kestrel_timer/

service.rs

use crate::config::ServiceConfig;
use crate::error::TimerError;
use crate::task::{CallbackWrapper, TaskCompletionReason, TaskId};
use crate::wheel::Wheel;
use futures::stream::{FuturesUnordered, StreamExt};
use futures::future::BoxFuture;
use parking_lot::Mutex;
use std::sync::Arc;
use std::time::Duration;
use tokio::sync::mpsc;
use tokio::task::JoinHandle;

/// TimerService 命令类型
/// 
/// (Service command type)
enum ServiceCommand {
    /// 添加批量定时器句柄（仅包含必要数据：task_ids 和 completion_rxs）
    /// (Add batch timer handle, only contains necessary data: task_ids and completion_rxs)
    AddBatchHandle {
        task_ids: Vec<TaskId>,
        completion_rxs: Vec<tokio::sync::oneshot::Receiver<TaskCompletionReason>>,
    },
    /// 添加单个定时器句柄（仅包含必要数据：task_id 和 completion_rx）
    /// (Add single timer handle, only contains necessary data: task_id and completion_rx)
    AddTimerHandle {
        task_id: TaskId,
        completion_rx: tokio::sync::oneshot::Receiver<TaskCompletionReason>,
    },
}

/// TimerService - 基于 Actor 模式的定时器服务
/// (TimerService - timer service based on Actor pattern)
/// 
/// 管理多个定时器句柄，监听所有超时事件，并将 TaskId 聚合转发给用户。
/// (Manages multiple timer handles, listens to all timeout events, and aggregates TaskId to be forwarded to the user.)
/// # 特性 (Features)
/// - 自动监听所有添加的定时器句柄的超时事件
///      (Automatically listens to all added timer handles' timeout events)
/// - 超时后自动从内部管理中移除该任务
///      (Automatically removes the task from internal management after timeout)
/// - 将超时的 TaskId 转发到统一的通道供用户接收
///      (Aggregates TaskId to be forwarded to the user's unified channel)
/// - 支持动态添加 BatchHandle 和 TimerHandle
///      (Supports dynamic addition of BatchHandle and TimerHandle)
///
/// # 示例 (Examples)
/// ```no_run
/// use kestrel_timer::{TimerWheel, TimerService, CallbackWrapper, ServiceConfig};
/// use std::time::Duration;
///
/// #[tokio::main]
/// async fn main() {
///     let timer = TimerWheel::with_defaults();
///     let mut service = timer.create_service(ServiceConfig::default());
///     
///     // 使用两步式 API 通过 service 批量调度定时器
///     // (Use two-step API to batch schedule timers through service)
///     let callbacks: Vec<(Duration, Option<CallbackWrapper>)> = (0..5)
///         .map(|i| {
///             let callback = Some(CallbackWrapper::new(move || async move {
///                 println!("Timer {} fired!", i);
///             }));
///             (Duration::from_millis(100), callback)
///         })
///         .collect();
///     // (Create batch of tasks with callbacks)
///     let tasks = TimerService::create_batch_with_callbacks(callbacks);
///     service.register_batch(tasks).unwrap();
///     // (Register batch of tasks)
///     
///     // 接收超时通知
///     // (Receive timeout notifications)
///     let mut rx = service.take_receiver().unwrap();
///     // (Take receiver and receive timeout notifications)
///     while let Some(task_id) = rx.recv().await {
///         // (Receive timeout notification)
///         println!("Task {:?} completed", task_id);
///     }
/// }
/// ```
pub struct TimerService {
    /// 命令发送端
    command_tx: mpsc::Sender<ServiceCommand>,
    /// 超时接收端
    timeout_rx: Option<mpsc::Receiver<TaskId>>,
    /// Actor 任务句柄
    actor_handle: Option<JoinHandle<()>>,
    /// 时间轮引用（用于直接调度定时器）
    wheel: Arc<Mutex<Wheel>>,
    /// Actor 关闭信号发送端
    shutdown_tx: Option<tokio::sync::oneshot::Sender<()>>,
}

impl TimerService {
    /// 创建新的 TimerService
    /// Create new TimerService
    ///
    /// # 参数 (Parameters)
    /// - `wheel`: 时间轮引用
    ///      (Timing wheel reference)
    /// - `config`: 服务配置
    ///      (Service configuration)
    ///
    /// # 注意 (Notes)
    /// 通常不直接调用此方法，而是使用 `TimerWheel::create_service()` 来创建。
    ///      (Typically not called directly, but used to create through `TimerWheel::create_service()`)
    ///
    pub(crate) fn new(wheel: Arc<Mutex<Wheel>>, config: ServiceConfig) -> Self {
        let (command_tx, command_rx) = mpsc::channel(config.command_channel_capacity);
        let (timeout_tx, timeout_rx) = mpsc::channel(config.timeout_channel_capacity);

        let (shutdown_tx, shutdown_rx) = tokio::sync::oneshot::channel();
        let actor = ServiceActor::new(command_rx, timeout_tx, shutdown_rx);
        let actor_handle = tokio::spawn(async move {
            actor.run().await;
        });

        Self {
            command_tx,
            timeout_rx: Some(timeout_rx),
            actor_handle: Some(actor_handle),
            wheel,
            shutdown_tx: Some(shutdown_tx),
        }
    }

    /// 获取超时接收器（转移所有权）
    ///  (Get timeout receiver, transfer ownership)
    /// 
    /// # 返回 (Returns)
    /// 超时通知接收器，如果已经被取走则返回 None
    ///  (Timeout notification receiver, if already taken, returns None)
    ///
    /// # 注意 (Notes)
    /// 此方法只能调用一次，因为它会转移接收器的所有权
    ///  (This method can only be called once, because it transfers ownership of the receiver)
    ///
    /// # 示例 (Examples)s
    /// ```no_run
    /// # use kestrel_timer::{TimerWheel, ServiceConfig};
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults();
    /// let mut service = timer.create_service(ServiceConfig::default());
    /// 
    /// let mut rx = service.take_receiver().unwrap();
    /// while let Some(task_id) = rx.recv().await {
    ///     println!("Task {:?} timed out", task_id);
    /// }
    /// # }
    /// ```
    pub fn take_receiver(&mut self) -> Option<mpsc::Receiver<TaskId>> {
        self.timeout_rx.take()
    }

