# -*- coding: utf-8 -*-
'''
Module for managing container and VM images

.. versionadded:: 2014.7.0
'''
from __future__ import absolute_import, print_function, unicode_literals

# Import python libs
import os
import uuid
import pprint
import logging
try:
    from shlex import quote as _cmd_quote  # pylint: disable=E0611
except ImportError:
    from pipes import quote as _cmd_quote

# Import salt libs
import salt.syspaths
import salt.utils.kickstart
import salt.utils.path
import salt.utils.preseed
import salt.utils.stringutils
import salt.utils.validate.path
import salt.utils.yast
from salt.exceptions import SaltInvocationError

# Import 3rd-party libs
from salt.ext import six

log = logging.getLogger(__name__)

CMD_MAP = {
    'yum': ('yum', 'rpm'),
    'deb': ('debootstrap',),
    'pacman': ('pacman',),
}

EPEL_URL = 'http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm'


def __virtual__():
    '''
    By default, this will be available on all platforms; but not all distros
    will necessarily be supported
    '''
    return True


def bootstrap(
        platform,
        root,
        img_format='dir',
        fs_format='ext2',
        fs_opts=None,
        arch=None,
        flavor=None,
        repo_url=None,
        static_qemu=None,
        img_size=None,
        mount_dir=None,
        pkg_cache=None,
        pkgs=None,
        exclude_pkgs=None,
        epel_url=EPEL_URL,
    ):
    '''
    Create an image for a specific platform.

    Please note that this function *MUST* be run as root, as images that are
    created make files belonging to root.

    platform
        Which platform to use to create the image. Currently supported platforms
        are rpm, deb and pacman.

    root
        Local path to create the root of the image filesystem.

    img_format
        Which format to create the image in. By default, just copies files into
        a directory on the local filesystem (``dir``). Future support will exist
        for ``sparse``.

    fs_format
        When using a non-``dir`` ``img_format``, which filesystem to format the
        image to. By default, ``ext2``.

    fs_opts
        When using a non-``dir`` ``img_format``, a dict of opts may be
        specified.

    arch
        Architecture to install packages for, if supported by the underlying
        bootstrap tool. Currently only used for deb.

    flavor
        Which flavor of operating system to install. This correlates to a
        specific directory on the distribution repositories. For instance,
        ``wheezy`` on Debian.

    repo_url
        Mainly important for Debian-based repos. Base URL for the mirror to
        install from. (e.x.: http://ftp.debian.org/debian/)

    static_qemu
        Local path to the static qemu binary required for this arch.
        (e.x.: /usr/bin/qemu-amd64-static)

    pkg_confs
        The location of the conf files to copy into the image, to point the
        installer to the right repos and configuration.

    img_size
        If img_format is not ``dir``, then the size of the image must be
        specified.

    mount_dir
        If img_format is not ``dir``, then the image must be mounted somewhere.
        If the ``mount_dir`` is not specified, then it will be created at
        ``/opt/salt-genesis.<random_uuid>``. This directory will be unmounted
        and removed when the process is finished.

    pkg_cache
        This points to a directory containing a cache of package files to be
        copied to the image. It does not need to be specified.

    pkgs
        A list of packages to be installed on this image. For RedHat, this
        will include ``yum``, ``centos-release`` and ``iputils`` by default.

    exclude_pkgs
        A list of packages to be excluded. If you do not want to install the
        defaults, you need to include them in this list.

    epel_url
        The URL to download the EPEL release package from.

