"""
Mercurial Fileserver Backend

To enable, add ``hgfs`` to the :conf_master:`fileserver_backend` option in the
Master config file.

.. code-block:: yaml

    fileserver_backend:
      - hgfs

.. note::
    ``hg`` also works here. Prior to the 2018.3.0 release, *only* ``hg`` would
    work.

After enabling this backend, branches, bookmarks, and tags in a remote
mercurial repository are exposed to salt as different environments. This
feature is managed by the :conf_master:`fileserver_backend` option in the salt
master config file.

This fileserver has an additional option :conf_master:`hgfs_branch_method` that
will set the desired branch method. Possible values are: ``branches``,
``bookmarks``, or ``mixed``. If using ``branches`` or ``mixed``, the
``default`` branch will be mapped to ``base``.


.. versionchanged:: 2014.1.0
    The :conf_master:`hgfs_base` master config parameter was added, allowing
    for a branch other than ``default`` to be used for the ``base``
    environment, and allowing for a ``base`` environment to be specified when
    using an :conf_master:`hgfs_branch_method` of ``bookmarks``.


:depends:   - mercurial
            - python bindings for mercurial (``python-hglib``)
"""


import copy
import errno
import fnmatch
import glob
import hashlib
import logging
import os
import shutil
from datetime import datetime

import salt.fileserver
import salt.utils.data
import salt.utils.files
import salt.utils.gzip_util
import salt.utils.hashutils
import salt.utils.stringutils
import salt.utils.url
import salt.utils.versions
from salt.exceptions import FileserverConfigError
from salt.utils.event import tagify

VALID_BRANCH_METHODS = ("branches", "bookmarks", "mixed")
PER_REMOTE_OVERRIDES = ("base", "branch_method", "mountpoint", "root")


# pylint: disable=import-error
try:
    import hglib

    HAS_HG = True
except ImportError:
    HAS_HG = False
# pylint: enable=import-error


log = logging.getLogger(__name__)

# Define the module's virtual name
__virtualname__ = "hgfs"
__virtual_aliases__ = ("hg",)


def __virtual__():
    """
    Only load if mercurial is available
    """
    if __virtualname__ not in __opts__["fileserver_backend"]:
        return False
    if not HAS_HG:
        log.error(
            "Mercurial fileserver backend is enabled in configuration "
            "but could not be loaded, is hglib installed?"
        )
        return False
    if __opts__["hgfs_branch_method"] not in VALID_BRANCH_METHODS:
        log.error(
            "Invalid hgfs_branch_method '%s'. Valid methods are: %s",
            __opts__["hgfs_branch_method"],
            VALID_BRANCH_METHODS,
        )
        return False
    if salt.utils.path.which("hg") is None:
        log.error("hgfs requested but hg executable is not available.")
        return False
    return __virtualname__


def _all_branches(repo):
    """
    Returns all branches for the specified repo
    """
    # repo.branches() returns a list of 3-tuples consisting of
    # (branch name, rev #, nodeid)
    # Example: [('default', 4, '7c96229269fa')]
    branches = [
        (salt.utils.stringutils.to_str(x[0]), x[1], salt.utils.stringutils.to_str(x[2]))
        for x in repo.branches()
    ]
    return branches


def _get_branch(repo, name):
    """
    Find the requested branch in the specified repo
    """
    try:
        return [x for x in _all_branches(repo) if x[0] == name][0]
    except IndexError:
        return False


def _all_bookmarks(repo):
    """
    Returns all bookmarks for the specified repo
    """
    # repo.bookmarks() returns a tuple containing the following:
    #   1. A list of 3-tuples consisting of (bookmark name, rev #, nodeid)
    #   2. The index of the current bookmark (-1 if no current one)
    # Example: ([('mymark', 4, '7c96229269fa')], -1)
    bookmarks = [
        (salt.utils.stringutils.to_str(x[0]), x[1], salt.utils.stringutils.to_str(x[2]))
        for x in repo.bookmarks()[0]
    ]
    return bookmarks


def _get_bookmark(repo, name):
    """
    Find the requested bookmark in the specified repo
    """
    try:
        return [x for x in _all_bookmarks(repo) if x[0] == name][0]
    except IndexError:
        return False


