extends Node3D
class_name FPSCameraRig

## FPS camera rig — mouse look, head bob, FOV kick, wall-run tilt, plus
## movement-feel feedback driven by MovementStateMachine events:
##   - landing dip scaled by impact speed
##   - pitch impulse (vault kick) with spring decay
##   - smooth crouch/slide eye height (follows the capsule's smoothed height)
##   - slide roll tilt and dash FOV punch
## Attach as child of the CharacterBody3D player. Camera3D is a child of this node.

@export var sensitivity: float = 0.002
@export var pitch_limit: float = 89.0

var params: MovementParams
var camera: Camera3D
var _bob_timer: float = 0.0
var _target_tilt: float = 0.0
var _current_tilt: float = 0.0
var _target_fov: float = 90.0
var _weapon_fov_override: float = -1.0
var _step_offset_y: float = 0.0

# Movement-feel feedback state
var _base_eye_y: float = 0.7
var _land_dip: float = 0.0          # current downward dip (springs back to 0)
var _pitch_impulse: float = 0.0     # extra camera pitch in radians, decays
var _dash_fov_kick: float = 0.0     # extra FOV from dashing, decays
var _machine: MovementStateMachine = null

# Third-person free-look: hold Alt to orbit the camera around the character
# without turning the character or aim; release and it springs back behind.
var _orbit_yaw: float = 0.0
var _orbit_pitch: float = 0.0
const ORBIT_PITCH_MIN := -1.2       # radians (looking down from above)
const ORBIT_PITCH_MAX := 0.5        # radians (looking up from below)
const ORBIT_RETURN_SPEED := 10.0


func _ready() -> void:
	Input.set_mouse_mode(Input.MOUSE_MODE_CAPTURED)
	camera = get_node_or_null("Camera3D")
	_base_eye_y = position.y
	if camera and params:
		camera.fov = SettingsManager.world_fov
		_target_fov = SettingsManager.world_fov
	# Explicitly enable callbacks — set_script() at runtime doesn't auto-register them
	set_process_input(true)
	set_process(true)
	# The state machine may be added after us; hook events once the tree settles.
	call_deferred("_connect_machine")


func _connect_machine() -> void:
	var player := get_parent()
	if not player:
		return
	var sm = player.get_node_or_null("MovementStateMachine")
	if sm and sm is MovementStateMachine:
		_machine = sm
		if not sm.movement_event.is_connected(_on_movement_event):
			sm.movement_event.connect(_on_movement_event)


func _on_movement_event(ev: String, data: Dictionary) -> void:
	match ev:
		"land":
			var fall_speed: float = data.get("fall_speed", 0.0)
			var scale_p: float = params.land_dip_scale if params else 0.012
			var max_p: float = params.land_dip_max if params else 0.25
			_land_dip = clampf(fall_speed * scale_p, 0.0, max_p)
		"dash":
			_dash_fov_kick = 15.0
		"vault":
			pass  # pitch impulse is applied via add_pitch_impulse by the machine


func _input(event: InputEvent) -> void:
	if event is InputEventMouseMotion and Input.get_mouse_mode() == Input.MOUSE_MODE_CAPTURED:
		var is_ads = camera and camera.fov < SettingsManager.world_fov - 5.0
		var sens = SettingsManager.ads_sensitivity if is_ads else SettingsManager.mouse_sensitivity
		if _free_looking():
			# Alt held in third person: orbit the camera around the character;
			# the character keeps facing (and aiming) where it was.
			_orbit_yaw = wrapf(_orbit_yaw - event.relative.x * sens, -PI, PI)
			_orbit_pitch = clampf(_orbit_pitch - event.relative.y * sens,
				ORBIT_PITCH_MIN, ORBIT_PITCH_MAX)
		else:
			# Yaw: rotate the player (parent)
			get_parent().rotate_y(-event.relative.x * sens)
			# Pitch: rotate this pivot
			rotation.x = clampf(rotation.x - event.relative.y * sens, deg_to_rad(-pitch_limit), deg_to_rad(pitch_limit))

	# Toggle mouse capture with Escape
	if event is InputEventKey and event.pressed and event.keycode == KEY_ESCAPE:
		if Input.get_mouse_mode() == Input.MOUSE_MODE_CAPTURED:
			Input.set_mouse_mode(Input.MOUSE_MODE_VISIBLE)
		else:
			Input.set_mouse_mode(Input.MOUSE_MODE_CAPTURED)


## True while the player is holding Alt to look around in third person.
func _free_looking() -> bool:
	var p := get_parent()
	return p != null and "third_person" in p and p.third_person \
		and Input.is_key_pressed(KEY_ALT) \
		and Input.get_mouse_mode() == Input.MOUSE_MODE_CAPTURED


func _process(delta: float) -> void:
	if not camera or not params:
		return

	var player: CharacterBody3D = get_parent() as CharacterBody3D
	if not player:
		return

