path: root/git-phab

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# PYTHON_ARGCOMPLETE_OK
#
# git-phab - git subcommand to integrate with phabricator
#
# Copyright (C) 2008  Owen Taylor
# Copyright (C) 2015  Xavier Claessens <xavier.claessens@collabora.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, If not, see
# http://www.gnu.org/licenses/.

import base64
import configparser
import logging
import socket
import tempfile
import subprocess
import argparse
import argcomplete
from datetime import datetime
import git
import gitdb
import os
import re
import sys
import json

import appdirs
import phabricator
import shutil

from urllib.parse import urlsplit, urlunsplit


ON_WINDOWS = os.name == 'nt'


class Colors:
    HEADER = '\033[95m'
    OKBLUE = '\033[94m'
    OKGREEN = '\033[92m'
    WARNING = '\033[93m'
    FAIL = '\033[91m'
    ENDC = '\033[0m'

    force_disable = False

    @classmethod
    def disable(cls):
        cls.HEADER = ''
        cls.OKBLUE = ''
        cls.OKGREEN = ''
        cls.WARNING = ''
        cls.FAIL = ''
        cls.ENDC = ''

    @classmethod
    def enable(cls):
        if cls.force_disable:
            return

        cls.HEADER = '\033[95m'
        cls.OKBLUE = '\033[94m'
        cls.OKGREEN = '\033[92m'
        cls.WARNING = '\033[93m'
        cls.FAIL = '\033[91m'
        cls.ENDC = '\033[0m'


def stash(func):
    def wrapper(self, *args):
        needs_stash = self.repo.is_dirty()
        if needs_stash:
            if not self.autostash:
                self.die(
                    "Repository is dirty. Aborting.\n"
                    "You can use `--autostash` to automatically"
                    " stash uncommitted changes\n"
                    "You can also `git config [--global] phab.autostash true`"
                    " to make it permanent")
            print("Stashing current changes before attaching patches")
            self.repo.git.stash()
        try:
            func(self, *args)
        finally:
            if needs_stash:
                print("Restoring stashed changes")
                stash_name = "stash@{0}"
                if self.repo.is_dirty():
                    # This might happen if some linting tool starts
                    # changing the code.
                    stash_name = "stash@{1}"
                    print("Some more changes have been done"
                          " during the process, stashing them"
                          " and going back to the state before attaching.\n"
                          " You can see those with `git stash show stash@{0}`")
                    self.repo.git.stash()
                self.repo.git.stash('pop', stash_name)

    return wrapper


class GitPhab:

    def __init__(self):
        self.task = None
        self.differential = None
        self.task_or_revision = None
        self.remote = None
        self.assume_yes = False
        self.reviewers = None
        self.cc = None
        self.projects = None
        self.output_directory = None
        self.phab_repo = None
        self.staging_url = None
        self.autostash = False

        self.repo = git.Repo(os.getcwd(), search_parent_directories=True)
        self.read_arcconfig()

        self._phabricator = None
        self._phab_user = None

    @property
    def phabricator(self):
        if self._phabricator:
            return self._phabricator

        if self.arcrc:
            try:
                with open(self.arcrc) as f:
                    phabricator.ARCRC.update(json.load(f))
            except FileNotFoundError:
                self.die("Failed to load a given arcrc file, %s" % self.arcrc)

        needs_credential = False
        try:
            host = self.phabricator_uri + "/api/"
            self._phabricator = phabricator.Phabricator(timeout=120, host=host)

            if not self.phabricator.token and not self.phabricator.certificate:
                needs_credential = True

            # FIXME, workaround
            # https://github.com/disqus/python-phabricator/issues/37
            self._phabricator.differential.creatediff.api.interface[
                "differential"]["creatediff"]["required"]["changes"] = dict
        except phabricator.ConfigurationError:
            needs_credential = True

        if needs_credential:
            if self.setup_login_certificate():
                self.die("Try again now that the login certificate has been"
                         " added")
            else:
                self.die("Please setup login certificate before trying again")

        return self._phabricator

    @property
    def phab_user(self):
        if self._phab_user:
            return self._phab_user

        self._phab_user = self.phabricator.user.whoami()

        return self._phab_user

    def setup_login_certificate(self):
        token = input("""LOGIN TO PHABRICATOR
Open this page in your browser and login to Phabricator if necessary:

%s/conduit/login/

Then paste the API Token on that page below.

