import os

import posixpath

from rhodecode.lib.vcs.backends.base import BaseChangeset

from rhodecode.lib.vcs.conf import settings

from rhodecode.lib.vcs.exceptions import  ChangesetDoesNotExistError, \

    ChangesetError, ImproperArchiveTypeError, NodeDoesNotExistError, VCSError

from rhodecode.lib.vcs.nodes import AddedFileNodesGenerator, \

    ChangedFileNodesGenerator, DirNode, FileNode, NodeKind, \

    RemovedFileNodesGenerator, RootNode, SubModuleNode

from rhodecode.lib.vcs.utils import safe_str, safe_unicode, date_fromtimestamp

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

from rhodecode.lib.vcs.utils.paths import get_dirs_for_path

from rhodecode.lib.vcs.utils.hgcompat import archival, hex

class MercurialChangeset(BaseChangeset):

    """

    Represents state of the repository at the single revision.

    """

    def __init__(self, repository, revision):

        self.repository = repository

        self.raw_id = revision

        self._ctx = repository._repo[revision]

        self.revision = self._ctx._rev

        self.nodes = {}

    @LazyProperty

    def tags(self):

        return map(safe_unicode, self._ctx.tags())

    @LazyProperty

    def branch(self):

        return  safe_unicode(self._ctx.branch())

    @LazyProperty

    def bookmarks(self):

        return map(safe_unicode, self._ctx.bookmarks())

    @LazyProperty

    def message(self):

        return safe_unicode(self._ctx.description())

    @LazyProperty

    def commiter(self):

    @LazyProperty

    def author(self):

        return safe_unicode(self._ctx.user())

    @LazyProperty

    def date(self):

        return date_fromtimestamp(*self._ctx.date())

    @LazyProperty

    def _timestamp(self):

        return self._ctx.date()[0]

    @LazyProperty

    def status(self):

        """

        Returns modified, added, removed, deleted files for current changeset

        """

        return self.repository._repo.status(self._ctx.p1().node(),

                                            self._ctx.node())

    @LazyProperty

    def _file_paths(self):

        return list(self._ctx)

    @LazyProperty

    def _dir_paths(self):

        p = list(set(get_dirs_for_path(*self._file_paths)))

        p.insert(0, '')

        return p

    @LazyProperty

    def _paths(self):

        return self._dir_paths + self._file_paths

    @LazyProperty

    def id(self):

        if self.last:

            return u'tip'

        return self.short_id

    @LazyProperty

    def short_id(self):

        return self.raw_id[:12]

    @LazyProperty

    def parents(self):

        """

        Returns list of parents changesets.

        """

        return [self.repository.get_changeset(parent.rev())

                for parent in self._ctx.parents() if parent.rev() >= 0]

    @LazyProperty

    def children(self):

        """

        Returns list of children changesets.

        """

        return [self.repository.get_changeset(child.rev())

                for child in self._ctx.children() if child.rev() >= 0]

    def next(self, branch=None):

        if branch and self.branch != branch:

            raise VCSError('Branch option used on changeset not belonging '

                           'to that branch')

        def _next(changeset, branch):

            try:

                next_ = changeset.revision + 1

                next_rev = changeset.repository.revisions[next_]

            except IndexError:

                raise ChangesetDoesNotExistError

            cs = changeset.repository.get_changeset(next_rev)

            if branch and branch != cs.branch:

                return _next(cs, branch)

            return cs

        return _next(self, branch)

    def prev(self, branch=None):

        if branch and self.branch != branch:

            raise VCSError('Branch option used on changeset not belonging '

                           'to that branch')

        def _prev(changeset, branch):

            try:

                prev_ = changeset.revision - 1

                if prev_ < 0:

                    raise IndexError

                prev_rev = changeset.repository.revisions[prev_]

            except IndexError:

                raise ChangesetDoesNotExistError

            cs = changeset.repository.get_changeset(prev_rev)

            if branch and branch != cs.branch:

                return _prev(cs, branch)

            return cs

        return _prev(self, branch)

    def diff(self, ignore_whitespace=True, context=3):

        return ''.join(self._ctx.diff(git=True,

                                      ignore_whitespace=ignore_whitespace,

                                      context=context))

    def _fix_path(self, path):

        """

        Paths are stored without trailing slash so we need to get rid off it if

        needed. Also mercurial keeps filenodes as str so we need to decode

        from unicode to str

        """

        if path.endswith('/'):

            path = path.rstrip('/')

        return safe_str(path)

    def _get_kind(self, path):

        path = self._fix_path(path)

        if path in self._file_paths:

            return NodeKind.FILE

        elif path in self._dir_paths:

            return NodeKind.DIR

        else:

            raise ChangesetError("Node does not exist at the given path %r"

                % (path))

    def _get_filectx(self, path):

        path = self._fix_path(path)

        if self._get_kind(path) != NodeKind.FILE:

            raise ChangesetError("File does not exist for revision %r at "

                " %r" % (self.raw_id, path))

        return self._ctx.filectx(path)

    def _extract_submodules(self):

        """

        returns a dictionary with submodule information from substate file

        of hg repository

        """

        return self._ctx.substate

    def get_file_mode(self, path):

        """

        Returns stat mode of the file at the given ``path``.

        """

        fctx = self._get_filectx(path)

        if 'x' in fctx.flags():

            return 0100755

        else:

            return 0100644

    def get_file_content(self, path):

        """

        Returns content of the file at given ``path``.

        """

        fctx = self._get_filectx(path)

        return fctx.data()

    def get_file_size(self, path):

        """

        Returns size of the file at given ``path``.

        """

        fctx = self._get_filectx(path)

        return fctx.size()

    def get_file_changeset(self, path):

        """

        Returns last commit of the file at the given ``path``.

        """

        node = self.get_node(path)

        return node.history[0]

    def get_file_history(self, path):

        """

        Returns history of file as reversed list of ``Changeset`` objects for

        which file at given ``path`` has been modified.

        """

        fctx = self._get_filectx(path)

        nodes = [fctx.filectx(x).node() for x in fctx.filelog()]

        changesets = [self.repository.get_changeset(hex(node))

            for node in reversed(nodes)]

        return changesets

    def get_file_annotate(self, path):

        """

        Returns a generator of four element tuples with

            lineno, sha, changeset lazy loader and line

        """