# coding=utf-8

# SPDX-FileCopyrightText: Copyright (c) 2022 The torch-harmonics Authors. All rights reserved.
# SPDX-License-Identifier: BSD-3-Clause
#
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import os, sys
import warnings

from setuptools import setup, find_packages
from setuptools.command.install import install

# some code to handle the building of custom modules
FORCE_CUDA_EXTENSION = os.getenv("FORCE_CUDA_EXTENSION", "0") == "1"
BUILD_CPP = BUILD_CUDA = False

# try to import torch
try:
    import torch

    print(f"setup.py with torch {torch.__version__}")
    from torch.utils.cpp_extension import BuildExtension, CppExtension

    BUILD_CPP = True
    from torch.utils.cpp_extension import CUDA_HOME, CUDAExtension

    BUILD_CUDA = FORCE_CUDA_EXTENSION or (torch.cuda.is_available() and (CUDA_HOME is not None))
except (ImportError, TypeError, AssertionError, AttributeError) as e:
    warnings.warn(f"building custom extensions skipped: {e}")

def get_compile_args(module_name):
    """If user runs build with TORCH_HARMONICS_DEBUG=1 set, it will use debugging flags to build"""
    debug_mode = os.environ.get('TORCH_HARMONICS_DEBUG', '0') == '1'
    if debug_mode:
        print(f"WARNING: Compiling {module_name} with debugging flags")
        return {
            'cxx': ['-g', '-O0', '-Wall'],
            'nvcc': ['-g', '-G', '-O0']
        }
    else:
        print(f"NOTE: Compiling {module_name} with release flags")
        return {
            'cxx': ['-O3', "-DNDEBUG"],
            'nvcc': ['-O3', "-DNDEBUG"]
        }

def get_ext_modules():

    ext_modules = []
    cmdclass = {}

    if BUILD_CPP:
        print(f"Compiling helper routines for torch-harmonics.")
        ext_modules.append(CppExtension("disco_helpers", ["torch_harmonics/csrc/disco/disco_helpers.cpp"]))
        cmdclass["build_ext"] = BuildExtension

    if BUILD_CUDA:
        print(f"Compiling custom CUDA kernels for torch-harmonics.")
        ext_modules.append(
            CUDAExtension(
                "disco_cuda_extension",
                [
                    "torch_harmonics/csrc/disco/disco_interface.cu",
                    "torch_harmonics/csrc/disco/disco_cuda_fwd.cu",
                    "torch_harmonics/csrc/disco/disco_cuda_bwd.cu",
                ],
                extra_compile_args=get_compile_args("disco")
            )
        )
        ext_modules.append(
            CUDAExtension(
                name="attention_cuda_extension",
                sources=[
                    "torch_harmonics/csrc/attention/attention_fwd_cuda.cu",
                    "torch_harmonics/csrc/attention/attention_bwd_cuda.cu",
                    "torch_harmonics/csrc/attention/attention_interface.cu",
                    "torch_harmonics/csrc/attention/attention_row_offset.cu"
                ],
                extra_compile_args=get_compile_args("neighborhood_attention")
            )
        )
        cmdclass["build_ext"] = BuildExtension

    return ext_modules, cmdclass

if __name__ == "__main__":

    ext_modules, cmdclass = get_ext_modules()

    setup(
        packages=find_packages(),
        ext_modules=ext_modules,
        cmdclass=cmdclass,
    )