ruchy 4.1.2

//! Async runtime support for Ruchy
//!
//! Provides async/await functionality and Future trait integration

#![cfg(any(feature = "notebook", feature = "mcp"))]

use std::future::Future as StdFuture;
use std::pin::Pin;
use std::task::{Context, Poll};
use std::time::Duration;
use tokio::time::sleep;

/// Async runtime for executing futures
pub struct AsyncRuntime {
    // In a real implementation, this would manage the executor
}

impl AsyncRuntime {
    /// Create a new async runtime
    pub fn new() -> Self {
        Self {}
    }

    /// Spawn a future on the runtime
    pub fn spawn<T>(&self, future: impl StdFuture<Output = T> + Send + 'static) -> JoinHandle<T>
    where
        T: Send + 'static,
    {
        JoinHandle {
            handle: tokio::spawn(future),
        }
    }

    /// Sleep for a duration
    pub async fn sleep(&self, duration: Duration) {
        sleep(duration).await;
    }
}

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

/// Handle to a spawned future
pub struct JoinHandle<T> {
    handle: tokio::task::JoinHandle<T>,
}

impl<T> StdFuture for JoinHandle<T> {
    type Output = T;

    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
        match Pin::new(&mut self.handle).poll(cx) {
            Poll::Ready(Ok(value)) => Poll::Ready(value),
            Poll::Ready(Err(_)) => panic!("Task panicked"),
            Poll::Pending => Poll::Pending,
        }
    }
}

/// Ruchy's Future trait (wraps `std::future::Future`)
pub trait Future {
    type Output;

    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>;
}

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

    #[test]
    fn test_async_runtime_new() {
        let _runtime = AsyncRuntime::new();
        // Should create runtime
        // Test passes without panic;
    }

    #[test]
    fn test_async_runtime_default() {
        let _runtime = AsyncRuntime::default();
        // Should create runtime via default
        // Test passes without panic;
    }

    #[tokio::test]
    async fn test_async_runtime_sleep() {
        let runtime = AsyncRuntime::new();
        runtime.sleep(Duration::from_millis(1)).await;
        // Should sleep without panic
        // Test passes without panic;
    }

    #[tokio::test]
    async fn test_async_runtime_sleep_actually_waits() {
        // Mutation test: Verify sleep actually delays execution (not just a no-op)
        use std::time::Instant;
        let runtime = AsyncRuntime::new();
        let start = Instant::now();
        runtime.sleep(Duration::from_millis(50)).await;
        let elapsed = start.elapsed();
        assert!(
            elapsed >= Duration::from_millis(40),
            "Sleep should delay at least 40ms, got {elapsed:?}"
        );
    }

    #[tokio::test]
    async fn test_async_runtime_spawn() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async { 42 });
        let result = handle.await;
        assert_eq!(result, 42);
    }

    #[tokio::test]
    async fn test_async_runtime_spawn_multiple() {
        let runtime = AsyncRuntime::new();
        let handle1 = runtime.spawn(async { 10 });
        let handle2 = runtime.spawn(async { 20 });
        let handle3 = runtime.spawn(async { 30 });

        assert_eq!(handle1.await, 10);
        assert_eq!(handle2.await, 20);
        assert_eq!(handle3.await, 30);
    }

    #[tokio::test]
    async fn test_async_runtime_spawn_with_sleep() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async {
            sleep(Duration::from_millis(1)).await;
            "completed"
        });
        let result = handle.await;
        assert_eq!(result, "completed");
    }

    // === EXTREME TDD Round 162 - Async Runtime Tests ===

    #[test]
    fn test_async_runtime_is_send_sync() {
        fn assert_send<T: Send>() {}
        fn assert_sync<T: Sync>() {}
        // AsyncRuntime should be Send + Sync
        assert_send::<AsyncRuntime>();
        assert_sync::<AsyncRuntime>();
    }

    #[tokio::test]
    async fn test_spawn_returns_correct_type_integer_r162() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async { 100i64 });
        let result: i64 = handle.await;
        assert_eq!(result, 100);
    }

    #[tokio::test]
    async fn test_spawn_returns_correct_type_string_r162() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async { String::from("hello world") });
        let result: String = handle.await;
        assert_eq!(result, "hello world");
    }

    #[tokio::test]
    async fn test_spawn_returns_correct_type_vec_r162() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async { vec![1, 2, 3, 4, 5] });
        let result: Vec<i32> = handle.await;
        assert_eq!(result, vec![1, 2, 3, 4, 5]);
    }