	# ── Third-person free-look orbit ──────────────────────────────────────
	var orbit := get_node_or_null("OrbitPivot")
	if orbit:
		if not _free_looking():
			# Spring back behind the character once Alt is released.
			var t := 1.0 - exp(-ORBIT_RETURN_SPEED * delta)
			_orbit_yaw = lerpf(_orbit_yaw, 0.0, t)
			_orbit_pitch = lerpf(_orbit_pitch, 0.0, t)
		orbit.rotation = Vector3(_orbit_pitch, _orbit_yaw, 0.0)

	if not _machine:
		_connect_machine()

	var state := ""
	if _machine:
		state = _machine.current_state
	var is_sliding := state == "slide"

	# ── FOV kick ──────────────────────────────────────────────────────────
	_target_fov = SettingsManager.world_fov
	var hspeed := Vector2(player.velocity.x, player.velocity.z).length()

	# Smoothly scale FOV based on speed above walking speed
	var speed_factor = clampf((hspeed - params.walk_speed) / (params.walk_speed * 0.5), 0.0, 1.0)
	_target_fov = lerpf(SettingsManager.world_fov, SettingsManager.world_fov + 20.0, speed_factor)

	# Dash punch decays on top
	_dash_fov_kick = lerpf(_dash_fov_kick, 0.0, 1.0 - exp(-6.0 * delta))
	_target_fov += _dash_fov_kick

	if _weapon_fov_override > 0.0:
		_target_fov = _weapon_fov_override

	camera.fov = lerpf(camera.fov, _target_fov, 1.0 - exp(-params.fov_lerp_speed * delta))

	# ── Crouch / slide eye height (follows the smoothed capsule) ──────────
	var crouch_factor := 0.0
	if _machine:
		crouch_factor = _machine.get_crouch_factor()
	var eye_drop: float = _machine.original_capsule_height * 0.5 if _machine else 0.9
	var target_eye_y: float = _base_eye_y - crouch_factor * eye_drop
	position.y = lerpf(position.y, target_eye_y, 1.0 - exp(-12.0 * delta))

	# ── Head bob ──────────────────────────────────────────────────────────
	if player.is_on_floor() and hspeed > 1.0 and not is_sliding:
		_bob_timer += delta * params.head_bob_frequency * (hspeed / params.walk_speed)
		var bob_y := sin(_bob_timer) * params.head_bob_amplitude
		var bob_x := cos(_bob_timer * 0.5) * params.head_bob_amplitude * 0.5
		camera.position.y = lerp(camera.position.y, bob_y, 0.3)
		camera.position.x = lerp(camera.position.x, bob_x, 0.3)
	else:
		_bob_timer = 0.0
		camera.position.y = lerp(camera.position.y, 0.0, 0.15)
		camera.position.x = lerp(camera.position.x, 0.0, 0.15)

	# ── Landing dip (springs back up) ─────────────────────────────────────
	_land_dip = lerpf(_land_dip, 0.0, 1.0 - exp(-8.0 * delta))
	camera.position.y -= _land_dip

	# ── Step Smoothing ─────────────────────────────────────────────────────
	_step_offset_y = lerpf(_step_offset_y, 0.0, 15.0 * delta)
	camera.position.y += _step_offset_y

	# ── Pitch impulse (vault kick etc.), spring-decayed ───────────────────
	_pitch_impulse = lerpf(_pitch_impulse, 0.0, 1.0 - exp(-7.0 * delta))
	camera.rotation.x = _pitch_impulse

	# ── Tilt: wall-run lean + slide roll ──────────────────────────────────
	var tilt_target := _target_tilt
	if is_sliding:
		# Subtle roll in the slide's steering direction
		var slide_roll: float = params.slide_tilt_angle
		tilt_target += -_machine.input_dir.x * slide_roll if _machine else 0.0
	_current_tilt = lerpf(_current_tilt, tilt_target, 1.0 - exp(-params.wall_run_tilt_speed * delta))
	camera.rotation.z = deg_to_rad(_current_tilt)

## Called by the movement system to set wall-run tilt direction.
## side: -1.0 (left wall), 1.0 (right wall), 0.0 (no tilt)
func set_wall_tilt(side: float) -> void:
	if params:
		_target_tilt = side * params.wall_run_tilt_angle
	else:
		_target_tilt = side * 12.0

func set_weapon_fov(fov: float) -> void:
	_weapon_fov_override = fov


## Called to reset tilt (e.g., on landing).
func clear_wall_tilt() -> void:
	_target_tilt = 0.0

## Kick the camera pitch (degrees); decays back smoothly. Used for vaults.
func add_pitch_impulse(degrees: float) -> void:
	_pitch_impulse += deg_to_rad(degrees)

## Adds an offset to the camera so that when the player physics body snaps up a step,
## the camera interpolates smoothly instead of snapping.
func add_step_offset(offset_y: float) -> void:
	_step_offset_y += offset_y