# lfs - hash-preserving large file support using Git-LFS protocol
#
# Copyright 2017 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.

"""lfs - large file support (EXPERIMENTAL)

Configs::

    [lfs]
    # Remote endpoint. Multiple protocols are supported:
    # - http(s)://user:pass@example.com/path
    #   git-lfs endpoint
    # - file:///tmp/path
    #   local filesystem, usually for testing
    # if unset, lfs will prompt setting this when it must use this value.
    # (default: unset)
    url = https://example.com/lfs

    # size of a file to make it use LFS
    threshold = 10M

    # how many times to retry before giving up on transferring an object
    retry = 5

    # the local directory to store lfs files for sharing across local clones.
    # If not set, the cache is located in an OS specific cache location.
    usercache = /path/to/global/cache
"""

from __future__ import absolute_import

from mercurial.i18n import _

from mercurial import (
    bundle2,
    changegroup,
    context,
    exchange,
    extensions,
    filelog,
    hg,
    localrepo,
    registrar,
    revlog,
    scmutil,
    upgrade,
    vfs as vfsmod,
)

from . import (
    blobstore,
    wrapper,
)

# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'

configtable = {}
configitem = registrar.configitem(configtable)

configitem('experimental', 'lfs.user-agent',
    default=None,
)

configitem('lfs', 'url',
    default=configitem.dynamicdefault,
)
configitem('lfs', 'usercache',
    default=None,
)
configitem('lfs', 'threshold',
    default=None,
)
configitem('lfs', 'retry',
    default=5,
)
# Deprecated
configitem('lfs', 'remotestore',
    default=None,
)
# Deprecated
configitem('lfs', 'dummy',
    default=None,
)
# Deprecated
configitem('lfs', 'git-lfs',
    default=None,
)

cmdtable = {}
command = registrar.command(cmdtable)

templatekeyword = registrar.templatekeyword()

def featuresetup(ui, supported):
    # don't die on seeing a repo with the lfs requirement
    supported |= {'lfs'}

def uisetup(ui):
    localrepo.localrepository.featuresetupfuncs.add(featuresetup)

def reposetup(ui, repo):
    # Nothing to do with a remote repo
    if not repo.local():
        return

    threshold = repo.ui.configbytes('lfs', 'threshold')

    repo.svfs.options['lfsthreshold'] = threshold
    repo.svfs.lfslocalblobstore = blobstore.local(repo)
    repo.svfs.lfsremoteblobstore = blobstore.remote(repo)

    # Push hook
    repo.prepushoutgoinghooks.add('lfs', wrapper.prepush)

    if 'lfs' not in repo.requirements:
        def checkrequireslfs(ui, repo, **kwargs):
            if 'lfs' not in repo.requirements:
                ctx = repo[kwargs['node']]
                # TODO: is there a way to just walk the files in the commit?
                if any(ctx[f].islfs() for f in ctx.files() if f in ctx):
                    repo.requirements.add('lfs')
                    repo._writerequirements()

        ui.setconfig('hooks', 'commit.lfs', checkrequireslfs, 'lfs')

def wrapfilelog(filelog):
    wrapfunction = extensions.wrapfunction

    wrapfunction(filelog, 'addrevision', wrapper.filelogaddrevision)
    wrapfunction(filelog, 'renamed', wrapper.filelogrenamed)
    wrapfunction(filelog, 'size', wrapper.filelogsize)

def extsetup(ui):
    wrapfilelog(filelog.filelog)

    wrapfunction = extensions.wrapfunction

    wrapfunction(scmutil, 'wrapconvertsink', wrapper.convertsink)

    wrapfunction(upgrade, '_finishdatamigration',
                 wrapper.upgradefinishdatamigration)

    wrapfunction(upgrade, 'preservedrequirements',
                 wrapper.upgraderequirements)

    wrapfunction(upgrade, 'supporteddestrequirements',
                 wrapper.upgraderequirements)

    wrapfunction(changegroup,
                 'supportedoutgoingversions',
                 wrapper.supportedoutgoingversions)
    wrapfunction(changegroup,
                 'allsupportedversions',
                 wrapper.allsupportedversions)

    wrapfunction(context.basefilectx, 'cmp', wrapper.filectxcmp)
    wrapfunction(context.basefilectx, 'isbinary', wrapper.filectxisbinary)
    context.basefilectx.islfs = wrapper.filectxislfs

    revlog.addflagprocessor(
        revlog.REVIDX_EXTSTORED,
        (
            wrapper.readfromstore,
            wrapper.writetostore,
            wrapper.bypasscheckhash,
        ),
    )

    wrapfunction(hg, 'clone', wrapper.hgclone)
    wrapfunction(hg, 'postshare', wrapper.hgpostshare)

    # Make bundle choose changegroup3 instead of changegroup2. This affects
    # "hg bundle" command. Note: it does not cover all bundle formats like
    # "packed1". Using "packed1" with lfs will likely cause trouble.
    names = [k for k, v in exchange._bundlespeccgversions.items() if v == '02']
    for k in names:
        exchange._bundlespeccgversions[k] = '03'

    # bundlerepo uses "vfsmod.readonlyvfs(othervfs)", we need to make sure lfs
    # options and blob stores are passed from othervfs to the new readonlyvfs.
    wrapfunction(vfsmod.readonlyvfs, '__init__', wrapper.vfsinit)

    # when writing a bundle via "hg bundle" command, upload related LFS blobs
    wrapfunction(bundle2, 'writenewbundle', wrapper.writenewbundle)

@templatekeyword('lfs_files')
def lfsfiles(repo, ctx, **args):
    """List of strings. LFS files added or modified by the changeset."""
    pointers = wrapper.pointersfromctx(ctx) # {path: pointer}
    return sorted(pointers.keys())

@command('debuglfsupload',
         [('r', 'rev', [], _('upload large files introduced by REV'))])
def debuglfsupload(ui, repo, **opts):
    """upload lfs blobs added by the working copy parent or given revisions"""
    revs = opts.get('rev', [])
    pointers = wrapper.extractpointers(repo, scmutil.revrange(repo, revs))
    wrapper.uploadblobs(repo, pointers)