# No 3rd-party modules here, see "3rd-party" note below
import io
import os
import os.path
import sys
import runpy
import subprocess
import re
import sysconfig


def main():

    os.chdir(os.path.dirname(os.path.abspath(__file__)))

    # These are neede for source fetching
    cmake_source_dir = "opencv"
    build_contrib = get_build_env_var_by_name("contrib")
    # headless flag to skip GUI deps if needed
    build_headless = get_build_env_var_by_name("headless")

    # Only import 3rd-party modules after having installed all the build dependencies:
    # any of them, or their dependencies, can be updated during that process,
    # leading to version conflicts
    minimum_supported_numpy = "1.11.1"

    if sys.version_info[:2] >= (3, 6):
        minimum_supported_numpy = "1.11.3"
    if sys.version_info[:2] >= (3, 7):
        minimum_supported_numpy = "1.14.5"

    numpy_version = get_or_install("numpy", minimum_supported_numpy)
    get_or_install("scikit-build")
    import skbuild

    if os.path.exists('.git'):

        import pip._internal.vcs.git as git
        g = git.Git()  # NOTE: pip API's are internal, this has to be refactored

        g.run_command(["submodule", "sync"])
        g.run_command(["submodule", "update", "--init", "--recursive", cmake_source_dir])

        if build_contrib:
            g.run_command(["submodule", "update", "--init", "--recursive", "opencv_contrib"])

    # https://stackoverflow.com/questions/1405913/python-32bit-or-64bit-mode
    x64 = sys.maxsize > 2**32

    package_name = "opencv-python"

    if build_contrib and not build_headless:
        package_name = "opencv-contrib-python"

    if build_contrib and build_headless:
        package_name = "opencv-contrib-python-headless"

    if build_headless and not build_contrib:
        package_name = "opencv-python-headless"

    long_description = io.open('README.md', encoding="utf-8").read()
    package_version = get_opencv_version()

    packages = ['cv2', 'cv2.data']

    package_data = {
        'cv2':
            ['*%s' % sysconfig.get_config_var('SO')] +
            (['*.dll'] if os.name == 'nt' else []) +
            ["LICENSE.txt", "LICENSE-3RD-PARTY.txt"],
        'cv2.data':
            ["*.xml"]
    }

    # Files from CMake output to copy to package.
    # Path regexes with forward slashes relative to CMake install dir.
    rearrange_cmake_output_data = {

        'cv2': ([r'bin/opencv_videoio_ffmpeg\d{3}%s\.dll' % ('_64' if x64 else '')] if os.name == 'nt' else []) +
        # In Windows, in python/X.Y/<arch>/; in Linux, in just python/X.Y/.
        # Naming conventions vary so widely between versions and OSes
        # had to give up on checking them.
        ['python/cv2[^/]*%(ext)s' % {'ext': re.escape(sysconfig.get_config_var('SO'))}],

        'cv2.data': [  # OPENCV_OTHER_INSTALL_PATH
            ('etc' if os.name == 'nt' else 'share/opencv4') +
            r'/haarcascades/.*\.xml'
        ]
    }

    # Files in sourcetree outside package dir that should be copied to package.
    # Raw paths relative to sourcetree root.
    files_outside_package_dir = {
        'cv2': ['LICENSE.txt', 'LICENSE-3RD-PARTY.txt']
    }

    cmake_args = ([
        "-G", "Visual Studio 14" + (" Win64" if x64 else '')
    ] if os.name == 'nt' else [
        "-G", "Unix Makefiles"  # don't make CMake try (and fail) Ninja first
    ]) + [
        # skbuild inserts PYTHON_* vars. That doesn't satisfy opencv build scripts in case of Py3
        "-DPYTHON%d_EXECUTABLE=%s" % (sys.version_info[0], sys.executable),
        "-DBUILD_opencv_python%d=ON" % sys.version_info[0],

        # When off, adds __init__.py and a few more helper .py's. We use our own helper files with a different structure.
        "-DOPENCV_SKIP_PYTHON_LOADER=ON",
        # Relative dir to install the built module to in the build tree.
        # The default is generated from sysconfig, we'd rather have a constant for simplicity
        "-DOPENCV_PYTHON%d_INSTALL_PATH=python" % sys.version_info[0],
        # Otherwise, opencv scripts would want to install `.pyd' right into site-packages,
        # and skbuild bails out on seeing that
        "-DINSTALL_CREATE_DISTRIB=ON",

        # See opencv/CMakeLists.txt for options and defaults
        "-DBUILD_opencv_apps=OFF",
        "-DBUILD_SHARED_LIBS=OFF",
        "-DBUILD_TESTS=OFF",
        "-DBUILD_PERF_TESTS=OFF",
        "-DBUILD_DOCS=OFF"
    ] + (["-DOPENCV_EXTRA_MODULES_PATH=" + os.path.abspath("opencv_contrib/modules")] if build_contrib else [])

