use libmcl_sys::*;
use rand::Rng;
use std::ffi::{c_void, CString};
use std::mem::size_of;

fn saxpy_seq(a: &i32, x: &Vec<i32>, y: &Vec<i32>, z: &mut Vec<i32>) {
    for i in 0..z.len() {
        z[i] = a * x[i] + y[i];
    }
}

fn saxpy_mcl(
    a: &mut i32,
    x: &mut Vec<i32>,
    y: &mut Vec<i32>,
    z: &mut Vec<i32>,
    reps: usize,
    sync: &bool,
) {
    let mut hdls: Vec<*mut mcl_handle> = Vec::new();
    unsafe {
        for i in 0..reps {
            let size: u64 = z.len() as u64;
            let mut pes: [u64; 3] = [size, 1, 1];
            let mut les: [u64; 3] = [1; 3];
            let kernel_path = CString::new("tests/saxpy.cl").unwrap();
            let kernel_name = CString::new("SAXPY").unwrap();

            let empty = CString::new("").unwrap();
            mcl_prg_load(kernel_path.into_raw(), empty.into_raw(), MCL_PRG_SRC.into());
            hdls.push(mcl_task_create());

            // Get a raw void ptr to our data to pass it to mcl C inteface
            let x_ptr: *mut c_void = x.as_mut_ptr() as *mut c_void;
            let y_ptr: *mut c_void = y.as_mut_ptr() as *mut c_void;
            let z_ptr: *mut c_void = z.as_mut_ptr() as *mut c_void;
            let a_ptr: *mut c_void = a as *mut _ as *mut c_void;
            let pes_ptr: *mut u64 = &mut pes as *mut _ as *mut u64;
            let les_ptr: *mut u64 = &mut les as *mut _ as *mut u64;

            assert_eq!(mcl_task_set_kernel(hdls[i], kernel_name.into_raw(), 4), 0);
            assert_eq!(
                mcl_task_set_arg(
                    hdls[i],
                    0,
                    x_ptr,
                    size * size_of::<i32>() as u64,
                    (MCL_ARG_BUFFER | MCL_ARG_INPUT).into()
                ),
                0
            );
            assert_eq!(
                mcl_task_set_arg(
                    hdls[i],
                    1,
                    a_ptr,
                    size_of::<i32>() as u64,
                    (MCL_ARG_SCALAR | MCL_ARG_INPUT).into()
                ),
                0
            );
            assert_eq!(
                mcl_task_set_arg(
                    hdls[i],
                    2,
                    y_ptr,
                    size * size_of::<i32>() as u64,
                    (MCL_ARG_BUFFER | MCL_ARG_INPUT).into()
                ),
                0
            );
            assert_eq!(
                mcl_task_set_arg(
                    hdls[i],
                    3,
                    z_ptr,
                    size * size_of::<i32>() as u64,
                    (MCL_ARG_BUFFER | MCL_ARG_OUTPUT).into()
                ),
                0
            );
            assert_eq!(mcl_exec(hdls[i], pes_ptr, les_ptr, MCL_TASK_ANY.into()), 0);

            if *sync {
                assert_eq!(mcl_wait(hdls[i]), 0);
            }
        }

        if !*sync {
            for i in 0..reps {
                assert_eq!(mcl_wait(hdls[i]), 0);
            }
        }

        for i in 0..reps {
            assert_eq!(mcl_hdl_free(hdls[i]), 0);
        }
    }
}

#[test]
fn saxpy() {
    unsafe {
        let workers = 2;
        let vec_size = 128;
        let reps = 100;
        let sync = false;

        assert_eq!(mcl_init(workers, MCL_NULL.into()), 0);

        let mut rng = rand::thread_rng();
        let mut a = rng.gen_range(0..100);

        // Generate x and y arrays of size vec_size and initialize with random numbers in [0, 100)
        let mut x: Vec<i32> = (0..vec_size).map(|_| rng.gen_range(0..100)).collect();
        let mut y: Vec<i32> = (0..vec_size).map(|_| rng.gen_range(0..100)).collect();

        // Allocate the z vectors that will hold the results.
        let mut z: Vec<i32> = vec![0; vec_size];
        let mut z_seq: Vec<i32> = vec![0; vec_size];

        saxpy_seq(&a, &x, &y, &mut z_seq);

        println!("Async mcl SAXPY");
        saxpy_mcl(&mut a, &mut x, &mut y, &mut z, reps, &sync);
        assert_eq!(z_seq, z);

        let mut z = vec![0; vec_size];
        let sync = true;

        println!("Sync mcl SAXPY");
        saxpy_mcl(&mut a, &mut x, &mut y, &mut z, reps, &sync);
        assert_eq!(z_seq, z);

        assert_eq!(mcl_finit(), 0);
    }
}