    /// 取消指定的任务
    /// (Cancel specified task)
    /// 
    /// # 参数 (Parameters)
    /// - `task_id`: 要取消的任务 ID
    ///      (Task ID to cancel)
    ///
    /// # 返回 (Returns)
    /// - `true`: 任务存在且成功取消
    ///      (Task exists and cancellation is successful)
    /// - `false`: 任务不存在或取消失败
    ///      (Task does not exist or cancellation fails)
    ///
    /// # 性能说明 (Performance Notes)
    /// 此方法使用直接取消优化，不需要等待 Actor 处理，大幅降低延迟
    ///      (This method uses direct cancellation optimization, does not need to wait for Actor processing, greatly reducing latency)
    ///
    /// # 示例 (Examples)
    /// ```no_run
    /// # use kestrel_timer::{TimerWheel, TimerService, CallbackWrapper, ServiceConfig};
    /// # use std::time::Duration;
    /// # 
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults();
    /// let service = timer.create_service(ServiceConfig::default());
    /// 
    /// // 使用两步式 API 调度定时器
    /// // (Use two-step API to schedule timers)
    /// let callback = Some(CallbackWrapper::new(|| async move {
    ///     println!("Timer fired!");
    /// }));
    /// let task = TimerService::create_task(Duration::from_secs(10), callback);
    /// let task_id = task.get_id();
    /// service.register(task).unwrap();
    /// 
    /// // 取消任务
    /// // (Cancel task)
    /// let cancelled = service.cancel_task(task_id);
    /// println!("Task cancelled: {}", cancelled);
    /// # }
    /// ```
    #[inline]
    pub fn cancel_task(&self, task_id: TaskId) -> bool {
        // 直接取消任务，无需通知 Actor
        // FuturesUnordered 会在任务被取消时自动清理
        //
        // Direct cancellation, no need to notify Actor
        // FuturesUnordered will automatically clean up when tasks are cancelled
        let mut wheel = self.wheel.lock();
        wheel.cancel(task_id)
    }

    /// 批量取消任务
    /// (Batch cancel tasks)
    /// 
    /// 使用底层的批量取消操作一次性取消多个任务，性能优于循环调用 cancel_task。
    /// (Use underlying batch cancellation operation to cancel multiple tasks at once, performance is better than calling cancel_task repeatedly.)
    /// 
    /// # 参数 (Parameters)
    /// - `task_ids`: 要取消的任务 ID 列表
    ///      (List of task IDs to cancel)
    ///
    /// # 返回 (Returns)
    /// 成功取消的任务数量
    ///      (Number of successfully cancelled tasks)
    ///
    /// # 示例 (Examples)
    /// ```no_run
    /// # use kestrel_timer::{TimerWheel, TimerService, CallbackWrapper, ServiceConfig};
    /// # use std::time::Duration;
    /// # 
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults();
    /// let service = timer.create_service(ServiceConfig::default());
    /// 
    /// let callbacks: Vec<(Duration, Option<CallbackWrapper>)> = (0..10)
    ///     .map(|i| {
    ///         let callback = Some(CallbackWrapper::new(move || async move {
    ///             println!("Timer {} fired!", i);
    ///         }));
    ///         (Duration::from_secs(10), callback)
    ///     })
    ///     .collect();
    /// let tasks = TimerService::create_batch_with_callbacks(callbacks);
    /// let task_ids: Vec<_> = tasks.iter().map(|t| t.get_id()).collect();
    /// service.register_batch(tasks).unwrap();
    /// 
    /// // 批量取消
    /// let cancelled = service.cancel_batch(&task_ids);
    /// println!("Cancelled {} tasks", cancelled);
    /// # }
    /// ```
    #[inline]
    pub fn cancel_batch(&self, task_ids: &[TaskId]) -> usize {
        if task_ids.is_empty() {
            return 0;
        }

        // 优化：直接使用底层的批量取消，无需通知 Actor
        // FuturesUnordered 会在任务被取消时自动清理
        let mut wheel = self.wheel.lock();
        wheel.cancel_batch(task_ids)
    }

    /// 推迟任务（替换回调）
    /// (Postpone task (replace callback))
    /// 
    /// # 参数 (Parameters)
    /// - `task_id`: 要推迟的任务 ID
    ///      (Task ID to postpone)
    /// - `new_delay`: 新的延迟时间（从当前时间点重新计算）
    ///      (New delay time (recalculated from current time point))
    /// - `callback`: 新的回调函数
    ///      (New callback function)
    ///
    /// # 返回 (Returns)
    /// - `true`: 任务存在且成功推迟
    ///      (Task exists and is successfully postponed)
    /// - `false`: 任务不存在或推迟失败
    ///      (Task does not exist or postponement fails)
    ///
    /// # 注意 (Notes)
    /// - 推迟后任务 ID 保持不变
    ///      (Task ID remains unchanged after postponement)
    /// - 原有的超时通知仍然有效
    ///      (Original timeout notification remains valid)
    /// - 回调函数会被替换为新的回调
    ///      (Callback function will be replaced with new callback)
    ///
    /// # 示例 (Examples)
    /// ```no_run
    /// # use kestrel_timer::{TimerWheel, TimerService, CallbackWrapper, ServiceConfig};
    /// # use std::time::Duration;
    /// # 
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults();
    /// let service = timer.create_service(ServiceConfig::default());
    /// 
    /// let callback = Some(CallbackWrapper::new(|| async {
    ///     println!("Original callback");
    /// }));
    /// let task = TimerService::create_task(Duration::from_secs(5), callback);
    /// let task_id = task.get_id();
    /// service.register(task).unwrap();
    /// 
    /// // 推迟并替换回调
    /// // (Postpone and replace callback)
    /// let new_callback = Some(CallbackWrapper::new(|| async { println!("New callback!"); }));
    /// let success = service.postpone(
    ///     task_id,
    ///     Duration::from_secs(10),
    ///     new_callback
    /// );
    /// println!("Postponed successfully: {}", success);
    /// # }
    /// ```
    #[inline]
    pub fn postpone(&self, task_id: TaskId, new_delay: Duration, callback: Option<CallbackWrapper>) -> bool {
        let mut wheel = self.wheel.lock();
        wheel.postpone(task_id, new_delay, callback)
    }