Paste API Token from that page and press <enter>: """ % self.phabricator_uri)
        path = os.path.join(os.environ['AppData'] if ON_WINDOWS
                            else os.path.expanduser('~'), '.arcrc')

        host = self.phabricator_uri + "/api/"
        host_token = {"token": token}
        try:
            with open(path) as f:
                arcrc = json.load(f)

                if arcrc.get("hosts"):
                    arcrc["hosts"][host] = host_token
                else:
                    arcrc = {
                        "hosts": {host: host_token}}

        except (FileNotFoundError, ValueError):
            arcrc = {"hosts": {host: host_token}}

        with open(path, "w") as f:
            print("Writing %s" % path)
            json.dump(arcrc, f, indent=2)

        return True

    # Copied from git-bz
    def die(self, message):
        print(message, file=sys.stderr)
        sys.exit(1)

    def prompt(self, message):
        if self.assume_yes:
            print(message + " [yn] y")
            return True

        try:
            while True:
                line = input(message + " [yn] ")
                if line == 'y' or line == 'Y':
                    return True
                elif line == 'n' or line == 'N':
                    return False
        except KeyboardInterrupt:
            # Ctrl+C doesn’t cause a newline
            print("")
            sys.exit(1)

    # Copied from git-bz
    def edit_file(self, filename):
        editor = self.repo.git.var("GIT_EDITOR")
        process = subprocess.Popen(editor + " " + filename, shell=True)
        process.wait()
        if process.returncode != 0:
            self.die("Editor exited with non-zero return code")

    # Copied from git-bz
    def edit_template(self, template):
        # Prompts the user to edit the text 'template' and returns list of
        # lines with comments stripped

        handle, filename = tempfile.mkstemp(".txt", "git-phab-")
        f = os.fdopen(handle, "w")
        f.write(template)
        f.close()

        self.edit_file(filename)

        with open(filename, 'r') as f:
            return [l for l in f.readlines() if not l.startswith("#")]

    def create_task(self, commits):
        task_infos = None
        while not task_infos:
            template = "\n# Please enter a task title and description " \
                "for the merge request.\n" \
                "# Commits from branch: %s:" % self.repo.active_branch.name

            Colors.disable()
            for c in commits:
                template += "\n# - %s" % self.format_commit(c)
            Colors.enable()

            task_infos = self.edit_template(template)

        description = ""
        title = task_infos[0]
        if len(task_infos) > 1:
            description = '\n'.join(task_infos[1:])

        reply = self.phabricator.maniphest.createtask(
            title=title, description=description,
            projectPHIDs=self.project_phids)

        return reply

    def task_from_branchname(self, bname):
        # Match 'foo/bar/T123-description'
        m = re.fullmatch('(.+/)?(T[0-9]+)(-.*)?', bname)
        return m.group(2) if m else None

    def revision_from_branchname(self, bname):
        # Match 'foo/bar/D123-description'
        m = re.fullmatch('(.+/)?(D[0-9]+)(-.*)?', bname)
        return m.group(2) if m else None

    def get_commits(self, revision_range):
        try:
            # See if the argument identifies a single revision
            commits = [self.repo.rev_parse(revision_range)]
        except:
            # If not, assume the argument is a range
            try:
                commits = list(self.repo.iter_commits(revision_range))
            except:
                # If not again, the argument must be invalid — perhaps the user
                # has accidentally specified a bug number but not a revision.
                commits = []

        if len(commits) == 0:
            self.die("'%s' does not name any commits. Use HEAD to specify "
                     "just the last commit" % revision_range)

        return commits

    def get_differential_link(self, commit):
        m = re.search('(^Differential Revision: )(.*)$',
                      commit.message, re.MULTILINE)
        return None if m is None else m.group(2)

    def get_differential_id(self, commit):
        link = self.get_differential_link(commit)
        return int(link[link.rfind('/') + 2:]) if link else None

    def format_commit(self, commit, status=None):
        result = u"%s%s%s —" % (Colors.HEADER, commit.hexsha[:7], Colors.ENDC)

        diffid = self.get_differential_id(commit)
        if not diffid:
            status = "Not attached"
        if diffid:
            result += u" D%s" % diffid
        if status:
            result += u" %s%s%s" % (
                Colors.OKGREEN if status == "Accepted" else Colors.WARNING,
                status,
                Colors.ENDC)

        return result + u" — %s" % commit.summary

    def print_commits(self, commits):
        statuses = {}
        for c in commits:
            diffid = self.get_differential_id(c)
            if diffid:
                statuses[int(diffid)] = "Unknown"

        reply = self.phabricator.differential.query(ids=list(statuses.keys()))
        if reply.response is None:
            print("Could not get informations about differentials status")
        else:
            for diff in reply:
                statuses[int(diff["id"])] = diff["statusName"]

        for c in commits:
            diffid = self.get_differential_id(c)
            status = statuses.get(int(diffid)) if diffid else None
            print(self.format_commit(c, status))

    def in_feature_branch(self):
        # If current branch is "master" it's obviously not a feature branch.
        if self.branch_name in ['master']:
            return False

        tracking = self.repo.head.reference.tracking_branch()