def _all_tags(repo):
    """
    Returns all tags for the specified repo
    """
    # repo.tags() returns a list of 4-tuples consisting of
    # (tag name, rev #, nodeid, islocal)
    # Example: [('1.0', 3, '3be15e71b31a', False),
    #           ('tip', 4, '7c96229269fa', False)]
    # Avoid returning the special 'tip' tag.
    return [
        (
            salt.utils.stringutils.to_str(x[0]),
            x[1],
            salt.utils.stringutils.to_str(x[2]),
            x[3],
        )
        for x in repo.tags()
        if salt.utils.stringutils.to_str(x[0]) != "tip"
    ]


def _get_tag(repo, name):
    """
    Find the requested tag in the specified repo
    """
    try:
        return [x for x in _all_tags(repo) if x[0] == name][0]
    except IndexError:
        return False


def _get_ref(repo, name):
    """
    Return ref tuple if ref is in the repo.
    """
    if name == "base":
        name = repo["base"]
    if name == repo["base"] or name in envs():
        if repo["branch_method"] == "branches":
            return _get_branch(repo["repo"], name) or _get_tag(repo["repo"], name)
        elif repo["branch_method"] == "bookmarks":
            return _get_bookmark(repo["repo"], name) or _get_tag(repo["repo"], name)
        elif repo["branch_method"] == "mixed":
            return (
                _get_branch(repo["repo"], name)
                or _get_bookmark(repo["repo"], name)
                or _get_tag(repo["repo"], name)
            )
    return False


def _get_manifest(repo, ref):
    """
    Get manifest for ref
    """
    # repo.manifest() returns a list of 5-tuples consisting of
    # ('b80de5d138758541c5f05265ad144ab9fa86d1db', '644', False, False, 'thing.sls')
    manifest = [
        (
            salt.utils.stringutils.to_str(x[0]),
            salt.utils.stringutils.to_str(x[1]),
            x[2],
            x[3],
            salt.utils.stringutils.to_str(x[4]),
        )
        for x in repo.manifest(rev=ref[1])
    ]
    return manifest


def _failhard():
    """
    Fatal fileserver configuration issue, raise an exception
    """
    raise FileserverConfigError("Failed to load hg fileserver backend")


def init():
    """
    Return a list of hglib objects for the various hgfs remotes
    """
    bp_ = os.path.join(__opts__["cachedir"], "hgfs")
    new_remote = False
    repos = []

    per_remote_defaults = {}
    for param in PER_REMOTE_OVERRIDES:
        per_remote_defaults[param] = str(__opts__["hgfs_{}".format(param)])

    for remote in __opts__["hgfs_remotes"]:
        repo_conf = copy.deepcopy(per_remote_defaults)
        if isinstance(remote, dict):
            repo_url = next(iter(remote))
            per_remote_conf = {
                key: str(val)
                for key, val in salt.utils.data.repack_dictlist(
                    remote[repo_url]
                ).items()
            }
            if not per_remote_conf:
                log.error(
                    "Invalid per-remote configuration for hgfs remote %s. If "
                    "no per-remote parameters are being specified, there may "
                    "be a trailing colon after the URL, which should be "
                    "removed. Check the master configuration file.",
                    repo_url,
                )
                _failhard()

            branch_method = per_remote_conf.get(
                "branch_method", per_remote_defaults["branch_method"]
            )
            if branch_method not in VALID_BRANCH_METHODS:
                log.error(
                    "Invalid branch_method '%s' for remote %s. Valid "
                    "branch methods are: %s. This remote will be ignored.",
                    branch_method,
                    repo_url,
                    ", ".join(VALID_BRANCH_METHODS),
                )
                _failhard()

            per_remote_errors = False
            for param in (x for x in per_remote_conf if x not in PER_REMOTE_OVERRIDES):
                log.error(
                    "Invalid configuration parameter '%s' for remote %s. "
                    "Valid parameters are: %s. See the documentation for "
                    "further information.",
                    param,
                    repo_url,
                    ", ".join(PER_REMOTE_OVERRIDES),
                )
                per_remote_errors = True
            if per_remote_errors:
                _failhard()

