# shallowrepo.py - shallow repository that uses remote filelogs
#
# Copyright 2013 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from mercurial.node import hex, nullid, nullrev, bin
from mercurial.i18n import _
from mercurial import localrepo, context, util, match, scmutil
from mercurial.extensions import wrapfunction
import remotefilelog, remotefilectx, fileserverclient, shallowbundle, os
import constants, shallowutil
from contentstore import remotefilelogcontentstore, unioncontentstore
from contentstore import remotecontentstore
from metadatastore import remotefilelogmetadatastore, unionmetadatastore
from metadatastore import remotemetadatastore
from datapack import datapackstore
from historypack import historypackstore

requirement = "remotefilelog"

def wraprepo(repo):
    class shallowrepository(repo.__class__):
        @util.propertycache
        def name(self):
            return self.ui.config('remotefilelog', 'reponame', '')

        @util.propertycache
        def fallbackpath(self):
            return repo.ui.config("remotefilelog", "fallbackpath",
                    # fallbackrepo is the old, deprecated name
                     repo.ui.config("remotefilelog", "fallbackrepo",
                       repo.ui.config("paths", "default")))

        def sparsematch(self, *revs, **kwargs):
            baseinstance = super(shallowrepository, self)
            if util.safehasattr(baseinstance, 'sparsematch'):
                return baseinstance.sparsematch(*revs, **kwargs)

            return None

        def file(self, f):
            if f[0] == '/':
                f = f[1:]

            if self.shallowmatch(f):
                return remotefilelog.remotefilelog(self.svfs, f, self)
            else:
                return super(shallowrepository, self).file(f)

        def filectx(self, path, changeid=None, fileid=None):
            if self.shallowmatch(path):
                return remotefilectx.remotefilectx(self, path, changeid, fileid)
            else:
                return super(shallowrepository, self).filectx(path, changeid,
                                                              fileid)

        @localrepo.unfilteredmethod
        def commitctx(self, ctx, error=False):
            """Add a new revision to current repository.
            Revision information is passed via the context argument.
            """

            # prefetch files that will likely be compared
            m1 = ctx.p1().manifest()
            files = []
            for f in ctx.modified() + ctx.added():
                fparent1 = m1.get(f, nullid)
                if fparent1 != nullid:
                    files.append((f, hex(fparent1)))
            self.fileservice.prefetch(files)
            return super(shallowrepository, self).commitctx(ctx, error=error)

        def prefetch(self, revs, base=None, pats=None, opts=None):
            """Prefetches all the necessary file revisions for the given revs
            """
            fallbackpath = self.fallbackpath
            if fallbackpath:
                # If we know a rev is on the server, we should fetch the server
                # version of those files, since our local file versions might
                # become obsolete if the local commits are stripped.
                localrevs = repo.revs('outgoing(%s)', fallbackpath)
                if base is not None and base != nullrev:
                    serverbase = list(repo.revs('first(reverse(::%s) - %ld)',
                                                base, localrevs))
                    if serverbase:
                        base = serverbase[0]
            else:
                localrevs = repo

            mf = repo.manifest
            if base is not None:
                mfdict = mf.read(repo[base].manifestnode())
                skip = set(mfdict.iteritems())
            else:
                skip = set()

            # Copy the skip set to start large and avoid constant resizing,
            # and since it's likely to be very similar to the prefetch set.
            files = skip.copy()
            serverfiles = skip.copy()
            visited = set()
            visited.add(nullrev)
            for rev in sorted(revs):
                ctx = repo[rev]
                if pats:
                    m = scmutil.match(ctx, pats, opts)
                sparsematch = repo.sparsematch(rev)

                mfnode = ctx.manifestnode()
                mfrev = mf.rev(mfnode)

                # Decompressing manifests is expensive.
                # When possible, only read the deltas.
                p1, p2 = mf.parentrevs(mfrev)
                if p1 in visited and p2 in visited:
                    mfdict = mf.readfast(mfnode)
                else:
                    mfdict = mf.read(mfnode)

                diff = mfdict.iteritems()
                if pats:
                    diff = (pf for pf in diff if m(pf[0]))
                if sparsematch:
                    diff = (pf for pf in diff if sparsematch(pf[0]))
                if rev not in localrevs:
                    serverfiles.update(diff)
                else:
                    files.update(diff)

                visited.add(mfrev)

            files.difference_update(skip)
            serverfiles.difference_update(skip)

            # Fetch files known to be on the server
            if serverfiles:
                results = [(path, hex(fnode)) for (path, fnode) in serverfiles]
                repo.fileservice.prefetch(results, force=True)

            # Fetch files that may or may not be on the server
            if files:
                results = [(path, hex(fnode)) for (path, fnode) in files]
                repo.fileservice.prefetch(results)

    repo.__class__ = shallowrepository

    repo.shallowmatch = match.always(repo.root, '')

    localpath = os.path.join(repo.svfs.vfs.base, 'data')
    if not os.path.exists(localpath):
        os.makedirs(localpath)

    # Instantiate local data stores
    localcontent = remotefilelogcontentstore(repo, localpath, repo.name,
                                             shared=False)
    localmetadata = remotefilelogmetadatastore(repo, localpath, repo.name,
                                               shared=False)

    # Instantiate shared cache stores
    cachepath = shallowutil.getcachepath(repo.ui)
    cachecontent = remotefilelogcontentstore(repo, cachepath, repo.name,
                                             shared=True)
    cachemetadata = remotefilelogmetadatastore(repo, cachepath, repo.name,
                                               shared=True)
    repo.sharedstore = cachecontent

    # Instantiate remote stores
    repo.fileservice = fileserverclient.fileserverclient(repo)
    remotecontent = remotecontentstore(repo.ui, repo.fileservice, cachecontent)
    remotemetadata = remotemetadatastore(repo.ui, repo.fileservice,
                                         cachemetadata)

    # Instantiate pack stores
    packpath = shallowutil.getpackpath(repo, constants.FILEPACK_CATEGORY)
    packcontentstore = datapackstore(
        packpath,
        usecdatapack=repo.ui.configbool('remotefilelog', 'fastdatapack'))
    packmetadatastore = historypackstore(packpath)

    # Instantiate union stores
    repo.contentstore = unioncontentstore(packcontentstore, cachecontent,
            localcontent, remotecontent, writestore=localcontent)
    repo.metadatastore = unionmetadatastore(packmetadatastore, cachemetadata,
            localmetadata, remotemetadata, writestore=localmetadata)

    fileservicedatawrite = cachecontent
    fileservicehistorywrite = cachecontent
    if repo.ui.configbool('remotefilelog', 'fetchpacks'):
        fileservicedatawrite = packcontentstore
        fileservicehistorywrite = packmetadatastore
    repo.fileservice.setstore(repo.contentstore, repo.metadatastore,
                              fileservicedatawrite, fileservicehistorywrite)

    # Record which ones are shared stores
    repo.shareddatastores = [packcontentstore, cachecontent]
    repo.sharedhistorystores = [packmetadatastore, cachemetadata]

    repo.includepattern = repo.ui.configlist("remotefilelog", "includepattern",
                                             None)
    repo.excludepattern = repo.ui.configlist("remotefilelog", "excludepattern",
                                             None)
    if repo.includepattern or repo.excludepattern:
        repo.shallowmatch = match.match(repo.root, '', None,
            repo.includepattern, repo.excludepattern)

    localpath = os.path.join(repo.svfs.vfs.base, 'data')
    if not os.path.exists(localpath):
        os.makedirs(localpath)