import os
import sys
from datetime import datetime
from typing import List

from setuptools import find_packages, setup

from op_builder.utils import (
    check_cuda_availability,
    check_pytorch_version,
    check_system_pytorch_cuda_match,
    get_cuda_bare_metal_version,
    get_pytorch_version,
    set_cuda_arch_list,
)

try:
    from torch.utils.cpp_extension import CUDA_HOME, BuildExtension

    TORCH_AVAILABLE = True
except ImportError:
    TORCH_AVAILABLE = False
    CUDA_HOME = None

# Some constants for installation checks
MIN_PYTORCH_VERSION_MAJOR = 1
MIN_PYTORCH_VERSION_MINOR = 10
THIS_DIR = os.path.dirname(os.path.abspath(__file__))
BUILD_CUDA_EXT = int(os.environ.get("CUDA_EXT", "0")) == 1
IS_NIGHTLY = int(os.environ.get("NIGHTLY", "0")) == 1

# a variable to store the op builder
ext_modules = []

# we do not support windows currently
if sys.platform == "win32":
    raise RuntimeError("Windows is not supported yet. Please try again within the Windows Subsystem for Linux (WSL).")


# check for CUDA extension dependencies
def environment_check_for_cuda_extension_build():
    if not TORCH_AVAILABLE:
        raise ModuleNotFoundError(
            "[extension] PyTorch is not found while CUDA_EXT=1. You need to install PyTorch first in order to build CUDA extensions"
        )

    if not CUDA_HOME:
        raise RuntimeError(
            "[extension] CUDA_HOME is not found while CUDA_EXT=1. You need to export CUDA_HOME environment variable or install CUDA Toolkit first in order to build CUDA extensions"
        )

    check_system_pytorch_cuda_match(CUDA_HOME)
    check_pytorch_version(MIN_PYTORCH_VERSION_MAJOR, MIN_PYTORCH_VERSION_MINOR)
    check_cuda_availability()


def fetch_requirements(path) -> List[str]:
    """
    This function reads the requirements file.

    Args:
        path (str): the path to the requirements file.

    Returns:
        The lines in the requirements file.
    """
    with open(path, "r") as fd:
        return [r.strip() for r in fd.readlines()]


def fetch_readme() -> str:
    """
    This function reads the README.md file in the current directory.

    Returns:
        The lines in the README file.
    """
    with open("README.md", encoding="utf-8") as f:
        return f.read()


def get_version() -> str:
    """
    This function reads the version.txt and generates the colossalai/version.py file.

    Returns:
        The library version stored in version.txt.
    """

    setup_file_path = os.path.abspath(__file__)
    project_path = os.path.dirname(setup_file_path)
    version_txt_path = os.path.join(project_path, "version.txt")
    version_py_path = os.path.join(project_path, "colossalai/version.py")

    with open(version_txt_path) as f:
        version = f.read().strip()

    # write version into version.py
    with open(version_py_path, "w") as f:
        f.write(f"__version__ = '{version}'\n")

        # look for pytorch and cuda version
        if BUILD_CUDA_EXT:
            torch_major, torch_minor, _ = get_pytorch_version()
            torch_version = f"{torch_major}.{torch_minor}"
            cuda_version = ".".join(get_cuda_bare_metal_version(CUDA_HOME))
        else:
            torch_version = None
            cuda_version = None

        # write the version into the python file
        if torch_version:
            f.write(f'torch = "{torch_version}"\n')
        else:
            f.write("torch = None\n")

        if cuda_version:
            f.write(f'cuda = "{cuda_version}"\n')
        else:
            f.write("cuda = None\n")

    return version


if BUILD_CUDA_EXT:
    environment_check_for_cuda_extension_build()
    set_cuda_arch_list(CUDA_HOME)

    from op_builder import ALL_OPS

    op_names = []

    # load all builders
    for name, builder_cls in ALL_OPS.items():
        op_names.append(name)
        ext_modules.append(builder_cls().builder())

    # show log
    op_name_list = ", ".join(op_names)
    print(f"[extension]  loaded builders for {op_name_list}")

# always put not nightly branch as the if branch
# otherwise github will treat colossalai-nightly as the project name
# and it will mess up with the dependency graph insights
if not IS_NIGHTLY:
    version = get_version()
    package_name = "colossalai"
else:
    # use date as the nightly version
    version = datetime.today().strftime("%Y.%m.%d")
    package_name = "colossalai-nightly"

setup(
    name=package_name,
    version=version,
    packages=find_packages(
        exclude=(
            "op_builder",
            "benchmark",
            "docker",
            "tests",
            "docs",
            "examples",
            "tests",
            "scripts",
            "requirements",
            "*.egg-info",
        )
    ),
    description="An integrated large-scale model training system with efficient parallelization techniques",
    long_description=fetch_readme(),
    long_description_content_type="text/markdown",
    license="Apache Software License 2.0",
    url="https://www.colossalai.org",
    project_urls={
        "Forum": "https://github.com/hpcaitech/ColossalAI/discussions",
        "Bug Tracker": "https://github.com/hpcaitech/ColossalAI/issues",
        "Examples": "https://github.com/hpcaitech/ColossalAI-Examples",
        "Documentation": "http://colossalai.readthedocs.io",
        "Github": "https://github.com/hpcaitech/ColossalAI",
    },
    ext_modules=ext_modules,
    cmdclass={"build_ext": BuildExtension} if ext_modules else {},
    install_requires=fetch_requirements("requirements/requirements.txt"),
    entry_points="""
        [console_scripts]
        colossalai=colossalai.cli:cli
    """,
    python_requires=">=3.6",
    classifiers=[
        "Programming Language :: Python :: 3",
        "License :: OSI Approved :: Apache Software License",
        "Environment :: GPU :: NVIDIA CUDA",
        "Topic :: Scientific/Engineering :: Artificial Intelligence",
        "Topic :: System :: Distributed Computing",
    ],
    package_data={
        "colossalai": [
            "_C/*.pyi",
            "kernel/cuda_native/csrc/*",
            "kernel/cuda_native/csrc/kernel/*",
            "kernel/cuda_native/csrc/kernels/include/*",
        ]
    },
)