            repo_conf.update(per_remote_conf)
        else:
            repo_url = remote

        if not isinstance(repo_url, str):
            log.error(
                "Invalid hgfs remote %s. Remotes must be strings, you may "
                "need to enclose the URL in quotes",
                repo_url,
            )
            _failhard()

        try:
            repo_conf["mountpoint"] = salt.utils.url.strip_proto(
                repo_conf["mountpoint"]
            )
        except TypeError:
            # mountpoint not specified
            pass

        hash_type = getattr(hashlib, __opts__.get("hash_type", "md5"))
        repo_hash = hash_type(repo_url.encode("utf-8")).hexdigest()
        rp_ = os.path.join(bp_, repo_hash)
        if not os.path.isdir(rp_):
            os.makedirs(rp_)

        if not os.listdir(rp_):
            # Only init if the directory is empty.
            client = hglib.init(rp_)
            client.close()
            new_remote = True
        repo = None
        try:
            try:
                repo = hglib.open(rp_)
            except hglib.error.ServerError:
                log.error(
                    "Cache path %s (corresponding remote: %s) exists but is not "
                    "a valid mercurial repository. You will need to manually "
                    "delete this directory on the master to continue to use this "
                    "hgfs remote.",
                    rp_,
                    repo_url,
                )
                _failhard()
            except Exception as exc:  # pylint: disable=broad-except
                log.error(
                    "Exception '%s' encountered while initializing hgfs remote %s",
                    exc,
                    repo_url,
                )
                _failhard()

            try:
                refs = repo.config(names=b"paths")
            except hglib.error.CommandError:
                refs = None

            # Do NOT put this if statement inside the except block above. Earlier
            # versions of hglib did not raise an exception, so we need to do it
            # this way to support both older and newer hglib.
            if not refs:
                # Write an hgrc defining the remote URL
                hgconfpath = os.path.join(rp_, ".hg", "hgrc")
                with salt.utils.files.fopen(hgconfpath, "w+") as hgconfig:
                    hgconfig.write("[paths]\n")
                    hgconfig.write(
                        salt.utils.stringutils.to_str("default = {}\n".format(repo_url))
                    )

            repo_conf.update(
                {
                    "repo": repo,
                    "url": repo_url,
                    "hash": repo_hash,
                    "cachedir": rp_,
                    "lockfile": os.path.join(
                        __opts__["cachedir"], "hgfs", "{}.update.lk".format(repo_hash)
                    ),
                }
            )
            repos.append(repo_conf)
        finally:
            if repo:
                repo.close()

    if new_remote:
        remote_map = os.path.join(__opts__["cachedir"], "hgfs/remote_map.txt")
        try:
            with salt.utils.files.fopen(remote_map, "w+") as fp_:
                timestamp = datetime.now().strftime("%d %b %Y %H:%M:%S.%f")
                fp_.write("# hgfs_remote map as of {}\n".format(timestamp))
                for repo in repos:
                    fp_.write(
                        salt.utils.stringutils.to_str(
                            "{} = {}\n".format(repo["hash"], repo["url"])
                        )
                    )
        except OSError:
            pass
        else:
            log.info("Wrote new hgfs_remote map to %s", remote_map)

    return repos


def _clear_old_remotes():
    """
    Remove cache directories for remotes no longer configured
    """
    bp_ = os.path.join(__opts__["cachedir"], "hgfs")
    try:
        cachedir_ls = os.listdir(bp_)
    except OSError:
        cachedir_ls = []
    repos = init()
    # Remove actively-used remotes from list
    for repo in repos:
        try:
            cachedir_ls.remove(repo["hash"])
        except ValueError:
            pass
    to_remove = []
    for item in cachedir_ls:
        if item in ("hash", "refs"):
            continue
        path = os.path.join(bp_, item)
        if os.path.isdir(path):
            to_remove.append(path)
    failed = []
    if to_remove:
        for rdir in to_remove:
            try:
                shutil.rmtree(rdir)
            except OSError as exc:
                log.error("Unable to remove old hgfs remote cachedir %s: %s", rdir, exc)
                failed.append(rdir)
            else:
                log.debug("hgfs removed old cachedir %s", rdir)
    for fdir in failed:
        to_remove.remove(fdir)
    return bool(to_remove), repos