    CLI Examples:

    .. code-block:: bash

        salt myminion genesis.bootstrap pacman /root/arch
        salt myminion genesis.bootstrap rpm /root/redhat
        salt myminion genesis.bootstrap deb /root/wheezy arch=amd64 \
            flavor=wheezy static_qemu=/usr/bin/qemu-x86_64-static

    '''
    if img_format not in ('dir', 'sparse'):
        raise SaltInvocationError('The img_format must be "sparse" or "dir"')

    if img_format == 'dir':
        # We can just use the root as the root
        if not __salt__['file.directory_exists'](root):
            try:
                __salt__['file.mkdir'](root)
            except Exception as exc:
                return {'Error': salt.utils.stringutils.to_unicode(pprint.pformat(exc))}
    elif img_format == 'sparse':
        if not img_size:
            raise SaltInvocationError('An img_size must be specified for a sparse file')
        if not mount_dir:
            mount_dir = '/opt/salt-genesis.{0}'.format(uuid.uuid4())
        __salt__['file.mkdir'](mount_dir, 'root', 'root', '755')
        __salt__['cmd.run'](('fallocate', '-l', img_size, root), python_shell=False)
        _mkpart(root, fs_format, fs_opts, mount_dir)

        loop1 = __salt__['cmd.run']('losetup -f')
        log.debug('First loop device is {0}'.format(loop1))
        __salt__['cmd.run']('losetup {0} {1}'.format(loop1, root))
        loop2 = __salt__['cmd.run']('losetup -f')
        log.debug('Second loop device is {0}'.format(loop2))
        start = six.text_type(2048 * 2048)
        __salt__['cmd.run']('losetup -o {0} {1} {2}'.format(start, loop2, loop1))
        __salt__['mount.mount'](mount_dir, loop2)

        _populate_cache(platform, pkg_cache, mount_dir)

    if mount_dir:
        root = mount_dir

    if pkgs is None:
        pkgs = []

    if exclude_pkgs is None:
        exclude_pkgs = []

    if platform in ('rpm', 'yum'):
        _bootstrap_yum(
            root,
            pkgs=pkgs,
            exclude_pkgs=exclude_pkgs,
            epel_url=epel_url,
        )
    elif platform == 'deb':
        _bootstrap_deb(
            root,
            arch=arch,
            flavor=flavor,
            repo_url=repo_url,
            static_qemu=static_qemu,
            pkgs=pkgs,
            exclude_pkgs=exclude_pkgs,
        )
    elif platform == 'pacman':
        _bootstrap_pacman(
            root,
            img_format=img_format,
            pkgs=pkgs,
            exclude_pkgs=exclude_pkgs,
        )

    if img_format != 'dir':
        blkinfo = __salt__['disk.blkid'](loop2)
        __salt__['file.replace'](
            '{0}/boot/grub/grub.cfg'.format(mount_dir),
            'ad4103fa-d940-47ca-8506-301d8071d467',  # This seems to be the default
            blkinfo[loop2]['UUID']
        )
        __salt__['mount.umount'](root)
        __salt__['cmd.run']('losetup -d {0}'.format(loop2))
        __salt__['cmd.run']('losetup -d {0}'.format(loop1))
        __salt__['file.rmdir'](mount_dir)


def _mkpart(root, fs_format, fs_opts, mount_dir):
    '''
    Make a partition, and make it bootable

    .. versionadded:: Beryllium
    '''
    __salt__['partition.mklabel'](root, 'msdos')
    loop1 = __salt__['cmd.run']('losetup -f')
    log.debug('First loop device is {0}'.format(loop1))
    __salt__['cmd.run']('losetup {0} {1}'.format(loop1, root))
    part_info = __salt__['partition.list'](loop1)
    start = six.text_type(2048 * 2048) + 'B'
    end = part_info['info']['size']
    __salt__['partition.mkpart'](loop1, 'primary', start=start, end=end)
    __salt__['partition.set'](loop1, '1', 'boot', 'on')
    part_info = __salt__['partition.list'](loop1)
    loop2 = __salt__['cmd.run']('losetup -f')
    log.debug('Second loop device is {0}'.format(loop2))
    start = start.rstrip('B')
    __salt__['cmd.run']('losetup -o {0} {1} {2}'.format(start, loop2, loop1))
    _mkfs(loop2, fs_format, fs_opts)
    __salt__['mount.mount'](mount_dir, loop2)
    __salt__['cmd.run']((
        'grub-install',
        '--target=i386-pc',
        '--debug',
        '--no-floppy',
        '--modules=part_msdos linux',
        '--boot-directory={0}/boot'.format(mount_dir),
        loop1
    ), python_shell=False)
    __salt__['mount.umount'](mount_dir)
    __salt__['cmd.run']('losetup -d {0}'.format(loop2))
    __salt__['cmd.run']('losetup -d {0}'.format(loop1))
    return part_info


def _mkfs(root, fs_format, fs_opts=None):
    '''
    Make a filesystem using the appropriate module

