class_name Mob
extends CharacterBody2D


signal selected

static var selected_unit: Mob

var is_selected = false :
	set(value):
		if value:
			Mob.selected_unit = self
			selected.emit()
		else:
			if Mob.selected_unit == self:
				Mob.selected_unit = null
		is_selected = value
		queue_redraw()

var is_hovered = false :
	set(value):
		is_hovered = value
		queue_redraw()

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

var current_path: PackedVector2Array
var current_path_idx = 0

var previous_path: PackedVector2Array
var previous_path_idx = 0

var previous_position: Vector2

var recent_closest_paths: Array[PackedVector2Array]

var roaming_mode = false

@export var speed: float = 100

@export var hp = 50


# Called when the node enters the scene tree for the first time.
func _ready():
	if not target:
		target = get_tree().current_scene.find_child("Goal")
	
	reset_path()
	Game.path_grid_changed.connect(func():
		reset_path()
		current_path_idx = min(1, current_path.size() - 1)
	)
	
	%HPBar.init(hp)
	set_hp(hp)


func _physics_process(delta):
	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
				Game.destroy_tower(tower)
	
	# if unit stuck in tower
	if previous_position == global_position: # doesn't work with 0.05 fluctuating position
		reset_path()
		roaming_mode = true


func _draw():
	if is_selected:
		draw_circle(
			Vector2.ZERO,
			8,
			Color(1, 1, 1, 0.75),
			false,
			1.0
		)
		modulate = Color(1.5, 1.5, 1.5)
	elif is_hovered:
		draw_circle(
			Vector2.ZERO,
			8,
			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 area.is_in_group("goal"):
		Game.score += 1
		queue_free()
	if area.is_in_group("path"):
		var path_node = 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 := (path[index]) - global_position
	var direction := displacement.normalized()
	var distance := displacement.length()

	var max_speed: float = (distance / delta)
	velocity = direction * minf(speed, max_speed)
	move_and_slide()


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


func reset_path():
	roaming_mode = false
	current_path = get_grid_path()
	
	if current_path.is_empty():
		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.global_position])
		
		# iterating between one or more closest paths
		elif recent_closest_paths.count(current_path) >= 2:
			roaming_mode = true
			current_path = PackedVector2Array([target.global_position])
			recent_closest_paths = []
	else:
		recent_closest_paths = []
		roaming_mode = false
	
	current_path_idx = 0

func get_grid_path(partial = false):
	#return Game.path_grid.get_point_path(
		#Game.map.local_to_map(global_position) * 2,
		#Game.map.local_to_map(target.global_position) * 2,
		#partial
	#)
	return Game.path_grid.get_point_path(
		Game.map.local_to_map(global_position),
		Game.map.local_to_map(target.global_position),
		partial
	)


func _on_input_event(_viewport: Node, event: InputEvent, _shape_idx: int) -> void:
	if Game.mode == Game.Mode.DEFAULT:
		if event.is_action_pressed("select"):
			is_selected = true
			$Label.text = str(hp)


func _on_mouse_entered() -> void:
	is_hovered = true

func _on_mouse_exited() -> void:
	is_hovered = false


func _on_tree_exiting() -> void:
	is_selected = false