import os

import posixpath

import mercurial.archival

import mercurial.node

import mercurial.obsutil

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

from kallithea.lib.vcs.conf import settings

from kallithea.lib.vcs.exceptions import ChangesetDoesNotExistError, ChangesetError, ImproperArchiveTypeError, NodeDoesNotExistError, VCSError

from kallithea.lib.vcs.nodes import (AddedFileNodesGenerator, ChangedFileNodesGenerator, DirNode, FileNode, NodeKind, RemovedFileNodesGenerator, RootNode,

                                     SubModuleNode)

from kallithea.lib.vcs.utils import ascii_bytes, ascii_str, date_fromtimestamp, safe_bytes, safe_str

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

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

class MercurialChangeset(BaseChangeset):

    """

    Represents state of the repository at a revision.

    """

    def __init__(self, repository, revision):

        self.repository = repository

        assert isinstance(revision, str), repr(revision)

        self._ctx = repository._repo[ascii_bytes(revision)]

        self.raw_id = ascii_str(self._ctx.hex())

        self.revision = self._ctx._rev

        self.nodes = {}

    @LazyProperty

    def tags(self):

        return [safe_str(tag) for tag in self._ctx.tags()]

    @LazyProperty

    def branch(self):

        return safe_str(self._ctx.branch())

    @LazyProperty

    def branches(self):

        return [safe_str(self._ctx.branch())]

    @LazyProperty

    def closesbranch(self):

        return self._ctx.closesbranch()

    @LazyProperty

    def obsolete(self):

        return self._ctx.obsolete()

    @LazyProperty

    def bumped(self):

        return self._ctx.phasedivergent()

    @LazyProperty

    def divergent(self):

        return self._ctx.contentdivergent()

    @LazyProperty

    def extinct(self):

        return self._ctx.extinct()

    @LazyProperty

    def unstable(self):

        return self._ctx.orphan()

    @LazyProperty

    def phase(self):

        if(self._ctx.phase() == 1):

            return 'Draft'

        elif(self._ctx.phase() == 2):

            return 'Secret'

        else:

            return ''

    @LazyProperty

    def successors(self):

        successors = mercurial.obsutil.successorssets(self._ctx._repo, self._ctx.node(), closest=True)

            # flatten the list here handles both divergent (len > 1)

            # and the usual case (len = 1)

    @LazyProperty

    def predecessors(self):

    @LazyProperty

    def bookmarks(self):

        return [safe_str(bookmark) for bookmark in self._ctx.bookmarks()]

    @LazyProperty

    def message(self):

        return safe_str(self._ctx.description())

    @LazyProperty

    def committer(self):

        return safe_str(self.author)

    @LazyProperty

    def author(self):

        return safe_str(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(safe_str(f) for f in 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 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')

        cs = self

        while True:

            try:

                next_ = cs.repository.revisions.index(cs.raw_id) + 1

                next_rev = cs.repository.revisions[next_]

            except IndexError:

                raise ChangesetDoesNotExistError

            cs = cs.repository.get_changeset(next_rev)

            if not branch or branch == cs.branch:

                return cs

    def prev(self, branch=None):

        if branch and self.branch != branch:

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

                           'to that branch')

        cs = self

        while True:

            try:

                prev_ = cs.repository.revisions.index(cs.raw_id) - 1

                if prev_ < 0:

                    raise IndexError

                prev_rev = cs.repository.revisions[prev_]

            except IndexError:

                raise ChangesetDoesNotExistError

            cs = cs.repository.get_changeset(prev_rev)

            if not branch or branch == cs.branch:

                return cs

    def diff(self):

        # Only used to feed diffstat

        return b''.join(self._ctx.diff())

    def _get_kind(self, path):

        path = path.rstrip('/')

        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 '%s'"

                % (path))

    def _get_filectx(self, path):

        path = path.rstrip('/')

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

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

                " '%s'" % (self.raw_id, path))

        return self._ctx.filectx(safe_bytes(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 b'x' in fctx.flags():

            return 0o100755

        else:

            return 0o100644

    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``.

        """

        return self.get_file_history(path, limit=1)[0]

    def get_file_history(self, path, limit=None):

        """

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

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

        """

        fctx = self._get_filectx(path)

        hist = []

        cnt = 0

        for cs in reversed([x for x in fctx.filelog()]):

            cnt += 1

            hist.append(mercurial.node.hex(fctx.filectx(cs).node()))

            if limit is not None and cnt == limit:

                break

        return [self.repository.get_changeset(node) for node in hist]

    def get_file_annotate(self, path):

        """

        Returns a generator of four element tuples with

            lineno, sha, changeset lazy loader and line

        """

        annotations = self._get_filectx(path).annotate()

        annotation_lines = [(annotateline.fctx, annotateline.text) for annotateline in annotations]

        for i, (fctx, line) in enumerate(annotation_lines):

            sha = ascii_str(fctx.hex())

            yield (i + 1, sha, lambda sha=sha: self.repository.get_changeset(sha), line)

    def fill_archive(self, stream=None, kind='tgz', prefix=None,

                     subrepos=False):

        """

        Fills up given stream.