# Copyright (c) 2015 SUSE Linux GmbH.  All rights reserved.
#
# This file is part of kiwi.
#
# kiwi 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.
#
# kiwi 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 kiwi.  If not, see <http://www.gnu.org/licenses/>
#
import os
from collections import namedtuple

# project
from .command import Command


class Kernel(object):
    """
        Implementes kernel lookup and extraction from given root tree
    """
    def __init__(self, root_dir):
        self.root_dir = root_dir
        # Calling functions.sh::suseStripKernel() will rename the
        # kernel file to a common name. The following list specifies
        # these names for the lookup of that kernel. Therefore it's
        # required that suseStripKernel() was called as part of the
        # images.sh script which is done by the kiwi provided boot
        # image descriptions
        self.kernel_names = [
            'vmlinux', 'vmlinuz'
        ]

    def get_kernel(self):
        for kernel_name in self.kernel_names:
            kernel_file = self.root_dir + '/boot/' + kernel_name
            if os.path.exists(kernel_file):
                version = Command.run(['kversion', kernel_file]).output
                if not version:
                    version = 'no-version-found'
                version = version.rstrip('\n')
                kernel = namedtuple(
                    'kernel', ['filename', 'version']
                )
                return kernel(
                    filename=kernel_file,
                    version=version
                )

    def get_xen_hypervisor(self):
        xen_hypervisor = self.root_dir + '/boot/xen.gz'
        if os.path.exists(xen_hypervisor):
            xen = namedtuple(
                'xen', ['filename', 'name']
            )
            return xen(
                filename=xen_hypervisor,
                name='xen.gz'
            )

    def copy_kernel(self, target_dir, file_name=None):
        kernel = self.get_kernel()
        if kernel:
            if not file_name:
                file_name = 'kernel-' + kernel.version + '.kernel'
            target_file = ''.join(
                [target_dir, '/', file_name]
            )
            Command.run(['cp', kernel.filename, target_file])

    def copy_xen_hypervisor(self, target_dir, file_name=None):
        xen = self.get_xen_hypervisor()
        if xen:
            if not file_name:
                file_name = 'hypervisor-' + xen.name
            target_file = ''.join(
                [target_dir, '/', file_name]
            )
            Command.run(['cp', xen.filename, target_file])