    # OS-specific components
    if (sys.platform == 'darwin' or sys.platform.startswith('linux')) and not build_headless:
        cmake_args.append("-DWITH_QT=4")

    if build_headless:
        # it seems that cocoa cannot be disabled so on macOS the package is not truly headless
        cmake_args.append("-DWITH_WIN32UI=OFF")
        cmake_args.append("-DWITH_QT=OFF")

    if sys.platform.startswith('linux'):
        cmake_args.append("-DWITH_V4L=ON")
        cmake_args.append("-DENABLE_PRECOMPILED_HEADERS=OFF")

    # Fixes for macOS builds
    if sys.platform == 'darwin':
        cmake_args.append("-DWITH_LAPACK=OFF")  # Some OSX LAPACK fns are incompatible, see
                                                # https://github.com/skvark/opencv-python/issues/21
        cmake_args.append("-DCMAKE_CXX_FLAGS=-stdlib=libc++")
        cmake_args.append("-DCMAKE_OSX_DEPLOYMENT_TARGET:STRING=10.8")

    if sys.platform.startswith('linux'):
        cmake_args.append("-DWITH_IPP=OFF")   # tests fail with IPP compiled with
                                              # devtoolset-2 GCC 4.8.2 or vanilla GCC 4.9.4
                                              # see https://github.com/skvark/opencv-python/issues/138
    if sys.platform.startswith('linux') and not x64:
        cmake_args.append("-DCMAKE_CXX_FLAGS=-U__STRICT_ANSI__")
        # patch openEXR when building on i386, see: https://github.com/openexr/openexr/issues/128
        subprocess.check_call("patch -p0 < patches/patchOpenEXR", shell=True)


    if 'CMAKE_ARGS' in os.environ:
        import shlex
        cmake_args.extend(shlex.split(os.environ['CMAKE_ARGS']))
        del shlex

    # ABI config variables are introduced in PEP 425
    if sys.version_info[:2] < (3, 2):
        import warnings
        warnings.filterwarnings('ignore', r"Config variable '[^']+' is unset, "
                                          r"Python ABI tag may be incorrect",
                                category=RuntimeWarning)
        del warnings

    # works via side effect
    RearrangeCMakeOutput(rearrange_cmake_output_data,
                         files_outside_package_dir,
                         package_data.keys())

    skbuild.setup(
        name=package_name,
        version=package_version,
        url='https://github.com/skvark/opencv-python',
        license='MIT',
        description='Wrapper package for OpenCV python bindings.',
        long_description=long_description,
        long_description_content_type="text/markdown",
        packages=packages,
        package_data=package_data,
        maintainer="Olli-Pekka Heinisuo",
        include_package_data=True,
        ext_modules=EmptyListWithLength(),
        install_requires="numpy>=%s" % numpy_version,
        classifiers=[
          'Development Status :: 5 - Production/Stable',
          'Environment :: Console',
          'Intended Audience :: Developers',
          'Intended Audience :: Education',
          'Intended Audience :: Information Technology',
          'Intended Audience :: Science/Research',
          'License :: OSI Approved :: MIT License',
          'Operating System :: MacOS',
          'Operating System :: Microsoft :: Windows',
          'Operating System :: POSIX',
          'Operating System :: Unix',
          'Programming Language :: Python',
          'Programming Language :: Python :: 2',
          'Programming Language :: Python :: 2.7',
          'Programming Language :: Python :: 3',
          'Programming Language :: Python :: 3.4',
          'Programming Language :: Python :: 3.5',
          'Programming Language :: Python :: 3.6',
          'Programming Language :: Python :: 3.7',
          'Programming Language :: C++',
          'Programming Language :: Python :: Implementation :: CPython',
          'Topic :: Scientific/Engineering',
          'Topic :: Scientific/Engineering :: Image Recognition',
          'Topic :: Software Development',
        ],
        cmake_args=cmake_args,
        cmake_source_dir=cmake_source_dir,
          )


class RearrangeCMakeOutput(object):
    """
        Patch SKBuild logic to only take files related to the Python package
        and construct a file hierarchy that SKBuild expects (see below)
    """
    _setuptools_wrap = None