    /// 批量推迟任务（保持原回调）
    /// (Batch postpone tasks, keep original callbacks)
    /// 
    /// # 参数 (Parameters)
    /// - `updates`: (任务ID, 新延迟) 的元组列表
    ///      (List of tuples of (task ID, new delay))
    ///
    /// # 返回 (Returns)
    /// 成功推迟的任务数量
    ///      (Number of successfully postponed tasks)
    ///
    /// # 示例 (Examples)
    /// ```no_run
    /// # use kestrel_timer::{TimerWheel, TimerService, CallbackWrapper, ServiceConfig};
    /// # use std::time::Duration;
    /// # 
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults();
    /// let service = timer.create_service(ServiceConfig::default());
    /// 
    /// let callbacks: Vec<(Duration, Option<CallbackWrapper>)> = (0..3)
    ///     .map(|i| {
    ///         let callback = Some(CallbackWrapper::new(move || async move {
    ///             println!("Timer {} fired!", i);
    ///         }));
    ///         (Duration::from_secs(5), callback)
    ///     })
    ///     .collect();
    /// let tasks = TimerService::create_batch_with_callbacks(callbacks);
    /// let task_ids: Vec<_> = tasks.iter().map(|t| t.get_id()).collect();
    /// service.register_batch(tasks).unwrap();
    /// 
    /// // 批量推迟（保持原回调）
    /// // (Batch postpone, keep original callbacks)
    /// let updates: Vec<_> = task_ids
    ///     .into_iter()
    ///     .map(|id| (id, Duration::from_secs(10)))
    ///     .collect();
    /// let postponed = service.postpone_batch(updates);
    /// println!("Postponed {} tasks", postponed);
    /// # }
    /// ```
    #[inline]
    pub fn postpone_batch(&self, updates: Vec<(TaskId, Duration)>) -> usize {
        if updates.is_empty() {
            return 0;
        }

        let mut wheel = self.wheel.lock();
        wheel.postpone_batch(updates)
    }

    /// 批量推迟任务（替换回调）
    /// (Batch postpone tasks, replace callbacks)
    /// 
    /// # 参数 (Parameters)
    /// - `updates`: (任务ID, 新延迟, 新回调) 的元组列表
    ///      (List of tuples of (task ID, new delay, new callback))
    ///
    /// # 返回 (Returns)
    /// 成功推迟的任务数量
    ///      (Number of successfully postponed tasks)
    ///
    /// # 示例 (Examples)
    /// ```no_run
    /// # use kestrel_timer::{TimerWheel, TimerService, CallbackWrapper, ServiceConfig};
    /// # use std::time::Duration;
    /// # 
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults();
    /// let service = timer.create_service(ServiceConfig::default());
    /// 
    /// // 创建 3 个任务，初始没有回调
    /// // (Create 3 tasks, initially no callbacks)
    /// let delays: Vec<Duration> = (0..3)
    ///     .map(|_| Duration::from_secs(5))
    ///     .collect();
    /// let tasks = TimerService::create_batch(delays);
    /// let task_ids: Vec<_> = tasks.iter().map(|t| t.get_id()).collect();
    /// service.register_batch(tasks).unwrap();
    /// 
    /// // 批量推迟并添加新回调
    /// // (Batch postpone and add new callbacks)
    /// let updates: Vec<_> = task_ids
    ///     .into_iter()
    ///     .enumerate()
    ///     .map(|(i, id)| {
    ///         let callback = Some(CallbackWrapper::new(move || async move {
    ///             println!("New callback {}", i);
    ///         }));
    ///         (id, Duration::from_secs(10), callback)
    ///     })
    ///     .collect();
    /// let postponed = service.postpone_batch_with_callbacks(updates);
    /// println!("Postponed {} tasks", postponed);
    /// # }
    /// ```
    #[inline]
    pub fn postpone_batch_with_callbacks(
        &self,
        updates: Vec<(TaskId, Duration, Option<CallbackWrapper>)>,
    ) -> usize {
        if updates.is_empty() {
            return 0;
        }

        let mut wheel = self.wheel.lock();
        wheel.postpone_batch_with_callbacks(updates)
    }

    /// 创建定时器任务（静态方法，申请阶段）
    /// (Create timer task (static method, apply stage))
    /// 
    /// # 参数 (Parameters)
    /// - `delay`: 延迟时间
    ///      (Delay time)
    /// - `callback`: 实现了 TimerCallback trait 的回调对象
    ///      (Callback object implementing TimerCallback trait)
    /// 
    /// # 返回 (Returns)
    /// 返回 TimerTask，需要通过 `register()` 注册
    ///      (Return TimerTask, needs to be registered through `register()`)
    /// 
    /// # 示例 (Examples)
    /// ```no_run
    /// # use kestrel_timer::{TimerWheel, TimerService, CallbackWrapper, ServiceConfig};
    /// # use std::time::Duration;
    /// # 
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults();
    /// let service = timer.create_service(ServiceConfig::default());
    /// 
    /// // 步骤 1: 创建任务
    /// // (Step 1: create task)
    /// let callback = Some(CallbackWrapper::new(|| async {
    ///     println!("Timer fired!");
    /// }));
    /// let task = TimerService::create_task(Duration::from_millis(100), callback);
    /// 
    /// let task_id = task.get_id();
    /// println!("Created task: {:?}", task_id);
    /// 
    /// // 步骤 2: 注册任务
    /// // (Step 2: register task)
    /// service.register(task).unwrap();
    /// # }
    /// ```
    #[inline]
    pub fn create_task(delay: Duration, callback: Option<CallbackWrapper>) -> crate::task::TimerTask {
        crate::timer::TimerWheel::create_task(delay, callback)
    }

    /// 批量创建定时器任务（静态方法，申请阶段，不带回调）
    /// (Create batch of timer tasks (static method, apply stage, no callbacks))
    /// 
    /// # 参数 (Parameters)
    /// - `delays`: 延迟时间列表
    ///      (List of delay times)
    /// 
    /// # 返回 (Returns)
    /// 返回 TimerTask 列表，需要通过 `register_batch()` 注册
    ///      (Return TimerTask list, needs to be registered through `register_batch()`)
    /// 
    /// # 示例 (Examples)
    /// ```no_run
    /// # use kestrel_timer::{TimerWheel, TimerService, CallbackWrapper, ServiceConfig};
    /// # use std::time::Duration;
    /// # 
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults();
    /// let service = timer.create_service(ServiceConfig::default());
    /// 
    /// // 步骤 1: 批量创建任务
    /// // (Step 1: create batch of tasks)
    /// let delays: Vec<Duration> = (0..3)
    ///     .map(|i| Duration::from_millis(100 * (i + 1)))
    ///     .collect();
    /// 
    /// let tasks = TimerService::create_batch(delays);
    /// println!("Created {} tasks", tasks.len());
    /// 
    /// // 步骤 2: 批量注册任务
    /// // (Step 2: register batch of tasks)
    /// service.register_batch(tasks).unwrap();
    /// # }
    /// ```
    #[inline]
    pub fn create_batch(delays: Vec<Duration>) -> Vec<crate::task::TimerTask> {
        crate::timer::TimerWheel::create_batch(delays)
    }
    
