extends Camera3D
## MOBA-style game camera: a perspective three-quarter view whose angle steepens as it
## zooms out (flat and close for fights, steep for the whole map). `zoom` is the visible
## ground height at the focus, the same measure the old orthographic camera used, so lane,
## base and grotto framings keep their meaning. The focus follows the terrain height.
## Blau's base sits bottom-left, Rot's top-right, as on the minimap (yaw 0).

const FOV_DEGREES: float = 34.0
const MIN_ZOOM: float = 11.0
const MAX_ZOOM: float = 100.0
const DEFAULT_ZOOM: float = 34.0
## Pitch at the closest and the widest zoom.
const PITCH_NEAR: float = -48.0
const PITCH_FAR: float = -70.0
const FOCUS_LIMIT: float = 42.0

var focus := Vector3.ZERO
var yaw: float = 0.0
var zoom: float = DEFAULT_ZOOM
var reduced_motion: bool = false
## Terrain height under a ground point; the world sets it (flat without a world).
var ground: Callable = func(_p: Vector2) -> float: return 0.0
var _goal_focus := Vector3.ZERO
var _goal_zoom: float = DEFAULT_ZOOM
var _goal_yaw: float = 0.0
var _dragging: bool = false

func _ready() -> void:
	projection = PROJECTION_PERSPECTIVE
	fov = FOV_DEGREES
	near = .5
	far = 700.0
	current = true
	_goal_focus = focus
	_apply()

static func pitch_for(value: float) -> float:
	return deg_to_rad(lerpf(PITCH_NEAR, PITCH_FAR, smoothstep(14.0, MAX_ZOOM, value)))

func distance_for(value: float) -> float:
	return value / (2.0 * tan(deg_to_rad(fov) * 0.5))

func look_at_point(point: Vector3, new_zoom: float = -1.0, instant: bool = false) -> void:
	_goal_focus = Vector3(clampf(point.x, -FOCUS_LIMIT, FOCUS_LIMIT), 0, clampf(point.z, -FOCUS_LIMIT, FOCUS_LIMIT))
	if new_zoom > 0.0:
		_goal_zoom = clampf(new_zoom, MIN_ZOOM, MAX_ZOOM)
	if instant or reduced_motion:
		focus = _goal_focus
		focus.y = ground.call(Vector2(focus.x, focus.z))
		zoom = _goal_zoom
		yaw = _goal_yaw
		_apply()

## The whole map (both bases, all lanes and the grotto) at once.
func overview(instant: bool = false) -> void:
	look_at_point(Vector3.ZERO, 92.0, instant)

## Quarter turns around the focus; R returns to the map-aligned view.
func rotate_step(direction: int) -> void:
	_goal_yaw += direction * PI * 0.25
	if reduced_motion:
		yaw = _goal_yaw
		_apply()

func reset_view(point: Vector3, instant: bool = false) -> void:
	_goal_yaw = 0.0
	look_at_point(point, DEFAULT_ZOOM, instant)
	if instant:
		yaw = 0.0
		_apply()

func _apply() -> void:
	var back := Vector3(0, 0, 1).rotated(Vector3.RIGHT, pitch_for(zoom)).rotated(Vector3.UP, yaw)
	position = focus + back * distance_for(zoom)
	look_at(focus, Vector3.UP)

func _process(delta: float) -> void:
	var pan := Vector2(Input.get_axis("ui_left", "ui_right"), Input.get_axis("ui_up", "ui_down"))
	if Input.is_physical_key_pressed(KEY_A): pan.x -= 1
	if Input.is_physical_key_pressed(KEY_D): pan.x += 1
	if Input.is_physical_key_pressed(KEY_W): pan.y -= 1
	if Input.is_physical_key_pressed(KEY_S): pan.y += 1
	if pan != Vector2.ZERO and not _text_focus():
		var right := Vector3(cos(yaw), 0, -sin(yaw))
		var forward := Vector3(-sin(yaw), 0, -cos(yaw))
		_goal_focus += (right * pan.x - forward * pan.y) * zoom * .9 * delta
		_goal_focus.x = clampf(_goal_focus.x, -FOCUS_LIMIT, FOCUS_LIMIT)
		_goal_focus.z = clampf(_goal_focus.z, -FOCUS_LIMIT, FOCUS_LIMIT)
	var t: float = 1.0 if reduced_motion else minf(1.0, delta * 7.0)
	var target_height: float = ground.call(Vector2(_goal_focus.x, _goal_focus.z))
	focus = focus.lerp(Vector3(_goal_focus.x, target_height, _goal_focus.z), t)
	zoom = lerpf(zoom, _goal_zoom, t)
	yaw = lerp_angle(yaw, _goal_yaw, t)
	_apply()

func _text_focus() -> bool:
	var owner: Control = get_viewport().gui_get_focus_owner()
	return owner is LineEdit or owner is TextEdit

## Ground outline of the current view (four corners on the focus plane) for the minimap.
func footprint() -> PackedVector2Array:
	var result := PackedVector2Array()
	var viewport: Viewport = get_viewport()
	if viewport == null:
		return result
	var extent: Vector2 = viewport.get_visible_rect().size
	for corner: Vector2 in [Vector2.ZERO, Vector2(extent.x, 0), extent, Vector2(0, extent.y)]:
		var origin: Vector3 = project_ray_origin(corner)
		var direction: Vector3 = project_ray_normal(corner)
		if direction.y > -0.02:
			direction.y = -0.02
		var hit: Vector3 = origin + direction * ((focus.y - origin.y) / direction.y)
		result.append(Vector2(hit.x, hit.z))
	return result

## World input only; the HUD consumes its own clicks before they reach here.
func handle_world_input(event: InputEvent) -> bool:
	if event is InputEventMouseButton and event.pressed:
		if event.button_index == MOUSE_BUTTON_WHEEL_UP:
			_goal_zoom = maxf(MIN_ZOOM, _goal_zoom - maxf(2.5, _goal_zoom * .09))
			return true
		if event.button_index == MOUSE_BUTTON_WHEEL_DOWN:
			_goal_zoom = minf(MAX_ZOOM, _goal_zoom + maxf(2.5, _goal_zoom * .09))
			return true
	if event is InputEventMouseButton and event.button_index == MOUSE_BUTTON_MIDDLE:
		_dragging = event.pressed
		return true
	if event is InputEventMouseMotion and _dragging:
		var right := Vector3(cos(yaw), 0, -sin(yaw))
		var forward := Vector3(-sin(yaw), 0, -cos(yaw))
		_goal_focus -= (right * event.relative.x - forward * event.relative.y) * zoom / 700.0
		_goal_focus.x = clampf(_goal_focus.x, -FOCUS_LIMIT, FOCUS_LIMIT)
		_goal_focus.z = clampf(_goal_focus.z, -FOCUS_LIMIT, FOCUS_LIMIT)
		return true
	return false