        # If current branch is not tracking any remote branch it's probably
        # a feature branch.
        if not tracking or not tracking.is_remote():
            return True

        # If the tracking remote branch has a different name we can assume
        # it's a feature branch (e.g. 'my-branch' is tracking 'origin/master')
        if tracking.remote_head != self.branch_name:
            return True

        # The current branch has the same name than its tracking remote branch
        # (e.g. "gnome-3-18" tracking "origin/gnome-3-18"). It's probably not
        # a feature branch.
        return False

    def branch_name_with_task(self):
        if self.branch_name.startswith(self.task):
            return self.branch_name

        name = self.task

        # Only append current branch name if it seems to be a feature branch.
        # We want "T123-fix-a-bug" but not "T123-master" or "T123-gnome-3-18".
        if self.in_feature_branch():
            name += '-' + self.branch_name

        return name

    def get_wip_branch(self):
        return "wip/phab/" + self.branch_name_with_task()

    def filter_already_proposed_commits(self, commits, all_commits):
        if not self.task or not self.remote:
            return

        remote_commit = None

        # Check if we already have a branch for current task on our remote
        remote = self.repo.remote(self.remote)
        bname = self.get_wip_branch()
        for r in remote.refs:
            if r.remote_head == bname:
                remote_commit = r.commit
                break

        try:
            # Fetch what has already been proposed on the task if we don't have
            # it locally yet.
            if not remote_commit:
                remote_commit = self.fetch_from_task()[0]

            # Get the index in commits and all_commits lists of the common
            # ancestor between HEAD and what has already been proposed.
            common_ancestor = self.repo.git.merge_base(remote_commit.hexsha,
                                                       commits[0].hexsha)
            common_commit = self.repo.commit(common_ancestor)
            commits_idx = commits.index(common_commit)
            all_commits_idx = all_commits.index(common_commit)
        except:
            return

        print("Excluding already proposed commits %s..%s" % (
              commits[-1].hexsha[:7], commits[commits_idx].hexsha[:7]))
        del commits[commits_idx:]
        del all_commits[all_commits_idx:]

    def read_arcconfig(self):
        path = os.path.join(self.repo.working_tree_dir, '.arcconfig')
        try:
            with open(path) as f:
                self.arcconfig = json.load(f)
        except FileNotFoundError as e:
            self.die("Could not find any .arcconfig file.\n"
                     "Make sure the current repository is properly configured "
                     "for phabricator")

        path = os.path.join(self.repo.git_dir, 'arc', 'config')
        try:
            with open(path) as f:
                self.arcconfig.update(json.load(f))
        except FileNotFoundError as e:
            pass

        try:
            self.phabricator_uri = self.arcconfig["phabricator.uri"]
        except KeyError as e:
            self.die("Could not find '%s' in .arcconfig.\n"
                     "Make sure the current repository is properly configured "
                     "for phabricator" % e.args[0])

        # Remove trailing '/' if any
        if self.phabricator_uri[-1] == '/':
            self.phabricator_uri = self.phabricator_uri[:-1]

    def get_config_path(self):
        return os.path.join(appdirs.user_config_dir('git'), 'phab')

    def read_config(self):
        path = self.get_config_path()
        try:
            with open(path) as f:
                self.config = json.load(f)
        except FileNotFoundError:
            self.config = {}

        if 'emails' not in self.config:
            self.config['emails'] = {}

    def write_config(self):
        path = self.get_config_path()

        dir = os.path.dirname(path)
        if not os.path.exists(dir):
            os.makedirs(dir)

        with open(path, 'w') as f:
            json.dump(self.config, f, sort_keys=True, indent=4,
                      separators=(',', ': '))

    def ensure_project_phids(self):
        by_names = self.phabricator.project.query(names=self.projects)
        by_slugs = self.phabricator.project.query(slugs=self.projects)

        if not by_names and not by_slugs:
            self.die("%sProjects `%s` doesn't seem to exist%s" %
                     (Colors.FAIL, self.projects, Colors.ENDC))

        self.project_phids = []
        project_map = {}
        for reply in (by_names, by_slugs):
            if not reply.data:
                continue
            for (phid, data) in reply.data.items():
                project_map[data["name"].lower()] = phid
                for s in data["slugs"]:
                    project_map[s.lower()] = phid

