#!/usr/bin/python3

#

# Copyright (C) 2015 Red Hat

#

# This library is free software; you can redistribute it and/or

# modify it under the terms of the GNU Lesser General Public

# License as published by the Free Software Foundation; either

# version 2 of the License, or (at your option) any later version.

#

# This library 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

# Lesser General Public License for more details.

#

# You should have received a copy of the GNU Lesser General Public

# License along with this library; if not, write to the

# Free Software Foundation, Inc., 59 Temple Place - Suite 330,

# Boston, MA 02111-1307, USA.

import os

import sys

if len(sys.argv) == 1:

    sysroot = ''

else:

    sysroot = sys.argv[1]

bootloader = sys.argv[2]

loaderpath = sysroot + '/boot/loader/entries'

syslinuxpath = sysroot + '/boot/syslinux/syslinux.cfg'

if bootloader == "grub2":

    sys.stdout.write('GRUB2 configuration validation not implemented.\n')

    sys.exit(0)

def fatal(msg):

    sys.stderr.write(msg)

    sys.stderr.write('\n')

    sys.exit(1)

def entry_get_version(entry):

    return int(entry['version'])

def get_ostree_option(optionstring):

    for o in optionstring.split():

        if o.startswith('ostree='):

            return o[8:]

    raise ValueError('ostree= not found')

entries = []

syslinux_entries = []

# Parse loader configs

for fname in os.listdir(loaderpath):

    path = os.path.join(loaderpath, fname)

    with open(path) as f:

        entry = {}

        for line in f:

            line = line.strip()

            if (line == '' or line.startswith('#')):

                continue

            s = line.find(' ')

            assert s > 0

            k = line[0:s]

            v = line[s+1:]

            entry[k] = v

        entries.append(entry)

    entries.sort(key=entry_get_version, reverse=True)

# Parse SYSLINUX config

with open(syslinuxpath) as f:

    in_ostree_config = False

    syslinux_entry = None

    syslinux_default = None

    for line in f:

        line = line.strip()

        if line.startswith('DEFAULT '):

            if syslinux_entry is not None:

                syslinux_default = line.split(' ', 1)[1]

        elif line.startswith('LABEL '):

            if syslinux_entry is not None:

                syslinux_entries.append(syslinux_entry)

            syslinux_entry = {}

            syslinux_entry['title'] = line.split(' ', 1)[1]

        elif line.startswith('KERNEL '):

            syslinux_entry['linux'] = line.split(' ', 1)[1]

        elif line.startswith('INITRD '):

            syslinux_entry['initrd'] = line.split(' ', 1)[1]

        elif line.startswith('APPEND '):

            syslinux_entry['options'] = line.split(' ', 1)[1]

    if syslinux_entry is not None:

        syslinux_entries.append(syslinux_entry)

if len(entries) != len(syslinux_entries):

    fatal("Found {0} loader entries, but {1} SYSLINUX entries\n".format(len(entries), len(syslinux_entries)))

def assert_matches_key(a, b, key):

    aval = a[key]

    bval = b[key]

    if aval != bval:

        fatal("Mismatch on {0}: {1} != {2}".format(key, aval, bval))

for i,(entry,syslinuxentry) in enumerate(zip(entries, syslinux_entries)):

    assert_matches_key(entry, syslinuxentry, 'linux')

    assert_matches_key(entry, syslinuxentry, 'initrd')

    entry_ostree = get_ostree_option(entry['options'])

    syslinux_ostree = get_ostree_option(syslinuxentry['options'])

    if entry_ostree != syslinux_ostree:

        fatal("Mismatch on ostree option: {0} != {1}".format(entry_ostree, syslinux_ostree))

sys.stdout.write('SYSLINUX configuration validated\n')

sys.exit(0)