r"""
The torch package contains data structures for multi-dimensional
tensors and defines mathematical operations over these tensors.
Additionally, it provides many utilities for efficient serializing of
Tensors and arbitrary types, and other useful utilities.

It has a CUDA counterpart, that enables you to run your tensor computations
on an NVIDIA GPU with compute capability >= 3.0.
"""

import os
import sys
import platform
import textwrap
import ctypes
import warnings

if sys.version_info < (3,):
    raise Exception("Python 2 has reached end-of-life and is no longer supported by PyTorch.")

from ._utils import _import_dotted_name
from ._utils_internal import get_file_path, prepare_multiprocessing_environment, \
    USE_RTLD_GLOBAL_WITH_LIBTORCH, USE_GLOBAL_DEPS
# TODO(torch_deploy) figure out how to freeze version.py in fbcode build
if sys.executable == 'torch_deploy':
    __version__ = "torch-deploy-1.8"
else:
    from .version import __version__
from ._six import string_classes as _string_classes

from typing import Set, Type, TYPE_CHECKING

__all__ = [
    'typename', 'is_tensor', 'is_storage', 'set_default_tensor_type',
    'set_rng_state', 'get_rng_state', 'manual_seed', 'initial_seed', 'seed',
    'save', 'load', 'set_printoptions', 'chunk', 'split', 'stack', 'matmul',
    'no_grad', 'enable_grad', 'rand', 'randn',
    'DoubleStorage', 'FloatStorage', 'LongStorage', 'IntStorage',
    'ShortStorage', 'CharStorage', 'ByteStorage', 'BoolStorage',
    'DoubleTensor', 'FloatTensor', 'LongTensor', 'IntTensor',
    'ShortTensor', 'CharTensor', 'ByteTensor', 'BoolTensor', 'Tensor',
    'lobpcg', 'use_deterministic_algorithms', 'set_deterministic',
    'are_deterministic_algorithms_enabled', 'is_deterministic'
]

################################################################################
# Load the extension module
################################################################################

if sys.platform == 'win32':
    pfiles_path = os.getenv('ProgramFiles', 'C:\\Program Files')
    py_dll_path = os.path.join(sys.exec_prefix, 'Library', 'bin')
    th_dll_path = os.path.join(os.path.dirname(__file__), 'lib')

    # When users create a virtualenv that inherits the base environment,
    # we will need to add the corresponding library directory into
    # DLL search directories. Otherwise, it will rely on `PATH` which
    # is dependent on user settings.
    if sys.exec_prefix != sys.base_exec_prefix:
        base_py_dll_path = os.path.join(sys.base_exec_prefix, 'Library', 'bin')
    else:
        base_py_dll_path = ''

    dll_paths = list(filter(os.path.exists, [th_dll_path, py_dll_path, base_py_dll_path]))

    if all([not os.path.exists(os.path.join(p, 'nvToolsExt64_1.dll')) for p in dll_paths]):
        nvtoolsext_dll_path = os.path.join(
            os.getenv('NVTOOLSEXT_PATH', os.path.join(pfiles_path, 'NVIDIA Corporation', 'NvToolsExt')), 'bin', 'x64')
    else:
        nvtoolsext_dll_path = ''

    from .version import cuda as cuda_version
    import glob
    if cuda_version and all([not glob.glob(os.path.join(p, 'cudart64*.dll')) for p in dll_paths]):
        cuda_version_1 = cuda_version.replace('.', '_')
        cuda_path_var = 'CUDA_PATH_V' + cuda_version_1
        default_path = os.path.join(pfiles_path, 'NVIDIA GPU Computing Toolkit', 'CUDA', 'v' + cuda_version)
        cuda_path = os.path.join(os.getenv(cuda_path_var, default_path), 'bin')
    else:
        cuda_path = ''

    dll_paths.extend(filter(os.path.exists, [nvtoolsext_dll_path, cuda_path]))

    kernel32 = ctypes.WinDLL('kernel32.dll', use_last_error=True)
    with_load_library_flags = hasattr(kernel32, 'AddDllDirectory')
    prev_error_mode = kernel32.SetErrorMode(0x0001)

    kernel32.LoadLibraryW.restype = ctypes.c_void_p
    if with_load_library_flags:
        kernel32.AddDllDirectory.restype = ctypes.c_void_p
        kernel32.LoadLibraryExW.restype = ctypes.c_void_p