        try:
            for p in self.projects:
                if p not in project_map:
                    print("%sProject `%s` doesn't seem to exist%s" %
                          (Colors.FAIL, p, Colors.ENDC))
                    raise
                self.project_phids.append(project_map[p])
        except:
            self.die("Failed to look up projects in Phabricator")

    def validate_remote(self):
        # If a remote is setup ensure that it's valid
        # Validate that self.remote exists
        try:
            self.repo.remote(self.remote)
        except:
            print("%s%s not a valid remote, can't use it%s." % (
                Colors.HEADER, self.remote, Colors.ENDC))
            self.remote = None
            return

        # Get remote's fetch URL. Unfortunately we can't get it from config
        # using remote.config_reader.get('url') otherwise it won't rewrite the
        # URL using url.*.insteadOf configs.
        try:
            output = self.repo.git.remote('show', '-n', self.remote)
            m = re.search('Fetch URL: (.*)$', output, re.MULTILINE)
            self.remote_url = m.group(1)
        except:
            self.die("Failed to get fetch URL for remote %s" % self.remote)

        # Make sure the user knows what he's doing if the remote's fetch URL is
        # using ssh, otherwise reviewers might not be able to pull their
        # branch.
        url = urlsplit(self.remote_url)
        if url.scheme in ["ssh", "git+ssh"]:
            try:
                force_ssh = self.repo.config_reader().get_value(
                    'phab', 'force-ssh-remote')
            except:
                force_ssh = False

            if not force_ssh:
                ret = self.prompt(
                    "The configured phab.remote (%s) is using ssh.\n"
                    "It means it might not be readable by some people.\n"
                    "Are you sure you want to continue?" % self.remote)
                if ret:
                    writer = self.repo.config_writer()
                    writer.set_value('phab', 'force-ssh-remote', True)
                    writer.release()
                else:
                    pushurl = urlunsplit(url)
                    fetchurl = urlunsplit(url._replace(scheme='git'))
                    self.die("To reconfigure your remote, run:\n"
                             "  git remote set-url {0} {1}\n"
                             "  git remote set-url --push {0} {2}\n"
                             "Note that if you're using url.*.insteadOf you "
                             "could define url.*.pushInsteadOf as well."
                             .format(self.remote, fetchurl, pushurl))

    def validate_args(self):
        self.read_arcconfig()
        self.read_config()

        if not self.remote:
            try:
                self.remote = self.repo.config_reader().get_value(
                    'phab', 'remote')
            except:
                pass

        if self.remote:
            self.validate_remote()

        try:
            self.autostash |= self.repo.config_reader().get_value(
                'phab', 'autostash')
        except (configparser.NoOptionError, configparser.NoSectionError):
            pass

        # Try to guess the task from branch name
        if self.repo.head.is_detached:
            self.die("HEAD is currently detached. Aborting.")
        self.branch_name = self.repo.head.reference.name
        self.branch_task = self.task_from_branchname(self.branch_name)

        if not self.task and self.task != "T":
            self.task = self.branch_task

        # Validate the self.task is in the right format
        if self.task and not re.fullmatch('T[0-9]*', self.task):
            self.die("Task '%s' is not in the correct format. "
                     "Expecting 'T123'." % self.task)

        if self.task_or_revision:
            if re.fullmatch('T[0-9]*', self.task_or_revision):
                self.task = self.task_or_revision
            elif re.fullmatch('D[0-9]*', self.task_or_revision):
                self.differential = self.task_or_revision
            else:
                self.die("Task or revision '%s' is not in the correct format. "
                         "Expecting 'T123' or 'D123'." % self.task_or_revision)

        if hasattr(self, 'revision_range') and not self.revision_range:
            tracking = self.repo.head.reference.tracking_branch()
            if not tracking:
                self.die("There is no tracking information for the current "
                         "branch.\n"
                         "Please specify the patches you want to attach by "
                         "setting the <revision range> \n\n"
                         "If you wish to set tracking information for this "
                         "branch you can do so with: \n"
                         "  git branch --set-upstream-to <remote>/<branch> %s"
                         % self.branch_name)
            self.revision_range = str(tracking) + '..'
            print("Using revision range '%s'" % self.revision_range)

        if not self.reviewers:
            self.reviewers = self.arcconfig.get("default-reviewers")

        self.projects = self.projects.split(',') if self.projects else []
        if "project" in self.arcconfig:
            self.projects.append(self.arcconfig["project"])
        if "project.name" in self.arcconfig:
            self.projects.append(self.arcconfig["project.name"])
        if "projects" in self.arcconfig:
            for p in self.arcconfig["projects"].split(','):
                self.projects.append(p)
        self.projects = [s.strip().lower() for s in self.projects]
        if len(self.projects) == 0:
            self.die("No project has been defined.\n"
                     "You can add 'projects': 'p1, p2' in your .arcconfig\n"
                     "Aborting.")