def clear_cache():
    """
    Completely clear hgfs cache
    """
    fsb_cachedir = os.path.join(__opts__["cachedir"], "hgfs")
    list_cachedir = os.path.join(__opts__["cachedir"], "file_lists/hgfs")
    errors = []
    for rdir in (fsb_cachedir, list_cachedir):
        if os.path.exists(rdir):
            try:
                shutil.rmtree(rdir)
            except OSError as exc:
                errors.append("Unable to delete {}: {}".format(rdir, exc))
    return errors


def clear_lock(remote=None):
    """
    Clear update.lk

    ``remote`` can either be a dictionary containing repo configuration
    information, or a pattern. If the latter, then remotes for which the URL
    matches the pattern will be locked.
    """

    def _do_clear_lock(repo):
        def _add_error(errlist, repo, exc):
            msg = "Unable to remove update lock for {} ({}): {} ".format(
                repo["url"], repo["lockfile"], exc
            )
            log.debug(msg)
            errlist.append(msg)

        success = []
        failed = []
        if os.path.exists(repo["lockfile"]):
            try:
                os.remove(repo["lockfile"])
            except OSError as exc:
                if exc.errno == errno.EISDIR:
                    # Somehow this path is a directory. Should never happen
                    # unless some wiseguy manually creates a directory at this
                    # path, but just in case, handle it.
                    try:
                        shutil.rmtree(repo["lockfile"])
                    except OSError as exc:
                        _add_error(failed, repo, exc)
                else:
                    _add_error(failed, repo, exc)
            else:
                msg = "Removed lock for {}".format(repo["url"])
                log.debug(msg)
                success.append(msg)
        return success, failed

    if isinstance(remote, dict):
        return _do_clear_lock(remote)

    cleared = []
    errors = []
    for repo in init():
        try:
            if remote:
                try:
                    if not fnmatch.fnmatch(repo["url"], remote):
                        continue
                except TypeError:
                    # remote was non-string, try again
                    if not fnmatch.fnmatch(repo["url"], str(remote)):
                        continue
            success, failed = _do_clear_lock(repo)
            cleared.extend(success)
            errors.extend(failed)
        finally:
            repo["repo"].close()
    return cleared, errors


def lock(remote=None):
    """
    Place an update.lk

    ``remote`` can either be a dictionary containing repo configuration
    information, or a pattern. If the latter, then remotes for which the URL
    matches the pattern will be locked.
    """

    def _do_lock(repo):
        success = []
        failed = []
        if not os.path.exists(repo["lockfile"]):
            try:
                with salt.utils.files.fopen(repo["lockfile"], "w"):
                    pass
            except OSError as exc:
                msg = "Unable to set update lock for {} ({}): {} ".format(
                    repo["url"], repo["lockfile"], exc
                )
                log.debug(msg)
                failed.append(msg)
            else:
                msg = "Set lock for {}".format(repo["url"])
                log.debug(msg)
                success.append(msg)
        return success, failed

    if isinstance(remote, dict):
        return _do_lock(remote)

    locked = []
    errors = []
    for repo in init():
        try:
            if remote:
                try:
                    if not fnmatch.fnmatch(repo["url"], remote):
                        continue
                except TypeError:
                    # remote was non-string, try again
                    if not fnmatch.fnmatch(repo["url"], str(remote)):
                        continue
            success, failed = _do_lock(repo)
            locked.extend(success)
            errors.extend(failed)
        finally:
            repo["repo"].close()

