from os.path import join
import sh
from pythonforandroid.recipe import NDKRecipe
from pythonforandroid.util import current_directory
from pythonforandroid.logger import shprint
from multiprocessing import cpu_count


class OpenCVRecipe(NDKRecipe):
    '''
    .. versionchanged:: 0.7.1
        rewrote recipe to support the python bindings (cv2.so) and enable the
        build of most of the libraries of the opencv's package, so we can
        process images, videos, objects, photos...
    '''
    version = '4.0.1'
    url = 'https://github.com/opencv/opencv/archive/{version}.zip'
    depends = ['numpy']
    patches = ['patches/p4a_build.patch']
    generated_libraries = [
        'libopencv_features2d.so',
        'libopencv_imgproc.so',
        'libopencv_stitching.so',
        'libopencv_calib3d.so',
        'libopencv_flann.so',
        'libopencv_ml.so',
        'libopencv_videoio.so',
        'libopencv_core.so',
        'libopencv_highgui.so',
        'libopencv_objdetect.so',
        'libopencv_video.so',
        'libopencv_dnn.so',
        'libopencv_imgcodecs.so',
        'libopencv_photo.so',
    ]

    def get_lib_dir(self, arch):
        return join(self.get_build_dir(arch.arch), 'build', 'lib', arch.arch)

    def get_recipe_env(self, arch):
        env = super().get_recipe_env(arch)
        env['ANDROID_NDK'] = self.ctx.ndk_dir
        env['ANDROID_SDK'] = self.ctx.sdk_dir
        return env

    def build_arch(self, arch):
        build_dir = join(self.get_build_dir(arch.arch), 'build')
        shprint(sh.mkdir, '-p', build_dir)

        opencv_extras = []
        if 'opencv_extras' in self.ctx.recipe_build_order:
            opencv_extras_dir = self.get_recipe(
                'opencv_extras', self.ctx).get_build_dir(arch.arch)
            opencv_extras = [
                f'-DOPENCV_EXTRA_MODULES_PATH={opencv_extras_dir}/modules',
                '-DBUILD_opencv_legacy=OFF',
            ]

        with current_directory(build_dir):
            env = self.get_recipe_env(arch)

            python_major = self.ctx.python_recipe.version[0]
            python_include_root = self.ctx.python_recipe.include_root(arch.arch)
            python_site_packages = self.ctx.get_site_packages_dir()
            python_link_root = self.ctx.python_recipe.link_root(arch.arch)
            python_link_version = self.ctx.python_recipe.major_minor_version_string
            if 'python3' in self.ctx.python_recipe.name:
                python_link_version += 'm'
            python_library = join(python_link_root,
                                  'libpython{}.so'.format(python_link_version))
            python_include_numpy = join(python_site_packages,
                                        'numpy', 'core', 'include')

            shprint(sh.cmake,
                    '-DP4A=ON',
                    '-DANDROID_ABI={}'.format(arch.arch),
                    '-DANDROID_STANDALONE_TOOLCHAIN={}'.format(self.ctx.ndk_dir),
                    '-DANDROID_NATIVE_API_LEVEL={}'.format(self.ctx.ndk_api),
                    '-DANDROID_EXECUTABLE={}/tools/android'.format(env['ANDROID_SDK']),

                    '-DCMAKE_TOOLCHAIN_FILE={}'.format(
                        join(self.ctx.ndk_dir, 'build', 'cmake',
                             'android.toolchain.cmake')),
                    # Make the linkage with our python library, otherwise we
                    # will get dlopen error when trying to import cv2's module.
                    '-DCMAKE_SHARED_LINKER_FLAGS=-L{path} -lpython{version}'.format(
                        path=python_link_root,
                        version=python_link_version),

                    '-DBUILD_WITH_STANDALONE_TOOLCHAIN=ON',
                    # Force to build as shared libraries the cv2's dependant
                    # libs or we will not be able to link with our python
                    '-DBUILD_SHARED_LIBS=ON',
                    '-DBUILD_STATIC_LIBS=OFF',

                    # Disable some opencv's features
                    '-DBUILD_opencv_java=OFF',
                    '-DBUILD_opencv_java_bindings_generator=OFF',
                    # '-DBUILD_opencv_highgui=OFF',
                    # '-DBUILD_opencv_imgproc=OFF',
                    # '-DBUILD_opencv_flann=OFF',
                    '-DBUILD_TESTS=OFF',
                    '-DBUILD_PERF_TESTS=OFF',
                    '-DENABLE_TESTING=OFF',
                    '-DBUILD_EXAMPLES=OFF',
                    '-DBUILD_ANDROID_EXAMPLES=OFF',

                    # Force to only build our version of python
                    '-DBUILD_OPENCV_PYTHON{major}=ON'.format(major=python_major),
                    '-DBUILD_OPENCV_PYTHON{major}=OFF'.format(
                        major='2' if python_major == '3' else '3'),

                    # Force to install the `cv2.so` library directly into
                    # python's site packages (otherwise the cv2's loader fails
                    # on finding the cv2.so library)
                    '-DOPENCV_SKIP_PYTHON_LOADER=ON',
                    '-DOPENCV_PYTHON{major}_INSTALL_PATH={site_packages}'.format(
                        major=python_major, site_packages=python_site_packages),

                    # Define python's paths for: exe, lib, includes, numpy...
                    '-DPYTHON_DEFAULT_EXECUTABLE={}'.format(self.ctx.hostpython),
                    '-DPYTHON{major}_EXECUTABLE={host_python}'.format(
                        major=python_major, host_python=self.ctx.hostpython),
                    '-DPYTHON{major}_INCLUDE_PATH={include_path}'.format(
                        major=python_major, include_path=python_include_root),
                    '-DPYTHON{major}_LIBRARIES={python_lib}'.format(
                        major=python_major, python_lib=python_library),
                    '-DPYTHON{major}_NUMPY_INCLUDE_DIRS={numpy_include}'.format(
                        major=python_major, numpy_include=python_include_numpy),
                    '-DPYTHON{major}_PACKAGES_PATH={site_packages}'.format(
                        major=python_major, site_packages=python_site_packages),

                    *opencv_extras,

                    self.get_build_dir(arch.arch),
                    _env=env)
            shprint(sh.make, '-j' + str(cpu_count()), 'opencv_python' + python_major)
            # Install python bindings (cv2.so)
            shprint(sh.cmake, '-DCOMPONENT=python', '-P', './cmake_install.cmake')
            # Copy third party shared libs that we need in our final apk
            sh.cp('-a', sh.glob('./lib/{}/lib*.so'.format(arch.arch)),
                  self.ctx.get_libs_dir(arch.arch))


recipe = OpenCVRecipe()