        if "repository.callsign" in self.arcconfig:
            reply = self.phabricator.repository.query(
                callsigns=[self.arcconfig["repository.callsign"]])

            if len(reply) > 1:
                self.die("Multiple repositories returned for callsign ‘{}’.\n"
                         "You should check your Phabricator "
                         "configuration.".format(
                             self.arcconfig["repository.callsign"]))
        else:
            uris = [remote.url for remote in self.repo.remotes]
            reply = self.phabricator.repository.query(
                remoteURIs=uris)

            if len(reply) > 1:
                tracking = self.repo.head.reference.tracking_branch()
                # Use the remote that this branch is tracking.
                uris = [remote.url for remote in self.repo.remotes
                        if remote.name == tracking.remote_name]
                reply = self.phabricator.repository.query(
                    remoteURIs=uris)

                if len(reply) > 1:
                    self.die("Multiple repositories returned for remote URIs "
                             "({}).\nYou should check your Phabricator "
                             "configuration.".format(', '.join(uris)))

        try:
            self.phab_repo = reply[0]
        except IndexError:
            self.die("Could not determine Phabricator repository\n"
                     "You should check your git remote URIs match those "
                     "in Phabricator, or set 'repository.callsign' in "
                     "'.arcconfig'")

        if self.phab_repo.get("staging"):
            self.staging_url = self.phab_repo.get("staging").get("uri")

    def line_in_headers(self, line, headers):
        for header in headers:
            if re.match('^' + re.escape(header), line, flags=re.I):
                return True
        return False

    def parse_commit_msg(self, msg):
        subject = None
        body = []
        git_fields = []
        phab_fields = []
        updates = None

        # Those are common one-line git field headers
        git_headers = ['Signed-off-by:', 'Acked-by:', 'Reported-by:',
                       'Tested-by:', 'Reviewed-by:']
        # Those are understood by Phabricator
        phab_headers = ['Cc:', 'differential revision:']

        for line in msg.splitlines():
            if updates is not None:
                updates.append(line)
                continue

            if not subject:
                subject = line
                continue

            if self.line_in_headers(line, git_headers):
                if line not in git_fields:
                    git_fields.append(line)
                continue

            if self.line_in_headers(line, phab_headers):
                if line not in phab_fields:
                    phab_fields.append(line)
                continue

            if line == '---':
                updates = []
                continue

            body.append(line)

        return subject, body, git_fields, phab_fields, updates

    def strip_updates(self, msg):
        """
        Return msg with the part after a line containing only "---" removed.
        This is a convention used in tools like git-am and Patchwork to
        separate the real commit message from meta-discussion, like so:

        From: Mickey Mouse <mickey@example.com>
        Subject: Fix alignment

        Previously, the text was 6px too far to the left.

        Bug: http://example.com/bugs/123
        Cc: donald@example.com
        ---
        v2: don't change vertical alignment, spotted in Donald's review
        """
        return msg.split('\n---\n', 1)[0]

    def format_field(self, field, ask=False):
        # This is the list of fields phabricator will search by default in
        # commit message, case insensitive. It will confuse phabricator's
        # parser if they appear in the subject or body of the commit message.
        blacklist = ['title:', 'summary:', 'test plan:', 'testplan:',
                     'tested:', 'tests:', 'reviewer:', 'reviewers:',
                     'reviewed by:', 'cc:', 'ccs:', 'subscriber:',
                     'subscribers:', 'project:', 'projects:',
                     'maniphest task:', 'maniphest tasks:',
                     'differential revision:', 'conflicts:', 'git-svn-id:',
                     'auditors:']

        for header in blacklist:
            header_ = header[:-1] + '_:'
            f = re.sub('^' + re.escape(header), header_, field, flags=re.I)
            if (f != field) and (
                not ask or self.prompt(
                    "Commit message contains '%s'.\n"
                    "It could confuse Phabricator's parser.\n"
                    "Do you want to suffix it with an underscore?" %
                    header)):
                field = f

        return field

    def format_commit_msg(self, subject, body, git_fields, phab_fields,
                          ask=False):
        subject = subject.strip()
        body = '\n'.join(body).strip('\r\n')
        fields = '\n'.join(git_fields + phab_fields).strip()

        subject = self.format_field(subject, ask)
        body = self.format_field(body, ask)

        return '\n\n'.join([subject, body, fields])

    def format_user(self, fullname):
        # Check if the email is in our config
        email = self.config['emails'].get(fullname)
        if email:
            return "%s <%s>" % (fullname, email)