    return locked, errors


def update():
    """
    Execute an hg pull on all of the repos
    """
    # data for the fileserver event
    data = {"changed": False, "backend": "hgfs"}
    # _clear_old_remotes runs init(), so use the value from there to avoid a
    # second init()
    data["changed"], repos = _clear_old_remotes()
    for repo in repos:
        try:
            if os.path.exists(repo["lockfile"]):
                log.warning(
                    "Update lockfile is present for hgfs remote %s, skipping. "
                    "If this warning persists, it is possible that the update "
                    "process was interrupted. Removing %s or running "
                    "'salt-run fileserver.clear_lock hgfs' will allow updates "
                    "to continue for this remote.",
                    repo["url"],
                    repo["lockfile"],
                )
                continue
            _, errors = lock(repo)
            if errors:
                log.error(
                    "Unable to set update lock for hgfs remote %s, skipping.",
                    repo["url"],
                )
                continue
            log.debug("hgfs is fetching from %s", repo["url"])
            repo["repo"].open()
            curtip = repo["repo"].tip()
            try:
                repo["repo"].pull()
            except Exception as exc:  # pylint: disable=broad-except
                log.error(
                    "Exception %s caught while updating hgfs remote %s",
                    exc,
                    repo["url"],
                    exc_info_on_loglevel=logging.DEBUG,
                )
            else:
                newtip = repo["repo"].tip()
                if curtip[1] != newtip[1]:
                    data["changed"] = True
        finally:
            repo["repo"].close()
        clear_lock(repo)

    env_cache = os.path.join(__opts__["cachedir"], "hgfs/envs.p")
    if data.get("changed", False) is True or not os.path.isfile(env_cache):
        env_cachedir = os.path.dirname(env_cache)
        if not os.path.exists(env_cachedir):
            os.makedirs(env_cachedir)
        new_envs = envs(ignore_cache=True)
        with salt.utils.files.fopen(env_cache, "wb+") as fp_:
            fp_.write(salt.payload.dumps(new_envs))
            log.trace("Wrote env cache data to %s", env_cache)

    # if there is a change, fire an event
    if __opts__.get("fileserver_events", False):
        with salt.utils.event.get_event(
            "master",
            __opts__["sock_dir"],
            opts=__opts__,
            listen=False,
        ) as event:
            event.fire_event(data, tagify(["hgfs", "update"], prefix="fileserver"))
    try:
        salt.fileserver.reap_fileserver_cache_dir(
            os.path.join(__opts__["cachedir"], "hgfs/hash"), find_file
        )
    except OSError:
        # Hash file won't exist if no files have yet been served up
        pass


def _env_is_exposed(env):
    """
    Check if an environment is exposed by comparing it against a whitelist and
    blacklist.
    """
    return salt.utils.stringutils.check_whitelist_blacklist(
        env,
        whitelist=__opts__["hgfs_saltenv_whitelist"],
        blacklist=__opts__["hgfs_saltenv_blacklist"],
    )


def envs(ignore_cache=False):
    """
    Return a list of refs that can be used as environments
    """
    if not ignore_cache:
        env_cache = os.path.join(__opts__["cachedir"], "hgfs/envs.p")
        cache_match = salt.fileserver.check_env_cache(__opts__, env_cache)
        if cache_match is not None:
            return cache_match
    ret = set()

    for repo in init():
        try:
            repo["repo"].open()
            if repo["branch_method"] in ("branches", "mixed"):
                for branch in _all_branches(repo["repo"]):
                    branch_name = branch[0]
                    if branch_name == repo["base"]:
                        branch_name = "base"
                    ret.add(branch_name)
            if repo["branch_method"] in ("bookmarks", "mixed"):
                for bookmark in _all_bookmarks(repo["repo"]):
                    bookmark_name = bookmark[0]
                    if bookmark_name == repo["base"]:
                        bookmark_name = "base"
                    ret.add(bookmark_name)
            ret.update([x[0] for x in _all_tags(repo["repo"])])
        finally:
            repo["repo"].close()
    return [x for x in sorted(ret) if _env_is_exposed(x)]


def find_file(path, tgt_env="base", **kwargs):  # pylint: disable=W0613
    """
    Find the first file to match the path and ref, read the file out of hg
    and send the path to the newly cached file
    """
    fnd = {"path": "", "rel": ""}
    if os.path.isabs(path) or tgt_env not in envs():
        return fnd

