import contextlib

import errno

import os

import posixpath

import stat

from typing import (

    Any,

    Callable,

    Iterator,

    Optional,

)

from .i18n import _

from . import (

    encoding,

    error,

    policy,

    pycompat,

    util,

)

rustdirs = policy.importrust('dirstate', 'Dirs')

parsers = policy.importmod('parsers')

def _lowerclean(s: bytes) -> bytes:

    return encoding.hfsignoreclean(s.lower())

class pathauditor:

    """ensure that a filesystem path contains no banned components.

    the following properties of a path are checked:

    - ends with a directory separator

    - under top-level .hg

    - starts at the root of a windows drive

    - contains ".."

    More check are also done about the file system states:

    - traverses a symlink (e.g. a/symlink_here/b)

    - inside a nested repository (a callback can be used to approve

      some nested repositories, e.g., subrepositories)

    The file system checks are only done when 'realfs' is set to True (the

    default). They should be disable then we are auditing path for operation on

    stored history.

    If 'cached' is set to True, audited paths and sub-directories are cached.

    Be careful to not keep the cache of unmanaged directories for long because

    audited paths may be replaced with symlinks.

    """

    def __init__(self, root, callback=None, realfs=True, cached=False):

        self.audited = set()

        self.auditeddir = dict()

        self.root = root

        self._realfs = realfs

        self._cached = cached

        self.callback = callback

        if os.path.lexists(root) and not util.fscasesensitive(root):

            self.normcase = util.normcase

        else:

            self.normcase = lambda x: x

    def __call__(self, path: bytes, mode: Optional[Any] = None) -> None:

        """Check the relative path.

        path may contain a pattern (e.g. foodir/**.txt)"""

        path = util.localpath(path)

        if path in self.audited:

            return

        # AIX ignores "/" at end of path, others raise EISDIR.

        if util.endswithsep(path):

            raise error.InputError(

                _(b"path ends in directory separator: %s") % path

            )

        parts = util.splitpath(path)

        if (

            os.path.splitdrive(path)[0]

            or _lowerclean(parts[0]) in (b'.hg', b'.hg.', b'')

            or pycompat.ospardir in parts

        ):

            raise error.InputError(

                _(b"path contains illegal component: %s") % path

            )

        # Windows shortname aliases

        if b"~" in path:

            for p in parts:

                if b"~" in p:

                    first, last = p.split(b"~", 1)

                    if last.isdigit() and first.upper() in [b"HG", b"HG8B6C"]:

                        raise error.InputError(

                            _(b"path contains illegal component: %s") % path

                        )

        if b'.hg' in _lowerclean(path):

            lparts = [_lowerclean(p) for p in parts]

            for p in b'.hg', b'.hg.':

                if p in lparts[1:]:

                    pos = lparts.index(p)

                    base = os.path.join(*parts[:pos])

                    raise error.InputError(

                        _(b"path '%s' is inside nested repo %r")

                        % (path, pycompat.bytestr(base))

                    )

        if self._realfs:

            # It's important that we check the path parts starting from the root.

            # We don't want to add "foo/bar/baz" to auditeddir before checking if

            # there's a "foo/.hg" directory. This also means we won't accidentally

            # traverse a symlink into some other filesystem (which is potentially

            # expensive to access).

            for prefix in finddirs_rev_noroot(path):

                if prefix in self.auditeddir:

                    res = self.auditeddir[prefix]

                else:

                    res = pathauditor._checkfs_exists(

                        self.root, prefix, path, self.callback

                    )

                    if self._cached:

                        self.auditeddir[prefix] = res

                if not res:

                    break

        if self._cached:

            self.audited.add(path)

    @staticmethod

    def _checkfs_exists(

        root,

        prefix: bytes,

        path: bytes,

        callback: Optional[Callable[[bytes], bool]] = None,

    ):

        """raise exception if a file system backed check fails.