        # Check if the email is in git log
        output = self.repo.git.shortlog(summary=True, email=True, number=True)
        m = re.search(re.escape(fullname) + ' <.*>$', output, re.MULTILINE)
        if m:
            return m.group(0)

        # Ask user for the email
        email = input("Please enter email address for %s: " % fullname).strip()
        if len(email) > 0:
            self.config['emails'][fullname] = email
            self.write_config()
            return "%s <%s>" % (fullname, email)

        return None

    def get_reviewers_and_tasks(self, commit):
        reviewers = set()
        tasks = []

        diffid = self.get_differential_id(commit)
        if not diffid:
            return reviewers, tasks

        # This seems to be the only way to get the Maniphest and
        # reviewers of a differential.
        reply = self.phabricator.differential.getcommitmessage(
            revision_id=diffid)
        msg = reply.response

        # Get tasks bound to this differential
        m = re.search('^Maniphest Tasks: (.*)$', msg, re.MULTILINE)
        tasks = [t.strip() for t in m.group(1).split(',')] if m else []

        # Get people who approved this differential
        m = re.search('^Reviewed By: (.*)$', msg, re.MULTILINE)
        usernames = [r.strip() for r in m.group(1).split(',')] if m else []
        if usernames:
            reply = self.phabricator.user.query(usernames=usernames)
            for user in reply:
                person = self.format_user(user['realName'])
                if person:
                    reviewers.add(person)

        return reviewers, tasks

    def remove_ourself_from_reviewers(self):
        if self.reviewers is None:
            return
        username = self.phab_user.userName
        reviewers = [r.strip() for r in self.reviewers.split(',')]
        reviewers = list(filter(lambda r: r != username, reviewers))
        self.reviewers = ','.join(reviewers)

    def run_linter(self):
        if not os.path.exists(".pre-commit-config.yaml"):
            if os.path.exists(".arclint"):
                subprocess.check_call("arc lint --never-apply-patches",
                                      shell=True)
                return None
            else:
                return None
        command = ["pre-commit", "run", "--files"]

        for f in reversed(self.repo.git.show(
                "--name-only", "--diff-filter=ACMR", "HEAD").split("\n")):
            if not f:
                break
            command.append(f)

        return subprocess.check_output(command).decode("utf-8")

    def blob_is_binary(self, blob):
        if not blob:
            return False

        bytes = blob.data_stream[-1].read()
        # The mime_type field of a gitpython blob is based only on its filename
        # which means that files like 'configure.ac' will return weird MIME
        # types, unsuitable for working out whether they are text. Instead,
        # check whether any of the bytes in the blob are non-ASCII.
        textchars = bytearray({7, 8, 9, 10, 12, 13, 27} |
                              set(range(0x20, 0x100)) - {0x7f})
        return bool(bytes.translate(None, textchars))

    def get_changes_for_diff(self, diff):
        def file_len(fname):
            i = 0
            try:
                with open(fname) as f:
                    for i, l in enumerate(f):
                        pass
            except (FileNotFoundError, IsADirectoryError, UnicodeDecodeError):
                return 0

            return i + 1

        def set_mode(properties, mode):
            if mode is None:
                return
            if mode == 57344:
                # Special case for submodules!
                m = 160000
            else:
                m = str(oct(mode))[2:]

            properties["unix:filemode"] = m

        change_filename = None
        _type = 0
        oldpath = diff.a_path
        patch_lines = str(diff.diff.decode("utf-8")).split("\n")
        currentpath = diff.b_path
        old_properties = {}
        new_properties = {}

        change_filename = diff.b_path
        if diff.new_file:
            _type = 1
            oldpath = None
        elif diff.deleted_file:
            _type = 3
            change_filename = diff.a_path
            currentpath = diff.a_path
        elif diff.renamed:
            _type = 6

        set_mode(old_properties, diff.a_mode)
        set_mode(new_properties, diff.b_mode)
        added_lines = 0
        removed_lines = 0
        for l in patch_lines:
            if l.startswith("+"):
                added_lines += 1
            elif l.startswith("-"):
                removed_lines += 1

