jellytau/src-tauri/src/playback_reporting/throttle.rs

//! Event throttler for position update reporting
//!
//! This module is fully implemented but not yet integrated with the player.
//! Dead code warnings are suppressed until integration is complete.

#![allow(dead_code)]

use crate::utils::lock::MutexSafe;
use std::collections::HashMap;
use std::sync::{Arc, Mutex};
use std::time::{Duration, Instant};

/// Event throttler to prevent spam from frequent position updates.
///
/// Tracks the last report time for each item and ensures reports are only
/// sent at most once per throttle duration (default 30 seconds).
pub struct EventThrottler {
    last_report_time: Arc<Mutex<HashMap<String, Instant>>>,
    throttle_duration: Duration,
}

impl EventThrottler {
    /// Creates a new EventThrottler with 30 second default interval
    pub fn new() -> Self {
        Self::with_duration(Duration::from_secs(30))
    }

    /// Creates a new EventThrottler with custom interval
    pub fn with_duration(duration: Duration) -> Self {
        Self {
            last_report_time: Arc::new(Mutex::new(HashMap::new())),
            throttle_duration: duration,
        }
    }

    /// Checks if enough time has elapsed since the last report for this item
    pub fn should_report(&self, item_id: &str) -> bool {
        let last_times = self.last_report_time.lock_safe();

        if let Some(last_time) = last_times.get(item_id) {
            let elapsed = last_time.elapsed();
            if elapsed < self.throttle_duration {
                log::debug!(
                    "[EventThrottler] Skipping report for {}, last reported {:.1}s ago (threshold: {}s)",
                    item_id,
                    elapsed.as_secs_f64(),
                    self.throttle_duration.as_secs()
                );
                return false;
            }
        }

        true
    }

    /// Marks the item as reported at the current time
    pub fn mark_reported(&self, item_id: &str) {
        let mut last_times = self.last_report_time.lock_safe();
        last_times.insert(item_id.to_string(), Instant::now());

        log::debug!(
            "[EventThrottler] Marked {} as reported at {:?}",
            item_id,
            Instant::now()
        );
    }

    /// Clears all tracked report times
    pub fn clear(&self) {
        let mut last_times = self.last_report_time.lock_safe();
        last_times.clear();
        log::debug!("[EventThrottler] Cleared all tracked report times");
    }

    /// Removes a specific item from tracking
    pub fn clear_item(&self, item_id: &str) {
        let mut last_times = self.last_report_time.lock_safe();
        last_times.remove(item_id);
        log::debug!("[EventThrottler] Cleared tracking for {}", item_id);
    }
}

impl Default for EventThrottler {
    fn default() -> Self {
        Self::new()
    }
}

impl Clone for EventThrottler {
    fn clone(&self) -> Self {
        Self {
            last_report_time: Arc::clone(&self.last_report_time),
            throttle_duration: self.throttle_duration,
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::thread;

    #[test]
    fn test_throttler_allows_first_report() {
        let throttler = EventThrottler::new();
        assert!(throttler.should_report("item1"));
    }

    #[test]
    fn test_throttler_blocks_immediate_second_report() {
        let throttler = EventThrottler::new();
        assert!(throttler.should_report("item1"));
        throttler.mark_reported("item1");
        assert!(!throttler.should_report("item1"));
    }

    #[test]
    fn test_throttler_allows_report_after_duration() {
        let throttler = EventThrottler::with_duration(Duration::from_millis(100));
        assert!(throttler.should_report("item1"));
        throttler.mark_reported("item1");
        assert!(!throttler.should_report("item1"));

        thread::sleep(Duration::from_millis(150));
        assert!(throttler.should_report("item1"));
    }

    #[test]
    fn test_throttler_handles_multiple_items() {
        let throttler = EventThrottler::new();
        assert!(throttler.should_report("item1"));
        throttler.mark_reported("item1");

        assert!(throttler.should_report("item2"));
        throttler.mark_reported("item2");

        assert!(!throttler.should_report("item1"));
        assert!(!throttler.should_report("item2"));
    }

    #[test]
    fn test_throttler_clear() {
        let throttler = EventThrottler::new();
        throttler.mark_reported("item1");
        assert!(!throttler.should_report("item1"));

        throttler.clear();
        assert!(throttler.should_report("item1"));
    }

    #[test]
    fn test_throttler_clear_item() {
        let throttler = EventThrottler::new();
        throttler.mark_reported("item1");
        throttler.mark_reported("item2");

        assert!(!throttler.should_report("item1"));
        assert!(!throttler.should_report("item2"));

        throttler.clear_item("item1");
        assert!(throttler.should_report("item1"));
        assert!(!throttler.should_report("item2"));
    }

    #[test]
    fn test_throttler_clone_shares_state() {
        let throttler1 = EventThrottler::new();
        throttler1.mark_reported("item1");

        let throttler2 = throttler1.clone();
        assert!(!throttler2.should_report("item1"));

        throttler2.mark_reported("item2");
        assert!(!throttler1.should_report("item2"));
    }
}