# Copyright 2013-2023 Lawrence Livermore National Security, LLC and other
# Spack Project Developers. See the top-level COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)
import collections
import re

import llnl.util.tty as tty

import spack.compiler
from spack.package import *


class Xlc(Package):
    """IBM XL C/C++ is an advanced, high-performance compiler that can be
    used for developing complex, computationally intensive programs, including
    interlanguage calls with C and Fortran programs.
    """

    homepage = "https://www.ibm.com/support/knowledgecenter/SSXVZZ_16.1.1/com.ibm.compilers.linux.doc/welcome.html"

    variant("r", default=True, description="The _r version of compilers")

    def install(self, spec, prefix):
        raise InstallError(
            "XL compilers are not installable yet, but can be "
            "detected on a system where they are supplied by vendor"
        )

    executables = [r"xlc", r"xlC", r"xlc\+\+"]

    @classmethod
    def determine_version(cls, exe):
        version_regex = re.compile(r"([0-9]?[0-9]\.[0-9])")
        try:
            output = spack.compiler.get_compiler_version_output(exe, "-qversion")
            # Exclude spurious Fortran compilers
            if "Fortran" in output:
                return None

            match = version_regex.search(output)
            if match:
                return match.group(1)
        except spack.util.executable.ProcessError:
            pass
        except Exception as e:
            tty.debug(str(e))

    @classmethod
    def determine_variants(cls, exes, version_str):
        variants = collections.defaultdict(dict)
        for exe in exes:
            # Determine the variant of the spec
            variant_str = "+r" if "_r" in exe else "~r"
            if "xlc++" in exe:
                variants[variant_str]["cxx"] = exe
                continue

            if "xlc" in exe:
                variants[variant_str]["c"] = exe
                continue

        results = []
        for variant_str, compilers in variants.items():
            results.append((variant_str, {"compilers": compilers}))

        return results

    @property
    def cc(self):
        if self.spec.external:
            return self.spec.extra_attributes["compilers"]["c"]
        msg = "cannot retrieve C compiler [spec is not concrete]"
        assert self.spec.concrete, msg

    @property
    def cxx(self):
        if self.spec.external:
            return self.spec.extra_attributes["compilers"]["cxx"]
        msg = "cannot retrieve C compiler [spec is not concrete]"
        assert self.spec.concrete, msg