        is_text = (not self.blob_is_binary(diff.a_blob) and
                   not self.blob_is_binary(diff.b_blob))
        if is_text:
            if diff.deleted_file:
                file_length = 0
                old_length = len([l for l in patch_lines if
                                  l.startswith('-')])
            else:
                file_length = file_len(os.path.join(
                    self.repo.working_dir, diff.b_path))
                old_length = max(0, file_length - added_lines + removed_lines)

            metadata = {"line:first": 0}
            hunks = [{
                "newOffset": "0" if diff.deleted_file else "1",
                "oldOffset": "0" if diff.new_file else "1",
                "oldLength": old_length,
                "newLength": file_length,
                "addLines": added_lines,
                "delLines": removed_lines,
                "corpus": "\n".join(patch_lines[1:])
            }]
            filetype = "1"
        else:
            hunks = []

            if not diff.deleted_file:
                b_phab_file = self.phabricator.file.upload(
                    data_base64=base64.standard_b64encode(
                        diff.b_blob.data_stream[-1].read()).decode("utf-8"))
            else:
                b_phab_file = None

            if not diff.new_file:
                a_phab_file = self.phabricator.file.upload(
                    data_base64=base64.standard_b64encode(
                        diff.a_blob.data_stream[-1].read()).decode("utf-8"))
            else:
                a_phab_file = None

            filetype = "3"
            metadata = {
                "old:file:size": diff.a_blob.size if diff.a_blob else 0,
                "old:file:mime-type": diff.a_blob.mime_type if diff.a_blob else
                '',
                "old:binary-phid": a_phab_file.response if a_phab_file else '',
                "new:file:size": diff.b_blob.size if diff.b_blob else 0,
                "new:file:mime-type": diff.b_blob.mime_type if diff.b_blob else
                '',
                "new:binary-phid": b_phab_file.response if b_phab_file else '',
            }

        return change_filename, {"metadata": metadata,
                                 "oldProperties": old_properties,
                                 "newProperties": new_properties,
                                 "oldPath": oldpath,
                                 "currentPath": currentpath,
                                 "type": _type,
                                 "fileType": filetype,
                                 "hunks": hunks
                                 }

    def get_git_diffs(self, commit):
        if commit.parents:
            diffs = commit.parents[0].diff(
                create_patch=True, unified=999999999)
        else:
            diffs = commit.diff(git.diff.NULL_TREE if
                                hasattr(git.diff, "NULL_TREE") else "root",
                                create_patch=True,
                                unified=999999999)
        return diffs

    def create_diff(self, commit, linter_status):
        changes = {}
        parent_commit = ""
        diffs = self.get_git_diffs(commit)
        if commit.parents:
            parent_commit = self.repo.head.object.parents[0].hexsha

        for diff in diffs:
            changed_file, change = self.get_changes_for_diff(diff)
            changes[changed_file] = change

        print("    * Pushing new diff... ", end='')
        diff = self.phabricator.differential.creatediff(
            changes=changes,
            sourceMachine=socket.gethostname(),
            sourcePath=self.repo.working_dir,
            sourceControlSystem="git",
            sourceControlPath="",
            sourceControlBaseRevision=parent_commit,
            creationMethod="git-phab",
            lintStatus=linter_status,
            unitStatus="none",
            parentRevisionID="",
            authorPHID=self.phab_user.phid,
            repositoryUUID="",
            branch=self.branch_name,
            repositoryPHID=self.phab_repo["phid"])
        print("%sOK%s" % (Colors.OKGREEN, Colors.ENDC))

        return diff

    def get_diff_staging_ref(self, diffid):
        return "refs/tags/phabricator/diff/%s" % diffid

    def push_diff_to_staging(self, diff, commit):
        if not self.staging_url:
            print("    * %sNo staging repo set, not pushing diff %s%s" % (
                Colors.FAIL, diff.diffid, Colors.ENDC))
            return None

        print("    * Pushing diff %d on the staging repo... " %
              diff.diffid, end='')
        try:
            remote_ref = self.get_diff_staging_ref(diff.diffid)
            self.repo.git.push(self.staging_url, "%s:%s" % (commit.hexsha,
                                                            remote_ref))
            print("%sOK%s" % (Colors.OKGREEN, Colors.ENDC))

            return remote_ref
        except git.exc.GitCommandError as e:
            print("%sERROR %s(%s)" % (Colors.FAIL,
                                      Colors.ENDC,
                                      e.stderr.strip("\n")))
        return None

    def update_local_commit_info(self, diff, commit):
        commit_infos = {
            commit.hexsha: {
                "commit": commit.hexsha,
                "time": commit.authored_date,
                "tree": commit.tree.hexsha,
                "parents": [p.hexsha for p in commit.parents],
                "author": commit.author.name,
                "authorEmail": commit.author.email,
                "message": commit.message,
            }
        }

