"""
load library for lowlevel FUSE implementation
"""

import os

BORG_FUSE_IMPL = os.environ.get('BORG_FUSE_IMPL', 'pyfuse3,llfuse')

for FUSE_IMPL in BORG_FUSE_IMPL.split(','):
    FUSE_IMPL = FUSE_IMPL.strip()
    if FUSE_IMPL == 'pyfuse3':
        try:
            import pyfuse3 as llfuse
        except ImportError:
            pass
        else:
            has_llfuse = False
            has_pyfuse3 = True
            break
    elif FUSE_IMPL == 'llfuse':
        try:
            import llfuse
        except ImportError:
            pass
        else:
            has_llfuse = True
            has_pyfuse3 = False
            break
    elif FUSE_IMPL == 'none':
        pass
    else:
        raise RuntimeError("unknown fuse implementation in BORG_FUSE_IMPL: '%s'" % BORG_FUSE_IMPL)
else:
    llfuse = None
    has_llfuse = False
    has_pyfuse3 = False