    /// 批量创建定时器任务（静态方法，申请阶段，带回调）
    /// 
    /// # 参数 (Parameters)
    /// - `callbacks`: (延迟时间, 回调) 的元组列表
    ///      (List of tuples of (delay time, callback))
    /// 
    /// # 返回 (Returns)
    /// 返回 TimerTask 列表，需要通过 `register_batch()` 注册
    ///      (Return TimerTask list, needs to be registered through `register_batch()`)
    /// 
    /// # 示例 (Examples)
    /// ```no_run
    /// # use kestrel_timer::{TimerWheel, TimerService, CallbackWrapper, ServiceConfig};
    /// # use std::time::Duration;
    /// # 
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults();
    /// let service = timer.create_service(ServiceConfig::default());
    /// 
    /// // 步骤 1: 批量创建任务
    /// // (Step 1: create batch of tasks with callbacks)
    /// let callbacks: Vec<(Duration, Option<CallbackWrapper>)> = (0..3)
    ///     .map(|i| {
    ///         let callback = Some(CallbackWrapper::new(move || async move {
    ///             println!("Timer {} fired!", i);
    ///         }));
    ///         (Duration::from_millis(100 * (i + 1)), callback)
    ///     })
    ///     .collect();
    /// 
    /// let tasks = TimerService::create_batch_with_callbacks(callbacks);
    /// println!("Created {} tasks", tasks.len());
    /// 
    /// // 步骤 2: 批量注册任务
    /// // (Step 2: register batch of tasks with callbacks)
    /// service.register_batch(tasks).unwrap();
    /// # }
    /// ```
    #[inline]
    pub fn create_batch_with_callbacks(callbacks: Vec<(Duration, Option<CallbackWrapper>)>) -> Vec<crate::task::TimerTask> {
        crate::timer::TimerWheel::create_batch_with_callbacks(callbacks)
    }
    
    /// 注册定时器任务到服务（注册阶段）
    /// (Register timer task to service (registration phase))
    /// 
    /// # 参数 (Parameters)
    /// - `task`: 通过 `create_task()` 创建的任务
    ///      (Task created via `create_task()`)
    /// 
    /// # 返回 (Returns)
    ///      (Task created via `create_task()`)
    /// - `Ok(())`: 注册成功
    ///      (Register successfully)
    /// - `Err(TimerError::RegisterFailed)`: 注册失败（内部通道已满或已关闭）
    ///      (Register failed (internal channel is full or closed))
    /// 
    /// # 示例 (Examples)
    /// ```no_run
    /// # use kestrel_timer::{TimerWheel, TimerService, CallbackWrapper, ServiceConfig};
    /// # use std::time::Duration;
    /// # 
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults();
    /// let service = timer.create_service(ServiceConfig::default());
    /// 
    /// let callback = Some(CallbackWrapper::new(|| async move {
    ///     println!("Timer fired!");
    /// }));
    /// let task = TimerService::create_task(Duration::from_millis(100), callback);
    /// let task_id = task.get_id();
    /// 
    /// service.register(task).unwrap();
    /// # }
    /// ```
    #[inline]
    pub fn register(&self, task: crate::task::TimerTask) -> Result<(), TimerError> {
        let (completion_tx, completion_rx) = tokio::sync::oneshot::channel();
        let notifier = crate::task::CompletionNotifier(completion_tx);
        
        let task_id = task.id;
        
        // 单次加锁完成所有操作
        //   (Single lock, complete all operations)
        {
            let mut wheel_guard = self.wheel.lock();
            wheel_guard.insert(task, notifier);
        }
        
        // 添加到服务管理（只发送必要数据）
        //   (Add to service management, only send necessary data)
        self.command_tx
            .try_send(ServiceCommand::AddTimerHandle {
                task_id,
                completion_rx,
            })
            .map_err(|_| TimerError::RegisterFailed)?;
        
        Ok(())
    }
    
    /// 批量注册定时器任务到服务（注册阶段）
    /// (Batch register timer tasks to service (registration phase))
    /// 
    /// # 参数 (Parameters)
    /// - `tasks`: 通过 `create_batch()` 创建的任务列表
    ///      (List of tasks created via `create_batch()`)
    /// 
    /// # 返回 (Returns)
    ///      (List of tasks created via `create_batch()`)
    /// - `Ok(())`: 注册成功
    ///      (Register successfully)
    /// - `Err(TimerError::RegisterFailed)`: 注册失败（内部通道已满或已关闭）
    ///      (Register failed (internal channel is full or closed))
    /// 
    /// # 示例 (Examples)
    /// ```no_run
    /// # use kestrel_timer::{TimerWheel, TimerService, CallbackWrapper, ServiceConfig};
    /// # use std::time::Duration;
    /// # 
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults();
    /// let service = timer.create_service(ServiceConfig::default());
    /// 
    /// let callbacks: Vec<(Duration, Option<CallbackWrapper>)> = (0..3)
    ///     .map(|i| {
    ///         let callback = Some(CallbackWrapper::new(move || async move {
    ///             println!("Timer {} fired!", i);
    ///         }));
    ///         (Duration::from_secs(1), callback)
    ///     })
    ///     .collect();
    /// let tasks = TimerService::create_batch_with_callbacks(callbacks);
    /// 
    /// service.register_batch(tasks).unwrap();
    /// # }
    /// ```
    #[inline]
    pub fn register_batch(&self, tasks: Vec<crate::task::TimerTask>) -> Result<(), TimerError> {
        let task_count = tasks.len();
        let mut completion_rxs = Vec::with_capacity(task_count);
        let mut task_ids = Vec::with_capacity(task_count);
        let mut prepared_tasks = Vec::with_capacity(task_count);
        
        // 步骤1: 准备所有 channels 和 notifiers（无锁）
        // 优化：使用 for 循环代替 map + collect，避免闭包捕获开销
        // (Step 1: Prepare all channels and notifiers)
        // (Optimize: use for loop instead of map + collect, avoid closure capture overhead)
        for task in tasks {
            let (completion_tx, completion_rx) = tokio::sync::oneshot::channel();
            let notifier = crate::task::CompletionNotifier(completion_tx);
            
            task_ids.push(task.id);
            completion_rxs.push(completion_rx);
            prepared_tasks.push((task, notifier));
        }
        
        // 步骤2: 单次加锁，批量插入
        // (Step 2: Single lock, batch insert)
        {
            let mut wheel_guard = self.wheel.lock();
            wheel_guard.insert_batch(prepared_tasks);
        }
        
        // 添加到服务管理（只发送必要数据）
        // (Add to service management, only send necessary data)
        self.command_tx
            .try_send(ServiceCommand::AddBatchHandle {
                task_ids,
                completion_rxs,
            })
            .map_err(|_| TimerError::RegisterFailed)?;
        