        Return a bool that indicates that the directory (or file) exists."""

        curpath = os.path.join(root, prefix)

        try:

            st = os.lstat(curpath)

        except OSError as err:

            if err.errno == errno.ENOENT:

                return False

            # EINVAL can be raised as invalid path syntax under win32.

            # They must be ignored for patterns can be checked too.

            if err.errno not in (errno.ENOENT, errno.ENOTDIR, errno.EINVAL):

                raise

        else:

            if stat.S_ISLNK(st.st_mode):

                msg = _(b'path %r traverses symbolic link %r') % (

                    pycompat.bytestr(path),

                    pycompat.bytestr(prefix),

                )

                raise error.Abort(msg)

            elif stat.S_ISDIR(st.st_mode) and os.path.isdir(

                os.path.join(curpath, b'.hg')

            ):

                if not callback or not callback(curpath):

                    msg = _(b"path '%s' is inside nested repo %r")

                    raise error.Abort(msg % (path, pycompat.bytestr(prefix)))

        return True

    def check(self, path: bytes) -> bool:

        try:

            self(path)

            return True

        except (OSError, error.Abort):

            return False

    @contextlib.contextmanager

    def cached(self):

        if self._cached:

            yield

        else:

            try:

                self._cached = True

                yield

            finally:

                self.audited.clear()

                self.auditeddir.clear()

                self._cached = False

    def clear_audit_cache(self):

        """reset all audit cache

        intended for debug and performance benchmark purposes"""

        self.audited.clear()

        self.auditeddir.clear()

def canonpath(

    root: bytes,

    cwd: bytes,

    myname: bytes,

    auditor: Optional[pathauditor] = None,

) -> bytes:

    """return the canonical path of myname, given cwd and root

    >>> def check(root, cwd, myname):

    ...     a = pathauditor(root, realfs=False)

    ...     try:

    ...         return canonpath(root, cwd, myname, a)

    ...     except error.Abort:

    ...         return 'aborted'

    >>> def unixonly(root, cwd, myname, expected='aborted'):

    ...     if pycompat.iswindows:

    ...         return expected

    ...     return check(root, cwd, myname)

    >>> def winonly(root, cwd, myname, expected='aborted'):

    ...     if not pycompat.iswindows:

    ...         return expected

    ...     return check(root, cwd, myname)

    >>> winonly(b'd:\\\\repo', b'c:\\\\dir', b'filename')

    'aborted'

    >>> winonly(b'c:\\\\repo', b'c:\\\\dir', b'filename')

    'aborted'

    >>> winonly(b'c:\\\\repo', b'c:\\\\', b'filename')

    'aborted'

    >>> winonly(b'c:\\\\repo', b'c:\\\\', b'repo\\\\filename',

    ...         b'filename')

    'filename'

    >>> winonly(b'c:\\\\repo', b'c:\\\\repo', b'filename', b'filename')

    'filename'

    >>> winonly(b'c:\\\\repo', b'c:\\\\repo\\\\subdir', b'filename',

    ...         b'subdir/filename')

    'subdir/filename'

    >>> unixonly(b'/repo', b'/dir', b'filename')

    'aborted'

    >>> unixonly(b'/repo', b'/', b'filename')

    'aborted'

    >>> unixonly(b'/repo', b'/', b'repo/filename', b'filename')

    'filename'

    >>> unixonly(b'/repo', b'/repo', b'filename', b'filename')

    'filename'

    >>> unixonly(b'/repo', b'/repo/subdir', b'filename', b'subdir/filename')

    'subdir/filename'

    """

    if util.endswithsep(root):

        rootsep = root

    else:

        rootsep = root + pycompat.ossep

    name = myname

    if not os.path.isabs(name):

        name = os.path.join(root, cwd, name)

    name = os.path.normpath(name)

    if auditor is None:

        auditor = pathauditor(root)

    if name != rootsep and name.startswith(rootsep):

        name = name[len(rootsep) :]

        auditor(name)

        return util.pconvert(name)

    elif name == root:

        return b''

    else:

