# phabricator.py - simple Phabricator integration

#

# 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.

"""simple Phabricator integration

This extension provides a ``phabsend`` command which sends a stack of

changesets to Phabricator without amending commit messages, and a ``phabread``

command which prints a stack of revisions in a format suitable

for :hg:`import`.

By default, Phabricator requires ``Test Plan`` which might prevent some

changeset from being sent. The requirement could be disabled by changing

``differential.require-test-plan-field`` config server side.

Config::

    [phabricator]

    # Phabricator URL

    url = https://phab.example.com/

    # API token. Get it from https://$HOST/conduit/login/

    token = cli-xxxxxxxxxxxxxxxxxxxxxxxxxxxx

    # Repo callsign. If a repo has a URL https://$HOST/diffusion/FOO, then its

    # callsign is "FOO".

    callsign = FOO

"""

from __future__ import absolute_import

import json

import re

from mercurial.i18n import _

from mercurial import (

    encoding,

    error,

    mdiff,

    obsolete,

    patch,

    registrar,

    scmutil,

    tags,

    url as urlmod,

    util,

)

cmdtable = {}

command = registrar.command(cmdtable)

def urlencodenested(params):

    """like urlencode, but works with nested parameters.

    For example, if params is {'a': ['b', 'c'], 'd': {'e': 'f'}}, it will be

    flattened to {'a[0]': 'b', 'a[1]': 'c', 'd[e]': 'f'} and then passed to

    urlencode. Note: the encoding is consistent with PHP's http_build_query.

    """

    flatparams = util.sortdict()

    def process(prefix, obj):

        items = {list: enumerate, dict: lambda x: x.items()}.get(type(obj))

        if items is None:

            flatparams[prefix] = obj

        else:

            for k, v in items(obj):

                if prefix:

                    process('%s[%s]' % (prefix, k), v)

                else:

                    process(k, v)

    process('', params)

    return util.urlreq.urlencode(flatparams)

def readurltoken(repo):

    """return conduit url, token and make sure they exist

    Currently read from [phabricator] config section. In the future, it might

    make sense to read from .arcconfig and .arcrc as well.

    """

    values = []

    section = 'phabricator'

    for name in ['url', 'token']:

        value = repo.ui.config(section, name)

        if not value:

            raise error.Abort(_('config %s.%s is required') % (section, name))

        values.append(value)

    return values

def callconduit(repo, name, params):

    """call Conduit API, params is a dict. return json.loads result, or None"""

    host, token = readurltoken(repo)

    url, authinfo = util.url('/'.join([host, 'api', name])).authinfo()

    urlopener = urlmod.opener(repo.ui, authinfo)

    repo.ui.debug('Conduit Call: %s %s\n' % (url, params))

    params = params.copy()

    params['api.token'] = token

    request = util.urlreq.request(url, data=urlencodenested(params))

    body = urlopener.open(request).read()

    repo.ui.debug('Conduit Response: %s\n' % body)

    parsed = json.loads(body)

    if parsed.get(r'error_code'):

        msg = (_('Conduit Error (%s): %s')

               % (parsed[r'error_code'], parsed[r'error_info']))

        raise error.Abort(msg)

    return parsed[r'result']

@command('debugcallconduit', [], _('METHOD'))

def debugcallconduit(ui, repo, name):

    """call Conduit API

    Call parameters are read from stdin as a JSON blob. Result will be written

    to stdout as a JSON blob.

    """

    params = json.loads(ui.fin.read())

    result = callconduit(repo, name, params)

    s = json.dumps(result, sort_keys=True, indent=2, separators=(',', ': '))

    ui.write('%s\n' % s)

def getrepophid(repo):

    """given callsign, return repository PHID or None"""

    # developer config: phabricator.repophid

    repophid = repo.ui.config('phabricator', 'repophid')

    if repophid:

        return repophid

    callsign = repo.ui.config('phabricator', 'callsign')

    if not callsign:

        return None

    query = callconduit(repo, 'diffusion.repository.search',

                        {'constraints': {'callsigns': [callsign]}})

    if len(query[r'data']) == 0:

        return None

    repophid = encoding.strtolocal(query[r'data'][0][r'phid'])

    repo.ui.setconfig('phabricator', 'repophid', repophid)

    return repophid

def getmapping(ctx):

    """return (node, associated Differential Revision ID) or (None, None)

    Examines all precursors and their tags. Tags with format like "D1234" are

    considered a match and the node with that tag, and the number after "D"

    (ex. 1234) will be returned.

    """

    unfi = ctx.repo().unfiltered()

    nodemap = unfi.changelog.nodemap

    for n in obsolete.allprecursors(unfi.obsstore, [ctx.node()]):

        if n in nodemap:

            for tag in unfi.nodetags(n):

                if m:

                    return n, int(m.group(1))

    return None, None

def getdiff(ctx, diffopts):

    """plain-text diff without header (user, commit message, etc)"""

    output = util.stringio()

    for chunk, _label in patch.diffui(ctx.repo(), ctx.p1().node(), ctx.node(),

                                      None, opts=diffopts):

        output.write(chunk)

    return output.getvalue()

def creatediff(ctx):

    """create a Differential Diff"""

    repo = ctx.repo()

    repophid = getrepophid(repo)

    # Create a "Differential Diff" via "differential.createrawdiff" API

    params = {'diff': getdiff(ctx, mdiff.diffopts(git=True, context=32767))}

    if repophid:

        params['repositoryPHID'] = repophid

    diff = callconduit(repo, 'differential.createrawdiff', params)

    if not diff:

        raise error.Abort(_('cannot create diff for %s') % ctx)

    return diff

def writediffproperties(ctx, diff):

    """write metadata to diff so patches could be applied losslessly"""

    params = {

        'diff_id': diff[r'id'],

        'name': 'hg:meta',

        'data': json.dumps({

            'user': ctx.user(),

            'date': '%d %d' % ctx.date(),

        }),

    }

    callconduit(ctx.repo(), 'differential.setdiffproperty', params)

def createdifferentialrevision(ctx, revid=None, parentrevid=None):

    """create or update a Differential Revision

    If revid is None, create a new Differential Revision, otherwise update

    revid. If parentrevid is not None, set it as a dependency.

