from . import syscall as syscall


def exit(code: int):
    syscall._syscall1(uint64(syscall.Syscall.EXIT), uint64(code))

def thread_exit():
    """当前用户线程显式退出：内核回收其用户栈并标记线程结束（不返回）。"""
    syscall._syscall0(uint64(syscall.Syscall.THREAD_EXIT))

def yield_cpu():
    # S3e：原走 WAIT_WINDOW(0,2)（UI 私有 syscall，已随内核 UI 一并删除）。
    # 语义等价的是 Linux 对齐段里的 sched_yield ⇒ 内核同样是 try_reschedule()。
    syscall._syscall0(uint64(syscall.Syscall.YIELD))

def get_pid() -> int:
    """当前进程 pid（getpid）。/dev/desk 的事件按 pid 过滤，建窗前就要拿到它。"""
    return int(syscall._syscall0(uint64(syscall.Syscall.GETPID)))

def spawn(path: const str, blocking: int = 0) -> int:
    return int(syscall._syscall2(uint64(syscall.Syscall.SPAWN), uint64(path), uint64(blocking)))

def thread_create(func: rawptr, arg: rawptr = None) -> int:
    return int(syscall._syscall2(uint64(syscall.Syscall.THREAD_CREATE), uint64(func), uint64(arg)))


class Thread:
    _tid: int
    _func: rawptr
    _arg: rawptr
    _running: int

    def __init__(self, func: rawptr, arg: rawptr = None):
        self._func = func
        self._arg = arg
        self._tid = -1
        self._running = 0

    def start(self) -> int:
        if self._running: return -1
        self._tid = thread_create(self._func, self._arg)
        if self._tid < 0: return -1
        self._running = 1
        return 0

    def is_alive(self) -> int:
        return self._running

    def get_tid(self) -> int:
        return self._tid


class Process:
    _pid: int
    _path: [128]char

    def __init__(self, path: const str):
        self._pid = -1
        i: int = 0
        for ch in path:
            if i >= 127: break
            self._path[i] = ch
            i += 1
        self._path[i] = 0

    def start(self) -> int:
        self._pid = spawn(&self._path[0], 0)
        return self._pid

    def start_blocking(self) -> int:
        self._pid = spawn(&self._path[0], 1)
        return self._pid

    def get_pid(self) -> int:
        return self._pid