############################################################################
# Copyright (c) Wolf Vollprecht, Johan Mabille and Sylvain Corlay          #
# Copyright (c) QuantStack                                                 #
#                                                                          #
# Distributed under the terms of the BSD 3-Clause License.                 #
#                                                                          #
# The full license is in the file LICENSE, distributed with this software. #
############################################################################

from setuptools import setup, Extension
from setuptools.command.build_ext import build_ext
import sys
import os
import setuptools

__version__ = '0.0.1'


class get_pybind_include(object):
    """Helper class to determine the pybind11 include path

    The purpose of this class is to postpone importing pybind11
    until it is actually installed, so that the ``get_include()``
    method can be invoked. """

    def __init__(self, user=False):
        self.user = user

    def __str__(self):
        import pybind11
        return pybind11.get_include(self.user)

class get_numpy_include(object):
    """Helper class to determine the numpy include path

    The purpose of this class is to postpone importing numpy
    until it is actually installed, so that the ``get_include()``
    method can be invoked. """

    def __str__(self):
        import numpy
        return numpy.get_include()

ext_modules = [
    Extension(
        'xtensor_python_test',
        ['main.cpp'],
        include_dirs=[
            # Path to pybind11 headers
            '../include/',
            get_pybind_include(),
            get_pybind_include(user=True),
            # Path to numpy headers
            get_numpy_include(),
            os.path.join(sys.prefix, 'include'),
            os.path.join(sys.prefix, 'Library', 'include')
        ],
        language='c++'
    ),
]


def has_flag(compiler, flagname):
    """Return a boolean indicating whether a flag name is supported on
    the specified compiler.
    """
    import tempfile
    with tempfile.NamedTemporaryFile('w', suffix='.cpp') as f:
        f.write('int main (int argc, char **argv) { return 0; }')
        try:
            compiler.compile([f.name], extra_postargs=[flagname])
        except setuptools.distutils.errors.CompileError:
            return False
    return True


def cpp_flag(compiler):
    """Return the -std=c++17 compiler flag  and errors when the flag is
    no available.
    """
    if has_flag(compiler, '-std=c++20'):
        return '-std=c++20'
    else:
        raise RuntimeError('C++17 support is required by xtensor!')


class BuildExt(build_ext):
    """A custom build extension for adding compiler-specific options."""
    c_opts = {
        'msvc': ['/EHsc'],
        'unix': [],
    }

    if sys.platform == 'darwin':
        c_opts['unix'] += ['-stdlib=libc++', '-mmacosx-version-min=10.13']

    def build_extensions(self):
        ct = self.compiler.compiler_type
        opts = self.c_opts.get(ct, [])
        if ct == 'unix':
            opts.append('-DVERSION_INFO="%s"' % self.distribution.get_version())
            opts.append(cpp_flag(self.compiler))
            if has_flag(self.compiler, '-fvisibility=hidden'):
                opts.append('-fvisibility=hidden')
        elif ct == 'msvc':
            opts.append('/DVERSION_INFO=\\"%s\\"' % self.distribution.get_version())
            opts.append('/std:c++20')
        for ext in self.extensions:
            ext.extra_compile_args = opts
        build_ext.build_extensions(self)

setup(
    name='xtensor_python_test',
    version=__version__,
    author='Sylvain Corlay',
    author_email='sylvain.corlay@gmail.com',
    url='https://github.com/pybind/python_example',
    description='An example project using xtensor-python',
    long_description='',
    ext_modules=ext_modules,
    install_requires=['pybind11>=2.0.1'],
    cmdclass={'build_ext': BuildExt},
    zip_safe=False,
)