#!/usr/bin/python3
# Copyright (C) 2019 Jelmer Vernooij
#
# This program 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 2 of the License, or
# (at your option) any later version.
#
# This program 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 this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA


"""Debhelper utility functions."""

import os
import subprocess
from typing import Dict, Optional

from .lintian import read_debhelper_lintian_data_file


DEBHELPER_BUILD_STEPS = ["configure", "build", "test", "install", "clean"]


def detect_debhelper_buildsystem(step: Optional[str] = None) -> Optional[str]:
    """Detect the build system for debhelper

    Args:
      step: Optional step to determine the buildsystem for
    Returns:
      Build system name or None, if none could be found
    """
    if os.path.exists("configure.ac") or os.path.exists("configure.in"):
        return "autoconf"
    output = subprocess.check_output(
        [
            "perl",
            "-w",
            "-MDebian::Debhelper::Dh_Lib",
            "-MDebian::Debhelper::Dh_Buildsystems",
            "-e",
            """\
Debian::Debhelper::Dh_Lib::init();
my $b=Debian::Debhelper::Dh_Buildsystems::load_buildsystem(undef, %(step)s);\
if (defined($b)) { print($b->NAME); } else { print("_undefined_"); }\
"""
            % {"step": ("'%s'" % step) if step is not None else "undef"},
        ]
    ).decode()
    if output == "_undefined_":
        return None
    return output


LINTIAN_COMPAT_LEVEL_PATH = "/usr/share/lintian/data/debhelper/compat-level"


def _get_lintian_compat_levels() -> Dict[str, int]:
    with open(LINTIAN_COMPAT_LEVEL_PATH, "r") as f:
        return {
            key: int(value) for (key, value) in read_debhelper_lintian_data_file(f, "=")
        }


def lowest_non_deprecated_compat_level() -> int:
    """Find the lowest non-deprecated debhelper compat level."""
    return _get_lintian_compat_levels()["deprecated"]


def highest_stable_compat_level() -> int:
    """Find the highest stable debhelper compat level."""
    return _get_lintian_compat_levels()["recommended"]


def pedantic_compat_level() -> int:
    """Find the highest stable debhelper compat level."""
    return _get_lintian_compat_levels()["pedantic"]


def maximum_debhelper_compat_version(compat_release: str) -> int:
    """Retrieve the maximum supported debhelper compat version fior a release.

    Args:
      compat_release: A release name (Debian or Ubuntu, currently)
    Returns:
      debhelper compat version
    """
    from .release_info import key_package_version

    debhelper_version = key_package_version("debhelper", compat_release)
    if debhelper_version is None:
        max_version = lowest_non_deprecated_compat_level()
    else:
        max_version = int(str(debhelper_version).split(".")[0])
    return max_version


def write_rules_template(path, buildsystem=None, addons=None, env=None):
    if addons is None:
        addons = []
    dh_args = ["$@"]
    if buildsystem:
        dh_args.append("--buildsystem=%s" % buildsystem)
    for addon in addons:
        dh_args.append("--with=%s" % addon)

    with open(path, "w") as f:
        f.write(
            """\
#!/usr/bin/make -f

"""
        )
        if env:
            for key, value in env.items():
                f.write("export %s := %s\n" % (key, value))
            f.write("\n")

        f.write(
            """\
%:
\tdh """
            + " ".join(dh_args)
            + """
"""
        )
    os.chmod(path, 0o755)
