class_name Unit
extends CharacterBody2D


signal reached_goal
signal selected

static var selected_unit: Unit

var is_selected = false :
	set(value):
		if value:
			Unit.selected_unit = self
			selected.emit()
			$Label.visible = true
			line.visible = true
		else:
			if Unit.selected_unit == self:
				Unit.selected_unit = null
			$Label.visible = false
			line.visible = false
		is_selected = value
		queue_redraw()

var is_hovered = false :
	set(value):
		if value:
			$Label.visible = true
		else:
			if not is_selected:
				$Label.visible = false
		is_hovered = value
		queue_redraw()

var target_path: NodePath
var target: Node2D:
	set(value):
		target = value
		reset_path()
var immediate_target: Vector2

var current_path: PackedVector2Array
var current_path_idx = 0 :
	set(value):
		current_path_idx = value
		if line:
			line.points = PackedVector2Array(current_path.slice(value))

var previous_position: Vector2
var recent_closest_paths: Array[PackedVector2Array]

var stuck_position_accumulator = 0.0

var roaming_mode = false

# rpc owner id
@export var owner_id = 1

@export var unit_resource: UnitResource

var base_speed: float = 100
var speed: float = base_speed
var hp = 50 :
	set = set_hp

@onready var line: Line2D = $UnitPathLine.duplicate()

var sprite: AnimatedSprite2D:
	get():
		if not sprite:
			return get_node("AnimatedSprite2D")
		return sprite


func _init():
	scale = Vector2(Client.current_stage.map.tile_set.tile_size) / Vector2(16, 16)


func _ready():
	# setup with data from UnitResource
	sprite.sprite_frames = unit_resource.sprite_frames
	base_speed = unit_resource.speed
	hp = unit_resource.hp
	
	base_speed *= scale.x
	speed = base_speed
	
	if not target:
		if target_path:
			target = get_node(target_path)
	
	line.name = "Line@" + name
	get_parent().add_child(line)
	
	reset_path()
	Client.current_stage.path_grid_changed.connect(func():
		# TODO: get current position from owner_id rpc
		
		var has_intersection = Client.array_intersect(current_path, Stage.last_solid_set_points)
		# bug: when setting two towers in close succession, new tower overwrites old last solid points
		#print(current_path)
		#print(Stage.last_solid_set_points)
		if has_intersection:
			#print("true")
			reset_path()
			current_path_idx = min(1, current_path.size() - 1)
	)
	
	%HPBar.init(hp)
	set_hp(hp)
	
	var sprite_texture: Texture2D = sprite.sprite_frames.get_frame_texture("down", 0)
	$SelectionArea/CollisionShape2D.shape.size = sprite_texture.get_size()


func _physics_process(delta):
	if not multiplayer.is_server():
		return
	
	previous_position = global_position
	
	if not current_path.is_empty():
		if (global_position - current_path[current_path_idx]).is_zero_approx():
			current_path_idx += 1
		if current_path_idx >= current_path.size():
			reset_path()
	
		walk_along_path(current_path, current_path_idx, delta)
		
		if roaming_mode:
			var collision = get_last_slide_collision()
			if collision:
				var tower = collision.get_collider() as Node2D
				Client.destroy_tower(tower)
	
	# if unit stuck in tower
	var position_difference = abs(previous_position - global_position)
	if position_difference.x < 0.1 and position_difference.y < 0.1:
		stuck_position_accumulator += delta
		if stuck_position_accumulator >= 1.0:
			reset_path()
	else:
		stuck_position_accumulator = 0
	
	#Client.update_unit(get_path(), to_network_data())


func _draw():
	if is_selected:
		draw_circle(
			sprite.position,
			Client.current_stage.map.tile_set.tile_size.x * 0.75,
			Color(1, 1, 1, 0.75),
			false,
			1.0
		)
		modulate = Color(1.5, 1.5, 1.5)
	elif is_hovered:
		draw_circle(
			sprite.position,
			Client.current_stage.map.tile_set.tile_size.x * 0.75,
			Color(1, 1, 1, 0.5),
			false,
			1.0
		)
		modulate = Color(1.25, 1.25, 1.25)
	else:
		modulate = Color(1, 1, 1)


func _on_navigation_base_area_entered(area: Area2D):
	if not multiplayer.is_server():
		return
	
	if area.is_in_group("goal"):
		reached_goal.emit()
		queue_free()
	if area.is_in_group("path"):
		var path_node: PathNode = area.get_parent()
		if path_node == target:
			target = path_node.next_node


func walk_along_path(path: PackedVector2Array, index: int, delta: float):
	immediate_target = path[index]
	var displacement: Vector2 = immediate_target - global_position
	var direction := displacement.normalized()
	var distance := displacement.length()