    dest = os.path.join(__opts__["cachedir"], "hgfs/refs", tgt_env, path)
    hashes_glob = os.path.join(
        __opts__["cachedir"], "hgfs/hash", tgt_env, "{}.hash.*".format(path)
    )
    blobshadest = os.path.join(
        __opts__["cachedir"], "hgfs/hash", tgt_env, "{}.hash.blob_sha1".format(path)
    )
    lk_fn = os.path.join(
        __opts__["cachedir"], "hgfs/hash", tgt_env, "{}.lk".format(path)
    )
    destdir = os.path.dirname(dest)
    hashdir = os.path.dirname(blobshadest)
    if not os.path.isdir(destdir):
        try:
            os.makedirs(destdir)
        except OSError:
            # Path exists and is a file, remove it and retry
            os.remove(destdir)
            os.makedirs(destdir)
    if not os.path.isdir(hashdir):
        try:
            os.makedirs(hashdir)
        except OSError:
            # Path exists and is a file, remove it and retry
            os.remove(hashdir)
            os.makedirs(hashdir)

    for repo in init():
        try:
            if repo["mountpoint"] and not path.startswith(
                repo["mountpoint"] + os.path.sep
            ):
                continue
            repo_path = path[len(repo["mountpoint"]) :].lstrip(os.path.sep)
            if repo["root"]:
                repo_path = os.path.join(repo["root"], repo_path)

            repo["repo"].open()
            ref = _get_ref(repo, tgt_env)
            if not ref:
                # Branch or tag not found in repo, try the next
                repo["repo"].close()
                continue
            salt.fileserver.wait_lock(lk_fn, dest)
            if os.path.isfile(blobshadest) and os.path.isfile(dest):
                with salt.utils.files.fopen(blobshadest, "r") as fp_:
                    sha = fp_.read()
                    if sha == ref[2]:
                        fnd["rel"] = path
                        fnd["path"] = dest
                        repo["repo"].close()
                        return fnd
            try:
                repo["repo"].cat(
                    [salt.utils.stringutils.to_bytes("path:{}".format(repo_path))],
                    rev=ref[2],
                    output=dest,
                )
            except hglib.error.CommandError:
                repo["repo"].close()
                continue
            with salt.utils.files.fopen(lk_fn, "w"):
                pass
            for filename in glob.glob(hashes_glob):
                try:
                    os.remove(filename)
                except Exception:  # pylint: disable=broad-except
                    pass
            with salt.utils.files.fopen(blobshadest, "w+") as fp_:
                fp_.write(salt.utils.stringutils.to_str(ref[2]))
            try:
                os.remove(lk_fn)
            except OSError:
                pass
            fnd["rel"] = path
            fnd["path"] = dest
            try:
                # Converting the stat result to a list, the elements of the
                # list correspond to the following stat_result params:
                # 0 => st_mode=33188
                # 1 => st_ino=10227377
                # 2 => st_dev=65026
                # 3 => st_nlink=1
                # 4 => st_uid=1000
                # 5 => st_gid=1000
                # 6 => st_size=1056233
                # 7 => st_atime=1468284229
                # 8 => st_mtime=1456338235
                # 9 => st_ctime=1456338235
                fnd["stat"] = list(os.stat(dest))
            except Exception:  # pylint: disable=broad-except
                pass
        finally:
            repo["repo"].close()
        return fnd
    return fnd


def serve_file(load, fnd):
    """
    Return a chunk from a file based on the data received
    """
    if "env" in load:
        # "env" is not supported; Use "saltenv".
        load.pop("env")

    ret = {"data": "", "dest": ""}
    if not all(x in load for x in ("path", "loc", "saltenv")):
        return ret
    if not fnd["path"]:
        return ret
    ret["dest"] = fnd["rel"]
    gzip = load.get("gzip", None)
    fpath = os.path.normpath(fnd["path"])
    with salt.utils.files.fopen(fpath, "rb") as fp_:
        fp_.seek(load["loc"])
        data = fp_.read(__opts__["file_buffer_size"])
        if data and not salt.utils.files.is_binary(fpath):
            data = data.decode(__salt_system_encoding__)
        if gzip and data:
            data = salt.utils.gzip_util.compress(data, gzip)
            ret["gzip"] = gzip
        ret["data"] = data
    return ret


def file_hash(load, fnd):
    """
    Return a file hash, the hash type is set in the master config file
    """
    if "env" in load:
        # "env" is not supported; Use "saltenv".
        load.pop("env")

