#import "modules/std.sx";

main :: () {
    n1 : s32 = 1;
    n2 : s32 = 2;
    n3 : s32 = 3;
    
    f1 := closure((x: s32) -> s32 => x + n1);
    f2 := closure((x: s32) -> s32 => x + n2);
    f3 := closure((x: s32) -> s32 => x + n3);
    
    print("f1: {}\n", f1(10));
    print("f2: {}\n", f2(10));
    print("f3: {}\n", f3(10));
    
    // closure struct field
    Button :: struct {
        label: string;
        on_press: Closure(s32) -> void;
    }
    btn_val := 99;
    btn_cb := closure((id: s32) {
        print("btn: {} {}\n", id, btn_val);
    });
    btn := Button.{ label = "OK", on_press = btn_cb };
    btn.on_press(1);
    
    // optional closure
    f_none : ?Closure(s64) -> s64 = null;
    if f_none != null { print("should not print\n"); }
    else { print("opt-closure: none\n"); }
    
    // closure factory
    make_adder :: (n: s32) -> Closure(s32) -> s32 {
        closure((x: s32) -> s32 => x + n);
    }
    add5 := make_adder(5);
    add10 := make_adder(10);
    print("factory: {} {}\n", add5(100), add10(100));
    
    // HOF compose
    compose :: (f: Closure(s32) -> s32, g: Closure(s32) -> s32) -> Closure(s32) -> s32 {
        closure((x: s32) -> s32 => f(g(x)));
    }
    double :: (x: s32) -> s32 { return x * 2; }
    cf := compose(add5, double);
    print("compose: {}\n", cf(10));
    
    // closure with array
    sort_bubble :: (arr: [*]s32, cnt: s64, less: Closure(s32, s32) -> bool) {
        i : s64 = 0;
        while i < cnt {
            j : s64 = 0;
            while j < cnt - 1 {
                if less(arr[j + 1], arr[j]) {
                    tmp := arr[j];
                    arr[j] = arr[j + 1];
                    arr[j + 1] = tmp;
                }
                j += 1;
            }
            i += 1;
        }
    }
    sort_arr : [5]s32 = .[5, 3, 1, 4, 2];
    sort_bubble(xx @sort_arr, 5, closure((a: s32, b: s32) -> bool {
        return a < b;
    }));
    print("sort: {} {} {} {} {}\n", sort_arr[0], sort_arr[1], sort_arr[2], sort_arr[3], sort_arr[4]);
    
    // Many closures with string captures
    tag1 := "hello";
    tag2 := "world";
    sf1 := closure((x: s32) { print("sf1: {} {}\n", tag1, x); });
    sf2 := closure((x: s32) { print("sf2: {} {}\n", tag2, x); });
    sf1(1);
    sf2(2);
    
    print("=== DONE ===\n");
}