# unionrepo.py - repository class for viewing union of repository changesets

#

# Derived from bundlerepo.py

# Copyright 2006, 2007 Benoit Boissinot <bboissin@gmail.com>

# Copyright 2013 Unity Technologies, Mads Kiilerich <madski@unity3d.com>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

"""Repository class for "in-memory pull" of one local repository to another,

allowing operations like diff and log with revsets.

"""

from __future__ import absolute_import

from .i18n import _

from .node import nullid

from . import (

    changelog,

    cmdutil,

    encoding,

    error,

    filelog,

    localrepo,

    manifest,

    mdiff,

    pathutil,

    revlog,

    util,

    vfs as vfsmod,

)

class unionrevlog(revlog.revlog):

    def __init__(self, opener, indexfile, revlog2, linkmapper):

        # How it works:

        # To retrieve a revision, we just need to know the node id so we can

        # look it up in revlog2.

        #

        # To differentiate a rev in the second revlog from a rev in the revlog,

        # we check revision against repotiprev.

        opener = vfsmod.readonlyvfs(opener)

        revlog.revlog.__init__(self, opener, indexfile)

        self.revlog2 = revlog2

        n = len(self)

        self.repotiprev = n - 1

        self.bundlerevs = set() # used by 'bundle()' revset expression

        for rev2 in self.revlog2:

            rev = self.revlog2.index[rev2]

            # rev numbers - in revlog2, very different from self.rev

            _start, _csize, rsize, base, linkrev, p1rev, p2rev, node = rev

            flags = _start & 0xFFFF

            if linkmapper is None: # link is to same revlog

                assert linkrev == rev2 # we never link back

                link = n

            else: # rev must be mapped from repo2 cl to unified cl by linkmapper

                link = linkmapper(linkrev)

            if linkmapper is not None: # link is to same revlog

                base = linkmapper(base)

            if node in self.nodemap:

                # this happens for the common revlog revisions

                self.bundlerevs.add(self.nodemap[node])

                continue

            p1node = self.revlog2.node(p1rev)

            p2node = self.revlog2.node(p2rev)

            # TODO: it's probably wrong to set compressed length to None, but

            # I have no idea if csize is valid in the base revlog context.

            e = (flags, None, rsize, base,

                 link, self.rev(p1node), self.rev(p2node), node)

            self.index.append(e)

            self.nodemap[node] = n

            self.bundlerevs.add(n)

            n += 1

    def _chunk(self, rev):

        if rev <= self.repotiprev:

            return revlog.revlog._chunk(self, rev)

        return self.revlog2._chunk(self.node(rev))

    def revdiff(self, rev1, rev2):

        """return or calculate a delta between two revisions"""

        if rev1 > self.repotiprev and rev2 > self.repotiprev:

            return self.revlog2.revdiff(

                self.revlog2.rev(self.node(rev1)),

                self.revlog2.rev(self.node(rev2)))

        elif rev1 <= self.repotiprev and rev2 <= self.repotiprev:

            return self.baserevdiff(rev1, rev2)

        return mdiff.textdiff(self.revision(rev1), self.revision(rev2))

    def revision(self, nodeorrev, _df=None, raw=False):

        """return an uncompressed revision of a given node or revision

        number.

        """

        if isinstance(nodeorrev, int):

            rev = nodeorrev

            node = self.node(rev)

        else:

            node = nodeorrev

            rev = self.rev(node)

        if node == nullid:

            return ""

        if rev > self.repotiprev:

            text = self.revlog2.revision(node)

            self._revisioncache = (node, rev, text)

        else:

            text = self.baserevision(rev)

            # already cached

        return text

    def baserevision(self, nodeorrev):

        # Revlog subclasses may override 'revision' method to modify format of

        # content retrieved from revlog. To use unionrevlog with such class one

        # needs to override 'baserevision' and make more specific call here.

        return revlog.revlog.revision(self, nodeorrev)

    def baserevdiff(self, rev1, rev2):

        # Exists for the same purpose as baserevision.

        return revlog.revlog.revdiff(self, rev1, rev2)

    def addrevision(self, text, transaction, link, p1=None, p2=None, d=None):

        raise NotImplementedError

    def addgroup(self, deltas, transaction, addrevisioncb=None):

        raise NotImplementedError

    def strip(self, rev, minlink):

        raise NotImplementedError

    def checksize(self):

        raise NotImplementedError

class unionchangelog(unionrevlog, changelog.changelog):

    def __init__(self, opener, opener2):

        changelog.changelog.__init__(self, opener)

        linkmapper = None

        changelog2 = changelog.changelog(opener2)

        unionrevlog.__init__(self, opener, self.indexfile, changelog2,

                             linkmapper)

    def baserevision(self, nodeorrev):

