# SPDX-License-Identifier: Apache-2.0
# Copyright 2013-2020 The Meson development team

from __future__ import annotations

from pathlib import Path
import functools
import os
import typing as T

from ..options import OptionKey
from .base import DependencyException, DependencyMethods
from .cmake import CMakeDependency
from .detect import packages
from .pkgconfig import PkgConfigDependency
from .factory import factory_methods

if T.TYPE_CHECKING:
    from ..environment import Environment
    from ..mesonlib import MachineChoice
    from .factory import DependencyGenerator
    from .base import DependencyObjectKWs


@factory_methods({DependencyMethods.PKGCONFIG, DependencyMethods.CMAKE})
def scalapack_factory(env: 'Environment', for_machine: 'MachineChoice',
                      kwargs: DependencyObjectKWs,
                      methods: T.List[DependencyMethods]) -> T.List['DependencyGenerator']:
    candidates: T.List['DependencyGenerator'] = []

    if DependencyMethods.PKGCONFIG in methods:
        static_opt = kwargs['static'] if kwargs.get('static') is not None else env.coredata.optstore.get_value_for(OptionKey('prefer_static'))
        mkl = 'mkl-static-lp64-iomp' if static_opt else 'mkl-dynamic-lp64-iomp'
        candidates.append(functools.partial(
            MKLPkgConfigDependency, mkl, env, kwargs))

        for pkg in ['scalapack-openmpi', 'scalapack']:
            candidates.append(functools.partial(
                PkgConfigDependency, pkg, env, kwargs))

    if DependencyMethods.CMAKE in methods:
        candidates.append(functools.partial(
            CMakeDependency, 'Scalapack', env, kwargs))

    return candidates

packages['scalapack'] = scalapack_factory


class MKLPkgConfigDependency(PkgConfigDependency):

    """PkgConfigDependency for Intel MKL.

    MKL's pkg-config is pretty much borked in every way. We need to apply a
    bunch of fixups to make it work correctly.
    """

    def __init__(self, name: str, env: 'Environment', kwargs: DependencyObjectKWs,
                 language: T.Optional[str] = None):
        _m = os.environ.get('MKLROOT')
        self.__mklroot = Path(_m).resolve() if _m else None

        # We need to call down into the normal super() method even if we don't
        # find mklroot, otherwise we won't have all of the instance variables
        # initialized that meson expects.
        super().__init__(name, env, kwargs, language=language)

        # Doesn't work with gcc on windows, but does on Linux
        if env.machines[self.for_machine].is_windows() and self.clib_compiler.id == 'gcc':
            self.is_found = False

        # This can happen either because we're using GCC, we couldn't find the
        # mklroot, or the pkg-config couldn't find it.
        if not self.is_found:
            return

        assert self.version != '', 'This should not happen if we didn\'t return above'

        if self.version == 'unknown':
            # At least by 2020 the version is in the pkg-config, just not with
            # the correct name
            v = self.get_variable(pkgconfig='Version', default_value='')

            if not v and self.__mklroot:
                try:
                    v = (
                        self.__mklroot.as_posix()
                        .split('compilers_and_libraries_')[1]
                        .split('/', 1)[0]
                    )
                except IndexError:
                    pass

            if v:
                assert isinstance(v, str)
                self.version = v

    def _set_libs(self) -> None:
        if self.__mklroot is None:
            raise DependencyException('MKLROOT not set')

        super()._set_libs()

        if self.env.machines[self.for_machine].is_windows():
            suffix = '.lib'
        elif self.static:
            suffix = '.a'
        else:
            suffix = ''
        libdir = self.__mklroot / 'lib/intel64'

        if self.clib_compiler.id == 'gcc':
            for i, a in enumerate(self.link_args):
                # only replace in filename, not in directory names
                dirname, basename = os.path.split(a)
                if 'mkl_intel_lp64' in basename:
                    basename = basename.replace('intel', 'gf')
                    self.link_args[i] = '/' + os.path.join(dirname, basename)
        # MKL pkg-config omits scalapack
        # be sure "-L" and "-Wl" are first if present
        i = 0
        for j, a in enumerate(self.link_args):
            if a.startswith(('-L', '-Wl')):
                i = j + 1
            elif j > 3:
                break
        if self.env.machines[self.for_machine].is_windows() or self.static:
            self.link_args.insert(
                i, str(libdir / ('mkl_scalapack_lp64' + suffix))
            )
            self.link_args.insert(
                i + 1, str(libdir / ('mkl_blacs_intelmpi_lp64' + suffix))
            )
        else:
            self.link_args.insert(i, '-lmkl_scalapack_lp64')
            self.link_args.insert(i + 1, '-lmkl_blacs_intelmpi_lp64')

    def _set_cargs(self) -> None:
        if self.__mklroot is None:
            raise DependencyException('MKLROOT not set')

        allow_system = False
        if self.language == 'fortran':
            # gfortran doesn't appear to look in system paths for INCLUDE files,
            # so don't allow pkg-config to suppress -I flags for system paths
            allow_system = True
        cflags = self.pkgconfig.cflags(self.name, allow_system, define_variable=(('prefix', self.__mklroot.as_posix()),))
        self.compile_args = self._convert_mingw_paths(cflags)