    for dll_path in dll_paths:
        if sys.version_info >= (3, 8):
            os.add_dll_directory(dll_path)
        elif with_load_library_flags:
            res = kernel32.AddDllDirectory(dll_path)
            if res is None:
                err = ctypes.WinError(ctypes.get_last_error())
                err.strerror += f' Error adding "{dll_path}" to the DLL directories.'
                raise err

    try:
        ctypes.CDLL('vcruntime140.dll')
        ctypes.CDLL('msvcp140.dll')
        if cuda_version not in ('9.2', '10.0'):
            ctypes.CDLL('vcruntime140_1.dll')
    except OSError:
        print('''Microsoft Visual C++ Redistributable is not installed, this may lead to the DLL load failure.
                 It can be downloaded at https://aka.ms/vs/16/release/vc_redist.x64.exe''')

    dlls = glob.glob(os.path.join(th_dll_path, '*.dll'))
    path_patched = False
    for dll in dlls:
        is_loaded = False
        if with_load_library_flags:
            res = kernel32.LoadLibraryExW(dll, None, 0x00001100)
            last_error = ctypes.get_last_error()
            if res is None and last_error != 126:
                err = ctypes.WinError(last_error)
                err.strerror += f' Error loading "{dll}" or one of its dependencies.'
                raise err
            elif res is not None:
                is_loaded = True
        if not is_loaded:
            if not path_patched:
                os.environ['PATH'] = ';'.join(dll_paths + [os.environ['PATH']])
                path_patched = True
            res = kernel32.LoadLibraryW(dll)
            if res is None:
                err = ctypes.WinError(ctypes.get_last_error())
                err.strerror += f' Error loading "{dll}" or one of its dependencies.'
                raise err

    kernel32.SetErrorMode(prev_error_mode)


# See Note [Global dependencies]
def _load_global_deps():
    if platform.system() == 'Windows' or sys.executable == 'torch_deploy':
        return

    lib_name = 'libtorch_global_deps' + ('.dylib' if platform.system() == 'Darwin' else '.so')
    here = os.path.abspath(__file__)
    lib_path = os.path.join(os.path.dirname(here), 'lib', lib_name)

    ctypes.CDLL(lib_path, mode=ctypes.RTLD_GLOBAL)


if (USE_RTLD_GLOBAL_WITH_LIBTORCH or os.getenv('TORCH_USE_RTLD_GLOBAL')) and \
        platform.system() != 'Windows':
    # Do it the hard way.  You might want to load libtorch with RTLD_GLOBAL in a
    # few circumstances:
    #
    #   1. You're in a build environment (e.g., fbcode) where
    #      libtorch_global_deps is not available, but you still need
    #      to get mkl to link in with RTLD_GLOBAL or it will just
    #      not work.
    #
    #   2. You're trying to run PyTorch under UBSAN and you need
    #      to ensure that only one copy of libtorch is loaded, so
    #      vptr checks work properly
    #
    # If you're using this setting, you must verify that all the libraries
    # you load consistently use the same libstdc++, or you may have
    # mysterious segfaults.
    #
    import os as _dl_flags
    if not hasattr(_dl_flags, 'RTLD_GLOBAL') or not hasattr(_dl_flags, 'RTLD_LAZY'):
        try:
            # next try if DLFCN exists
            import DLFCN as _dl_flags  # type: ignore
        except ImportError:
            # as a last attempt, use compile-time constants
            import torch._dl as _dl_flags  # type: ignore
    old_flags = sys.getdlopenflags()
    sys.setdlopenflags(_dl_flags.RTLD_GLOBAL | _dl_flags.RTLD_LAZY)
    from torch._C import *
    sys.setdlopenflags(old_flags)
    del old_flags
    del _dl_flags

else:
    # Easy way.  You want this most of the time, because it will prevent
    # C++ symbols from libtorch clobbering C++ symbols from other
    # libraries, leading to mysterious segfaults.
    #
    # If building in an environment where libtorch_global_deps isn't available
    # like parts of fbsource, but where RTLD_GLOBAL causes segfaults, you will
    # want USE_RTLD_GLOBAL_WITH_LIBTORCH = False and USE_GLOBAL_DEPS = False
    #
    # See Note [Global dependencies]
    if USE_GLOBAL_DEPS:
        _load_global_deps()
    from torch._C import *

# Appease the type checker; ordinarily this binding is inserted by the
# torch._C module initialization code in C
if TYPE_CHECKING:
    import torch._C as _C