    #[tokio::test]
    async fn test_spawn_returns_option_some_r162() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async { Some(42) });
        let result: Option<i32> = handle.await;
        assert_eq!(result, Some(42));
    }

    #[tokio::test]
    async fn test_spawn_returns_option_none_r162() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async { None::<i32> });
        let result: Option<i32> = handle.await;
        assert_eq!(result, None);
    }

    #[tokio::test]
    async fn test_spawn_returns_result_ok_r162() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async { Ok::<_, String>(42) });
        let result: Result<i32, String> = handle.await;
        assert_eq!(result, Ok(42));
    }

    #[tokio::test]
    async fn test_spawn_returns_result_err_r162() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async { Err::<i32, _>("error".to_string()) });
        let result: Result<i32, String> = handle.await;
        assert_eq!(result, Err("error".to_string()));
    }

    #[tokio::test]
    async fn test_spawn_returns_tuple_r162() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async { (1, "two", 3.0) });
        let result = handle.await;
        assert_eq!(result, (1, "two", 3.0));
    }

    #[tokio::test]
    async fn test_spawn_concurrent_execution_r162() {
        use std::sync::atomic::{AtomicUsize, Ordering};
        use std::sync::Arc;

        let runtime = AsyncRuntime::new();
        let counter = Arc::new(AtomicUsize::new(0));

        let c1 = counter.clone();
        let c2 = counter.clone();
        let c3 = counter.clone();

        let h1 = runtime.spawn(async move {
            c1.fetch_add(1, Ordering::SeqCst);
        });
        let h2 = runtime.spawn(async move {
            c2.fetch_add(10, Ordering::SeqCst);
        });
        let h3 = runtime.spawn(async move {
            c3.fetch_add(100, Ordering::SeqCst);
        });

        h1.await;
        h2.await;
        h3.await;

        assert_eq!(counter.load(Ordering::SeqCst), 111);
    }

    #[tokio::test]
    async fn test_sleep_zero_duration_r162() {
        let runtime = AsyncRuntime::new();
        // Zero duration should complete immediately
        runtime.sleep(Duration::from_secs(0)).await;
    }

    #[tokio::test]
    async fn test_sleep_very_short_duration_r162() {
        let runtime = AsyncRuntime::new();
        let start = std::time::Instant::now();
        runtime.sleep(Duration::from_nanos(1)).await;
        // Should complete very quickly (under 100ms even with scheduling overhead)
        assert!(start.elapsed() < Duration::from_millis(100));
    }

    #[tokio::test]
    async fn test_spawn_with_captured_variables_r162() {
        let runtime = AsyncRuntime::new();
        let x = 10;
        let y = 20;
        let handle = runtime.spawn(async move { x + y });
        assert_eq!(handle.await, 30);
    }

    #[tokio::test]
    async fn test_spawn_nested_async_r162() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async {
            let inner = async { 42 };
            inner.await
        });
        assert_eq!(handle.await, 42);
    }

    #[tokio::test]
    async fn test_multiple_runtimes_r162() {
        let runtime1 = AsyncRuntime::new();
        let runtime2 = AsyncRuntime::new();

        let h1 = runtime1.spawn(async { 1 });
        let h2 = runtime2.spawn(async { 2 });

        assert_eq!(h1.await, 1);
        assert_eq!(h2.await, 2);
    }

    #[tokio::test]
    async fn test_spawn_empty_closure_r162() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async {});
        handle.await; // Should complete without panic
    }

    #[tokio::test]
    async fn test_spawn_with_loop_r162() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async {
            let mut sum = 0;
            for i in 0..10 {
                sum += i;
            }
            sum
        });
        assert_eq!(handle.await, 45);
    }

    #[tokio::test]
    async fn test_spawn_with_match_r162() {
        let runtime = AsyncRuntime::new();
        let handle = runtime.spawn(async {
            let x = Some(42);
            match x {
                Some(v) => v * 2,
                None => 0,
            }
        });
        assert_eq!(handle.await, 84);
    }

    #[tokio::test]
    async fn test_spawn_chain_r162() {
        let runtime = AsyncRuntime::new();

        let h1 = runtime.spawn(async { 10 });
        let v1 = h1.await;

        let h2 = runtime.spawn(async move { v1 + 20 });
        let v2 = h2.await;

        let h3 = runtime.spawn(async move { v2 + 30 });
        let v3 = h3.await;

        assert_eq!(v3, 60);
    }
}