    """

    repo = ctx.repo()

    diff = creatediff(ctx)

    writediffproperties(ctx, diff)

    transactions = [{'type': 'update', 'value': diff[r'phid']}]

    # Use a temporary summary to set dependency. There might be better ways but

    # I cannot find them for now. But do not do that if we are updating an

    # existing revision (revid is not None) since that introduces visible

    # churns (someone edited "Summary" twice) on the web page.

    if parentrevid and revid is None:

        summary = 'Depends on D%s' % parentrevid

        transactions += [{'type': 'summary', 'value': summary},

                         {'type': 'summary', 'value': ' '}]

    # Parse commit message and update related fields.

    desc = ctx.description()

    info = callconduit(repo, 'differential.parsecommitmessage',

                       {'corpus': desc})

    for k, v in info[r'fields'].items():

        if k in ['title', 'summary', 'testPlan']:

            transactions.append({'type': k, 'value': v})

    params = {'transactions': transactions}

    if revid is not None:

        # Update an existing Differential Revision

        params['objectIdentifier'] = revid

    revision = callconduit(repo, 'differential.revision.edit', params)

    if not revision:

        raise error.Abort(_('cannot create revision for %s') % ctx)

    return revision

@command('phabsend',

         [('r', 'rev', [], _('revisions to send'), _('REV'))],

         _('REV [OPTIONS]'))

def phabsend(ui, repo, *revs, **opts):

    """upload changesets to Phabricator

    If there are multiple revisions specified, they will be send as a stack

    with a linear dependencies relationship using the order specified by the

    revset.

    For the first time uploading changesets, local tags will be created to

    maintain the association. After the first time, phabsend will check

    obsstore and tags information so it can figure out whether to update an

    existing Differential Revision, or create a new one.

    """

    revs = list(revs) + opts.get('rev', [])

    revs = scmutil.revrange(repo, revs)

    # Send patches one by one so we know their Differential Revision IDs and

    # can provide dependency relationship

    lastrevid = None

    for rev in revs:

        ui.debug('sending rev %d\n' % rev)

        ctx = repo[rev]

        # Get Differential Revision ID

        oldnode, revid = getmapping(ctx)

        if oldnode != ctx.node():

            # Create or update Differential Revision

            revision = createdifferentialrevision(ctx, revid, lastrevid)

            newrevid = int(revision[r'object'][r'id'])

            if revid:

                action = _('updated')

            else:

                action = _('created')

            # Create a local tag to note the association

            tagname = 'D%d' % newrevid

            tags.tag(repo, tagname, ctx.node(), message=None, user=None,

                     date=None, local=True)

        else:

            # Nothing changed. But still set "newrevid" so the next revision

            # could depend on this one.

            newrevid = revid

            action = _('skipped')

        ui.write(_('D%s: %s - %s: %s\n') % (newrevid, action, ctx,

                                            ctx.description().split('\n')[0]))

        lastrevid = newrevid

_summaryre = re.compile('^Summary:\s*', re.M)

def readpatch(repo, params, recursive=False):

    """generate plain-text patch readable by 'hg import'

    params is passed to "differential.query". If recursive is True, also return

    dependent patches.

    """

    # Differential Revisions

    drevs = callconduit(repo, 'differential.query', params)

    if len(drevs) == 1:

        drev = drevs[0]

    else:

        raise error.Abort(_('cannot get Differential Revision %r') % params)

    repo.ui.note(_('reading D%s\n') % drev[r'id'])

    diffid = max(int(v) for v in drev[r'diffs'])

    body = callconduit(repo, 'differential.getrawdiff', {'diffID': diffid})

    desc = callconduit(repo, 'differential.getcommitmessage',

                       {'revision_id': drev[r'id']})

    header = '# HG changeset patch\n'

    # Remove potential empty "Summary:"

    desc = _summaryre.sub('', desc)

    # Try to preserve metadata (user, date) from hg:meta property

    diffs = callconduit(repo, 'differential.querydiffs', {'ids': [diffid]})

    props = diffs[str(diffid)][r'properties'] # could be empty list or dict

    if props and r'hg:meta' in props:

        meta = props[r'hg:meta']

        for k, v in meta.items():

            header += '# %s %s\n' % (k.capitalize(), v)

    patch = ('%s%s\n%s') % (header, desc, body)

    # Check dependencies

    if recursive:

        auxiliary = drev.get(r'auxiliary', {})

        depends = auxiliary.get(r'phabricator:depends-on', [])

        for phid in depends:

            patch = readpatch(repo, {'phids': [phid]}, recursive=True) + patch

    return patch

@command('phabread',

         [('', 'stack', False, _('read dependencies'))],

         _('REVID [OPTIONS]'))

def phabread(ui, repo, revid, **opts):

    """print patches from Phabricator suitable for importing

    REVID could be a Differential Revision identity, like ``D123``, or just the

    number ``123``, or a full URL like ``https://phab.example.com/D123``.

    If --stack is given, follow dependencies information and read all patches.

    """

    try:

        revid = int(revid.split('/')[-1].replace('D', ''))

    except ValueError:

        raise error.Abort(_('invalid Revision ID: %s') % revid)

    patch = readpatch(repo, {'ids': [revid]}, recursive=opts.get('stack'))

    ui.write(patch)