extends Node
class_name StateGround

var machine: MovementStateMachine
var params: MovementParams:
	get: return machine.params

var _footstep_timer: float = 0.0

func enter(_data: Dictionary = {}) -> void:
	machine.on_ground = true
	machine.current_jump_count = 0
	# Clear wall tilt on landing
	var rig = _get_camera_rig()
	if rig:
		rig.clear_wall_tilt()

	# Ensure capsule is correct when entering ground state
	_update_capsule_height()


func exit() -> void:
	pass


func update(delta: float) -> void:
	var player := machine.player
	var vel: Vector3 = player.velocity

	# ── Jump (coyote time + jump buffer) ──────────────────────────────────
	if machine.input_jump_just_pressed and machine.coyote_timer > 0.0 and machine.jump_cooldown_timer <= 0.0:
		player.velocity.y = params.jump_velocity
		machine.current_jump_count = 1
		machine.on_ground = false
		machine.coyote_timer = 0.0
		machine.register_chain_mechanic("jump")
		machine.jump_cooldown_timer = params.jump_cooldown
		if player.jump_player:
			player.jump_player.play()
		machine.switch_to("air")
		return

	# Jump buffer: player pressed jump just before landing
	if machine.on_ground and machine.jump_buffer_time > 0.0 and machine.jump_cooldown_timer <= 0.0:
		player.velocity.y = params.jump_velocity
		machine.current_jump_count = 1
		machine.on_ground = false
		machine.jump_buffer_time = 0.0
		machine.register_chain_mechanic("jump")
		machine.jump_cooldown_timer = params.jump_cooldown
		if player.jump_player:
			player.jump_player.play()
		machine.switch_to("air")
		return

	# ── Slide (crouch while moving fast enough) ───────────────────────────
	if machine.input_crouch and machine.slide_cooldown_timer <= 0.0:
		var hspeed := Vector3(player.velocity.x, 0.0, player.velocity.z).length()
		if hspeed > params.slide_min_speed:
			machine.switch_to("slide")
			return

	# ── Determine target speed ────────────────────────────────────────────
	var wish_dir: Vector3 = machine.wish_dir_world
	var speed := params.walk_speed
	if machine.input_crouch:
		speed = params.crouch_speed
	var effective_speed := machine.get_effective_speed(speed)

	# ── Horizontal movement (exponential interpolation for smoothness) ───
	var hvel := Vector3(vel.x, 0.0, vel.z)
	var target_vel := wish_dir * effective_speed

	if wish_dir.length_squared() > 0.0:
		hvel = hvel.lerp(target_vel, 1.0 - exp(-params.ground_acceleration * delta))
	else:
		hvel = hvel.lerp(Vector3.ZERO, 1.0 - exp(-params.ground_deceleration * delta))

	vel.x = hvel.x
	vel.z = hvel.z

	# ── Gravity (correct direction: downward) ─────────────────────────────
	if not player.is_on_floor():
		vel.y -= params.gravity * delta
	else:
		# Snap to floor: small downward velocity keeps is_on_floor() stable
		# ONLY if we aren't being launched upward by an impulse!
		if vel.y <= 0.0:
			vel.y = -0.5

	player.velocity = vel
	player.move_and_slide()

	_update_capsule_height()

	var current_hspeed = Vector2(player.velocity.x, player.velocity.z).length()
	if current_hspeed > 1.0:
		_footstep_timer -= delta
		if _footstep_timer <= 0.0:
			if player.footstep_player:
				player.footstep_player.play()
			_footstep_timer = max(0.2, 3.0 / current_hspeed)
	else:
		_footstep_timer = 0.0

	# ── Update ground status ──────────────────────────────────────────────
	if player.is_on_floor():
		machine.on_ground = true
		machine.current_jump_count = 0
	else:
		machine.on_ground = false

	# ── Launch or Falling off ledge → air state ───────────────────────────
	if not machine.on_ground:
		if player.velocity.y > 0.0 or machine.coyote_timer <= 0.0:
			machine.switch_to("air")
			return

	# ── Wall run check ────────────────────────────────────────────────────
	var wall_n := machine.detect_wall_horizontal()
	if wall_n != Vector3.ZERO and machine.input_dir.length() > 0.1:
		if not player.is_on_floor():
			machine.switch_to("wall_run")
			return

	# ── Dash ──────────────────────────────────────────────────────────────
	if machine.input_dash:
		var hspeed := Vector3(player.velocity.x, 0.0, player.velocity.z).length()
		if hspeed > 0.1 or machine.input_dir.length() > 0.1:
			machine.switch_to("dash")
			return


func _get_camera_rig():
	if machine.player and machine.player.has_node("HeadPivot"):
		return machine.player.get_node("HeadPivot")
	return null


func _update_capsule_height() -> void:
	var shape = _get_capsule()
	if shape:
		if machine.input_crouch:
			shape.height = machine.original_capsule_height * 0.5
		else:
			shape.height = machine.original_capsule_height


func _get_capsule() -> CapsuleShape3D:
	for child in machine.player.get_children():
		if child is CollisionShape3D and child.shape is CapsuleShape3D:
			return child.shape as CapsuleShape3D
	return null