import os
import re
import subprocess
import sys

import pybind11
from setuptools import setup, Extension
from setuptools.command.build_ext import build_ext

project_path = os.path.dirname(os.path.realpath(__file__))


# A CMakeExtension needs a sourcedir instead of a file list.
# The name must be the _single_ output extension from the CMake build.
# If you need multiple extensions, see scikit-build.
class CMakeExtension(Extension):
    def __init__(self, name, sourcedir=""):
        Extension.__init__(self, name, sources=[])
        self.sourcedir = os.path.abspath(sourcedir)


class CMakeBuild(build_ext):
    def build_extension(self, ext):
        from setuptools_scm import get_version

        version = get_version(root='.', relative_to=__file__)

        extdir = os.path.abspath(os.path.dirname(self.get_ext_fullpath(ext.name)))

        # required for auto-detection of auxiliary "native" libs
        if not extdir.endswith(os.path.sep):
            extdir += os.path.sep

        cfg = "Debug" if self.debug else "RelWithDebInfo"
        if 'QUICKTEX_DEBUG' in os.environ:
            cfg = "Debug"

        # CMake lets you override the generator - we need to check this.
        # Can be set with Conda-Build, for example.
        cmake_generator = os.environ.get("CMAKE_GENERATOR", "")

        # Set Python_EXECUTABLE instead if you use PYBIND11_FINDPYTHON
        cmake_args = [
            "-DCMAKE_LIBRARY_OUTPUT_DIRECTORY={}".format(extdir),
            "-Dpybind11_DIR={}".format(pybind11.get_cmake_dir()),
            "-DPython_EXECUTABLE={}".format(sys.executable),
            "-DPython_ROOT_DIR={}".format(os.path.dirname(sys.executable)),
            "-DQUICKTEX_VERSION_INFO={}".format(version),  # include version info in module
            "-DQUICKTEX_MODULE_ONLY=TRUE",  # only build the module, not the wrapper
            "-DCMAKE_BUILD_TYPE={}".format(cfg),  # not used on MSVC, but no harm
            # clear cached make program binary, see https://github.com/pypa/setuptools/issues/2912
            "-U",
            "CMAKE_MAKE_PROGRAM",
        ]
        build_args = []

        if self.compiler.compiler_type != "msvc":
            # Using Ninja-build since it a) is available as a wheel and b)
            # multithreads automatically. MSVC would require all variables be
            # exported for Ninja to pick it up, which is a little tricky to do.
            # Users can override the generator with CMAKE_GENERATOR in CMake
            # 3.15+.
            if not cmake_generator:
                cmake_args += ["-GNinja"]

        else:
            # Single config generators are handled "normally"
            single_config = any(x in cmake_generator for x in {"NMake", "Ninja"})

            # CMake allows an arch-in-generator style for backward compatibility
            contains_arch = any(x in cmake_generator for x in {"ARM", "Win64"})

            # Convert distutils Windows platform specifiers to CMake -A arguments
            plat_to_cmake = {"win32": "Win32", "win-amd64": "x64", "win-arm32": "ARM", "win-arm64": "ARM64"}

            # Specify the arch if using MSVC generator, but only if it doesn't
            # contain a backward-compatibility arch spec already in the
            # generator name.
            if not single_config and not contains_arch:
                cmake_args += ["-A", plat_to_cmake[self.plat_name]]

            # Multi-config generators have a different way to specify configs
            if not single_config:
                cmake_args += ["-DCMAKE_LIBRARY_OUTPUT_DIRECTORY_{}={}".format(cfg.upper(), extdir)]
                build_args += ["--config", cfg]

        if sys.platform.startswith("darwin"):
            # Cross-compile support for macOS - respect ARCHFLAGS if set
            archs = re.findall(r"-arch (\S+)", os.environ.get("ARCHFLAGS", ""))
            if archs:
                cmake_args += ["-DCMAKE_OSX_ARCHITECTURES={}".format(";".join(archs))]

        # Set CMAKE_BUILD_PARALLEL_LEVEL to control the parallel build level
        # across all generators.
        if "CMAKE_BUILD_PARALLEL_LEVEL" not in os.environ:
            # self.parallel is a Python 3 only way to set parallel jobs by hand
            # using -j in the build_ext call, not supported by pip or PyPA-build.
            if hasattr(self, "parallel") and self.parallel:
                # CMake 3.12+ only.
                build_args += ["-j{}".format(self.parallel)]

        if not os.path.exists(self.build_temp):
            os.makedirs(self.build_temp)

        subprocess.check_call(["cmake", ext.sourcedir] + cmake_args, cwd=self.build_temp)
        subprocess.check_call(["cmake", "--build", ".", "--target", ext.name] + build_args, cwd=self.build_temp)


# The information here can also be placed in setup.cfg - better separation of
# logic and declaration, and simpler if you include description/version in a file.
setup(use_scm_version=True, ext_modules=[CMakeExtension("_quicktex")], cmdclass={"build_ext": CMakeBuild})