# Copyright (c) 2024-2025 Microsoft
# Licensed under The MIT License [see LICENSE for details]

import os
import platform
import subprocess
import sys
import urllib
import warnings

import torch
from packaging.version import parse
from setuptools import find_packages, setup
from torch.utils.cpp_extension import CUDA_HOME, BuildExtension, CUDAExtension
from wheel.bdist_wheel import bdist_wheel as _bdist_wheel

# PEP0440 compatible formatted version, see:
# https://www.python.org/dev/peps/pep-0440/
#
# release markers:
#   X.Y
#   X.Y.Z   # For bugfix releases
#
# pre-release markers:
#   X.YaN   # Alpha release
#   X.YbN   # Beta release
#   X.YrcN  # Release Candidate
#   X.Y     # Final release

# version.py defines the VERSION and VERSION_SHORT variables.
# We use exec here so we don't import allennlp whilst setting up.
VERSION = {}  # type: ignore
with open("minference/version.py", "r") as version_file:
    exec(version_file.read(), VERSION)

INSTALL_REQUIRES = [
    "transformers>=4.37.0",
    "accelerate",
    "torch",
    "triton",
    "einops",
]
QUANLITY_REQUIRES = [
    "black==21.4b0",
    "flake8>=3.8.3",
    "isort>=5.5.4",
    "pre-commit",
    "pytest",
    "pytest-xdist",
]
DEV_REQUIRES = INSTALL_REQUIRES + QUANLITY_REQUIRES


# ninja build does not work unless include_dirs are abs path
this_dir = os.path.dirname(os.path.abspath(__file__))

PACKAGE_NAME = "minference"

BASE_WHEEL_URL = (
    "https://github.com/microsoft/MInference/releases/download/{tag_name}/{wheel_name}"
)

# FORCE_BUILD: Force a fresh build locally, instead of attempting to find prebuilt wheels
# SKIP_CUDA_BUILD: Intended to allow CI to use a simple `python setup.py sdist` run to copy over raw files, without any cuda compilation
FORCE_BUILD = os.getenv("MINFERENCE_FORCE_BUILD", "FALSE") == "TRUE"
SKIP_CUDA_BUILD = os.getenv("MINFERENCE_SKIP_CUDA_BUILD", "FALSE") == "TRUE"


def check_if_cuda_home_none(global_option: str) -> None:
    if CUDA_HOME is not None:
        return
    # warn instead of error because user could be downloading prebuilt wheels, so nvcc won't be necessary
    # in that case.
    warnings.warn(
        f"{global_option} was requested, but nvcc was not found.  Are you sure your environment has nvcc available?  "
        "If you're installing within a container from https://hub.docker.com/r/pytorch/pytorch, "
        "only images whose names contain 'devel' will provide nvcc."
    )


cmdclass = {}
ext_modules = []

if not SKIP_CUDA_BUILD:
    print("\n\ntorch.__version__  = {}\n\n".format(torch.__version__))
    TORCH_MAJOR = int(torch.__version__.split(".")[0])
    TORCH_MINOR = int(torch.__version__.split(".")[1])

    # Check, if ATen/CUDAGeneratorImpl.h is found, otherwise use ATen/cuda/CUDAGeneratorImpl.h
    # See https://github.com/pytorch/pytorch/pull/70650
    generator_flag = []
    torch_dir = torch.__path__[0]
    if os.path.exists(
        os.path.join(torch_dir, "include", "ATen", "CUDAGeneratorImpl.h")
    ):
        generator_flag = ["-DOLD_GENERATOR_PATH"]

    check_if_cuda_home_none("minference")

    ext_modules.append(
        CUDAExtension(
            name="minference.cuda",
            sources=[
                os.path.join("csrc", "kernels.cpp"),
                os.path.join("csrc", "vertical_slash_index.cu"),
            ],
            extra_compile_args=["-std=c++17", "-O3"],
        )
    )


def get_minference_version() -> str:
    version = VERSION["VERSION"]

    local_version = os.environ.get("MINFERENCE_LOCAL_VERSION")
    if local_version:
        return f"{version}+{local_version}"
    else:
        return str(version)


def get_platform():
    """
    Returns the platform name as used in wheel filenames.
    """
    if sys.platform.startswith("linux"):
        return f"linux_{platform.uname().machine}"
    elif sys.platform == "darwin":
        mac_version = ".".join(platform.mac_ver()[0].split(".")[:2])
        return f"macosx_{mac_version}_x86_64"
    elif sys.platform == "win32":
        return "win_amd64"
    else:
        raise ValueError("Unsupported platform: {}".format(sys.platform))


def get_wheel_url():
    # Determine the version numbers that will be used to determine the correct wheel
    # We're using the CUDA version used to build torch, not the one currently installed
    # _, cuda_version_raw = get_cuda_bare_metal_version(CUDA_HOME)
    torch_cuda_version = parse(torch.version.cuda)
    torch_version_raw = parse(torch.__version__)
    # For CUDA 11, we only compile for CUDA 11.8, and for CUDA 12 we only compile for CUDA 12.2
    # to save CI time. Minor versions should be compatible.
    torch_cuda_version = (
        parse("11.8") if torch_cuda_version.major == 11 else parse("12.2")
    )
    python_version = f"cp{sys.version_info.major}{sys.version_info.minor}"
    platform_name = get_platform()
    minference_version = get_minference_version()
    # cuda_version = f"{cuda_version_raw.major}{cuda_version_raw.minor}"
    cuda_version = f"{torch_cuda_version.major}{torch_cuda_version.minor}"
    torch_version = f"{torch_version_raw.major}.{torch_version_raw.minor}"

