# -*- coding: utf-8 -*-

"""

    vcs.nodes

    ~~~~~~~~~

    Module holding everything related to vcs nodes.

    :created_on: Apr 8, 2010

    :copyright: (c) 2010-2011 by Marcin Kuzminski, Lukasz Balcerzak.

"""

import functools

import mimetypes

import posixpath

import stat

from kallithea.lib.vcs.backends.base import EmptyChangeset

from kallithea.lib.vcs.exceptions import NodeError, RemovedFileNodeError

from kallithea.lib.vcs.utils import safe_bytes, safe_str, safe_unicode

from kallithea.lib.vcs.utils.lazy import LazyProperty

class NodeKind:

    SUBMODULE = -1

    DIR = 1

    FILE = 2

class NodeState:

    ADDED = u'added'

    CHANGED = u'changed'

    NOT_CHANGED = u'not changed'

    REMOVED = u'removed'

class NodeGeneratorBase(object):

    """

    Base class for removed added and changed filenodes, it's a lazy generator

    class that will create filenodes only on iteration or call

    The len method doesn't need to create filenodes at all

    """

    def __init__(self, current_paths, cs):

        self.cs = cs

        self.current_paths = current_paths

    def __getitem__(self, key):

        assert isinstance(key, slice), key

        for p in self.current_paths[key]:

            yield self.cs.get_node(p)

    def __len__(self):

        return len(self.current_paths)

    def __iter__(self):

        for p in self.current_paths:

            yield self.cs.get_node(p)

class AddedFileNodesGenerator(NodeGeneratorBase):

    """

    Class holding Added files for current changeset

    """

    pass

class ChangedFileNodesGenerator(NodeGeneratorBase):

    """

    Class holding Changed files for current changeset

    """

    pass

class RemovedFileNodesGenerator(NodeGeneratorBase):

    """

    Class holding removed files for current changeset

    """

    def __iter__(self):

        for p in self.current_paths:

            yield RemovedFileNode(path=p)

    def __getitem__(self, key):

        assert isinstance(key, slice), key

        for p in self.current_paths[key]:

            yield RemovedFileNode(path=p)

@functools.total_ordering

class Node(object):

    """

    Simplest class representing file or directory on repository.  SCM backends

    should use ``FileNode`` and ``DirNode`` subclasses rather than ``Node``

    directly.

    Node's ``path`` cannot start with slash as we operate on *relative* paths

    only. Moreover, every single node is identified by the ``path`` attribute,

    so it cannot end with slash, too. Otherwise, path could lead to mistakes.

    """

    def __init__(self, path, kind):

        if path.startswith('/'):

            raise NodeError("Cannot initialize Node objects with slash at "

                            "the beginning as only relative paths are supported")

        self.path = safe_str(path.rstrip('/'))  # we store paths as str

        if path == '' and kind != NodeKind.DIR:

            raise NodeError("Only DirNode and its subclasses may be "

                            "initialized with empty path")

        self.kind = kind

        #self.dirs, self.files = [], []

        if self.is_root() and not self.is_dir():

            raise NodeError("Root node cannot be FILE kind")

    @LazyProperty

    def parent(self):

        parent_path = self.get_parent_path()

        if parent_path:

            if self.changeset:

                return self.changeset.get_node(parent_path)

            return DirNode(parent_path)

        return None

    @LazyProperty

    def name(self):

        """

        Returns name of the node so if its path

        then only last part is returned.

        """

        return safe_unicode(self.path.rstrip('/').split('/')[-1])

    def _get_kind(self):

        return self._kind

    def _set_kind(self, kind):

        if hasattr(self, '_kind'):

            raise NodeError("Cannot change node's kind")

        else:

            self._kind = kind

            # Post setter check (path's trailing slash)

            if self.path.endswith('/'):

                raise NodeError("Node's path cannot end with slash")

    kind = property(_get_kind, _set_kind)