    .. versionadded:: Beryllium
    '''
    if fs_opts is None:
        fs_opts = {}

    if fs_format in ('ext2', 'ext3', 'ext4'):
        __salt__['extfs.mkfs'](root, fs_format, **fs_opts)
    elif fs_format in ('btrfs',):
        __salt__['btrfs.mkfs'](root, **fs_opts)
    elif fs_format in ('xfs',):
        __salt__['xfs.mkfs'](root, **fs_opts)


def _populate_cache(platform, pkg_cache, mount_dir):
    '''
    If a ``pkg_cache`` directory is specified, then use it to populate the
    disk image.
    '''
    if not pkg_cache:
        return
    if not os.path.isdir(pkg_cache):
        return

    if platform == 'pacman':
        cache_dir = '{0}/var/cache/pacman/pkg'.format(mount_dir)

    __salt__['file.mkdir'](cache_dir, 'root', 'root', '755')
    __salt__['file.copy'](pkg_cache, cache_dir, recurse=True, remove_existing=True)


def _bootstrap_yum(
        root,
        pkg_confs='/etc/yum*',
        pkgs=None,
        exclude_pkgs=None,
        epel_url=EPEL_URL,
    ):
    '''
    Bootstrap an image using the yum tools

    root
        The root of the image to install to. Will be created as a directory if
        it does not exist. (e.x.: /root/arch)

    pkg_confs
        The location of the conf files to copy into the image, to point yum
        to the right repos and configuration.

    pkgs
        A list of packages to be installed on this image. For RedHat, this
        will include ``yum``, ``centos-release`` and ``iputils`` by default.

    exclude_pkgs
        A list of packages to be excluded. If you do not want to install the
        defaults, you need to include them in this list.

    epel_url
        The URL to download the EPEL release package from.

    TODO: Set up a pre-install overlay, to copy files into /etc/ and so on,
        which are required for the install to work.
    '''
    if pkgs is None:
        pkgs = []
    elif isinstance(pkgs, six.string_types):
        pkgs = pkgs.split(',')

    default_pkgs = ('yum', 'centos-release', 'iputils')
    for pkg in default_pkgs:
        if pkg not in pkgs:
            pkgs.append(pkg)

    if exclude_pkgs is None:
        exclude_pkgs = []
    elif isinstance(exclude_pkgs, six.string_types):
        exclude_pkgs = exclude_pkgs.split(',')

    for pkg in exclude_pkgs:
        pkgs.remove(pkg)

    _make_nodes(root)
    release_files = [rf for rf in os.listdir('/etc') if rf.endswith('release')]
    __salt__['cmd.run']('cp /etc/resolv/conf {rfs} {root}/etc'.format(root=_cmd_quote(root), rfs=' '.join(release_files)))
    __salt__['cmd.run']('cp -r {rfs} {root}/etc'.format(root=_cmd_quote(root), rfs=' '.join(release_files)))
    __salt__['cmd.run']('cp -r {confs} {root}/etc'.format(root=_cmd_quote(root), confs=_cmd_quote(pkg_confs)))

    yum_args = ['yum', 'install', '--installroot={0}'.format(_cmd_quote(root)), '-y'] + pkgs
    __salt__['cmd.run'](yum_args, python_shell=False)

    if 'epel-release' not in exclude_pkgs:
        __salt__['cmd.run'](
            ('rpm', '--root={0}'.format(_cmd_quote(root)), '-Uvh', epel_url),
            python_shell=False
        )