        # Although changelog doesn't override 'revision' method, some extensions

        # may replace this class with another that does. Same story with

        # manifest and filelog classes.

        return changelog.changelog.revision(self, nodeorrev)

    def baserevdiff(self, rev1, rev2):

        return changelog.changelog.revdiff(self, rev1, rev2)

class unionmanifest(unionrevlog, manifest.manifestrevlog):

    def __init__(self, opener, opener2, linkmapper):

        manifest.manifestrevlog.__init__(self, opener)

        manifest2 = manifest.manifestrevlog(opener2)

        unionrevlog.__init__(self, opener, self.indexfile, manifest2,

                             linkmapper)

    def baserevision(self, nodeorrev):

        return manifest.manifestrevlog.revision(self, nodeorrev)

    def baserevdiff(self, rev1, rev2):

        return manifest.manifestrevlog.revdiff(self, rev1, rev2)

class unionfilelog(filelog.filelog):

    def __init__(self, opener, path, opener2, linkmapper, repo):

        filelog.filelog.__init__(self, opener, path)

        filelog2 = filelog.filelog(opener2, path)

        self._revlog = unionrevlog(opener, self.indexfile,

                                   filelog2._revlog, linkmapper)

        self._repo = repo

        self.repotiprev = self._revlog.repotiprev

        self.revlog2 = self._revlog.revlog2

    def baserevision(self, nodeorrev):

        return filelog.filelog.revision(self, nodeorrev)

    def baserevdiff(self, rev1, rev2):

        return filelog.filelog.revdiff(self, rev1, rev2)

    def iscensored(self, rev):

        """Check if a revision is censored."""

        if rev <= self.repotiprev:

            return filelog.filelog.iscensored(self, rev)

        node = self.node(rev)

        return self.revlog2.iscensored(self.revlog2.rev(node))

class unionpeer(localrepo.localpeer):

    def canpush(self):

        return False

class unionrepository(object):

    """Represents the union of data in 2 repositories.

    Instances are not usable if constructed directly. Use ``instance()``

    or ``makeunionrepository()`` to create a usable instance.

    """

    def __init__(self, repo2, url):

        self.repo2 = repo2

        self._url = url

        self.ui.setconfig('phases', 'publish', False, 'unionrepo')

    @localrepo.unfilteredpropertycache

    def changelog(self):

        return unionchangelog(self.svfs, self.repo2.svfs)

    @localrepo.unfilteredpropertycache

    def manifestlog(self):

        rootstore = unionmanifest(self.svfs, self.repo2.svfs,

                                  self.unfiltered()._clrev)

        return manifest.manifestlog(self.svfs, self, rootstore,

                                    self.narrowmatch())

    def _clrev(self, rev2):

        """map from repo2 changelog rev to temporary rev in self.changelog"""

        node = self.repo2.changelog.node(rev2)

        return self.changelog.rev(node)

    def url(self):

        return self._url

    def file(self, f):

        return unionfilelog(self.svfs, f, self.repo2.svfs,

                            self.unfiltered()._clrev, self)

    def close(self):

        self.repo2.close()

    def cancopy(self):

        return False

    def peer(self):

        return unionpeer(self)

    def getcwd(self):

        return encoding.getcwd() # always outside the repo

def instance(ui, path, create, intents=None, createopts=None):

    if create:

        raise error.Abort(_('cannot create new union repository'))

    parentpath = ui.config("bundle", "mainreporoot")

    if not parentpath:

        # try to find the correct path to the working directory repo

        parentpath = cmdutil.findrepo(encoding.getcwd())

        if parentpath is None:

            parentpath = ''

    if parentpath:

        # Try to make the full path relative so we get a nice, short URL.

        # In particular, we don't want temp dir names in test outputs.

        cwd = encoding.getcwd()

        if parentpath == cwd:

            parentpath = ''

        else:

            cwd = pathutil.normasprefix(cwd)

            if parentpath.startswith(cwd):

                parentpath = parentpath[len(cwd):]

    if path.startswith('union:'):

        s = path.split(":", 1)[1].split("+", 1)

        if len(s) == 1:

            repopath, repopath2 = parentpath, s[0]

        else:

            repopath, repopath2 = s

    else:

        repopath, repopath2 = parentpath, path

    return makeunionrepository(ui, repopath, repopath2)

def makeunionrepository(ui, repopath1, repopath2):

    """Make a union repository object from 2 local repo paths."""

    repo1 = localrepo.instance(ui, repopath1, create=False)

    repo2 = localrepo.instance(ui, repopath2, create=False)

    url = 'union:%s+%s' % (util.expandpath(repopath1),

                           util.expandpath(repopath2))

    class derivedunionrepository(unionrepository, repo1.__class__):

        pass

    repo = repo1

    repo.__class__ = derivedunionrepository

    unionrepository.__init__(repo1, repo2, url)

    return repo