# SPDX-License-Identifier: GPL-2.0-only
import errno
import hashlib
import os
import os.path
import stat
import sys
import tarfile
from pathlib import Path

import cfg

__appname = sys.argv[0]


class Opk:

    valid_control_fields = [
        'Architecture',
        'Conffiles',
        'Conflicts',
        'Depends',
        'Description',
        'Essential',
        'Filename',
        'Homepage',
        'InstalledSize',
        'MD5Sum',
        'Maintainer',
        'OE',
        'Package',
        'Priority',
        'Provides',
        'Recommends',
        'Replaces',
        'Section',
        'Size',
        'Source',
        'Suggests',
        'Version',
        ]

    control = None
    postinst = None
    postrm = None
    preinst = None
    prerm = None

    def __init__(self, subdirectory=None, **control):
        for k in control.keys():
            if k not in self.valid_control_fields:
                raise Exception('Invalid control field: {}'.format(k))
        if 'Package' not in control.keys():
            print('Cannot create opk without Package name.\n')
            return None
        if 'Architecture' not in control.keys():
            control['Architecture'] = 'all'
        if 'Version' not in control.keys():
            control['Version'] = '1.0'
        if subdirectory is not None:
            self._relative_dir = Path(subdirectory)
        else:
            self._relative_dir = None
        self.control = control

    def write(self, tar_not_ar=False, data_files=None, compression='gz'):
        COMPRESSORS = ['gz', 'bz2', 'xz']
        if compression not in COMPRESSORS:
            raise Exception('Invalid compression type: {}. '
                            'Supported compressors: {}'.format(
                                compression,
                                ', '.join(COMPRESSORS)))

        control_file = 'control.tar.' + compression
        data_file = 'data.tar.' + compression
        tar_mode = 'w:' + compression

        TEMP_FILES = ['control', control_file, data_file, 'preinst',
                      'postinst', 'prerm', 'postrm', 'debian-binary']

        # process a final filename for the package
        dirname = self._relative_dir or ''
        basename = self.control.get(
            'Filename',
            '{Package}_{Version}_{Architecture}.opk'.format(**self.control)
            )
        filename = os.path.join(dirname, basename)
        self.control['Filename'] = filename

        for f in TEMP_FILES + [filename]:
            if os.path.exists(f):
                os.unlink(f)

        with open('debian-binary', 'w') as f:
            f.write('2.0\n')

        with open('control', 'w') as f:
            for k in self.control.keys():
                f.write('{}: {}\n'.format(k, self.control[k]))

        if self.preinst:
            with open('preinst', 'w') as f:
                os.fchmod(f.fileno(), 0o755)
                f.write(self.preinst)

        if self.postinst:
            with open('postinst', 'w') as f:
                os.fchmod(f.fileno(), 0o755)
                f.write(self.postinst)

        if self.prerm:
            with open('prerm', 'w') as f:
                os.fchmod(f.fileno(), 0o755)
                f.write(self.prerm)

        if self.postrm:
            with open('postrm', 'w') as f:
                os.fchmod(f.fileno(), 0o755)
                f.write(self.postrm)

        with tarfile.open(control_file, tar_mode) as tar:
            tar.add('control')
            if self.preinst: tar.add('preinst')
            if self.postinst: tar.add('postinst')
            if self.prerm: tar.add('prerm')
            if self.postrm: tar.add('postrm')

        with tarfile.open(data_file, tar_mode) as tar:
            if data_files:
                for df in data_files:
                    tar.add(df)

        if self._relative_dir is not None:
            self._relative_dir.mkdir(parents=True, exist_ok=True)
        if tar_not_ar:
            with tarfile.open(filename, tar_mode) as tar:
                tar.add(control_file)
                tar.add(data_file)
        else:
            os.system('ar q {0} {1} {2} {3} 2>/dev/null'.format(
                filename,
                'debian-binary',
                control_file,
                data_file))

        for f in TEMP_FILES:
            if os.path.exists(f):
                os.unlink(f)

        return filename


def md5sum_file(fname):
    f = open(fname, 'rb')
    md5 = hashlib.md5()
    chunk_size = 4096
    for chunk in iter(lambda: f.read(chunk_size), b''):
        md5.update(chunk)
    return md5.hexdigest()


class OpkGroup:
    def __init__(self):
        self.opk_list = []

    def add(self, **control):
        opk = Opk(**control)
        self.opk_list.append(opk)
        return opk

    def addOpk(self, opk):
        self.opk_list.append(opk)

    def removeOpk(self, opk):
        self.opk_list.remove(opk)

    def write_list(self, filename='Packages'):
        f = open(filename, 'w')
        for opk in self.opk_list:
            for k in opk.control.keys():
                f.write('{}: {}\n'.format(k, opk.control[k]))
            fname = opk.control['Filename']
            fsize = os.stat(fname).st_size
            md5sum = md5sum_file(fname)
            f.write('Size: {}\n'.format(fsize))
            f.write('MD5Sum: {}\n'.format(md5sum))
            f.write('\n')
        f.close()

    def write_opk(self, tar_not_ar=False, compression='gz'):
        for o in self.opk_list:
            o.write(tar_not_ar=tar_not_ar, compression=compression)


def fail(msg):
    print('%s: Test failed: %s' % (__appname, msg))
    exit(-1)


# Expected failure: For issues we know haven't been fixed yet. As these aren't
# regressions don't return an error condition.
def xfail(msg):
    print('%s: Expected failure: %s' % (__appname, msg))
    exit(0)


def regress_init():
    """Initialisation and sanity checking."""

    if not os.access(cfg.opkgcl, os.X_OK):
        fail('Cannot exec {}'.format(cfg.opkgcl))

    try:
        os.makedirs(cfg.opkdir)
    except OSError as exception:
        if exception.errno != errno.EEXIST:
            raise

    os.chdir(cfg.opkdir)

    os.system('rm -fr {}'.format(cfg.offline_root))

    confdir = os.environ['SYSCONFDIR'] + '/opkg'
    os.makedirs(('{}'+confdir).format(cfg.offline_root))
    f = open(('{}'+confdir+'/opkg.conf').format(cfg.offline_root), 'w')
    f.write('arch all 1\n')
    f.write('src test file:{}\n'.format(cfg.opkdir))
    f.close()