use std::future::Future;
use std::pin::Pin;
use crate::system::{add_advanced, WorkloadHints};
use crate::optimizer::gpu;

/// Experimental: Async implementation of the add operation.
/// 
/// WHY: v0.7 adds async support to avoid blocking the main thread (or Tauri UI thread)
/// during massive computations. It integrates both CPU-parallel and GPU paths.
pub fn add_async(a: Vec<f32>, b: Vec<f32>, hints: WorkloadHints) -> Pin<Box<dyn Future<Output = Vec<f32>> + Send>> {
    let _scope = crate::profiling::ProfileScope::new("Async Operation Entry", None);
    Box::pin(async move {
        // 1. Try GPU async path if preferred
        if hints.prefer_gpu {
            let gpu_res = gpu::with_backend(|backend| {
                backend.add_async(a.clone(), b.clone())
            });
            
            if let Some(fut) = gpu_res {
                if let Ok(res) = fut.await {
                    return res;
                }
            }
        }

        // 2. Fallback to CPU execution (wrapped in a blocking task)
        // Note: For a real library, we'd use tokio::spawn_blocking or similar.
        // Here we'll simulate it using a standard thread for demo purposes 
        // to keep dependencies minimal.
        let (tx, rx) = std::sync::mpsc::channel();
        std::thread::spawn(move || {
            let mut out = vec![0.0; a.len()];
            add_advanced(&a, &b, &mut out, hints);
            let _ = tx.send(out);
        });
        
        rx.recv().unwrap_or_else(|_| Vec::new())
    })
}
