5")
		)
	)


func _add_water_particles() -> void:
	var particles := GPUParticles3D.new()
	particles.name = "SuspendedWaterParticles"
	particles.position = Vector3(0.0, -45.0, -65.0)
	particles.amount = 520
	particles.lifetime = 14.0
	particles.preprocess = 14.0
	particles.fixed_fps = 30
	particles.visibility_aabb = AABB(
		Vector3(-85.0, -55.0, -125.0),
		Vector3(170.0, 110.0, 250.0)
	)

	var particle_motion := ParticleProcessMaterial.new()
	particle_motion.emission_shape = ParticleProcessMaterial.EMISSION_SHAPE_BOX
	particle_motion.emission_box_extents = Vector3(78.0, 48.0, 118.0)
	particle_motion.direction = Vector3(0.25, 0.12, 0.08)
	particle_motion.spread = 35.0
	particle_motion.initial_velocity_min = 0.025
	particle_motion.initial_velocity_max = 0.11
	particle_motion.gravity = Vector3.ZERO
	particle_motion.scale_min = 0.035
	particle_motion.scale_max = 0.11
	particles.process_material = particle_motion

	var mote_mesh := QuadMesh.new()
	mote_mesh.size = Vector2(0.075, 0.075)
	var mote_material := StandardMaterial3D.new()
	mote_material.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
	mote_material.billboard_mode = BaseMaterial3D.BILLBOARD_ENABLED
	mote_material.albedo_color = Color(0.62, 0.88, 0.92, 0.42)
	mote_material.roughness = 0.15
	mote_mesh.material = mote_material
	particles.draw_pass_1 = mote_mesh
	add_child(particles)


func _add_static_box(node_name: String, box_position: Vector3, box_size: Vector3, color: Color) -> StaticBody3D:
	var body := StaticBody3D.new()
	body.name = node_name
	body.position = box_position
	add_child(body)

	var mesh_instance := MeshInstance3D.new()
	var mesh := BoxMesh.new()
	mesh.size = box_size
	mesh_instance.mesh = mesh
	var material := StandardMaterial3D.new()
	material.albedo_color = color
	material.roughness = 0.9
	mesh_instance.material_override = material
	body.add_child(mesh_instance)

	var collision_shape := CollisionShape3D.new()
	var shape := BoxShape3D.new()
	shape.size = box_size
	collision_shape.shape = shape
	body.add_child(collision_shape)
	return body


func _add_beacon(beacon_position: Vector3, color: Color) -> Node3D:
	var marker := Node3D.new()
	marker.position = beacon_position
	add_child(marker)

	var sphere_instance := MeshInstance3D.new()
	var sphere := SphereMesh.new()
	sphere.radius = 2.2
	sphere.height = 4.4
	sphere_instance.mesh = sphere
	var material := StandardMaterial3D.new()
	material.albedo_color = color
	material.emission_enabled = true
	material.emission = color
	material.emission_energy_multiplier = 4.0
	sphere_instance.material_override = material
	marker.add_child(sphere_instance)

	var light := OmniLight3D.new()
	light.omni_range = 18.0
	light.light_energy = 5.0
	light.light_color = color
	marker.add_child(light)
	return marker


func _add_guide_chain(guide_positions: Array, color: Color) -> Node3D:
	var group := Node3D.new()
	group.name = "MissionGuideChain"
	add_child(group)

	for guide_position in guide_positions:
		var guide := Node3D.new()
		guide.position = guide_position
		group.add_child(guide)

		var guide_mesh_instance := MeshInstance3D.new()
		var guide_mesh := SphereMesh.new()
		guide_mesh.radius = 0.38
		guide_mesh.height = 0.76
		guide_mesh_instance.mesh = guide_mesh
		var guide_material := StandardMaterial3D.new()
		guide_material.albedo_color = color
		guide_material.emission_enabled = true
		guide_material.emission = color
		guide_material.emission_energy_multiplier = 1.5
		guide_mesh_instance.material_override = guide_material
		guide.add_child(guide_mesh_instance)

		var guide_light := OmniLight3D.new()
		guide_light.omni_range = 7.0
		guide_light.light_energy = 1.8
		guide_light.light_color = color
		guide.add_child(guide_light)

	return group


func _ensure_input_actions() -> void:
	_register_key_action("move_forward", KEY_W)
	_register_key_action("move_backward", KEY_S)
	_register_key_action("move_left", KEY_A)
	_register_key_action("move_right", KEY_D)
	_register_key_action("ascend", KEY_SPACE)
	_register_key_action("descend", KEY_CTRL)
	_register_key_action("boost", KEY_SHIFT)
	_register_key_action("abandon_vehicle", KEY_X)
	_register_key_action("debug_critical", KEY_F9)
	_register_key_action("restart_poc", KEY_ENTER)
	_register_key_action("toggle_mouse_capture", KEY_ESCAPE)


func _register_key_action(action_name: StringName, physical_keycode: Key) -> void:
	if not InputMap.has_action(action_name):
		InputMap.add_action(action_name)
	if InputMap.action_get_events(action_name).is_empty():
		var key_event := InputEventKey.new()
		key_event.physical_keycode = physical_keycode
		InputMap.action_add_event(action_name, key_event)