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
	machine.can_wall_climb = true
	# Clear wall tilt on landing
	var rig = _get_camera_rig()
	if rig:
		rig.clear_wall_tilt()


func exit() -> void:
	pass


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

	# ── Jump (direct press w/ coyote, or buffered from before landing) ────
	if machine.jump_cooldown_timer <= 0.0:
		var pressed := machine.input_jump_just_pressed and machine.coyote_timer > 0.0
		var buffered := machine.on_ground and machine.jump_buffer_time > 0.0
		if pressed or buffered:
			machine.do_jump()
			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 + 1.0:
			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
	hvel = _next_horizontal_velocity(
		hvel, target_vel, wish_dir.length_squared() > 0.0, delta)

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

	# ── Gravity / floor snap ──────────────────────────────────────────────
	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()

	# ── Stair Stepping ────────────────────────────────────────────────────
	if wish_dir.length_squared() > 0.01 and not machine.input_crouch:
		_try_step_up(player, wish_dir, hvel)

	var current_hspeed = Vector2(player.velocity.x, player.velocity.z).length()
	if current_hspeed > 1.0 and player.is_on_floor():
		_footstep_timer -= delta
		if _footstep_timer <= 0.0:
			if player.has_method("play_footstep"):
				player.play_footstep(current_hspeed)
			_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 interaction (Vault, Climb) ───────────────────────────────────
	if machine.input_dir.length() > 0.1 and machine.input_dir.y <= 0.0 \
			and machine.wall_cooldown_timer <= 0.0 and not machine.input_crouch:
		var fwd_wall = machine.detect_wall_forward()
		if fwd_wall.hit:
			var hspeed := Vector3(player.velocity.x, 0.0, player.velocity.z).length()
			if fwd_wall.is_short and hspeed > 3.0:
				machine.do_vault()
				machine.switch_to("air")
				return
			elif not fwd_wall.is_short:
				# Check if moving directly into wall and looking generally towards it
				var look_dir := -player.global_transform.basis.z
				var looking_towards := look_dir.dot(-fwd_wall.normal) > 0.0
				var moving_towards := machine.wish_dir_world.dot(-fwd_wall.normal) > cos(deg_to_rad(params.wall_climb_max_angle))

				if looking_towards and moving_towards and machine.can_wall_climb:
					machine.wall_normal = fwd_wall.normal
					machine.switch_to("wall_climb")
					return

	# ── Dash ──────────────────────────────────────────────────────────────
	if machine.input_dash and machine.can_dash():
		machine.switch_to("dash")
		return


func _next_horizontal_velocity(current: Vector3, target: Vector3,
		has_input: bool, delta: float) -> Vector3:
	var response := params.ground_acceleration \
		if has_input else params.ground_deceleration
	return current.lerp(target if has_input else Vector3.ZERO,
		1.0 - exp(-response * delta))


func _try_step_up(player: CharacterBody3D, wish_dir: Vector3, hvel: Vector3) -> void:
	for i in range(player.get_slide_collision_count()):
		var col = player.get_slide_collision(i)
		if abs(col.get_normal().y) < 0.3: # Hit a wall
			var max_step_height = 0.95
			var space_state = player.get_world_3d().direct_space_state
			var feet_y = player.global_position.y - (machine.original_capsule_height / 2.0)

			# Raycast down from above the step
			var fwd = wish_dir.normalized()
			var ray_start = player.global_position + fwd * 0.65
			ray_start.y = feet_y + max_step_height + 0.1
			var ray_end = ray_start - Vector3.UP * (max_step_height + 0.2)

			var ray = PhysicsRayQueryParameters3D.create(ray_start, ray_end)
			ray.exclude = [player.get_rid()]
			var hit = space_state.intersect_ray(ray)

			if not hit.is_empty() and hit.normal.y > 0.7:
				var step_height = hit.position.y - feet_y
				if step_height > 0.01 and step_height <= max_step_height:
					# Check if we have headroom to move up
					var head_ray_start = player.global_position
					head_ray_start.y += (machine.original_capsule_height / 2.0)
					var head_ray_end = head_ray_start + Vector3.UP * (step_height + 0.1)
					var head_ray = PhysicsRayQueryParameters3D.create(head_ray_start, head_ray_end)
					head_ray.exclude = [player.get_rid()]

					if space_state.intersect_ray(head_ray).is_empty():
						# Check if there is enough space to move forward after stepping up
						var test_transform = player.global_transform
						test_transform.origin.y += step_height + 0.05
						if not player.test_move(test_transform, fwd * 0.15):
							# We can safely step up
							player.global_position.y += step_height + 0.01
							if player.head_pivot and player.head_pivot.has_method("add_step_offset"):
								player.head_pivot.add_step_offset(-(step_height + 0.01))
							# Push slightly forward to get onto the step
							player.global_position += fwd * 0.1
							# Restore horizontal velocity that was lost from hitting the wall
							player.velocity.x = hvel.x
							player.velocity.z = hvel.z
							break


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