# osutil.py - CFFI version of osutil.c

#

# Copyright 2016 Maciej Fijalkowski <fijall@gmail.com>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import os

import stat as statmod

from ..pure.osutil import *

from .. import (

    pycompat,

)

if pycompat.sysplatform == 'darwin':

    from . import _osutil

    ffi = _osutil.ffi

    lib = _osutil.lib

    listdir_batch_size = 4096

    # tweakable number, only affects performance, which chunks

    # of bytes do we get back from getattrlistbulk

    attrkinds = [None] * 20 # we need the max no for enum VXXX, 20 is plenty

    attrkinds[lib.VREG] = statmod.S_IFREG

    attrkinds[lib.VDIR] = statmod.S_IFDIR

    attrkinds[lib.VLNK] = statmod.S_IFLNK

    attrkinds[lib.VBLK] = statmod.S_IFBLK

    attrkinds[lib.VCHR] = statmod.S_IFCHR

    attrkinds[lib.VFIFO] = statmod.S_IFIFO

    attrkinds[lib.VSOCK] = statmod.S_IFSOCK

    class stat_res(object):

        def __init__(self, st_mode, st_mtime, st_size):

            self.st_mode = st_mode

            self.st_mtime = st_mtime

            self.st_size = st_size

    tv_sec_ofs = ffi.offsetof("struct timespec", "tv_sec")

    buf = ffi.new("char[]", listdir_batch_size)

    def listdirinternal(dfd, req, stat, skip):

        ret = []

        while True:

            r = lib.getattrlistbulk(dfd, req, buf, listdir_batch_size, 0)

            if r == 0:

                break

            if r == -1:

                raise OSError(ffi.errno, os.strerror(ffi.errno))

            cur = ffi.cast("val_attrs_t*", buf)

            for i in range(r):

                lgt = cur.length

                assert lgt == ffi.cast('uint32_t*', cur)[0]

                ofs = cur.name_info.attr_dataoffset

                str_lgt = cur.name_info.attr_length

                base_ofs = ffi.offsetof('val_attrs_t', 'name_info')

                name = str(ffi.buffer(ffi.cast("char*", cur) + base_ofs + ofs,

                           str_lgt - 1))

                tp = attrkinds[cur.obj_type]

                if name == "." or name == "..":

                    continue

                if skip == name and tp == statmod.S_ISDIR:

                    return []

                if stat:

                    mtime = cur.mtime.tv_sec

                    mode = (cur.accessmask & ~lib.S_IFMT)| tp

                    ret.append((name, tp, stat_res(st_mode=mode, st_mtime=mtime,

                                st_size=cur.datalength)))

                else:

                    ret.append((name, tp))

                cur = ffi.cast("val_attrs_t*", int(ffi.cast("intptr_t", cur))

                    + lgt)

        return ret

    def listdir(path, stat=False, skip=None):

        req = ffi.new("struct attrlist*")

        req.bitmapcount = lib.ATTR_BIT_MAP_COUNT

        req.commonattr = (lib.ATTR_CMN_RETURNED_ATTRS |

                          lib.ATTR_CMN_NAME |

                          lib.ATTR_CMN_OBJTYPE |

                          lib.ATTR_CMN_ACCESSMASK |

                          lib.ATTR_CMN_MODTIME)

        req.fileattr = lib.ATTR_FILE_DATALENGTH

        dfd = lib.open(path, lib.O_RDONLY, 0)

        if dfd == -1:

            raise OSError(ffi.errno, os.strerror(ffi.errno))

        try:

            ret = listdirinternal(dfd, req, stat, skip)

        finally:

            try:

                lib.close(dfd)

            except BaseException:

                pass # we ignore all the errors from closing, not

                # much we can do about that

        return ret