        # Determine whether `name' is in the hierarchy at or beneath `root',

        # by iterating name=dirname(name) until that causes no change (can't

        # check name == '/', because that doesn't work on windows). The list

        # `rel' holds the reversed list of components making up the relative

        # file name we want.

        rel = []

        while True:

            try:

                s = util.samefile(name, root)

            except OSError:

                s = False

            if s:

                if not rel:

                    # name was actually the same as root (maybe a symlink)

                    return b''

                rel.reverse()

                name = os.path.join(*rel)

                auditor(name)

                return util.pconvert(name)

            dirname, basename = util.split(name)

            rel.append(basename)

            if dirname == name:

                break

            name = dirname

        # A common mistake is to use -R, but specify a file relative to the repo

        # instead of cwd.  Detect that case, and provide a hint to the user.

        hint = None

        try:

            if cwd != root:

                canonpath(root, root, myname, auditor)

                relpath = util.pathto(root, cwd, b'')

                if relpath.endswith(pycompat.ossep):

                    relpath = relpath[:-1]

                hint = _(b"consider using '--cwd %s'") % relpath

        except error.Abort:

            pass

        raise error.Abort(

            _(b"%s not under root '%s'") % (myname, root), hint=hint

        )

def normasprefix(path: bytes) -> bytes:

    """normalize the specified path as path prefix

    Returned value can be used safely for "p.startswith(prefix)",

    "p[len(prefix):]", and so on.

    For efficiency, this expects "path" argument to be already

    normalized by "os.path.normpath", "os.path.realpath", and so on.

    See also issue3033 for detail about need of this function.

    >>> normasprefix(b'/foo/bar').replace(pycompat.ossep, b'/')

    '/foo/bar/'

    >>> normasprefix(b'/').replace(pycompat.ossep, b'/')

    '/'

    """

    d, p = os.path.splitdrive(path)

    if len(p) != len(pycompat.ossep):

        return path + pycompat.ossep

    else:

        return path

def finddirs(path: bytes) -> Iterator[bytes]:

    pos = path.rfind(b'/')

    while pos != -1:

        yield path[:pos]

        pos = path.rfind(b'/', 0, pos)

    yield b''

def finddirs_rev_noroot(path: bytes) -> Iterator[bytes]:

    pos = path.find(pycompat.ossep)

    while pos != -1:

        yield path[:pos]

        pos = path.find(pycompat.ossep, pos + 1)

class dirs:

    '''a multiset of directory names from a set of file paths'''

    def __init__(self, map, only_tracked=False):

        """

        a dict map indicates a dirstate while a list indicates a manifest

        """

        self._dirs = {}

        addpath = self.addpath

        if isinstance(map, dict) and only_tracked:

            for f, s in map.items():

                if s.state != b'r':

                    addpath(f)

        elif only_tracked:

            msg = b"`only_tracked` is only supported with a dict source"

            raise error.ProgrammingError(msg)

        else:

            for f in map:

                addpath(f)

    def addpath(self, path: bytes) -> None:

        dirs = self._dirs

        for base in finddirs(path):

            if base.endswith(b'/'):

                raise ValueError(

                    "found invalid consecutive slashes in path: %r" % base

                )

            if base in dirs:

                dirs[base] += 1

                return

            dirs[base] = 1

    def delpath(self, path: bytes) -> None:

        dirs = self._dirs

        for base in finddirs(path):

            if dirs[base] > 1:

                dirs[base] -= 1

                return

            del dirs[base]

    def __iter__(self):

        return iter(self._dirs)

    def __contains__(self, d: bytes) -> bool:

        return d in self._dirs

if hasattr(parsers, 'dirs'):

    dirs = parsers.dirs

if rustdirs is not None:

    dirs = rustdirs

# forward two methods from posixpath that do what we need, but we'd

# rather not let our internals know that we're thinking in posix terms

# - instead we'll let them be oblivious.