	var max_speed: float = (distance / delta)
	velocity = direction * minf(speed, max_speed)
	
	for effect in get_effects():
		if effect.has_method("apply_physics"):
			effect.apply_physics(delta)
		# todo: changing velocity here doesn't work nicely
		# todo: because the velocity expects ??to each the point??, so it stutters
	
	if velocity.x > 0 and velocity.y == 0:
		sprite.play("right")
	elif velocity.x < 0 and velocity.y == 0:
		sprite.play("left")
	elif velocity.x == 0 and velocity.y > 0:
		sprite.play("down")
	elif velocity.x == 0 and velocity.y < 0:
		sprite.play("up")
	elif velocity.x > 0 and velocity.y > 0:
		sprite.play("down_right")
	elif velocity.x > 0 and velocity.y < 0:
		sprite.play("up_right")
	elif velocity.x < 0 and velocity.y > 0:
		sprite.play("down_left")
	elif velocity.x < 0 and velocity.y < 0:
		sprite.play("up_left")
	
	move_and_slide()


func set_hp(value):
	hp = value
	
	if get_node("%HPBar"):
		%HPBar.set_value(value)
	if get_node("Label"):
		$Label.text = str(hp)
	
	if hp <= 0:
		queue_free()


func get_effects():
	var effects = []
	for node in get_children():
		if is_instance_of(node, Effect):
			effects.append(node)
	
	return effects

func add_effect(effect: Effect):
	var node = get_node_or_null(NodePath(effect.name)) as Effect
	if node and not node.is_stackable:
		node.set_duration(node.duration)
	else:
		add_child(effect)


func reset_path():
	roaming_mode = false
	current_path = get_grid_path()
	
	if current_path.is_empty():
		# TODO: nimm letzte route davor die noch ging, falls verfügbar
		# TODO: schneide ab bis eins vor neue tower position. (=partial path)
		# TODO: laufe bis dahin und checke dann end of partial path
		current_path = get_grid_path(true)
		recent_closest_paths.append(current_path)
		
		# reached end of partial path
		if current_path.size() == 1 and current_path[0] == global_position:
			roaming_mode = true
			current_path = PackedVector2Array([target.path_position + Vector2(16,16)])
		
		# iterating between one or more closest paths
		elif recent_closest_paths.count(current_path) >= 2:
			roaming_mode = true
			current_path = PackedVector2Array([target.path_position + Vector2(16,16)])
			recent_closest_paths = []
	else:
		recent_closest_paths = []
		roaming_mode = false
	
	current_path_idx = 0

	if line:
		line.points = PackedVector2Array(current_path)


func get_grid_path(partial = false):
	return Client.current_stage.path_grid.get_point_path(
		Client.current_stage.map.local_to_map(global_position),
		Client.current_stage.map.local_to_map(target.path_position),
		partial
	)


func _on_selection_area_input_event(_viewport: Node, event: InputEvent, _shape_idx: int) -> void:
	# disable remote select for now
	if owner_id != multiplayer.get_unique_id():
		return
	
	if Client.state is StateDefault:
		if event.is_action_pressed("select"):
			if selected_unit:
				selected_unit.is_selected = false
			is_selected = true
			$Label.text = str(hp)


func _on_selection_area_mouse_entered() -> void:
	is_hovered = true

func _on_selection_area_mouse_exited() -> void:
	is_hovered = false


func _on_tree_exiting() -> void:
	is_selected = false
	line.queue_free()
	
	Network.remove_unit.rpc(get_path())


class NetworkData extends Resource:
	var name: String
	var owner_id: int
	
	var position: Vector2
	
	var target_path: String
	
	var hp: int
	
	var base_speed: float
	var speed: float
	
	var sprite_frames_path: String
	
	var unit_resource: UnitResource

func to_network_data() -> NetworkData:
	var data = NetworkData.new()
	
	data.name = name
	data.owner_id = owner_id
	
	data.position = global_position
	
	data.target_path = target.get_path()
	
	data.hp = hp
	
	data.base_speed = base_speed
	data.speed = speed
	
	data.sprite_frames_path = sprite.sprite_frames.resource_path
	
	data.unit_resource = unit_resource
	
	return data


func update_with_network_data(_data: NetworkData):
	pass


static func from_network_data(data: NetworkData) -> Unit:
	var unit: Unit = preload("res://Units/Unit.tscn").instantiate()
	
	unit.name = data.name
	unit.owner_id = data.owner_id
	
	unit.global_position = data.position
	
	unit.target_path = data.target_path
	
	unit.hp = data.hp
	
	unit.base_speed = data.base_speed
	unit.speed = data.speed
	
	unit.sprite.sprite_frames = load(data.sprite_frames_path)
	
	unit.unit_resource = data.unit_resource
	
	return unit