def _bootstrap_deb(
        root,
        arch,
        flavor,
        repo_url=None,
        static_qemu=None,
        pkgs=None,
        exclude_pkgs=None,
    ):
    '''
    Bootstrap an image using the Debian tools

    root
        The root of the image to install to. Will be created as a directory if
        it does not exist. (e.x.: /root/wheezy)

    arch
        Architecture of the target image. (e.x.: amd64)

    flavor
        Flavor of Debian to install. (e.x.: wheezy)

    repo_url
        Base URL for the mirror to install from.
        (e.x.: http://ftp.debian.org/debian/)

    static_qemu
        Local path to the static qemu binary required for this arch.
        (e.x.: /usr/bin/qemu-amd64-static)

    pkgs
        A list of packages to be installed on this image.

    exclude_pkgs
        A list of packages to be excluded.
    '''

    if repo_url is None:
        repo_url = 'http://ftp.debian.org/debian/'

    if not salt.utils.path.which('debootstrap'):
        log.error('Required tool debootstrap is not installed.')
        return False

    if static_qemu and not salt.utils.validate.path.is_executable(static_qemu):
        log.error('Required tool qemu not '
                  'present/readable at: {0}'.format(static_qemu))
        return False

    if isinstance(pkgs, (list, tuple)):
        pkgs = ','.join(pkgs)
    if isinstance(exclude_pkgs, (list, tuple)):
        exclude_pkgs = ','.join(exclude_pkgs)

    deb_args = [
        'debootstrap',
        '--foreign',
        '--arch',
        _cmd_quote(arch)]

    if pkgs:
        deb_args += ['--include', _cmd_quote(pkgs)]
    if exclude_pkgs:
        deb_args += ['--exclude', _cmd_quote(exclude_pkgs)]

    deb_args += [
        _cmd_quote(flavor),
        _cmd_quote(root),
        _cmd_quote(repo_url),
    ]

    __salt__['cmd.run'](deb_args, python_shell=False)

    if static_qemu:
        __salt__['cmd.run'](
            'cp {qemu} {root}/usr/bin/'.format(
                qemu=_cmd_quote(static_qemu), root=_cmd_quote(root)
            )
        )

    env = {'DEBIAN_FRONTEND': 'noninteractive',
           'DEBCONF_NONINTERACTIVE_SEEN': 'true',
           'LC_ALL': 'C',
           'LANGUAGE': 'C',
           'LANG': 'C',
           'PATH': '/sbin:/bin:/usr/bin'}
    __salt__['cmd.run'](
        'chroot {root} /debootstrap/debootstrap --second-stage'.format(
            root=_cmd_quote(root)
        ),
        env=env
    )
    __salt__['cmd.run'](
        'chroot {root} dpkg --configure -a'.format(
            root=_cmd_quote(root)
        ),
        env=env
    )


def _bootstrap_pacman(
        root,
        pkg_confs='/etc/pacman*',
        img_format='dir',
        pkgs=None,
        exclude_pkgs=None,
    ):
    '''
    Bootstrap an image using the pacman tools

    root
        The root of the image to install to. Will be created as a directory if
        it does not exist. (e.x.: /root/arch)

    pkg_confs
        The location of the conf files to copy into the image, to point pacman
        to the right repos and configuration.

    img_format
        The image format to be used. The ``dir`` type needs no special
        treatment, but others need special treatment.

    pkgs
        A list of packages to be installed on this image. For Arch Linux, this
        will include ``pacman``, ``linux``, ``grub``, and ``systemd-sysvcompat``
        by default.

    exclude_pkgs
        A list of packages to be excluded. If you do not want to install the
        defaults, you need to include them in this list.
    '''
    _make_nodes(root)

    if pkgs is None:
        pkgs = []
    elif isinstance(pkgs, six.string_types):
        pkgs = pkgs.split(',')

    default_pkgs = ('pacman', 'linux', 'systemd-sysvcompat', 'grub')
    for pkg in default_pkgs:
        if pkg not in pkgs:
            pkgs.append(pkg)

    if exclude_pkgs is None:
        exclude_pkgs = []
    elif isinstance(exclude_pkgs, six.string_types):
        exclude_pkgs = exclude_pkgs.split(',')

    for pkg in exclude_pkgs:
        pkgs.remove(pkg)

    if img_format != 'dir':
        __salt__['mount.mount']('{0}/proc'.format(root), '/proc', fstype='', opts='bind')
        __salt__['mount.mount']('{0}/dev'.format(root), '/dev', fstype='', opts='bind')

