spaceship/GameController.gd

extends Node2D

@export var min_zoom: float = 0.4
@export var max_zoom: float = 6.0
@export var camera_follow_speed: float = 5.0
# Distance (world units) below which the camera snaps exactly onto the fleet
# instead of continuing to lerp. Without this the exponential lerp only ever
# approaches the target asymptotically and NEVER arrives, so the camera keeps
# drifting by a fraction of a pixel every single frame - forever, even with
# the fleet completely stationary. That kept the background shaders' camera_pos
# uniform changing every frame, which made screen tearing permanently visible
# as horizontal bands of the background shifted sideways against each other.
# Same class of bug (and same fix) as the ship arrival oscillation.
@export var camera_snap_distance: float = 0.5
@export var debug_input_logging: bool = false

@onready var camera: Camera2D = $Camera2D
@onready var fleet: Node2D = $Fleet
# Optional: scenes without a joystick (none currently) still work.
@onready var joystick: TouchJoystick = get_node_or_null("UI/Joystick")
# Navigation section. Optional so a scene without it still works.
@onready var pivot_cw_button: IconButton = get_node_or_null("UI/PivotCWButton")
@onready var pivot_ccw_button: IconButton = get_node_or_null("UI/PivotCCWButton")

var touches: Dictionary = {}
var pinch_active: bool = false
var pinch_start_distance: float = 0.0
var pinch_start_zoom: float = 1.0



# Held pivot buttons turn the formation continuously at this rate; a quick
# tap that accumulates less than PIVOT_MIN_STEP is topped up to it on
# release, so tapping still produces a clear, visible nudge.
const PIVOT_SPEED: float = 1.6
const PIVOT_MIN_STEP: float = PI / 10.0

var pivot_hold_amount: float = 0.0
# Touch index currently holding each pivot button, or -1. These buttons are
# driven straight from raw touch events rather than through _gui_input,
# because Godot's Control GUI treats touch as a single emulated pointer and
# will not reliably deliver a SECOND simultaneous finger to another
# Control - which meant pivoting while steering with the joystick silently
# did nothing. The joystick already bypasses the GUI for the same reason.
var pivot_cw_touch: int = -1
var pivot_ccw_touch: int = -1

# --- keyboard and mouse ----------------------------------------------------
# The touch UI is the whole story on a phone. On a machine with a keyboard -
# which in practice means the web build - WASD or the arrow keys steer, Q/E
# pivot the formation, and the wheel zooms. Clicking the icon buttons already
# works without any code here, because the project emulates touch from the
# mouse (see project.godot), which is the same path the buttons already read.
#
# Keys are tracked from events rather than polled off the Input singleton so
# the whole thing is drivable from a headless test.
const KEY_DIRECTIONS: Dictionary = {
	KEY_W: Vector2.UP, KEY_UP: Vector2.UP,
	KEY_S: Vector2.DOWN, KEY_DOWN: Vector2.DOWN,
	KEY_A: Vector2.LEFT, KEY_LEFT: Vector2.LEFT,
	KEY_D: Vector2.RIGHT, KEY_RIGHT: Vector2.RIGHT,
}
const KEY_PIVOT_CW: int = KEY_E
const KEY_PIVOT_CCW: int = KEY_Q
const WHEEL_ZOOM_STEP: float = 1.12

@onready var keyboard_hint: Label = get_node_or_null("UI/KeyboardHintLabel")

var keys_down: Dictionary = {}
var keyboard_seen: bool = false
var keyboard_steering: bool = false


func _ready() -> void:
	if joystick != null:
		joystick.direction_changed.connect(_on_joystick_direction)
	if keyboard_hint != null:
		keyboard_hint.visible = false


func _held_pivot_direction() -> float:
	var dir: float = 0.0
	if pivot_cw_button != null and pivot_cw_button.pressed_down:
		dir += 1.0
	if pivot_ccw_button != null and pivot_ccw_button.pressed_down:
		dir -= 1.0
	if keys_down.has(KEY_PIVOT_CW):
		dir += 1.0
	if keys_down.has(KEY_PIVOT_CCW):
		dir -= 1.0
	return clampf(dir, -1.0, 1.0)