        Ok(())
    }

    /// 优雅关闭 TimerService
    /// (Graceful shutdown of TimerService)
    /// 
    /// # 示例 (Examples)
    /// ```no_run
    /// # use kestrel_timer::{TimerWheel, ServiceConfig};
    /// # #[tokio::main]
    /// # async fn main() {
    /// let timer = TimerWheel::with_defaults();
    /// let mut service = timer.create_service(ServiceConfig::default());
    /// 
    /// // 使用 service...
    /// // (Use service...)
    /// 
    /// service.shutdown().await;
    /// # }
    /// ```
    pub async fn shutdown(mut self) {
        // (Take shutdown_tx and send shutdown signal)
        if let Some(shutdown_tx) = self.shutdown_tx.take() {
            let _ = shutdown_tx.send(());
        }
        // (Take actor_handle and await completion)
        if let Some(handle) = self.actor_handle.take() {
            let _ = handle.await;
        }
    }
}


impl Drop for TimerService {
    fn drop(&mut self) {
        if let Some(handle) = self.actor_handle.take() {
            handle.abort();
        }
    }
}

/// ServiceActor - 内部 Actor 实现
/// (ServiceActor - internal Actor implementation)
struct ServiceActor {
    /// 命令接收端
    command_rx: mpsc::Receiver<ServiceCommand>,
    /// 超时发送端
    timeout_tx: mpsc::Sender<TaskId>,
    /// Actor 关闭信号接收端
    shutdown_rx: tokio::sync::oneshot::Receiver<()>,
}

impl ServiceActor {
    fn new(command_rx: mpsc::Receiver<ServiceCommand>, timeout_tx: mpsc::Sender<TaskId>, shutdown_rx: tokio::sync::oneshot::Receiver<()>) -> Self {
        Self {
            command_rx,
            timeout_tx,
            shutdown_rx,
        }
    }

    async fn run(mut self) {
        // 使用 FuturesUnordered 来监听所有的 completion_rxs
        // 每个 future 返回 (TaskId, Result)
        //
        // (Use FuturesUnordered to listen to all completion_rxs)
        // (Each future returns (TaskId, Result))
        let mut futures: FuturesUnordered<BoxFuture<'static, (TaskId, Result<TaskCompletionReason, tokio::sync::oneshot::error::RecvError>)>> = FuturesUnordered::new();

        // 将 shutdown_rx 移出 self，以便在 select! 中使用 &mut
        // (Move shutdown_rx out of self, so it can be used in select! with &mut)
        let mut shutdown_rx = self.shutdown_rx;

        loop {
            tokio::select! {
                // 监听高优先级的关闭信号
                // (Listen to high-priority shutdown signal)
                _ = &mut shutdown_rx => {
                    // 收到关闭信号，立即退出循环
                    // (Receive shutdown signal, exit loop immediately)
                    break;
                }

                // 监听超时事件
                // (Listen to timeout events)
                Some((task_id, result)) = futures.next() => {
                    // 检查完成原因，只转发超时（Expired）事件，不转发取消（Cancelled）事件
                    // (Check completion reason, only forward expired (Expired) events, do not forward cancelled (Cancelled) events)
                    if let Ok(TaskCompletionReason::Expired) = result {
                        let _ = self.timeout_tx.send(task_id).await;
                    }
                    // 任务会自动从 FuturesUnordered 中移除
                    // (Task will be automatically removed from FuturesUnordered)
                }
                
                // 监听命令
                // (Listen to commands)
                Some(cmd) = self.command_rx.recv() => {
                    match cmd {
                        ServiceCommand::AddBatchHandle { task_ids, completion_rxs } => {
                            // 将所有任务添加到 futures 中
                            // (Add all tasks to futures)
                            for (task_id, rx) in task_ids.into_iter().zip(completion_rxs.into_iter()) {
                                let future: BoxFuture<'static, (TaskId, Result<TaskCompletionReason, tokio::sync::oneshot::error::RecvError>)> = Box::pin(async move {
                                    (task_id, rx.await)
                                });
                                futures.push(future);
                            }
                        }
                        ServiceCommand::AddTimerHandle { task_id, completion_rx } => {
                            // 添加到 futures 中
                            // (Add to futures)
                            let future: BoxFuture<'static, (TaskId, Result<TaskCompletionReason, tokio::sync::oneshot::error::RecvError>)> = Box::pin(async move {
                                (task_id, completion_rx.await)
                            });
                            futures.push(future);
                        }
                    }
                }
                
                // 如果没有任何 future 且命令通道已关闭，退出循环
                // (If no futures and command channel is closed, exit loop)
                else => {
                    break;
                }
            }
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::TimerWheel;
    use std::sync::atomic::{AtomicU32, Ordering};
    use std::sync::Arc;
    use std::time::Duration;

    #[tokio::test]
    async fn test_service_creation() {
        let timer = TimerWheel::with_defaults();
        let _service = timer.create_service(ServiceConfig::default());
    }


    #[tokio::test]
    async fn test_add_timer_handle_and_receive_timeout() {
        let timer = TimerWheel::with_defaults();
        let mut service = timer.create_service(ServiceConfig::default());

        // 创建单个定时器
        let task = TimerService::create_task(Duration::from_millis(50), Some(CallbackWrapper::new(|| async {})));
        let task_id = task.get_id();
        
        // 注册到 service
        service.register(task).unwrap();

        // 接收超时通知
        let mut rx = service.take_receiver().unwrap();
        let received_task_id = tokio::time::timeout(Duration::from_millis(200), rx.recv())
            .await
            .expect("Should receive timeout notification")
            .expect("Should receive Some value");

        assert_eq!(received_task_id, task_id);
    }


    #[tokio::test]
    async fn test_shutdown() {
        let timer = TimerWheel::with_defaults();
        let service = timer.create_service(ServiceConfig::default());

        // 添加一些定时器
        let task1 = TimerService::create_task(Duration::from_secs(10), None);
        let task2 = TimerService::create_task(Duration::from_secs(10), None);
        service.register(task1).unwrap();
        service.register(task2).unwrap();

        // 立即关闭（不等待定时器触发）
        service.shutdown().await;
    }



    #[tokio::test]
    async fn test_cancel_task() {
        let timer = TimerWheel::with_defaults();
        let service = timer.create_service(ServiceConfig::default());

        // 添加一个长时间的定时器
        let task = TimerService::create_task(Duration::from_secs(10), None);
        let task_id = task.get_id();
        
        service.register(task).unwrap();

        // 取消任务
        let cancelled = service.cancel_task(task_id);
        assert!(cancelled, "Task should be cancelled successfully");

        // 尝试再次取消同一个任务，应该返回 false
        let cancelled_again = service.cancel_task(task_id);
        assert!(!cancelled_again, "Task should not exist anymore");
    }

    #[tokio::test]
    async fn test_cancel_nonexistent_task() {
        let timer = TimerWheel::with_defaults();
        let service = timer.create_service(ServiceConfig::default());

        // 添加一个定时器以初始化 service
        let task = TimerService::create_task(Duration::from_millis(50), None);
        service.register(task).unwrap();