    # Determine wheel URL based on CUDA version, torch version, python version and OS
    wheel_filename = f"{PACKAGE_NAME}-{minference_version}+cu{cuda_version}torch{torch_version}-{python_version}-{python_version}-{platform_name}.whl"
    wheel_url = BASE_WHEEL_URL.format(
        tag_name=f"v{minference_version}", wheel_name=wheel_filename
    )
    return wheel_url, wheel_filename


class CachedWheelsCommand(_bdist_wheel):
    """
    The CachedWheelsCommand plugs into the default bdist wheel, which is ran by pip when it cannot
    find an existing wheel (which is currently the case for all flash attention installs). We use
    the environment parameters to detect whether there is already a pre-built version of a compatible
    wheel available and short-circuits the standard full build pipeline.
    """

    def run(self):
        if FORCE_BUILD:
            return super().run()
        wheel_url, wheel_filename = get_wheel_url()
        print("Guessing wheel URL: ", wheel_url)
        try:
            urllib.request.urlretrieve(wheel_url, wheel_filename)

            # Make the archive
            # Lifted from the root wheel processing command
            # https://github.com/pypa/wheel/blob/cf71108ff9f6ffc36978069acb28824b44ae028e/src/wheel/bdist_wheel.py#LL381C9-L381C85
            if not os.path.exists(self.dist_dir):
                os.makedirs(self.dist_dir)

            impl_tag, abi_tag, plat_tag = self.get_tag()
            archive_basename = f"{self.wheel_dist_name}-{impl_tag}-{abi_tag}-{plat_tag}"

            wheel_path = os.path.join(self.dist_dir, archive_basename + ".whl")
            print("Raw wheel path", wheel_path)
            os.rename(wheel_filename, wheel_path)
        except (urllib.error.HTTPError, urllib.error.URLError):
            print("Precompiled wheel not found. Building from source...")
            # If the wheel could not be downloaded, build from source
            super().run()


class NinjaBuildExtension(BuildExtension):
    def __init__(self, *args, **kwargs) -> None:
        # do not override env MAX_JOBS if already exists
        if not os.environ.get("MAX_JOBS"):
            import psutil

            # calculate the maximum allowed NUM_JOBS based on cores
            max_num_jobs_cores = max(1, os.cpu_count() // 2)

            # calculate the maximum allowed NUM_JOBS based on free memory
            free_memory_gb = psutil.virtual_memory().available / (
                1024**3
            )  # free memory in GB
            max_num_jobs_memory = int(
                free_memory_gb / 9
            )  # each JOB peak memory cost is ~8-9GB when threads = 4

            # pick lower value of jobs based on cores vs memory metric to minimize oom and swap usage during compilation
            max_jobs = max(1, min(max_num_jobs_cores, max_num_jobs_memory))
            os.environ["MAX_JOBS"] = str(max_jobs)

        super().__init__(*args, **kwargs)


setup(
    name="minference",
    version=get_minference_version(),
    author="The MInference team",
    author_email="hjiang@microsoft.com",
    description="To speed up Long-context LLMs' inference, approximate and dynamic sparse calculate the attention, which reduces inference latency by up to 10x for pre-filling on an A100 while maintaining accuracy.",
    long_description=open("README.md", encoding="utf8").read(),
    long_description_content_type="text/markdown",
    keywords="LLMs Inference, Long-Context LLMs, Dynamic Sparse Attention, Efficient Inference",
    license="MIT License",
    url="https://github.com/microsoft/MInference",
    classifiers=[
        "Intended Audience :: Science/Research",
        "Development Status :: 3 - Alpha",
        "Programming Language :: Python :: 3",
        "Topic :: Scientific/Engineering :: Artificial Intelligence",
    ],
    packages=find_packages(
        exclude=(
            "csrc",
            "dist",
            "examples",
            "experiments",
            "images",
            "test",
            "minference.egg-info",
        )
    ),
    extras_require={
        "dev": DEV_REQUIRES,
        "quality": QUANLITY_REQUIRES,
    },
    install_requires=INSTALL_REQUIRES,
    setup_requires=[
        "packaging",
        "psutil",
        "ninja",
    ],
    include_package_data=True,
    python_requires=">=3.8.0",
    zip_safe=False,
    ext_modules=ext_modules,
    cmdclass={"bdist_wheel": CachedWheelsCommand, "build_ext": NinjaBuildExtension}
    if ext_modules
    else {
        "bdist_wheel": CachedWheelsCommand,
    },
)
