print("\n--- Test: Class System Stress + Memory Observation ---");

// Class with fields and methods using `this`
class Node {
  var id;
  var payload;

  func setId(v) { this.id = v; }
  func setPayload(p) { this.payload = p; }

  func sum() {
    if (this.payload == none) return 0;
    if (this.payload.len() == 0) return 0;
    var i = 0;
    var s = 0;
    while (i < this.payload.len()) {
      s = s + this.payload[i];
      i = i + 1;
    }
    return s;
  }

  func describe() {
    return "Node(" + toString(this.id) + ", sum=" + toString(this.sum()) + ")";
  }
}

// Basic functional checks
var a = Node();
a.setId(7);
a.setPayload([1, 2, 4]);
assert(a.sum() == 7, "sum() should sum payload");
assert(type(a.describe()) == "string", "describe() returns string");

// Memory observation before creating many objects
var mbBefore = memoryUsage();
print("Memory before allocations (MB): " + toString(mbBefore));

// Create many objects and store them
var COUNT = 40000;  // adjust as needed for your machine
var nodes = [];
var i = 0;
while (i < COUNT) {
  var n = Node();
  n.setId(i);
  // small payload to keep variety, not too heavy
  n.setPayload([i % 10, (i * 2) % 10, (i * 3) % 10]);
  nodes.push(n);
  i = i + 1;
}

// Spot-check a few nodes
assert(nodes[0].sum() == (0 + 0 + 0), "node0 sum");
assert(nodes[1].sum() == (1 + 2 + 3), "node1 sum");
assert(type(nodes[100].describe()) == "string", "describe() type");

// Memory after allocation
var mbAfter = memoryUsage();
print("Memory after allocations (MB):  " + toString(mbAfter));

// Verify each object is callable and alive: call sum() on every node
var verify = 0;
i = 0;
while (i < COUNT) {
  verify = verify + nodes[i].sum();
  print(nodes[i].describe());

  i = i + 1;
}
print("Verification sum: " + toString(verify));

// Pause to allow manual inspection via Activity Monitor, etc.
print("Press Enter to clear references and observe memory...");
input();

// Clear references to allow GC/release by refcounts
nodes = [];

// Observe memory after clearing
var mbCleared = memoryUsage();
print("Memory after clear (MB):       " + toString(mbCleared));

print("Class stress + memory observation: DONE");