import t, c
from . import syscall as syscall

O_RDONLY:   t.CDefine = 0x01
O_WRONLY:   t.CDefine = 0x02
O_RDWR:     t.CDefine = 0x03
O_CREAT:    t.CDefine = 0x04
O_TRUNC:    t.CDefine = 0x08
O_APPEND:   t.CDefine = 0x30

SEEK_SET: t.CDefine = 0
SEEK_CUR: t.CDefine = 1
SEEK_END: t.CDefine = 2

DT_UNKNOWN: t.CDefine = 0
DT_FILE:    t.CDefine = 1
DT_DIR:     t.CDefine = 2

def open(path: t.CConst | t.CChar | t.CPtr, flags: t.CUInt32T) -> t.CInt:
    return t.CInt(syscall._syscall3(t.CUInt64T(syscall.OPEN), t.CUInt64T(path), t.CUInt64T(flags), 0))

def close(fd: t.CInt) -> t.CInt:
    return t.CInt(syscall._syscall1(t.CUInt64T(syscall.CLOSE), t.CUInt64T(fd)))

def read(fd: t.CInt, buf: t.CVoid | t.CPtr, count: t.CUInt32T) -> t.CInt:
    return t.CInt(syscall._syscall3(t.CUInt64T(syscall.READ), t.CUInt64T(fd), t.CUInt64T(buf), t.CUInt64T(count)))

def write(fd: t.CInt, buf: t.CVoid | t.CPtr, count: t.CUInt32T) -> t.CInt:
    return t.CInt(syscall._syscall3(t.CUInt64T(syscall.WRITE), t.CUInt64T(fd), t.CUInt64T(buf), t.CUInt64T(count)))

def seek(fd: t.CInt, offset: t.CUInt32T) -> t.CInt:
    return t.CInt(syscall._syscall3(t.CUInt64T(syscall.SEEK), t.CUInt64T(fd), t.CUInt64T(offset), 0))

def tell(fd: t.CInt) -> t.CUInt32T:
    return t.CUInt32T(syscall._syscall1(t.CUInt64T(syscall.TELL), t.CUInt64T(fd)))

def fsize(fd: t.CInt) -> t.CUInt32T:
    return t.CUInt32T(syscall._syscall1(t.CUInt64T(syscall.SIZE), t.CUInt64T(fd)))

def mkdir(path: t.CConst | t.CChar | t.CPtr) -> t.CInt:
    return t.CInt(syscall._syscall3(t.CUInt64T(syscall.MKDIR), t.CUInt64T(path), 0, 0))

def remove(path: t.CConst | t.CChar | t.CPtr) -> t.CInt:
    return t.CInt(syscall._syscall3(t.CUInt64T(syscall.REMOVE), t.CUInt64T(path), 0, 0))

def opendir(path: t.CConst | t.CChar | t.CPtr) -> t.CInt:
    return t.CInt(syscall._syscall3(t.CUInt64T(syscall.OPENDIR), t.CUInt64T(path), 0, 0))

def readdir(dd: t.CInt, info: t.CVoid | t.CPtr) -> t.CInt:
    return t.CInt(syscall._syscall3(t.CUInt64T(syscall.READDIR), t.CUInt64T(dd), t.CUInt64T(info), 0))

def closedir(dd: t.CInt) -> t.CInt:
    return t.CInt(syscall._syscall1(t.CUInt64T(syscall.CLOSEDIR), t.CUInt64T(dd)))

def stat(path: t.CConst | t.CChar | t.CPtr, info: t.CVoid | t.CPtr) -> t.CInt:
    return t.CInt(syscall._syscall3(t.CUInt64T(syscall.STAT), t.CUInt64T(path), t.CUInt64T(info), 0))

@t.Object
class FileIO:
    _fd: t.CInt
    _pos: t.CUInt32T
    _size: t.CUInt32T
    _flags: t.CUInt32T
    _closed: t.CInt

    def __init__(self, fd: t.CInt, flags: t.CUInt32T):
        self._fd = fd
        self._flags = flags
        self._pos = 0
        self._size = fsize(fd)
        self._closed = 0

    def read(self, buf: t.CVoid | t.CPtr, count: t.CUInt32T) -> t.CInt:
        if self._closed: return -1
        n: t.CInt = read(self._fd, buf, count)
        if n > 0:
            self._pos = self._pos + t.CUInt32T(n)
        return n

    def write(self, buf: t.CVoid | t.CPtr, count: t.CUInt32T) -> t.CInt:
        if self._closed: return -1
        n: t.CInt = write(self._fd, buf, count)
        if n > 0:
            self._pos = self._pos + t.CUInt32T(n)
            if self._pos > self._size:
                self._size = self._pos
        return n

    def seek(self, offset: t.CUInt32T) -> t.CInt:
        if self._closed: return -1
        res: t.CInt = seek(self._fd, offset)
        if res == 0:
            self._pos = offset
        return res

    def tell(self) -> t.CUInt32T:
        return self._pos

    def size(self) -> t.CUInt32T:
        return self._size

    def close(self) -> t.CInt:
        if self._closed: return 0
        self._closed = 1
        return close(self._fd)

    def is_closed(self) -> t.CInt:
        return self._closed

@t.Object
class DirIO:
    _dd: t.CInt
    _closed: t.CInt

    def __init__(self, dd: t.CInt):
        self._dd = dd
        self._closed = 0

    def read(self, info: t.CVoid | t.CPtr) -> t.CInt:
        if self._closed: return -1
        return readdir(self._dd, info)

    def close(self) -> t.CInt:
        if self._closed: return 0
        self._closed = 1
        return closedir(self._dd)

    def is_closed(self) -> t.CInt:
        return self._closed

def open_file(path: t.CConst | t.CChar | t.CPtr, flags: t.CUInt32T) -> FileIO | t.CPtr:
    fd: t.CInt = open(path, flags)
    if fd < 0:
        return None
    return FileIO(fd, flags)

def open_dir(path: t.CConst | t.CChar | t.CPtr) -> DirIO | t.CPtr:
    dd: t.CInt = opendir(path)
    if dd < 0:
        return None
    return DirIO(dd)