# Check to see if we can load C extensions, and if not provide some guidance
# on what the problem might be.
try:
    # _initExtension is chosen (arbitrarily) as a sentinel.
    from torch._C import _initExtension
except ImportError:
    import torch._C as _C_for_compiled_check

    # The __file__ check only works for Python 3.7 and above.
    if sys.version_info >= (3, 7) and _C_for_compiled_check.__file__ is None:
        raise ImportError(textwrap.dedent('''
            Failed to load PyTorch C extensions:
                It appears that PyTorch has loaded the `torch/_C` folder
                of the PyTorch repository rather than the C extensions which
                are expected in the `torch._C` namespace. This can occur when
                using the `install` workflow. e.g.
                    $ python setup.py install && python -c "import torch"

                This error can generally be solved using the `develop` workflow
                    $ python setup.py develop && python -c "import torch"  # This should succeed
                or by running Python from a different directory.
            ''').strip()) from None
    raise  # If __file__ is not None the cause is unknown, so just re-raise.


__all__ += [name for name in dir(_C)
            if name[0] != '_' and
            not name.endswith('Base')]

################################################################################
# Define basic utilities
################################################################################


def typename(o):
    if isinstance(o, torch.Tensor):
        return o.type()

    module = ''
    class_name = ''
    if hasattr(o, '__module__') and o.__module__ != 'builtins' \
            and o.__module__ != '__builtin__' and o.__module__ is not None:
        module = o.__module__ + '.'

    if hasattr(o, '__qualname__'):
        class_name = o.__qualname__
    elif hasattr(o, '__name__'):
        class_name = o.__name__
    else:
        class_name = o.__class__.__name__

    return module + class_name


def is_tensor(obj):
    r"""Returns True if `obj` is a PyTorch tensor.

    Note that this function is simply doing ``isinstance(obj, Tensor)``.
    Using that ``isinstance`` check is better for typechecking with mypy,
    and more explicit - so it's recommended to use that instead of
    ``is_tensor``.

    Args:
        obj (Object): Object to test
    """
    return isinstance(obj, torch.Tensor)


def is_storage(obj):
    r"""Returns True if `obj` is a PyTorch storage object.

    Args:
        obj (Object): Object to test
    """
    return type(obj) in _storage_classes


def set_default_tensor_type(t):
    r"""Sets the default ``torch.Tensor`` type to floating point tensor type
    ``t``. This type will also be used as default floating point type for
    type inference in :func:`torch.tensor`.

    The default floating point tensor type is initially ``torch.FloatTensor``.

    Args:
        t (type or string): the floating point tensor type or its name

    Example::

        >>> torch.tensor([1.2, 3]).dtype    # initial default for floating point is torch.float32
        torch.float32
        >>> torch.set_default_tensor_type(torch.DoubleTensor)
        >>> torch.tensor([1.2, 3]).dtype    # a new floating point tensor
        torch.float64

    """
    if isinstance(t, _string_classes):
        t = _import_dotted_name(t)
    _C._set_default_tensor_type(t)


def set_default_dtype(d):
    r"""Sets the default floating point dtype to :attr:`d`.
    This dtype is:

    1. The inferred dtype for python floats in :func:`torch.tensor`.
    2. Used to infer dtype for python complex numbers. The default complex dtype is set to
       ``torch.complex128`` if default floating point dtype is ``torch.float64``,
       otherwise it's set to ``torch.complex64``

    The default floating point dtype is initially ``torch.float32``.

    Args:
        d (:class:`torch.dtype`): the floating point dtype to make the default

    Example:
        >>> # initial default for floating point is torch.float32
        >>> torch.tensor([1.2, 3]).dtype
        torch.float32
        >>> # initial default for floating point is torch.complex64
        >>> torch.tensor([1.2, 3j]).dtype
        torch.complex64
        >>> torch.set_default_dtype(torch.float64)
        >>> torch.tensor([1.2, 3]).dtype    # a new floating point tensor
        torch.float64
        >>> torch.tensor([1.2, 3j]).dtype   # a new complex tensor
        torch.complex128

    """
    _C._set_default_dtype(d)

def use_deterministic_algorithms(d):
    r""" Sets whether PyTorch operations must use "deterministic"
    algorithms. That is, algorithms which, given the same input, and when
    run on the same software and hardware, always produce the same output.
    When True, operations will use deterministic algorithms when available,
    and if only nondeterministic algorithms are available they will throw a
    :class:RuntimeError when called.

    .. warning::
        This feature is in beta, and its design and implementation may change
        in the future.