// ffi-objc-arc-02 — #property(strong) on sx-defined class.
//
// Strong contract:
//   - setter retains the new value, releases the old.
//   - -dealloc releases each strong property ivar before freeing state.
//
// Observation: a child instance assigned to a parent's strong property
// stays alive after we drop our own reference. Without the strong
// setter, the child's refcount drops to 0 immediately when we release,
// and the parent ends up with a dangling pointer.
//
// We observe via TrackingAllocator. The KEY check is the dealloc count
// AT THE MIDPOINT — between dropping our child reference and releasing
// the parent. With strong+dealloc-cleanup: child stays alive across
// midpoint (no extra dealloc). Without: child is dead at midpoint.

#import "modules/std.sx";
#import "modules/std/mem.sx";
#import "modules/ffi/objc.sx";
#import "modules/build.sx";

SxStrongChild :: #objc_class("SxStrongChild") {
    #extends NSObject;
    tag: i32;
    alloc :: () -> *SxStrongChild;
}

SxStrongParent :: #objc_class("SxStrongParent") {
    #extends NSObject;
    child: *SxStrongChild #property(strong);
    alloc :: () -> *SxStrongParent;
}

main :: () -> i32 {
    inline if OS == .macos {
        gpa := GPA.init();
        tracker := TrackingAllocator.init(xx gpa);

        push Context.{ allocator = xx tracker, data = null } {
            d0 := tracker.dealloc_count;
            a0 := tracker.alloc_count;

            parent := SxStrongParent.alloc();
            child  := SxStrongChild.alloc();
            parent.child = child;   // dispatches setChild: via M2.2 property machinery
            child.release();

            // Midpoint: with strong setter, child is retained by parent;
            // tracker.dealloc_count should NOT have advanced beyond d0.
            // Without strong setter, child auto-dealloc'd on release.
            d_mid := tracker.dealloc_count;
            if d_mid != d0 {
                print("FAIL: child dealloc'd at midpoint (strong setter not retaining); delta={}\n",
                      d_mid - d0);
                return 1;
            }

            parent.release();

            // After parent.release: parent.dealloc fires, releases the
            // strong child ivar, child deallocs, state freed.
            d_end := tracker.dealloc_count;
            // Net: 2 allocs (parent + child state), 2 deallocs (both freed).
            // Balance check: dealloc delta == alloc delta.
            if d_end - d0 != tracker.alloc_count - a0 {
                print("FAIL: unbalanced; alloc={} dealloc={}\n",
                      tracker.alloc_count - a0, d_end - d0);
                return 1;
            }
        }

        print("strong property: ok\n");
    }
    inline if OS != .macos {
        print("skipped (not macos)\n");
    }
    0
}