#include "memory/MemoryManager.h"
#include "sys/Syscall.h"
#include "thread/Scheduler.h"
#include <bits/waitpid.h>

Result<u64> sys_waitpid(Registers*, SyscallArgs args)
{
    pid_t pid = (pid_t)args[0];
    int* status_ptr = (int*)args[1];
    int options = (int)args[2];

    Thread* thread = TRY(Result<Thread*>::from_option(Scheduler::find_by_pid(pid), ESRCH));

    while (thread->state != ThreadState::Exited)
    {
        if (options & WNOHANG) return err(EAGAIN);
        kernel_sleep(10);
    }

    int status = (int)thread->status;

    thread->state = ThreadState::Dying;

    if (status_ptr)
        if (!MemoryManager::copy_to_user_typed(status_ptr, &status)) return err(EFAULT);

    return (u64)pid;
}