class_name GCDTimer
extends RefCounted
## Global Cooldown timer. Server-authoritative.
## Controls the rhythm of combat: combo hits and on-GCD abilities
## consume a GCD tick; off-GCD abilities do not interact with this timer.

var _remaining: float = 0.0
var _total: float = 2.5
var _queue_window: float = 0.3  # Input queuing window (last 0.3s of sweep)

## Creates a new GCD timer with the given duration in seconds.
func _init(gcd_duration: float = 2.5):
	_total = gcd_duration
	_remaining = 0.0

## Returns true if the GCD is ready to accept a new on-GCD action.
func is_ready() -> bool:
	return _remaining <= 0.0

## Returns true if we're within the input queuing window.
## Actions pressed during this window will fire the instant the GCD completes.
func is_in_queue_window() -> bool:
	return _remaining > 0.0 and _remaining <= _queue_window

## Advances the timer by delta_time seconds. Call once per server tick.
func tick(delta_time: float) -> void:
	if _remaining > 0.0:
		_remaining = max(_remaining - delta_time, 0.0)

## Attempts to consume a GCD tick. Returns true if successful (GCD was ready),
## false if the GCD is still active. On success, restarts the full timer.
func consume() -> bool:
	if not is_ready():
		return false
	_remaining = _total
	return true

## Returns progress from 0.0 (just consumed) to 1.0 (ready).
## Used for UI radial sweep rendering.
func get_progress() -> float:
	if _total <= 0.0:
		return 1.0
	return 1.0 - (_remaining / _total)

## Returns the remaining time in seconds.
func get_remaining() -> float:
	return _remaining

## Returns the total GCD duration in seconds.
func get_total() -> float:
	return _total

## Modifies the GCD duration. Can be called by Artifact modifiers.
## If the GCD is currently active, the remaining time is scaled proportionally.
func set_duration(new_duration: float) -> void:
	if new_duration <= 0.0:
		push_warning("GCDTimer: duration must be > 0")
		return
	var progress := get_progress()
	_total = new_duration
	if _remaining > 0.0:
		_remaining = _total * (1.0 - progress)

## Resets the timer to ready state (e.g., between fights).
func reset() -> void:
	_remaining = 0.0