//! Arc refcount stress test - rapid announce/drop cycles
//! Tests for memory leaks in rapid channel creation/destruction with Arc values.

use announcement::Announcement;
use std::sync::Arc;
use std::thread;

/// Test: Arc refcount: cycle detection
///
/// Verifies: Arc reference cycles are handled correctly
/// Category: refcount
// Test 1: Rapid Arc refcount cycles (single-threaded)
#[test]
fn test_arc_refcount_rapid_cycles() {
    let data = Arc::new(vec![0u8; 1024]); // 1KB test data
    let initial_count = Arc::strong_count(&data);

    // Run 10,000 create/announce/drop cycles
    for i in 0..10_000 {
        {
            let (announcer, announcement) = Announcement::new();

            // Create a few listeners
            let l1 = announcement.listener();
            let l2 = announcement.listener();
            let l3 = announcement.listener();

            // Announce the Arc
            announcer.announce(data.clone()).unwrap();

            // Retrieve values
            let _v1 = l1.try_listen().unwrap();
            let _v2 = l2.try_listen().unwrap();
            let _v3 = l3.try_listen().unwrap();

            // Everything drops here when block ends
        }

        // Periodic check after everything has dropped
        if i % 1000 == 0 {
            let current_count = Arc::strong_count(&data);
            assert_eq!(
                current_count, initial_count,
                "Refcount leak detected at iteration {}: expected {}, got {}",
                i, initial_count, current_count
            );
        }
    }

    // Final verification
    assert_eq!(
        Arc::strong_count(&data),
        initial_count,
        "Final refcount mismatch after 10k cycles"
    );
}

/// Test: Refcount test: arc refcount mixed drop patterns
///
/// Verifies: Verifies arc refcount mixed drop patterns
/// Category: refcount
// Test 2: Rapid Arc cycles with mixed drop patterns
#[test]
fn test_arc_refcount_mixed_drop_patterns() {
    let data = Arc::new(vec![42u8; 512]);
    let initial_count = Arc::strong_count(&data);

    for i in 0..5_000 {
        {
            let (announcer, announcement) = Announcement::new();

            // Create various numbers of listeners
            let listener_count = (i % 10) + 1;
            let mut listeners = Vec::new();
            for _ in 0..listener_count {
                listeners.push(announcement.listener());
            }

            // Announce
            announcer.announce(data.clone()).unwrap();

            // Drop listeners in different patterns
            match i % 4 {
                0 => drop(listeners), // Drop all at once
                1 => {
                    // Drop one at a time
                    for l in listeners {
                        drop(l);
                    }
                }
                2 => {
                    // Retrieve then drop
                    let values: Vec<_> =
                        listeners.iter().map(|l| l.try_listen().unwrap()).collect();
                    drop(values);
                    drop(listeners);
                }
                _ => {
                    // Drop half, retrieve from rest
                    let mid = listeners.len() / 2;
                    drop(listeners.drain(0..mid).collect::<Vec<_>>());
                    for l in &listeners {
                        let _ = l.try_listen();
                    }
                }
            }

            // Block ends - everything drops including announcement
        }

        // Verify refcount periodically after everything dropped
        if i % 500 == 0 {
            assert_eq!(Arc::strong_count(&data), initial_count);
        }
    }

    assert_eq!(Arc::strong_count(&data), initial_count);
}

/// Test: Arc refcount: cycle detection
///
/// Verifies: Arc reference cycles are handled correctly
/// Category: refcount
// Test 3: Concurrent Arc refcount stress
#[test]
fn test_arc_refcount_concurrent_cycles() {
    let data = Arc::new(vec![0u8; 2048]);
    let initial_count = Arc::strong_count(&data);

    let mut handles = Vec::new();

    // 8 threads all doing rapid cycles
    for thread_id in 0..8 {
        let data_clone = data.clone();

        handles.push(thread::spawn(move || {
            for i in 0..1_000 {
                let (announcer, announcement) = Announcement::new();

                let mut listeners = Vec::new();
                for _ in 0..5 {
                    listeners.push(announcement.listener());
                }

                announcer.announce(data_clone.clone()).unwrap();

                // Mix of operations
                match i % 3 {
                    0 => {
                        // Just drop everything
                        drop(listeners);
                    }
                    1 => {
                        // Retrieve and verify
                        for l in &listeners {
                            let v = l.try_listen().unwrap();
                            assert_eq!(v.len(), 2048);
                        }
                    }
                    _ => {
                        // Mixed
                        let _ = listeners[0].try_listen();
                        drop(listeners);
                    }
                }

                if i % 100 == 0 && thread_id == 0 {
                    println!("Thread {} completed {} iterations", thread_id, i);
                }
            }
        }));
    }

    // Wait for all threads
    for handle in handles {
        handle.join().unwrap();
    }

    // Final refcount should be back to initial
    assert_eq!(
        Arc::strong_count(&data),
        initial_count,
        "Refcount leak after concurrent stress test"
    );
}

/// Test: Refcount test: arc refcount with announcer drop
///
/// Verifies: Verifies arc refcount with announcer drop
/// Category: refcount
// Test 4: Arc refcount with announcer drop (no announce)
#[test]
fn test_arc_refcount_with_announcer_drop() {
    let data = Arc::new(vec![1u8; 256]);
    let initial_count = Arc::strong_count(&data);

    for _ in 0..10_000 {
        let (announcer, announcement) = Announcement::<Arc<Vec<u8>>>::new();

        let _l1 = announcement.listener();
        let _l2 = announcement.listener();

        // Drop announcer WITHOUT announcing
        drop(announcer);

        // Listeners should see closed, no Arc refcount change for data
        // since it was never announced
    }

    // Refcount should be unchanged
    assert_eq!(Arc::strong_count(&data), initial_count);
}

/// Test: Refcount test: arc refcount with listener cloning
///
/// Verifies: Verifies arc refcount with listener cloning
/// Category: refcount
// Test 5: Arc refcount with listener cloning stress
#[test]
fn test_arc_refcount_with_listener_cloning() {
    let data = Arc::new(vec![7u8; 512]);
    let initial_count = Arc::strong_count(&data);

    for _ in 0..5_000 {
        let (announcer, announcement) = Announcement::new();

        let l1 = announcement.listener();

        // Clone listener many times
        let mut clones = vec![l1.clone()];
        for _ in 0..10 {
            clones.push(clones[0].clone());
        }

        announcer.announce(data.clone()).unwrap();

        // All clones retrieve
        for l in &clones {
            let _v = l.try_listen().unwrap();
        }

        // Everything drops
    }

    assert_eq!(Arc::strong_count(&data), initial_count);
}