#!/usr/bin/env python

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import os
import yaml

from jinja2 import contextfunction
from jinja2.runtime import Undefined


def debian_package_install(packages, clean_package_cache=True):
    """Jinja utility method for building debian-based package install command.

    apt-get is not capable of installing .deb files from a URL and the
    template logic to construct a series of steps to install regular packages
    from apt repos as well as .deb files that need to be downloaded, manually
    installed, and cleaned up is complicated. This method will construct the
    proper string required to install all packages in a way that's a bit
    easier to follow.

    :param packages: a list of strings that are either packages to install
    from an apt repo, or URLs to .deb files
    :type packages: list

    :returns: string suitable to provide to RUN command in a Dockerfile that
    will install the given packages
    :rtype: string
    """
    cmds = []

    # divide the list into two groups, one for regular packages and one for
    # URL packages
    reg_packages, url_packages = [], []
    for package in packages:
        if package.startswith('http'):
            url_packages.append(package)
        else:
            reg_packages.append(package)

    # handle the apt-get install
    if reg_packages:
        cmds.append('apt-get update')
        cmds.append('apt-get -y install --no-install-recommends {}'.format(
            ' '.join(reg_packages)
        ))
        if clean_package_cache:
            cmds.append('apt-get clean')
            cmds.append('rm -rf /var/lib/apt/lists/*')

    # handle URL packages
    for url in url_packages:
        # the path portion should be the file name
        name = url[url.rfind('/') + 1:]
        cmds.extend([
            'curl --location {} -o {}'.format(url, name),
            'dpkg -i {}'.format(name),
            'rm -rf {}'.format(name),
        ])

    # return the list of commands
    return ' && '.join(cmds)


@contextfunction
def enable_repos(context, reponames):
    """NOTE(hrw): we need to handle CentOS, Debian and Ubuntu with one macro.

    Repo names have to be simple names mapped to proper ones.  So 'ceph' ==
    'centos-ceph-nautilus' for CentOS, UCA for Ubuntu (enabled by default) and
    something else for Debian.
    """
    repofile = os.path.dirname(os.path.realpath(__file__)) + '/repos.yaml'
    with open(repofile, 'r') as repos_file:
        repo_data = {}
        for name, params in yaml.safe_load(repos_file).items():
            repo_data[name] = params

    # TODO(hrw): add checks for isinstance() and raise proper exception
    base_package_type = context.get('base_package_type')
    if isinstance(base_package_type, Undefined):
        raise

    base_distro = context.get('base_distro')
    base_arch = context.get('base_arch')
    distro_package_manager = context.get('distro_package_manager')

    commands = ''

    if base_package_type == 'rpm':
        # NOTE(hrw): we enable all repos with one call
        if distro_package_manager == 'yum':
            commands = 'yum-config-manager '
        elif distro_package_manager == 'dnf':
            commands = 'dnf config-manager '

    try:
        repo_list = repo_data['%s-%s' % (base_distro, base_arch)]
    except KeyError:
        # NOTE(hrw): Fallback to distro list
        repo_list = repo_data[base_distro]

    for repo in reponames:
        try:
            if base_package_type == 'rpm':
                commands += ' --enable %s' % repo_list[repo]
            elif base_package_type == 'deb':
                commands += 'echo "%s" ' % repo_list[repo]
                commands += '>/etc/apt/sources.list.d/%s.list; ' % repo
        except KeyError:
            pass
        # NOTE(hrw): tripleo builds have empty repolist
        except TypeError:
            pass

    if commands:
        commands = "RUN %s" % commands

    return commands