class_name Player
extends CharacterBody3D


signal bounced()
signal shot()
signal charge_canceled()


@export_group("Visuals")
@export var goal_animation_time: float = 1.0
@export var charge_gradient: Gradient
@export var power_line_material: StandardMaterial3D

@export_group("Movement")
@export var gravity: float
@export var friction: float
@export var friction_coef: float
@export var friction_pow: float
@export var power_scale: float
@export var power_sensitivity: float
@export var power_threshold: float
@export var stop_threshold: float

@export_group("Camera", "camera_")
@export_range(0,90,1,"radians_as_degrees") var camera_low_angle: float
@export_range(0,90,1,"radians_as_degrees") var camera_high_angle: float
@export_range(0,90,0.5,"radians_as_degrees") var camera_yaw_sensitivity: float
@export_range(0,90,0.5,"radians_as_degrees") var camera_pitch_sensitivity: float

@export_group("Node References")
@export var state_chart: StateChart
@export var graphics: Node3D
@export var power_indicator: Node3D
@export var camera_arm: SpringArm3D
@export var collision_shape: CollisionShape3D


var power: float = 0.0:
	set(value):
		power = clampf(value, 0.0, 1.0)

var charging_power: bool = false
var prev_velocity: Vector3 = Vector3.ZERO

var _entered_goal: Node3D = null


#region Builtin Overrides
func _ready() -> void:
	Input.mouse_mode = Input.MOUSE_MODE_CAPTURED


func _physics_process(delta: float) -> void:
	prev_velocity = velocity
	move_and_slide()
	state_chart.set_expression_property(&"velocity", velocity)


func _unhandled_input(event: InputEvent) -> void:
	if event.is_action_pressed(&"charge_shot"):
		state_chart.send_event(&"charge_pressed")
	if event.is_action_released(&"charge_shot"):
		state_chart.send_event(&"charge_released")
	
	if event is InputEventMouseMotion:
		camera_arm.rotate_y(event.screen_relative.x * camera_yaw_sensitivity)
		
		if charging_power:
			power += event.screen_relative.y * power_sensitivity
		else:
			camera_arm.rotation.x -= event.screen_relative.y * camera_pitch_sensitivity
			camera_arm.rotation.x = clampf(camera_arm.rotation.x, -camera_high_angle, -camera_low_angle)
#endregion


#region Public Functions
func enter_goal(goal: GoalPost) -> void:
	_entered_goal = goal
	state_chart.send_event(&"goal_entered")


func attach_to_pole(pole: WatermanPole) -> void:
	_attached_pole = pole
	state_chart.send_event(&"pole_attached")
#endregion


#region Charging
func _start_charge() -> void:
	charging_power = true
	power_indicator.visible = true
	power_indicator.scale.z = 0.0
	power = 0.0

func _update_charge(_delta: float) -> void:
	power_indicator.scale.z = power
	var camera_z = get_viewport().get_camera_3d().global_transform.basis.z
	camera_z.y = 0.0
	power_indicator.look_at(power_indicator.global_position + camera_z)
	power_line_material.albedo_color = charge_gradient.sample(power)

func _end_charge() -> void:
	charging_power = false
	power_indicator.visible = false
	if power >= power_threshold:
		var camera_z = get_viewport().get_camera_3d().global_transform.basis.z
		camera_z.y = 0.0
		velocity = -camera_z.normalized() * power * power_scale
		prev_velocity = velocity
		_bounce_on_walls(1.0/60.0)
		shot.emit()
	else:
		charge_canceled.emit()
#endregion


#region Moving
func _apply_gravity(delta: float) -> void:
	velocity.y -= gravity * delta

func _slow_to_stop(delta: float) -> void:
	if is_on_floor():
		var new_velocity = velocity * Vector3(1.0, 0.0, 1.0)
		
		#new_velocity = lerp(new_velocity, Vector3.ZERO, friction_coef * delta)
		#new_velocity = lerp(
			#new_velocity, Vector3.ZERO,
			#power_scale * pow(friction_coef / new_velocity.length(), friction_pow * delta)
		#)
		new_velocity = new_velocity.move_toward(Vector3.ZERO, friction * delta)
		if new_velocity.length_squared() <= stop_threshold * stop_threshold:
			new_velocity = Vector3.ZERO
		velocity.x = new_velocity.x
		velocity.z = new_velocity.z

func _bounce_on_walls(delta: float = 0.0) -> void:
	var h_vel = (prev_velocity * Vector3(1.0, 0.0, 1.0))
	var col = move_and_collide(h_vel * delta, true)
	if col:
		if col.get_angle() > floor_max_angle:
			h_vel = h_vel.bounce(col.get_normal())
			velocity.x = h_vel.x
			velocity.z = h_vel.z
			bounced.emit()
#endregion


#region Winning
func _start_winning() -> void:
	velocity = Vector3.ZERO
	prev_velocity = velocity
	collision_shape.disabled = true
	
	var tween = create_tween()
	tween.set_process_mode(Tween.TWEEN_PROCESS_PHYSICS)
	tween.tween_property(graphics, ^"scale", Vector3.ZERO, goal_animation_time)
	tween.set_parallel(true)
	tween.tween_property(graphics, ^"global_position", _entered_goal.global_position, goal_animation_time)
#endregion


#region Pole Spinning
var _attached_pole: WatermanPole = null
var _pole_angle: float = 0.0
var _pole_stored_speed: float = 0.0

func _start_pole_spin() -> void:
	_pole_stored_speed = flatten_vector(velocity).length()
	velocity = Vector3.ZERO
	var pole_xz = flatten_vector(_attached_pole.global_position)
	var self_xz = flatten_vector(global_position)
	_pole_angle = Vector3.FORWARD.angle_to(self_xz - pole_xz)

func _process_pole_spin(delta: float) -> void:
	# rise
	global_position.y += _attached_pole.rise_speed * delta
	global_position.y = clampf(
		global_position.y,
		_attached_pole.global_position.y,
		_attached_pole.top.global_position.y
	)
	
	# spin
	_pole_angle += _attached_pole.spin_speed * delta
	var pole_xz = flatten_vector(_attached_pole.global_position)
	var self_dir = Vector3.FORWARD.rotated(Vector3.UP, _pole_angle)
	var self_xz = pole_xz + self_dir * _attached_pole.offset
	global_position.x = self_xz.x
	global_position.z = self_xz.z

func _end_pole_spin() -> void:
	var pole_xz = flatten_vector(_attached_pole.global_position)
	var impulse = Vector3.FORWARD.rotated(Vector3.UP, _pole_angle) * _pole_stored_speed
	velocity.x = impulse.x
	velocity.z = impulse.z
#endregion


#region Helpers
func flatten_vector(vector: Vector3) -> Vector3:
	return Vector3(vector.x, 0.0, vector.z)
#endregion