func keyboard_direction() -> Vector2:
	var dir: Vector2 = Vector2.ZERO
	for key in KEY_DIRECTIONS:
		if keys_down.has(key):
			dir += KEY_DIRECTIONS[key]
	return Vector2.ZERO if dir == Vector2.ZERO else dir.normalized()


func _handle_key(event: InputEventKey) -> void:
	if event.echo:
		return
	if event.pressed:
		keys_down[event.keycode] = true
		_note_keyboard()
	else:
		keys_down.erase(event.keycode)
		# A quick tap of a pivot key gets the same minimum step a tapped
		# button does, rather than turning by a barely-visible sliver.
		if event.keycode == KEY_PIVOT_CW:
			_finish_pivot_tap(1.0)
		elif event.keycode == KEY_PIVOT_CCW:
			_finish_pivot_tap(-1.0)


func _note_keyboard() -> void:
	if keyboard_seen:
		return
	keyboard_seen = true
	if keyboard_hint != null:
		keyboard_hint.visible = true
	# The stick is only taken away where there is no touchscreen to work it
	# with. A touch device that also has a keyboard keeps both, and a device
	# wrongly reported as non-touch still shows the stick until the player
	# has demonstrably used a keyboard - so nobody is ever left with no way
	# to steer.
	if joystick != null and not DisplayServer.is_touchscreen_available():
		joystick.visible = false


func _button_holds(button: IconButton, at_position: Vector2) -> bool:
	return button != null and Rect2(button.global_position, button.size).has_point(at_position)


func _set_button_held(button: IconButton, held: bool) -> void:
	if button == null or button.pressed_down == held:
		return
	button.pressed_down = held
	button.queue_redraw()


# Returns true when a pivot button consumed the touch.
func _handle_pivot_touch(event: InputEventScreenTouch) -> bool:
	if event.pressed:
		if _button_holds(pivot_cw_button, event.position) and pivot_cw_touch == -1:
			pivot_cw_touch = event.index
			_set_button_held(pivot_cw_button, true)
			return true
		if _button_holds(pivot_ccw_button, event.position) and pivot_ccw_touch == -1:
			pivot_ccw_touch = event.index
			_set_button_held(pivot_ccw_button, true)
			return true
		return false

	if event.index == pivot_cw_touch:
		pivot_cw_touch = -1
		_set_button_held(pivot_cw_button, false)
		_finish_pivot_tap(1.0)
		return true
	if event.index == pivot_ccw_touch:
		pivot_ccw_touch = -1
		_set_button_held(pivot_ccw_button, false)
		_finish_pivot_tap(-1.0)
		return true
	return false


func _update_pivot(delta: float) -> void:
	var dir: float = _held_pivot_direction()
	if dir == 0.0:
		return
	var amount: float = PIVOT_SPEED * delta * dir
	pivot_hold_amount += absf(amount)
	_pivot(amount)


func _finish_pivot_tap(direction: float) -> void:
	# Fired on release. A press held long enough has already turned far
	# enough on its own; a brief tap gets topped up to the minimum step.
	if pivot_hold_amount < PIVOT_MIN_STEP:
		_pivot((PIVOT_MIN_STEP - pivot_hold_amount) * direction)
	pivot_hold_amount = 0.0


func _pivot(radians: float) -> void:
	# Turns the formation and re-seats the ships already flying it, so the
	# change is visible immediately rather than only on the next rebuild.
	# apply_formation() writes the new offsets into Fleet.formation_offsets,
	# which move_to()/move_in_direction() also read - so a pivot applied
	# while the joystick is steering survives the next steering update
	# instead of being overwritten by the old layout.
	GameState.rotate_formation(radians)
	fleet.apply_formation()


func _on_joystick_direction(direction: Vector2) -> void:
	# Steering is re-issued every frame in _process while the stick is held,
	# so this only needs to handle the release (stick back to centre).
	if direction == Vector2.ZERO:
		fleet.stop()


func _process(delta: float) -> void:
	_update_pivot(delta)

