@tool
class_name ProceduralBridge
extends Node3D

##############################
## EXPORT VARIABLES
##############################

@export var physics_server: bool = false:
	set(value):
		physics_server = value
		PhysicsServer3D.set_active(value)

@export var bridge_length: float = 0.0:
	set(value):
		bridge_length = value
		_update_supports()

@export var bridge_path_length: float = 0.0:
	set(value):
		bridge_path_length = value
		_update_path()

@export var max_path_gap: float = 0.0:
	set(value):
		max_path_gap = value
		_update_path()

@export var support_gap: float = 1.0:
	set(value):
		support_gap = value
		_update_support_transforms()

@export var support_y_offset: float = 0.0:
	set(value):
		support_y_offset = value
		_update_support_transforms()

@export_category("Control Nodes")
@export var length_control: Node3D
@export var support_control: Marker3D

@export_category("Resources")
@export var catwalk_material: Material
@export var path_plank_meshes: Array[ArrayMesh]
@export var support_plank_meshes: Array[ArrayMesh]
@export var sfx_plank_add: AudioStream
@export var sfx_plank_remove: AudioStream


##############################
## VARIABLES
##############################

var support_plank_length: float

var path_container: Node3D
var support_container: Node3D
var current_path_length: float = 0.0
var last_sfx_plank_add_time: float = 0.0
var last_sfx_plank_remove_time: float = 0.0

# { "action": "add"/"remove", "plank": MeshInstance3D, "index": int }
var tween_queue: Array[Dictionary]
var tween_timer: float = 0.0


##############################
## LIFECYCLE METHODS
##############################

func _ready():
	_ensure_containers()


func _process(delta):
	if length_control:
		bridge_path_length = -length_control.position.z
	if support_control:
		support_gap = abs(support_control.position.x) * 2.0
		support_y_offset = support_control.position.y
	_check_queue(delta)


func _physics_process(delta):
	if Engine.get_physics_frames() % 4 == 0:
		_check_bridge_gaps()


##############################
## PRIVATE METHODS
##############################

func _check_queue(delta: float):
	# Accumulate time
	tween_timer += delta
	# When enough time has passed and there is an action waiting, dequeue one and execute it
	var queue_size = tween_queue.size()
	if queue_size == 0:
		return
	var next = tween_queue.front()
	var timer_interval = remap(queue_size, 0, 20, 0.03, 0.008)
	if next.action == "add":
		timer_interval = 0.0
	if tween_timer >= timer_interval:
		tween_timer = 0.0
		var entry = tween_queue.pop_front()
		match entry.action:
			"add":
				var index = entry.index
				var add_delay = lerp(0.05, 0.3, index / 10.0)
				_add_plank_tween(entry.plank, add_delay)
			"remove":
				_remove_plank_tween(entry.plank)


func _check_bridge_gaps():
	_ensure_path_container()
	var collision_shapes: Array[CollisionShape3D]
	var last_shape: Shape3D = null
	for child in get_children():
		if child is CollisionShape3D:
			if child.shape == last_shape:
				child.shape = last_shape.duplicate()
			collision_shapes.append(child as CollisionShape3D)
			last_shape = child.shape

	for plank in path_container.get_children():
		plank = plank as MeshInstance3D
		if not plank.mesh:
			continue
		var plank_aabb = plank.mesh.get_aabb()
		var plank_visible = true
		for col in collision_shapes:
			# check if plank is within collision shape
			var shape = col.shape as BoxShape3D
			var plank_shape_aabb = col.global_transform.affine_inverse() * plank.global_transform * plank_aabb
			var shape_aabb = shape.get_debug_mesh().get_aabb()
			if shape_aabb.intersects(plank_shape_aabb):
				plank_visible = false
				break

		plank.visible = plank_visible


func _queue_tween(action: String, plank: MeshInstance3D):
	var action_count = 0
	for entry in tween_queue:
		if entry.action == action:
			action_count += 1
	plank.set_meta("queued_action", action)
	tween_queue.append({"action": action, "plank": plank, "index": action_count})


func _add_plank_tween(plank: MeshInstance3D, delay: float = 0.0):
	plank.transparency = 0.0
	plank.position.y = 0.6
	await G.wait(delay)
	if G.get_time() - last_sfx_plank_add_time > 0.1:
		G.wait(0.075).connect(func():
			if plank.visible:
				G.play_sound_at(sfx_plank_add, plank.global_position)
		)
		last_sfx_plank_add_time = G.get_time()
	var tween = create_tween()
	tween.tween_property(plank, "position:y", 0.0, 0.15)
	tween.tween_property(plank, "position:y", 0.1, 0.05)
	tween.tween_property(plank, "position:y", 0.0, 0.05)
	tween.tween_property(plank, "position:y", 0.1, 0.05)
	tween.tween_property(plank, "position:y", 0.0, 0.05)
	tween.finished.connect(func():
		plank.remove_meta("tween")
		plank.remove_meta("queued_action")
		var scale_tween = create_tween()
		scale_tween.tween_property(plank, "scale", Vector3(1.0, 0.8, 0.9), 0.05)
		scale_tween.tween_property(plank, "scale", Vector3.ONE, 0.1)
	)
	plank.set_meta("tween", tween)


func _remove_plank_tween(plank: MeshInstance3D):
	if plank.has_meta("tween") and plank.get_meta("tween") is Tween:
		plank.get_meta("tween").kill()

	var direction: int = 1
	if randf() < 0.5:
		direction = -1

	if G.get_time() - last_sfx_plank_remove_time > 0.075 and plank.visible:
		G.wait(0.075).connect(func():
			G.play_sound_at(sfx_plank_remove, plank.global_position, -5)
		)
		last_sfx_plank_remove_time = G.get_time()

