// use std::fs;
// use std::path::Path;
// use prometeu_core::{Value, VmFault};
// use prometeu_drivers::hardware::Hardware;
// use prometeu_hal::{HostContext, HostReturn, NativeInterface};
// use prometeu_vm::{LogicalFrameEndingReason, VirtualMachine};
// 
// struct MockNative;
// impl NativeInterface for MockNative {
//     fn syscall(&mut self, id: u32, _args: &[Value], ret: &mut HostReturn, _ctx: &mut HostContext) -> Result<(), VmFault> {
//         if id == 0x2010 { // InputPadSnapshot
//             for _ in 0..48 {
//                 ret.push_bool(false);
//             }
//         } else if id == 0x2011 { // InputTouchSnapshot
//             for _ in 0..6 {
//                 ret.push_int(0);
//             }
//         } else {
//             // Push one result for others that might expect it
//             // Based on results_count() in syscalls.rs, most return 1 except GfxClear565 (0)
//             if id != 0x1010 {
//                 ret.push_null();
//             }
//         }
//         Ok(())
//     }
// }
// 
// #[test]
// fn test_canonical_cartridge_heartbeat() {
//     let mut pbc_path = Path::new("../../test-cartridges/canonical/golden/program.pbc").to_path_buf();
//     if !pbc_path.exists() {
//         pbc_path = Path::new("test-cartridges/canonical/golden/program.pbc").to_path_buf();
//     }
//     
//     let pbc_bytes = fs::read(pbc_path).expect("Failed to read canonical PBC. Did you run the generation test?");
// 
//     // Determine entrypoint from the compiled module exports
//     let entry_symbol = "src/main/modules:frame";
//     
//     let mut vm = VirtualMachine::new(vec![], vec![]);
//     vm.initialize(pbc_bytes, entry_symbol).expect("Failed to initialize VM with canonical cartridge");
//     vm.prepare_call(entry_symbol);
//     
//     let mut native = MockNative;
//     let mut hw = Hardware::new();
//     let mut ctx = HostContext::new(Some(&mut hw));
//     
//     // Run for a reasonable budget
//     let report = vm.run_budget(1000, &mut native, &mut ctx).expect("VM failed to run");
//     
//     // Acceptance criteria:
//     // 1. No traps
//     match report.reason {
//         LogicalFrameEndingReason::Trap(trap) => panic!("VM trapped: {:?}", trap),
//         LogicalFrameEndingReason::Panic(msg) => panic!("VM panicked: {}", msg),
//         LogicalFrameEndingReason::Halted => {},
//         LogicalFrameEndingReason::EndOfRom => {},
//         LogicalFrameEndingReason::FrameSync => {},
//         LogicalFrameEndingReason::BudgetExhausted => {},
//         LogicalFrameEndingReason::Breakpoint => {},
//     }
//     
//     // 2. Deterministic output state (if any)
//     // Observação: a PVM agora sinaliza FRAME_SYNC imediatamente antes do RET do entry point.
//     // Quando o motivo é FRAME_SYNC, não exigimos pilha vazia (a limpeza final ocorre após o RET).
//     // Para os demais motivos (RET/Halted/EndOfRom), a pilha deve estar vazia para frame(): void.
//     if !matches!(report.reason, LogicalFrameEndingReason::FrameSync) {
//         assert_eq!(vm.operand_stack.len(), 0, "Stack should be empty after frame() execution");
//     }
//     
//     println!("Heartbeat test passed!");
// }