    if not all(x in load for x in ("path", "saltenv")):
        return ""
    ret = {"hash_type": __opts__["hash_type"]}
    relpath = fnd["rel"]
    path = fnd["path"]
    hashdest = os.path.join(
        __opts__["cachedir"],
        "hgfs/hash",
        load["saltenv"],
        "{}.hash.{}".format(relpath, __opts__["hash_type"]),
    )
    if not os.path.isfile(hashdest):
        ret["hsum"] = salt.utils.hashutils.get_hash(path, __opts__["hash_type"])
        with salt.utils.files.fopen(hashdest, "w+") as fp_:
            fp_.write(ret["hsum"])
        return ret
    else:
        with salt.utils.files.fopen(hashdest, "rb") as fp_:
            ret["hsum"] = salt.utils.stringutils.to_unicode(fp_.read())
        return ret


def _file_lists(load, form):
    """
    Return a dict containing the file lists for files and dirs
    """
    if "env" in load:
        # "env" is not supported; Use "saltenv".
        load.pop("env")

    list_cachedir = os.path.join(__opts__["cachedir"], "file_lists/hgfs")
    if not os.path.isdir(list_cachedir):
        try:
            os.makedirs(list_cachedir)
        except os.error:
            log.critical("Unable to make cachedir %s", list_cachedir)
            return []
    list_cache = os.path.join(list_cachedir, "{}.p".format(load["saltenv"]))
    w_lock = os.path.join(list_cachedir, ".{}.w".format(load["saltenv"]))
    cache_match, refresh_cache, save_cache = salt.fileserver.check_file_list_cache(
        __opts__, form, list_cache, w_lock
    )
    if cache_match is not None:
        return cache_match
    if refresh_cache:
        ret = {}
        ret["files"] = _get_file_list(load)
        ret["dirs"] = _get_dir_list(load)
        if save_cache:
            salt.fileserver.write_file_list_cache(__opts__, ret, list_cache, w_lock)
        return ret.get(form, [])
    # Shouldn't get here, but if we do, this prevents a TypeError
    return []


def file_list(load):
    """
    Return a list of all files on the file server in a specified environment
    """
    return _file_lists(load, "files")


def _get_file_list(load):
    """
    Get a list of all files on the file server in a specified environment
    """
    if "env" in load:
        # "env" is not supported; Use "saltenv".
        load.pop("env")

    if "saltenv" not in load or load["saltenv"] not in envs():
        return []
    ret = set()
    for repo in init():
        try:
            repo["repo"].open()
            ref = _get_ref(repo, load["saltenv"])
            if ref:
                manifest = _get_manifest(repo["repo"], ref=ref)
                for tup in manifest:
                    relpath = os.path.relpath(tup[4], repo["root"])
                    # Don't add files outside the hgfs_root
                    if not relpath.startswith("../"):
                        ret.add(os.path.join(repo["mountpoint"], relpath))
        finally:
            repo["repo"].close()
    return sorted(ret)


def file_list_emptydirs(load):  # pylint: disable=W0613
    """
    Return a list of all empty directories on the master
    """
    # Cannot have empty dirs in hg
    return []


def dir_list(load):
    """
    Return a list of all directories on the master
    """
    return _file_lists(load, "dirs")


def _get_dir_list(load):
    """
    Get a list of all directories on the master
    """
    if "env" in load:
        # "env" is not supported; Use "saltenv".
        load.pop("env")

    if "saltenv" not in load or load["saltenv"] not in envs():
        return []
    ret = set()
    for repo in init():
        try:
            repo["repo"].open()
            ref = _get_ref(repo, load["saltenv"])
            if ref:
                manifest = _get_manifest(repo["repo"], ref=ref)
                for tup in manifest:
                    filepath = tup[4]
                    split = filepath.rsplit("/", 1)
                    while len(split) > 1:
                        relpath = os.path.relpath(split[0], repo["root"])
                        # Don't add '.'
                        if relpath != ".":
                            # Don't add files outside the hgfs_root
                            if not relpath.startswith("../"):
                                ret.add(os.path.join(repo["mountpoint"], relpath))
                        split = split[0].rsplit("/", 1)
        finally:
            repo["repo"].close()
    if repo["mountpoint"]:
        ret.add(repo["mountpoint"])
    return sorted(ret)
