import os
import logging
import shutil
import errno
import stat

# code taken from
# https://hg.python.org/cpython/file/3.5/Lib/shutil.py

logger = logging.getLogger(__name__)


if hasattr(os, 'listxattr'):
    def _copyxattr(src, dst, *, follow_symlinks=True):
        """Copy extended filesystem attributes from `src` to `dst`.

        Overwrite existing attributes.

        If `follow_symlinks` is false, symlinks won't be followed.

        """

        try:
            names = os.listxattr(src, follow_symlinks=follow_symlinks)
        except OSError as e:
            if e.errno not in (errno.ENOTSUP, errno.ENODATA):
                raise
            return
        for name in names:
            try:
                value = os.getxattr(src, name, follow_symlinks=follow_symlinks)
                os.setxattr(dst, name, value, follow_symlinks=follow_symlinks)
            except OSError as e:
                if e.errno not in (errno.EPERM, errno.ENOTSUP, errno.ENODATA):
                    raise
else:
    def _copyxattr(*args, **kwargs):
        pass


def copystat(src, dst, *, follow_symlinks=True):
    """Copy all stat info (mode bits, atime, mtime, flags) from src to dst.

    If the optional flag `follow_symlinks` is not set, symlinks aren't followed if and
    only if both `src` and `dst` are symlinks.

    """
    def _nop(*args, ns=None, follow_symlinks=None):
        pass

    # follow symlinks (aka don't not follow symlinks)
    follow = follow_symlinks or not (
        os.path.islink(src) and os.path.islink(dst))
    if follow:
        # use the real function if it exists
        def lookup(name):
            return getattr(os, name, _nop)
    else:
        # use the real function only if it exists
        # *and* it supports follow_symlinks
        def lookup(name):
            fn = getattr(os, name, _nop)
            if fn in os.supports_follow_symlinks:
                return fn
            return _nop

    st = lookup("stat")(src, follow_symlinks=follow)
    mode = stat.S_IMODE(st.st_mode)

    try:
        lookup("utime")(dst, ns=(st.st_atime_ns, st.st_mtime_ns),
                        follow_symlinks=follow)
    except Exception as e:
        logger.error("A problem lookingup utime(%s) of %s; %s",
                     lookup("utime"), dst, e)

    # lookup("utime")(dst, ns=(st.st_atime_ns, st.st_mtime_ns),
    #                 follow_symlinks=follow)

    try:
        lookup("chmod")(dst, mode, follow_symlinks=follow)
    except NotImplementedError:
        # if we got a NotImplementedError, it's because
        #   * follow_symlinks=False,
        #   * lchown() is unavailable, and
        #   * either
        #       * fchownat() is unavailable or
        #       * fchownat() doesn't implement AT_SYMLINK_NOFOLLOW.
        #         (it returned ENOSUP.)
        # therefore we're out of options--we simply cannot chown the
        # symlink.  give up, suppress the error.
        # (which is what shutil always did in this circumstance.)
        pass
    if hasattr(st, 'st_flags'):
        try:
            lookup("chflags")(dst, st.st_flags, follow_symlinks=follow)
        except OSError as why:
            for err in 'EOPNOTSUPP', 'ENOTSUP':
                if hasattr(errno, err) and why.errno == getattr(errno, err):
                    break
            else:
                raise
    _copyxattr(src, dst, follow_symlinks=follow)


def copyfoo(src, dst, *, follow_symlinks=True):
    """Copy data and all stat info ("cp -p src dst"). Return the file's
    destination."

    The destination may be a directory.

    If follow_symlinks is false, symlinks won't be followed. This
    resembles GNU's "cp -P src dst".

    """
    if os.path.isdir(dst):
        dst = os.path.join(dst, os.path.basename(src))

    try:
        shutil.copyfile(src, dst, follow_symlinks=follow_symlinks)
    except Exception as e:
        logger.error("A problem copying the file data of %s to %s; %s",
                     src, dst, e)

    try:
        copystat(src, dst, follow_symlinks=follow_symlinks)
    except Exception as e:
        logger.error("A problem copying the file metadata of %s to %s; %s",
                     src, dst, e)
    return dst

print("copyfoo")
copyfoo("foo.bar", "foo.foo")


def copybar(src, dst, *, follow_symlinks=True):
    """Copy data and all stat info ("cp -p src dst"). Return the file's
    destination."

    The destination may be a directory.

    If follow_symlinks is false, symlinks won't be followed. This
    resembles GNU's "cp -P src dst".

    """
    if os.path.isdir(dst):
        dst = os.path.join(dst, os.path.basename(src))

    shutil.copyfile(src, dst, follow_symlinks=follow_symlinks)

    copystat(src, dst, follow_symlinks=follow_symlinks)
    return dst

print("copybar")
copybar("foo.bar", "bar.bar")

print("done")