        // 尝试取消一个不存在的任务（创建一个不会实际注册的任务ID）
        let fake_task = TimerService::create_task(Duration::from_millis(50), None);
        let fake_task_id = fake_task.get_id();
        // 不注册 fake_task
        let cancelled = service.cancel_task(fake_task_id);
        assert!(!cancelled, "Nonexistent task should not be cancelled");
    }


    #[tokio::test]
    async fn test_task_timeout_cleans_up_task_sender() {
        let timer = TimerWheel::with_defaults();
        let mut service = timer.create_service(ServiceConfig::default());

        // 添加一个短时间的定时器
        let task = TimerService::create_task(Duration::from_millis(50), None);
        let task_id = task.get_id();
        
        service.register(task).unwrap();

        // 等待任务超时
        let mut rx = service.take_receiver().unwrap();
        let received_task_id = tokio::time::timeout(Duration::from_millis(200), rx.recv())
            .await
            .expect("Should receive timeout notification")
            .expect("Should receive Some value");
        
        assert_eq!(received_task_id, task_id);

        // 等待一下确保内部清理完成
        tokio::time::sleep(Duration::from_millis(10)).await;

        // 尝试取消已经超时的任务，应该返回 false
        let cancelled = service.cancel_task(task_id);
        assert!(!cancelled, "Timed out task should not exist anymore");
    }

    #[tokio::test]
    async fn test_cancel_task_spawns_background_task() {
        let timer = TimerWheel::with_defaults();
        let service = timer.create_service(ServiceConfig::default());
        let counter = Arc::new(AtomicU32::new(0));

        // 创建一个定时器
        let counter_clone = Arc::clone(&counter);
        let task = TimerService::create_task(
            Duration::from_secs(10),
            Some(CallbackWrapper::new(move || {
                let counter = Arc::clone(&counter_clone);
                async move {
                    counter.fetch_add(1, Ordering::SeqCst);
                }
            })),
        );
        let task_id = task.get_id();
        
        service.register(task).unwrap();

        // 使用 cancel_task（会等待结果，但在后台协程中处理）
        let cancelled = service.cancel_task(task_id);
        assert!(cancelled, "Task should be cancelled successfully");

        // 等待足够长时间确保回调不会被执行
        tokio::time::sleep(Duration::from_millis(100)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 0, "Callback should not have been executed");

        // 验证任务已从 active_tasks 中移除
        let cancelled_again = service.cancel_task(task_id);
        assert!(!cancelled_again, "Task should have been removed from active_tasks");
    }

    #[tokio::test]
    async fn test_schedule_once_direct() {
        let timer = TimerWheel::with_defaults();
        let mut service = timer.create_service(ServiceConfig::default());
        let counter = Arc::new(AtomicU32::new(0));

        // 直接通过 service 调度定时器
        let counter_clone = Arc::clone(&counter);
        let task = TimerService::create_task(
            Duration::from_millis(50),
            Some(CallbackWrapper::new(move || {
                let counter = Arc::clone(&counter_clone);
                async move {
                    counter.fetch_add(1, Ordering::SeqCst);
                }
            })),
        );
        let task_id = task.get_id();
        service.register(task).unwrap();

        // 等待定时器触发
        let mut rx = service.take_receiver().unwrap();
        let received_task_id = tokio::time::timeout(Duration::from_millis(200), rx.recv())
            .await
            .expect("Should receive timeout notification")
            .expect("Should receive Some value");

        assert_eq!(received_task_id, task_id);
        
        // 等待回调执行
        tokio::time::sleep(Duration::from_millis(50)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 1);
    }

    #[tokio::test]
    async fn test_schedule_once_batch_direct() {
        let timer = TimerWheel::with_defaults();
        let mut service = timer.create_service(ServiceConfig::default());
        let counter = Arc::new(AtomicU32::new(0));

        // 直接通过 service 批量调度定时器
        let callbacks: Vec<_> = (0..3)
            .map(|_| {
                let counter = Arc::clone(&counter);
                (Duration::from_millis(50), Some(CallbackWrapper::new(move || {
                    let counter = Arc::clone(&counter);
                    async move {
                        counter.fetch_add(1, Ordering::SeqCst);
                    }
                    })))
            })
            .collect();

        let tasks = TimerService::create_batch_with_callbacks(callbacks);
        assert_eq!(tasks.len(), 3);
        service.register_batch(tasks).unwrap();

        // 接收所有超时通知
        let mut received_count = 0;
        let mut rx = service.take_receiver().unwrap();
        
        while received_count < 3 {
            match tokio::time::timeout(Duration::from_millis(200), rx.recv()).await {
                Ok(Some(_task_id)) => {
                    received_count += 1;
                }
                Ok(None) => break,
                Err(_) => break,
            }
        }

        assert_eq!(received_count, 3);
        
        // 等待回调执行
        tokio::time::sleep(Duration::from_millis(50)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 3);
    }

    #[tokio::test]
    async fn test_schedule_once_notify_direct() {
        let timer = TimerWheel::with_defaults();
        let mut service = timer.create_service(ServiceConfig::default());

        // 直接通过 service 调度仅通知的定时器（无回调）
        let task = TimerService::create_task(Duration::from_millis(50), None);
        let task_id = task.get_id();
        service.register(task).unwrap();

        // 接收超时通知
        let mut rx = service.take_receiver().unwrap();
        let received_task_id = tokio::time::timeout(Duration::from_millis(200), rx.recv())
            .await
            .expect("Should receive timeout notification")
            .expect("Should receive Some value");

        assert_eq!(received_task_id, task_id);
    }

    #[tokio::test]
    async fn test_schedule_and_cancel_direct() {
        let timer = TimerWheel::with_defaults();
        let service = timer.create_service(ServiceConfig::default());
        let counter = Arc::new(AtomicU32::new(0));

        // 直接调度定时器
        let counter_clone = Arc::clone(&counter);
        let task = TimerService::create_task(
            Duration::from_secs(10),
            Some(CallbackWrapper::new(move || {
                let counter = Arc::clone(&counter_clone);
                async move {
                    counter.fetch_add(1, Ordering::SeqCst);
                }
            })),
        );
        let task_id = task.get_id();
        service.register(task).unwrap();

        // 立即取消
        let cancelled = service.cancel_task(task_id);
        assert!(cancelled, "Task should be cancelled successfully");

        // 等待确保回调不会执行
        tokio::time::sleep(Duration::from_millis(100)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 0, "Callback should not have been executed");
    }

    #[tokio::test]
    async fn test_cancel_batch_direct() {
        let timer = TimerWheel::with_defaults();
        let service = timer.create_service(ServiceConfig::default());
        let counter = Arc::new(AtomicU32::new(0));