    # Have to wrap a function reference, or it's converted
    # into an instance method on attr assignment
    import argparse
    wraps = argparse.Namespace(_classify_installed_files=None)
    del argparse

    package_paths_re = None
    packages = None
    files_outside_package = None

    def __init__(self, package_paths_re, files_outside_package, packages):
        cls = self.__class__
        assert not cls.wraps._classify_installed_files, "Singleton object"
        import skbuild.setuptools_wrap

        cls._setuptools_wrap = skbuild.setuptools_wrap
        cls.wraps._classify_installed_files = cls._setuptools_wrap._classify_installed_files
        cls._setuptools_wrap._classify_installed_files = self._classify_installed_files_override

        cls.package_paths_re = package_paths_re
        cls.files_outside_package = files_outside_package
        cls.packages = packages

    def __del__(self):
        cls = self.__class__
        cls._setuptools_wrap._classify_installed_files = cls.wraps._classify_installed_files
        cls.wraps._classify_installed_files = None
        cls._setuptools_wrap = None

    def _classify_installed_files_override(self, install_paths,
            package_data, package_prefixes,
            py_modules, new_py_modules,
            scripts, new_scripts,
            data_files,
            cmake_source_dir, cmake_install_reldir):
        """
            From all CMake output, we're only interested in a few files
            and must place them into CMake install dir according
            to Python conventions for SKBuild to find them:
                package\
                    file
                    subpackage\
                        etc.
        """

        cls = self.__class__

        # 'relpath'/'reldir' = relative to CMAKE_INSTALL_DIR/cmake_install_dir
        # 'path'/'dir' = relative to sourcetree root
        cmake_install_dir = os.path.join(cls._setuptools_wrap.CMAKE_INSTALL_DIR(),
                                         cmake_install_reldir)
        install_relpaths = [os.path.relpath(p, cmake_install_dir) for p in install_paths]
        fslash_install_relpaths = [p.replace(os.path.sep, '/') for p in install_relpaths]
        relpaths_zip = list(zip(fslash_install_relpaths, install_relpaths))
        del install_relpaths, fslash_install_relpaths

        final_install_relpaths = []

        print("Copying files from CMake output")

        for package_name, relpaths_re in cls.package_paths_re.items():
            package_dest_reldir = package_name.replace('.', os.path.sep)
            for relpath_re in relpaths_re:
                found = False
                r = re.compile(relpath_re+'$')
                for fslash_relpath, relpath in relpaths_zip:
                    m = r.match(fslash_relpath)
                    if not m: continue
                    found = True
                    new_install_relpath = os.path.join(
                        package_dest_reldir,
                        os.path.basename(relpath))
                    cls._setuptools_wrap._copy_file(
                        os.path.join(cmake_install_dir, relpath),
                        os.path.join(cmake_install_dir, new_install_relpath),
                        hide_listing=False)
                    final_install_relpaths.append(new_install_relpath)
                    del m, fslash_relpath, new_install_relpath
                else:
                    if not found: raise Exception("Not found: '%s'" % relpath_re)
                del r, found

        del relpaths_zip

        print("Copying files from non-default sourcetree locations")

        for package_name, paths in cls.files_outside_package.items():
            package_dest_reldir = package_name.replace('.', os.path.sep)
            for path in paths:
                new_install_relpath = os.path.join(
                        package_dest_reldir,
                        # Don't yet have a need to copy
                        # to subdirectories of package dir
                        os.path.basename(path))
                cls._setuptools_wrap._copy_file(
                    path, os.path.join(cmake_install_dir, new_install_relpath),
                    hide_listing=False
                )
                final_install_relpaths.append(new_install_relpath)

        final_install_paths = [os.path.join(cmake_install_dir, p) for p in final_install_relpaths]

        return (cls.wraps._classify_installed_files)(
            final_install_paths,
            package_data, package_prefixes,
            py_modules, new_py_modules,
            scripts, new_scripts,
            data_files,
            # To get around a check that prepends source dir to paths and breaks package detection code.
            cmake_source_dir='',
            cmake_install_dir=cmake_install_reldir
        )


def install_packages(*requirements):
    # No more convenient way until PEP 518 is implemented; setuptools only handles eggs
    subprocess.check_call([sys.executable, "-m", "pip", "install"] + list(requirements))


def get_opencv_version():
    # cv_version.py should be generated by running find_version.py
    runpy.run_path("find_version.py")
    from cv_version import opencv_version
    return opencv_version


def get_build_env_var_by_name(flag_name):

    flag_set = False

    try:
        flag_set = bool(int(os.getenv('ENABLE_' + flag_name.upper() , None)))
    except Exception:
        pass

    if not flag_set:
        try:
            flag_set = bool(int(open(flag_name + ".enabled").read(1)))
        except Exception:
            pass

    return flag_set


def get_or_install(name, version=None):
    """ If a package is already installed, build against it. If not, install """
    # Do not import 3rd-party modules into the current process
    import json
    js_packages = json.loads(
        subprocess.check_output([sys.executable, "-m", "pip", "list", "--format", "json"]).decode('ascii'))  # valid names & versions are ASCII as per PEP 440
    try:
        [package] = (package for package in js_packages if package['name'] == name)
    except ValueError:
        install_packages("%s==%s" % (name, version) if version else name)
        return version
    else:
        return package['version']


# This creates a list which is empty but returns a length of 1.
# Should make the wheel a binary distribution and platlib compliant.
class EmptyListWithLength(list):
    def __len__(self):
        return 1


if __name__ == '__main__':
    main()