# -*- coding: utf-8 -*-
#
# diffoscope: in-depth comparison of files, archives, and directories
#
# Copyright © 2015 Jérémy Bobbio <lunar@debian.org>
#
# diffoscope 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.
#
# diffoscope 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 diffoscope.  If not, see <https://www.gnu.org/licenses/>.

import struct
import pytest
import subprocess

from diffoscope.comparators.cbfs import CbfsFile
from diffoscope.comparators.binary import FilesystemFile
from diffoscope.comparators.utils.specialize import specialize

from utils.data import data, get_data
from utils.tools import skip_unless_tools_exist
from utils.nonexisting import assert_non_existing


TEST_FILE1_PATH = data('text_ascii1')
TEST_FILE2_PATH = data('text_ascii2')


@pytest.fixture
def rom1(tmpdir):
    path = str(tmpdir.join('coreboot1'))

    subprocess.check_call((
        'cbfstool',
        path,
        'create',
        '-m', 'x86',
        '-s', '32768',
    ), shell=False)

    subprocess.check_call((
        'cbfstool',
        path,
        'add',
        '-f', TEST_FILE1_PATH,
        '-n', 'text',
        '-t', 'raw'
    ), shell=False)

    return specialize(FilesystemFile(path))


@pytest.fixture
def rom2(tmpdir):
    size = 32768
    path = str(tmpdir.join('coreboot2.rom'))

    subprocess.check_call((
        'cbfstool',
        path,
        'create',
        '-m', 'x86',
        '-s', '%s' % size,
    ), shell=False)

    subprocess.check_call((
        'cbfstool',
        path,
        'add',
        '-f', TEST_FILE2_PATH,
        '-n', 'text',
        '-t', 'raw',
    ), shell=False)

    # Remove the last 4 bytes to exercise the full header search
    buf = bytearray(size)
    with open(path, 'rb') as f:
        f.readinto(buf)

    with open(path, 'wb') as f:
        size = struct.unpack_from('!I', buf, offset=len(buf) - 4 - 32 + 8)[0]
        struct.pack_into('!I', buf, len(buf) - 4 - 32 + 8, size - 4)
        f.write(buf[:-4])

    return specialize(FilesystemFile(path))


@skip_unless_tools_exist('cbfstool')
def test_identification_using_offset(rom1):
    assert isinstance(rom1, CbfsFile)


@skip_unless_tools_exist('cbfstool')
def test_identification_without_offset(rom2):
    assert isinstance(rom2, CbfsFile)


@skip_unless_tools_exist('cbfstool')
def test_no_differences(rom1):
    difference = rom1.compare(rom1)
    assert difference is None


@pytest.fixture
def differences(rom1, rom2):
    difference = rom1.compare(rom2)
    return difference.details


@skip_unless_tools_exist('cbfstool')
def test_listing(differences):
    # Newer versions of cbfstool do not create the "legacy" header by default
    # and thus is missing from the diff.

    assert differences[0].unified_diff in (
        get_data('cbfs_listing_expected_diff'),
        get_data('cbfs_listing_no_legacy_header_expected_diff'),
    )


@skip_unless_tools_exist('cbfstool')
def test_content(differences):
    assert differences[1].source1 == 'text'
    assert differences[1].source2 == 'text'
    expected_diff = get_data('text_ascii_expected_diff')
    assert differences[1].unified_diff == expected_diff


@skip_unless_tools_exist('cbfstool')
def test_compare_non_existing(monkeypatch, rom1):
    assert_non_existing(monkeypatch, rom1)