        // 批量调度定时器
        let callbacks: Vec<_> = (0..10)
            .map(|_| {
                let counter = Arc::clone(&counter);
                (Duration::from_secs(10), Some(CallbackWrapper::new(move || {
                    let counter = Arc::clone(&counter);
                    async move {
                        counter.fetch_add(1, Ordering::SeqCst);
                    }
                    })))
            })
            .collect();

        let tasks = TimerService::create_batch_with_callbacks(callbacks);
        let task_ids: Vec<_> = tasks.iter().map(|t| t.get_id()).collect();
        assert_eq!(task_ids.len(), 10);
        service.register_batch(tasks).unwrap();

        // 批量取消所有任务
        let cancelled = service.cancel_batch(&task_ids);
        assert_eq!(cancelled, 10, "All 10 tasks should be cancelled");

        // 等待确保回调不会执行
        tokio::time::sleep(Duration::from_millis(100)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 0, "No callbacks should have been executed");
    }

    #[tokio::test]
    async fn test_cancel_batch_partial() {
        let timer = TimerWheel::with_defaults();
        let service = timer.create_service(ServiceConfig::default());
        let counter = Arc::new(AtomicU32::new(0));

        // 批量调度定时器
        let callbacks: Vec<_> = (0..10)
            .map(|_| {
                let counter = Arc::clone(&counter);
                (Duration::from_secs(10), Some(CallbackWrapper::new(move || {
                    let counter = Arc::clone(&counter);
                    async move {
                        counter.fetch_add(1, Ordering::SeqCst);
                    }
                    })))
            })
            .collect();

        let tasks = TimerService::create_batch_with_callbacks(callbacks);
        let task_ids: Vec<_> = tasks.iter().map(|t| t.get_id()).collect();
        service.register_batch(tasks).unwrap();

        // 只取消前5个任务
        let to_cancel: Vec<_> = task_ids.iter().take(5).copied().collect();
        let cancelled = service.cancel_batch(&to_cancel);
        assert_eq!(cancelled, 5, "5 tasks should be cancelled");

        // 等待确保前5个回调不会执行
        tokio::time::sleep(Duration::from_millis(100)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 0, "Cancelled tasks should not execute");
    }

    #[tokio::test]
    async fn test_cancel_batch_empty() {
        let timer = TimerWheel::with_defaults();
        let service = timer.create_service(ServiceConfig::default());

        // 取消空列表
        let empty: Vec<TaskId> = vec![];
        let cancelled = service.cancel_batch(&empty);
        assert_eq!(cancelled, 0, "No tasks should be cancelled");
    }

    #[tokio::test]
    async fn test_postpone() {
        let timer = TimerWheel::with_defaults();
        let mut service = timer.create_service(ServiceConfig::default());
        let counter = Arc::new(AtomicU32::new(0));

        // 注册一个任务，原始回调增加 1
        let counter_clone1 = Arc::clone(&counter);
        let task = TimerService::create_task(
            Duration::from_millis(50),
            Some(CallbackWrapper::new(move || {
                let counter = Arc::clone(&counter_clone1);
                async move {
                    counter.fetch_add(1, Ordering::SeqCst);
                }
                })),
        );
        let task_id = task.get_id();
        service.register(task).unwrap();

        // 推迟任务并替换回调，新回调增加 10
        let counter_clone2 = Arc::clone(&counter);
        let postponed = service.postpone(
            task_id,
            Duration::from_millis(100),
            Some(CallbackWrapper::new(move || {
                let counter = Arc::clone(&counter_clone2);
                async move {
                    counter.fetch_add(10, Ordering::SeqCst);
                }
            }))
        );
        assert!(postponed, "Task should be postponed successfully");

        // 接收超时通知（推迟后需要等待100ms，加上余量）
        let mut rx = service.take_receiver().unwrap();
        let received_task_id = tokio::time::timeout(Duration::from_millis(200), rx.recv())
            .await
            .expect("Should receive timeout notification")
            .expect("Should receive Some value");

        assert_eq!(received_task_id, task_id);
        
        // 等待回调执行
        tokio::time::sleep(Duration::from_millis(20)).await;
        
        // 验证新回调被执行（增加了 10 而不是 1）
        assert_eq!(counter.load(Ordering::SeqCst), 10);
    }

    #[tokio::test]
    async fn test_postpone_nonexistent_task() {
        let timer = TimerWheel::with_defaults();
        let service = timer.create_service(ServiceConfig::default());

        // 尝试推迟一个不存在的任务
        let fake_task = TimerService::create_task(Duration::from_millis(50), None);
        let fake_task_id = fake_task.get_id();
        // 不注册这个任务
        
        let postponed = service.postpone(fake_task_id, Duration::from_millis(100), None);
        assert!(!postponed, "Nonexistent task should not be postponed");
    }

    #[tokio::test]
    async fn test_postpone_batch() {
        let timer = TimerWheel::with_defaults();
        let mut service = timer.create_service(ServiceConfig::default());
        let counter = Arc::new(AtomicU32::new(0));

        // 注册 3 个任务
        let mut task_ids = Vec::new();
        for _ in 0..3 {
            let counter_clone = Arc::clone(&counter);
            let task = TimerService::create_task(
                Duration::from_millis(50),
            Some(CallbackWrapper::new(move || {
                let counter = Arc::clone(&counter_clone);
                async move {
                    counter.fetch_add(1, Ordering::SeqCst);
                }
            })),
        );
            task_ids.push((task.get_id(), Duration::from_millis(150), None));
            service.register(task).unwrap();
        }

        // 批量推迟
        let postponed = service.postpone_batch_with_callbacks(task_ids);
        assert_eq!(postponed, 3, "All 3 tasks should be postponed");

        // 等待原定时间 50ms，任务不应该触发
        tokio::time::sleep(Duration::from_millis(70)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 0);

        // 接收所有超时通知
        let mut received_count = 0;
        let mut rx = service.take_receiver().unwrap();
        
        while received_count < 3 {
            match tokio::time::timeout(Duration::from_millis(200), rx.recv()).await {
                Ok(Some(_task_id)) => {
                    received_count += 1;
                }
                Ok(None) => break,
                Err(_) => break,
            }
        }

        assert_eq!(received_count, 3);
        
        // 等待回调执行
        tokio::time::sleep(Duration::from_millis(20)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 3);
    }

    #[tokio::test]
    async fn test_postpone_batch_with_callbacks() {
        let timer = TimerWheel::with_defaults();
        let mut service = timer.create_service(ServiceConfig::default());
        let counter = Arc::new(AtomicU32::new(0));