    __salt__['file.mkdir'](
        '{0}/var/lib/pacman/local'.format(root), 'root', 'root', '755'
    )
    pac_files = [rf for rf in os.listdir('/etc') if rf.startswith('pacman.')]
    for pac_file in pac_files:
        __salt__['cmd.run']('cp -r /etc/{0} {1}/etc'.format(pac_file, _cmd_quote(root)))
    __salt__['file.copy']('/var/lib/pacman/sync', '{0}/var/lib/pacman/sync'.format(root), recurse=True)

    pacman_args = ['pacman', '--noconfirm', '-r', _cmd_quote(root), '-S'] + pkgs
    __salt__['cmd.run'](pacman_args, python_shell=False)

    if img_format != 'dir':
        __salt__['mount.umount']('{0}/proc'.format(root))
        __salt__['mount.umount']('{0}/dev'.format(root))


def _make_nodes(root):
    '''
    Make the minimum number of nodes inside of /dev/. Based on:

    https://wiki.archlinux.org/index.php/Linux_Containers
    '''
    dirs = (
        ('{0}/etc'.format(root), 'root', 'root', '755'),
        ('{0}/dev'.format(root), 'root', 'root', '755'),
        ('{0}/proc'.format(root), 'root', 'root', '755'),
        ('{0}/dev/pts'.format(root), 'root', 'root', '755'),
        ('{0}/dev/shm'.format(root), 'root', 'root', '1755'),
    )

    nodes = (
        ('{0}/dev/null'.format(root), 'c', 1, 3, 'root', 'root', '666'),
        ('{0}/dev/zero'.format(root), 'c', 1, 5, 'root', 'root', '666'),
        ('{0}/dev/random'.format(root), 'c', 1, 8, 'root', 'root', '666'),
        ('{0}/dev/urandom'.format(root), 'c', 1, 9, 'root', 'root', '666'),
        ('{0}/dev/tty'.format(root), 'c', 5, 0, 'root', 'root', '666'),
        ('{0}/dev/tty0'.format(root), 'c', 4, 0, 'root', 'root', '666'),
        ('{0}/dev/console'.format(root), 'c', 5, 1, 'root', 'root', '600'),
        ('{0}/dev/full'.format(root), 'c', 1, 7, 'root', 'root', '666'),
        ('{0}/dev/initctl'.format(root), 'p', 0, 0, 'root', 'root', '600'),
        ('{0}/dev/ptmx'.format(root), 'c', 5, 2, 'root', 'root', '666'),
    )

    for path in dirs:
        __salt__['file.mkdir'](*path)

    for path in nodes:
        __salt__['file.mknod'](*path)


def avail_platforms():
    '''
    Return which platforms are available

    CLI Example:

    .. code-block:: bash

        salt myminion genesis.avail_platforms
    '''
    ret = {}
    for platform in CMD_MAP:
        ret[platform] = True
        for cmd in CMD_MAP[platform]:
            if not salt.utils.path.which(cmd):
                ret[platform] = False
    return ret


def pack(name, root, path=None, pack_format='tar', compress='bzip2'):
    '''
    Pack up a directory structure, into a specific format

    CLI Examples:

    .. code-block:: bash

        salt myminion genesis.pack centos /root/centos
        salt myminion genesis.pack centos /root/centos pack_format='tar'
    '''
    if pack_format == 'tar':
        _tar(name, root, path, compress)


def unpack(name, dest=None, path=None, pack_format='tar', compress='bz2'):
    '''
    Unpack an image into a directory structure

