class_name OverworldCamera extends Camera3D

const COLLISION_MARGIN:float = 0.3

@export_category("Target")
@export var targetNode:Node3D = null
@export var pivotOffset:Vector3 = Vector3(0, 1.2, 0)

@export_category("Orbit")
@export var distance:float = 7.0
@export var minDistance:float = 5.0
@export var orbitSensitivity:float = 144.0
@export var orbitAcceleration:float = 600.0
@export var pitchMin:float = -80.0
@export var pitchMax:float = 70.0

@export_category("Mouse")
@export var mouseSensitivity:float = 0.3

@export_category("Auto-center")
@export var autoReturnDelay:float = 2.0
@export var autoReturnSpeed:float = 90.0
@export var autoReturnPitch:float = 30.0

@export_category("Collision")
@export_flags_3d_physics var collisionMask:int = 1

var _yaw:float = 0.0
var _pitch:float = 30.0
var _camVelocity:Vector2 = Vector2.ZERO
var _idleTimer:float = 0.0
var _mouseDelta:Vector2 = Vector2.ZERO
var _rightMouseHeld:bool = false

func _input(event:InputEvent) -> void:
  if event is InputEventMouseButton and event.button_index == MOUSE_BUTTON_RIGHT:
    _rightMouseHeld = event.pressed
    Input.mouse_mode = Input.MOUSE_MODE_CAPTURED if _rightMouseHeld else Input.MOUSE_MODE_VISIBLE
  elif event is InputEventMouseMotion and _rightMouseHeld:
    _mouseDelta += event.relative

func _process(delta:float) -> void:
  if targetNode == null:
    return

  var xMult:float = -1.0 if SETTINGS.invertCameraX else 1.0
  var yMult:float = 1.0 if SETTINGS.invertCameraY else -1.0

  var orbitInput:Vector2 = Input.get_vector(
    "camera_orbit_left", "camera_orbit_right",
    "camera_orbit_up", "camera_orbit_down"
  )

  # Controller input with speed ramp; instant stop on release
  var controllerActive:bool = orbitInput.length() > 0.01
  if controllerActive:
    _camVelocity = _camVelocity.move_toward(
      orbitInput * orbitSensitivity * SETTINGS.cameraSpeedController, orbitAcceleration * delta
    )
    _yaw += _camVelocity.x * delta * xMult
    _pitch += _camVelocity.y * delta * yMult
  else:
    _camVelocity = Vector2.ZERO

  # Right-click mouse drag
  var mouseActive:bool = _mouseDelta.length_squared() > 0.0
  if mouseActive:
    _yaw += _mouseDelta.x * mouseSensitivity * SETTINGS.cameraSpeedMouse * xMult
    _pitch += _mouseDelta.y * mouseSensitivity * SETTINGS.cameraSpeedMouse * yMult
    _mouseDelta = Vector2.ZERO

  # Auto-center behind player: only when player is moving and camera has been idle
  var centerPressed:bool = Input.is_action_just_pressed("center_camera")
  if centerPressed:
    _idleTimer = autoReturnDelay
  elif controllerActive or mouseActive:
    _idleTimer = 0.0
  else:
    var playerBody := targetNode as CharacterBody3D
    if playerBody != null and playerBody.velocity.length_squared() > 0.1:
      _idleTimer += delta
    else:
      _idleTimer = 0.0

  if _idleTimer >= autoReturnDelay:
    _pitch = move_toward(_pitch, autoReturnPitch, autoReturnSpeed * delta)
    var behindYaw:float = rad_to_deg(atan2(
      targetNode.global_transform.basis.z.x,
      targetNode.global_transform.basis.z.z
    ))
    var yawDiff:float = fposmod(behindYaw - _yaw + 180.0, 360.0) - 180.0
    _yaw += move_toward(0.0, yawDiff, autoReturnSpeed * delta)

  _pitch = clamp(_pitch, pitchMin, pitchMax)

  var pivot:Vector3 = targetNode.global_transform.origin + pivotOffset
  var yawRad:float = deg_to_rad(_yaw)
  var pitchRad:float = deg_to_rad(_pitch)
  var dir:Vector3 = Vector3(
    sin(yawRad) * cos(pitchRad),
    sin(pitchRad),
    cos(yawRad) * cos(pitchRad)
  )

  var finalPos:Vector3 = _resolvePosition(pivot, dir)
  global_transform.origin = finalPos
  look_at(pivot, Vector3.UP)

  # Feed actual position back so camera input resumes from where it really is
  var actualDir:Vector3 = (finalPos - pivot).normalized()
  _pitch = rad_to_deg(asin(clamp(actualDir.y, -1.0, 1.0)))
  _yaw = rad_to_deg(atan2(actualDir.x, actualDir.z))

# Returns the camera world position, respecting both minDistance and terrain.
func _resolvePosition(pivot:Vector3, dir:Vector3) -> Vector3:
  var desired:Vector3 = pivot + dir * distance
  var space:PhysicsDirectSpaceState3D = get_world_3d().direct_space_state
  var query:PhysicsRayQueryParameters3D = PhysicsRayQueryParameters3D.create(pivot, desired)
  query.collision_mask = collisionMask
  var hit:Dictionary = space.intersect_ray(query)

  if hit.is_empty():
    return desired

  var hitNormal:Vector3 = hit["normal"]
  var hitDist:float = (hit["position"] - pivot).length() - COLLISION_MARGIN

  if hitDist >= minDistance:
    # Terrain is beyond minDistance — simple pull-back along the ray
    return pivot + dir * hitDist

  # Terrain is closer than minDistance.
  # Find the closest point on the circle formed by intersecting:
  #   • the minDistance sphere centred on pivot
  #   • the terrain surface plane (inset by COLLISION_MARGIN along its normal)
  # That point is exactly minDistance from the pivot and flush with the surface.
  var d:float = hitNormal.dot(pivot - hit["position"]) - COLLISION_MARGIN
  var rSq:float = minDistance * minDistance - d * d
  if rSq <= 0.0:
    # Pivot is itself nearly on the terrain — sit at the tangent point
    return pivot - hitNormal * d

  var circleCenter:Vector3 = pivot - hitNormal * d
  var circleRadius:float = sqrt(rSq)

  # Project desired onto the terrain plane to get the on-plane direction
  var toDesired:Vector3 = desired - circleCenter
  toDesired -= hitNormal * hitNormal.dot(toDesired)
  if toDesired.length_squared() < 0.0001:
    # Desired is directly along the normal — any circle point is equally good
    return circleCenter

  return circleCenter + toDesired.normalized() * circleRadius