from os import environ
from os.path import join
from multiprocessing import cpu_count
import shutil

from pythonforandroid.recipe import Recipe
from pythonforandroid.util import BuildInterruptingException, build_platform


class Arch:

    command_prefix = None
    '''The prefix for NDK commands such as gcc.'''

    arch = ""
    '''Name of the arch such as: `armeabi-v7a`, `arm64-v8a`, `x86`...'''

    arch_cflags = []
    '''Specific arch `cflags`, expect to be overwrote in subclass if needed.'''

    common_cflags = [
        '-target {target}',
        '-fomit-frame-pointer'
    ]

    common_cppflags = [
        '-DANDROID',
        '-I{ctx.ndk.sysroot_include_dir}',
        '-I{python_includes}',
    ]

    common_ldflags = ['-L{ctx_libs_dir}']

    common_ldlibs = ['-lm']

    common_ldshared = [
        '-pthread',
        '-shared',
        '-Wl,-O1',
        '-Wl,-Bsymbolic-functions',
    ]

    def __init__(self, ctx):
        self.ctx = ctx

        # Allows injecting additional linker paths used by any recipe.
        # This can also be modified by recipes (like the librt recipe)
        # to make sure that some sort of global resource is available &
        # linked for all others.
        self.extra_global_link_paths = []

    def __str__(self):
        return self.arch

    @property
    def ndk_lib_dir(self):
        return join(self.ctx.ndk.sysroot_lib_dir, self.command_prefix)

    @property
    def ndk_lib_dir_versioned(self):
        return join(self.ndk_lib_dir, str(self.ctx.ndk_api))

    @property
    def include_dirs(self):
        return [
            "{}/{}".format(
                self.ctx.include_dir,
                d.format(arch=self))
            for d in self.ctx.include_dirs]

    @property
    def target(self):
        # As of NDK r19, the toolchains installed by default with the
        # NDK may be used in-place. The make_standalone_toolchain.py script
        # is no longer needed for interfacing with arbitrary build systems.
        # See: https://developer.android.com/ndk/guides/other_build_systems
        return '{triplet}{ndk_api}'.format(
            triplet=self.command_prefix, ndk_api=self.ctx.ndk_api
        )

    @property
    def clang_exe(self):
        """Full path of the clang compiler depending on the android's ndk
        version used."""
        return self.get_clang_exe()

    @property
    def clang_exe_cxx(self):
        """Full path of the clang++ compiler depending on the android's ndk
        version used."""
        return self.get_clang_exe(plus_plus=True)

    def get_clang_exe(self, with_target=False, plus_plus=False):
        """Returns the full path of the clang/clang++ compiler, supports two
        kwargs:

          - `with_target`: prepend `target` to clang
          - `plus_plus`: will return the clang++ compiler (defaults to `False`)
        """
        compiler = 'clang'
        if with_target:
            compiler = '{target}-{compiler}'.format(
                target=self.target, compiler=compiler
            )
        if plus_plus:
            compiler += '++'
        return join(self.ctx.ndk.llvm_bin_dir, compiler)

    def get_env(self, with_flags_in_cc=True):
        env = {}

        # HOME: User's home directory
        #
        # Many tools