	var dir_pos_x = plank.position.x
	dir_pos_x += randf_range(1.0, 3.0) * direction
	var dir_pos_y = randf_range(0.3, 3.0)
	var dir_pos_z = plank.position.z + randf_range(-1.0, 1.0)
	var dir_pos = Vector3(dir_pos_x, dir_pos_y, dir_pos_z)
	var force_dir = plank.global_position.direction_to(to_global(dir_pos))
	var rb = RigidBody3D.new()
	var col = CollisionShape3D.new()
	var shape = BoxShape3D.new()
	shape.size = plank.mesh.get_aabb().size
	col.shape = shape
	add_child(rb)
	rb.add_child(col)
	rb.global_transform = plank.global_transform
	plank.reparent(rb)
	var time = G.randf_range(1.75, 2.5)
	rb.gravity_scale = 2.0
	var force = force_dir * randf_range(5.0, 10.0)
	rb.continuous_cd = true
	rb.apply_impulse(force, Vector3(-0.75, 0, 0))
	var ang = randf_range(PI * 2.0, PI * 4.0)
	rb.apply_torque_impulse(Vector3(0, 0, ang * direction))

	var tween = create_tween()
	tween.tween_property(plank, "transparency", 1.0, time * 0.2).set_delay(time * 0.8)
	G.wait(time).connect(rb.free)


func _update_path():
	_ensure_path_container()
	if path_plank_meshes.size() == 0:
		return
	var total_length: float = 0.0
	var last_plank: MeshInstance3D
	if path_container.get_child_count() > 0:
		last_plank = path_container.get_child(path_container.get_child_count() - 1) as MeshInstance3D
		total_length = last_plank.get_meta("length_at_plank")

	if bridge_path_length < current_path_length:
		# loop over path children, remove any that are out of bounds
		for plank in path_container.get_children():
			plank = plank as MeshInstance3D
			var mesh = plank.mesh as ArrayMesh
			var aabb = mesh.get_aabb()
			var plank_length = aabb.size.x
			var z_pos = -plank.position.z
			# use plank_length as a buffer to remove planks that are out of bounds
			if z_pos > bridge_path_length + plank_length:
				# plank.free()
				if plank.has_meta("queued_action") and plank.get_meta("queued_action") == "add":
					var index = tween_queue.find_custom(func(e): return e.plank == plank)
					if index >= 0:
						tween_queue.remove_at(index)
					_queue_tween("remove", plank)
				elif not plank.has_meta("queued_action"):
					_queue_tween("remove", plank)

		current_path_length = bridge_path_length
	else:
		var i = 0
		while total_length < bridge_path_length:
			var plank = MeshInstance3D.new()
			var mesh = G.pick_random(path_plank_meshes) as ArrayMesh
			plank.mesh = mesh
			plank.set_surface_override_material(0, catwalk_material)
			path_container.add_child(plank)
			var aabb = mesh.get_aabb()
			var plank_length = aabb.size.x
			var gap = G.randf_range(0.0, max_path_gap)
			var z_pos = total_length + gap
			plank.position = Vector3(0.0, 0.0, -z_pos)
			plank.rotation_degrees = Vector3(0, 90, 0)
			total_length += plank_length + gap
			plank.transparency = 1.0
			_queue_tween("add", plank)
			plank.set_meta("length_at_plank", total_length)
			i += 1
			if i > 1000:
				printerr("Infinite loop")
				break

		current_path_length = total_length


func _update_support_transforms():
	_ensure_support_container()
	if support_plank_length == 0:
		_calculate_support_length()
	var support_count = support_container.get_child_count()
	for i in range(0, support_count, 2):
		var left_support = support_container.get_child(i) as MeshInstance3D
		var right_support = support_container.get_child(i + 1) as MeshInstance3D
		var z_pos = left_support.position.z
		left_support.position = Vector3(-support_gap / 2.0, support_y_offset, z_pos)
		right_support.position = Vector3(support_gap / 2.0, support_y_offset, z_pos)


func _update_supports():
	_ensure_support_container()
	if support_plank_length == 0:
		_calculate_support_length()
	for child in support_container.get_children():
		child.free()
	var support_count = int(bridge_length / support_plank_length)
	for i in range(support_count):
		var left_support = MeshInstance3D.new()
		left_support.mesh = support_plank_meshes[0]
		left_support.set_surface_override_material(0, catwalk_material)
		var z_pos = (i * support_plank_length) + (support_plank_length / 2.0)
		var right_support = left_support.duplicate()
		support_container.add_child(left_support)
		support_container.add_child(right_support)
		var half_gap = support_gap / 2.0
		left_support.position = Vector3(-half_gap, support_y_offset, -z_pos)
		right_support.position = Vector3(half_gap, support_y_offset, -z_pos)


func _calculate_support_length():
	if support_plank_meshes.size() == 0:
		return
	var mesh = support_plank_meshes[0]
	var aabb = mesh.get_aabb()
	print(aabb.size)
	support_plank_length = aabb.size.z


func _ensure_containers():
	_ensure_path_container()
	_ensure_support_container()


func _ensure_path_container():
	if path_container:
		return
	if has_node("PathContainer"):
		path_container = get_node("PathContainer")
	else:
		path_container = Node3D.new()
		path_container.name = "PathContainer"
		add_child(path_container)


func _ensure_support_container():
	if support_container:
		return
	if has_node("SupportContainer"):
		support_container = get_node("SupportContainer")
	else:
		support_container = Node3D.new()
		support_container.name = "SupportContainer"
		add_child(support_container)