"""
Copyright 2019 Attila Szollosi

This file is part of pmbootstrap.

pmbootstrap is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

pmbootstrap is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with pmbootstrap.  If not, see <http://www.gnu.org/licenses/>.
"""
import glob
import logging
import re
import os

import pmb.build
import pmb.config
import pmb.parse
import pmb.helpers.pmaports


def is_set(config, option):
    """
    Check, whether a boolean or tristate option is enabled
    either as builtin or module.
    """
    return re.search("^CONFIG_" + option + "=[ym]", config, re.M) is not None


def check(args, pkgname, details=False):
    """
    Check for necessary kernel config options.

    :returns: True when the check was successful, False otherwise
    """
    # Pkgname: allow omitting "linux-" prefix
    if pkgname.startswith("linux-"):
        flavor = pkgname.split("linux-")[1]
        logging.info("PROTIP: You can simply do 'pmbootstrap kconfig check " +
                     flavor + "'")
    else:
        flavor = pkgname

    # Read all kernel configs in the aport
    ret = True
    aport = pmb.helpers.pmaports.find(args, "linux-" + flavor)
    pkgver = pmb.parse.apkbuild(args, aport + "/APKBUILD")["pkgver"]
    for config_path in glob.glob(aport + "/config-*"):
        logging.debug("Check kconfig: " + config_path)
        with open(config_path) as handle:
            config = handle.read()

        # The architecture of the config is in the name, so it just needs to be
        # extracted
        config_arch = os.path.basename(config_path).split(".")[1]

        # Loop trough necessary config options, and print a warning,
        # if any is missing
        path = "linux-" + flavor + "/" + os.path.basename(config_path)
        for rule, archs_options in pmb.config.necessary_kconfig_options.items():
            # Skip options irrelevant for the current kernel's version
            if not pmb.parse.version.check_string(pkgver, rule):
                continue

            for archs, options in archs_options.items():
                if archs != "all":
                    # Split and check if the device's architecture architecture has special config
                    # options. If option does not contain the architecture of the device
                    # kernel, then just skip the option.
                    architectures = archs.split(" ")
                    if config_arch not in architectures:
                        continue

                for option, option_value in options.items():
                    if option_value not in [True, False]:
                        raise RuntimeError("kconfig check code can only handle"
                                           " True/False right now, given value '" +
                                           str(option_value) + "' is not supported. If you"
                                           " need this, please open an issue.")
                    if option_value != is_set(config, option):
                        ret = False
                        if details:
                            should = "should" if option_value else "should *not*"
                            link = ("https://wiki.postmarketos.org/wiki/"
                                    "Kernel_configuration#CONFIG_" + option)
                            logging.info("WARNING: " + path + ": CONFIG_" + option + " " +
                                         should + " be set. See <" + link +
                                         "> for details.")
                        else:
                            logging.warning("WARNING: " + path + " isn't configured"
                                            " properly for postmarketOS, run"
                                            " 'pmbootstrap kconfig check' for"
                                            " details!")
                            break
    return ret