    CLI Example:

    .. code-block:: bash

        salt myminion genesis.unpack centos /root/centos
    '''
    if pack_format == 'tar':
        _untar(name, dest, path, compress)


def _tar(name, root, path=None, compress='bzip2'):
    '''
    Pack up image in a tar format
    '''
    if path is None:
        path = os.path.join(salt.syspaths.BASE_FILE_ROOTS_DIR, 'img')
    if not __salt__['file.directory_exists'](path):
        try:
            __salt__['file.mkdir'](path)
        except Exception as exc:
            return {'Error': salt.utils.stringutils.to_unicode(pprint.pformat(exc))}

    compression, ext = _compress(compress)

    tarfile = '{0}/{1}.tar.{2}'.format(path, name, ext)
    out = __salt__['archive.tar'](
        options='{0}pcf'.format(compression),
        tarfile=tarfile,
        sources='.',
        dest=root,
    )


def _untar(name, dest=None, path=None, compress='bz2'):
    '''
    Unpack a tarball to be used as a container
    '''
    if path is None:
        path = os.path.join(salt.syspaths.BASE_FILE_ROOTS_DIR, 'img')

    if not dest:
        dest = path

    if not __salt__['file.directory_exists'](dest):
        try:
            __salt__['file.mkdir'](dest)
        except Exception as exc:
            return {'Error': salt.utils.stringutils.to_unicode(pprint.pformat(exc))}

    compression, ext = _compress(compress)

    tarfile = '{0}/{1}.tar.{2}'.format(path, name, ext)
    out = __salt__['archive.tar'](
        options='{0}xf'.format(compression),
        tarfile=tarfile,
        dest=dest,
    )


def _compress(compress):
    '''
    Resolve compression flags
    '''
    if compress in ('bz2', 'bzip2', 'j'):
        compression = 'j'
        ext = 'bz2'
    elif compress in ('gz', 'gzip', 'z'):
        compression = 'z'
        ext = 'gz'
    elif compress in ('xz', 'a', 'J'):
        compression = 'J'
        ext = 'xz'

    return compression, ext


def ldd_deps(filename, ret=None):
    '''
    Recurse through a set of dependencies reported by ``ldd``, to find
    associated dependencies.

    Please note that this does not necessarily resolve all (non-package)
    dependencies for a file; but it does help.

    CLI Example:

        salt myminion genesis.ldd_deps bash
        salt myminion genesis.ldd_deps /bin/bash
    '''
    if not os.path.exists(filename):
        filename = salt.utils.path.which(filename)

    if ret is None:
        ret = []

    out = __salt__['cmd.run'](('ldd', filename), python_shell=False)
    for line in out.splitlines():
        if not line.strip():
            continue
        dep_path = ''
        if '=>' in line:
            comps = line.split(' => ')
            dep_comps = comps[1].strip().split()
            if os.path.exists(dep_comps[0]):
                dep_path = dep_comps[0]
        else:
            dep_comps = line.strip().split()
            if os.path.exists(dep_comps[0]):
                dep_path = dep_comps[0]

        if dep_path:
            if dep_path not in ret:
                ret.append(dep_path)
                new_deps = ldd_deps(dep_path, ret)
                for dep in new_deps:
                    if dep not in ret:
                        ret.append(dep)

    return ret


def mksls(fmt, src, dst=None):
    '''
    Convert an installation file/script to an SLS file. Currently supports
    ``kickstart``, ``preseed``, and ``autoyast``.

    CLI Examples:

        salt <minion> genesis.mksls kickstart /path/to/kickstart.cfg
        salt <minion> genesis.mksls kickstart /path/to/kickstart.cfg /path/to/dest.sls

    .. versionadded:: Beryllium
    '''
    if fmt == 'kickstart':
        return salt.utils.kickstart.mksls(src, dst)
    elif fmt == 'preseed':
        return salt.utils.preseed.mksls(src, dst)
    elif fmt == 'autoyast':
        return salt.utils.yast.mksls(src, dst)