	# Keep the heading fresh while a control is held. Fleet advances its own
	# anchor in _process, so this only needs to report the direction. The
	# keyboard takes precedence, and releasing the keys has to stop the fleet
	# itself - unlike the stick, there is no centred-again signal to hook.
	var keyed: Vector2 = keyboard_direction()
	if keyed != Vector2.ZERO:
		keyboard_steering = true
		fleet.move_in_direction(keyed)
	elif keyboard_steering:
		keyboard_steering = false
		fleet.stop()
	elif joystick != null and joystick.direction != Vector2.ZERO:
		fleet.move_in_direction(joystick.direction)

	var target: Vector2 = fleet.get_centroid()
	if camera.global_position.distance_to(target) <= camera_snap_distance:
		# Snap and stop dead - see camera_snap_distance. Assigning the exact
		# target means a settled fleet produces a bit-identical camera position
		# frame after frame, so the background shaders stop re-rendering a
		# shifted image and tearing has nothing to reveal.
		camera.global_position = target
		return
	var t: float = clamp(camera_follow_speed * delta, 0.0, 1.0)
	camera.global_position = camera.global_position.lerp(target, t)


func _unhandled_input(event: InputEvent) -> void:
	if event is InputEventScreenTouch:
		_handle_touch(event)
	elif event is InputEventScreenDrag:
		_handle_drag(event)
	elif event is InputEventMagnifyGesture:
		_handle_magnify(event)
	elif event is InputEventKey:
		_handle_key(event)
	elif event is InputEventMouseButton and event.pressed:
		# Wheel zoom, the desktop equivalent of the pinch.
		if event.button_index == MOUSE_BUTTON_WHEEL_UP:
			_set_zoom(camera.zoom.x * WHEEL_ZOOM_STEP)
		elif event.button_index == MOUSE_BUTTON_WHEEL_DOWN:
			_set_zoom(camera.zoom.x / WHEEL_ZOOM_STEP)


func _handle_touch(event: InputEventScreenTouch) -> void:
	# The joystick gets first refusal on every touch, and only claims ones
	# that begin inside its own rect - so pinch-to-zoom still works anywhere
	# else on screen.
	if _handle_pivot_touch(event):
		return
	if joystick != null and joystick.visible and joystick.handle_touch(event):
		return

	if event.pressed:
		touches[event.index] = event.position
		if touches.size() == 2:
			_start_pinch()
		if debug_input_logging:
			print("DEBUG touch pressed idx=%d pos=%s active_touches=%d" % [event.index, event.position, touches.size()])
	else:
		touches.erase(event.index)
		if touches.size() < 2:
			pinch_active = false
		if debug_input_logging:
			print("DEBUG touch released idx=%d active_touches=%d" % [event.index, touches.size()])


func _handle_drag(event: InputEventScreenDrag) -> void:
	if joystick != null and joystick.visible and joystick.handle_drag(event):
		return
	if not touches.has(event.index):
		return
	touches[event.index] = event.position

	if pinch_active and touches.size() == 2 and pinch_start_distance > 0.0:
		var positions: Array = touches.values()
		var current_distance: float = positions[0].distance_to(positions[1])
		# Spreading the fingers apart zooms IN. Camera2D.zoom is a
		# magnification (larger = closer), so the ratio goes
		# current/start, not start/current.
		var new_zoom: float = pinch_start_zoom * (current_distance / max(pinch_start_distance, 1.0))
		_set_zoom(new_zoom)

		if debug_input_logging:
			print("DEBUG pinch drag distance=%.1f zoom=%.3f" % [current_distance, camera.zoom.x])


func _handle_magnify(event: InputEventMagnifyGesture) -> void:
	# Fallback path: some platforms (and desktop trackpads) report pinch as a
	# single semantic gesture instead of two raw touch streams. factor > 1
	# means the gesture is spreading outward, which zooms in - and since
	# Camera2D.zoom is a magnification, that multiplies.
	_set_zoom(camera.zoom.x * event.factor)
	if debug_input_logging:
		print("DEBUG magnify gesture factor=%.3f zoom=%.3f" % [event.factor, camera.zoom.x])


func _start_pinch() -> void:
	pinch_active = true
	var positions: Array = touches.values()
	pinch_start_distance = positions[0].distance_to(positions[1])
	pinch_start_zoom = camera.zoom.x


func _set_zoom(raw_zoom: float) -> void:
	var z: float = clamp(raw_zoom, min_zoom, max_zoom)
	camera.zoom = Vector2(z, z)