        // 注册 3 个任务
        let mut task_ids = Vec::new();
        for _ in 0..3 {
            let task = TimerService::create_task(
                Duration::from_millis(50),
                None,
            );
            task_ids.push(task.get_id());
            service.register(task).unwrap();
        }

        // 批量推迟并替换回调
        let updates: Vec<_> = task_ids
            .into_iter()
            .map(|id| {
                let counter_clone = Arc::clone(&counter);
                (id, Duration::from_millis(150), Some(CallbackWrapper::new(move || {
                    let counter = Arc::clone(&counter_clone);
                    async move {
                        counter.fetch_add(1, Ordering::SeqCst);
                    }
                    })))
            })
            .collect();

        let postponed = service.postpone_batch_with_callbacks(updates);
        assert_eq!(postponed, 3, "All 3 tasks should be postponed");

        // 等待原定时间 50ms，任务不应该触发
        tokio::time::sleep(Duration::from_millis(70)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 0);

        // 接收所有超时通知
        let mut received_count = 0;
        let mut rx = service.take_receiver().unwrap();
        
        while received_count < 3 {
            match tokio::time::timeout(Duration::from_millis(200), rx.recv()).await {
                Ok(Some(_task_id)) => {
                    received_count += 1;
                }
                Ok(None) => break,
                Err(_) => break,
            }
        }

        assert_eq!(received_count, 3);
        
        // 等待回调执行
        tokio::time::sleep(Duration::from_millis(20)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 3);
    }

    #[tokio::test]
    async fn test_postpone_batch_empty() {
        let timer = TimerWheel::with_defaults();
        let service = timer.create_service(ServiceConfig::default());

        // 推迟空列表
        let empty: Vec<(TaskId, Duration, Option<CallbackWrapper>)> = vec![];
        let postponed = service.postpone_batch_with_callbacks(empty);
        assert_eq!(postponed, 0, "No tasks should be postponed");
    }

    #[tokio::test]
    async fn test_postpone_keeps_timeout_notification_valid() {
        let timer = TimerWheel::with_defaults();
        let mut service = timer.create_service(ServiceConfig::default());
        let counter = Arc::new(AtomicU32::new(0));

        // 注册一个任务
        let counter_clone = Arc::clone(&counter);
        let task = TimerService::create_task(
            Duration::from_millis(50),
            Some(CallbackWrapper::new(move || {
                let counter = Arc::clone(&counter_clone);
                async move {
                    counter.fetch_add(1, Ordering::SeqCst);
                }
            })),
        );
        let task_id = task.get_id();
        service.register(task).unwrap();

        // 推迟任务
        service.postpone(task_id, Duration::from_millis(100), None);

        // 验证超时通知仍然有效（推迟后需要等待100ms，加上余量）
        let mut rx = service.take_receiver().unwrap();
        let received_task_id = tokio::time::timeout(Duration::from_millis(200), rx.recv())
            .await
            .expect("Should receive timeout notification")
            .expect("Should receive Some value");

        assert_eq!(received_task_id, task_id, "Timeout notification should still work after postpone");
        
        // 等待回调执行
        tokio::time::sleep(Duration::from_millis(20)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 1);
    }

    #[tokio::test]
    async fn test_cancelled_task_not_forwarded_to_timeout_rx() {
        let timer = TimerWheel::with_defaults();
        let mut service = timer.create_service(ServiceConfig::default());

        // 注册两个任务：一个会被取消，一个会正常到期
        let task1 = TimerService::create_task(Duration::from_secs(10), None);
        let task1_id = task1.get_id();
        service.register(task1).unwrap();

        let task2 = TimerService::create_task(Duration::from_millis(50), None);
        let task2_id = task2.get_id();
        service.register(task2).unwrap();

        // 取消第一个任务
        let cancelled = service.cancel_task(task1_id);
        assert!(cancelled, "Task should be cancelled");

        // 等待第二个任务到期
        let mut rx = service.take_receiver().unwrap();
        let received_task_id = tokio::time::timeout(Duration::from_millis(200), rx.recv())
            .await
            .expect("Should receive timeout notification")
            .expect("Should receive Some value");

        // 应该只收到第二个任务（到期的）的通知，不应该收到第一个任务（取消的）的通知
        assert_eq!(received_task_id, task2_id, "Should only receive expired task notification");

        // 验证没有其他通知（特别是被取消的任务不应该有通知）
        let no_more = tokio::time::timeout(Duration::from_millis(50), rx.recv()).await;
        assert!(no_more.is_err(), "Should not receive any more notifications");
    }

    #[tokio::test]
    async fn test_take_receiver_twice() {
        let timer = TimerWheel::with_defaults();
        let mut service = timer.create_service(ServiceConfig::default());

        // 第一次调用应该返回 Some
        let rx1 = service.take_receiver();
        assert!(rx1.is_some(), "First take_receiver should return Some");

        // 第二次调用应该返回 None
        let rx2 = service.take_receiver();
        assert!(rx2.is_none(), "Second take_receiver should return None");
    }

    #[tokio::test]
    async fn test_postpone_batch_without_callbacks() {
        let timer = TimerWheel::with_defaults();
        let mut service = timer.create_service(ServiceConfig::default());
        let counter = Arc::new(AtomicU32::new(0));

        // 注册 3 个任务，有原始回调
        let mut task_ids = Vec::new();
        for _ in 0..3 {
            let counter_clone = Arc::clone(&counter);
            let task = TimerService::create_task(
                Duration::from_millis(50),
                Some(CallbackWrapper::new(move || {
                    let counter = Arc::clone(&counter_clone);
                    async move {
                        counter.fetch_add(1, Ordering::SeqCst);
                    }
                })),
            );
            task_ids.push(task.get_id());
            service.register(task).unwrap();
        }

        // 批量推迟，不替换回调
        let updates: Vec<_> = task_ids
            .iter()
            .map(|&id| (id, Duration::from_millis(150)))
            .collect();
        let postponed = service.postpone_batch(updates);
        assert_eq!(postponed, 3, "All 3 tasks should be postponed");

        // 等待原定时间 50ms，任务不应该触发
        tokio::time::sleep(Duration::from_millis(70)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 0, "Callbacks should not fire yet");

        // 接收所有超时通知
        let mut received_count = 0;
        let mut rx = service.take_receiver().unwrap();
        
        while received_count < 3 {
            match tokio::time::timeout(Duration::from_millis(200), rx.recv()).await {
                Ok(Some(_task_id)) => {
                    received_count += 1;
                }
                Ok(None) => break,
                Err(_) => break,
            }
        }

        assert_eq!(received_count, 3, "Should receive 3 timeout notifications");
        
        // 等待回调执行
        tokio::time::sleep(Duration::from_millis(20)).await;
        assert_eq!(counter.load(Ordering::SeqCst), 3, "All callbacks should execute");
    }
}