        diffs = self.get_git_diffs(commit)
        has_binary = False
        for d in diffs:
            if d.b_blob and \
               self.blob_is_binary(d.b_blob):
                has_binary = True
                break

        if not has_binary and not self.staging_url:
            commit_infos[commit.hexsha]["raw_commit"] = \
                self.repo.git.format_patch("-1", "--stdout",
                                           commit.hexsha)

        self.phabricator.differential.setdiffproperty(
            diff_id=diff.diffid,
            name="local:commits",
            data=json.dumps(commit_infos))

    def attach_commit(self, commit, proposed_commits):
        linter_message = None
        print("    * Running linters...", end="")
        linter_status = "none"
        try:
            self.run_linter()
            print("%s OK%s" % (Colors.OKGREEN, Colors.ENDC))
            linter_status = "okay"
        except BaseException as e:
            linter_status = "fail"
            if isinstance(e, subprocess.CalledProcessError) and e.stdout:
                linter_result = e.stdout.decode("utf-8")
            else:
                linter_result = str(e)

            if not self.prompt("%s FAILED:\n\n%s\n\n%sAttach anyway?"
                               % (Colors.FAIL, linter_result, Colors.ENDC)):
                raise e

            linter_message = "**LINTER FAILURE:**\n\n```\n%s\n```" % (
                linter_result)

        diff = self.create_diff(commit, linter_status)
        phab = self.phabricator
        subject, body, git_fields, phab_fields, updates = \
            self.parse_commit_msg(commit.message)

        try:
            last_revision_id = self.get_differential_id(
                self.repo.head.commit.parents[0])
        except IndexError:
            last_revision_id = None

        # Make sure that we do no add dependency on already closed revision
        # (avoiding making query on the server when not needed)
        if last_revision_id and \
                self.repo.head.commit.parents[0] not in proposed_commits and \
                not self.phabricator.differential.query(
                    ids=[last_revision_id], status="status-closed"):
            body.append("Depends on D%s" % last_revision_id)
        phab_fields.append("Projects: %s" % ','.join(self.project_phids))

        summary = ('\n'.join(body) + '\n' +
                   '\n'.join(git_fields)).strip('\r\n')

        revision_id = self.get_differential_id(self.repo.head.commit)
        if revision_id:
            arc_message = phab.differential.getcommitmessage(
                revision_id=revision_id, edit="update",
                fields=phab_fields).response
        else:
            arc_message = phab.differential.getcommitmessage(
                edit="create", fields=phab_fields).response

            subject_formatted = self.format_field(subject, True)
            # The substitution below should cover:
            # "<<Replace this line with your Revision Title>>"
            # "<<Replace this line with your revision title>"
            arc_message = re.sub(
                "<<Replace this line with your Revision Title>>?",
                subject_formatted,
                arc_message,
                flags=re.I)
            assert subject_formatted in arc_message

            if summary != '':
                arc_message = arc_message.replace(
                    "Summary: ",
                    "Summary:\n" + self.format_field(summary, True))

            if self.reviewers:
                arc_message = arc_message.replace(
                    "Reviewers: ", "Reviewers: " + self.reviewers)

            if self.cc:
                arc_message = arc_message.replace(
                    "Subscribers: ", "Subscribers: " + self.cc)

        arc_message = '\n'.join([
            l for l in arc_message.split("\n")
            if not l.startswith("#")])

        if self.task:
            arc_message += "\n\nManiphest Tasks: %s" % (
                self.task)

        parsed_message = phab.differential.parsecommitmessage(
            corpus=arc_message)

        fields = parsed_message["fields"]
        fields["title"] = subject
        if not revision_id:
            revision = phab.differential.createrevision(fields=fields,
                                                        diffid=diff.diffid)

            if linter_message:
                self.phabricator.differential.createcomment(
                    revision_id=int(revision.revisionid),
                    message=linter_message, action="none")

            return True, revision, diff
        else:
            message = None
            if updates:
                message = "\n".join([u for u in updates if u])
            if not message:
                message = self.message
            if not message:
                message = self.edit_template(
                    "\n# Explain the changes you made since last "
                    " commit proposal\n# Last commit:\n#------\n#\n# %s" %
                    subject)
                message = "\n".join(message)

            fields["summary"] = summary
            if linter_message:
                message += "\n\n%s" % linter_message

            return False, phab.differential.updaterevision(
                id=revision_id, fields=fields,
                diffid=diff.diffid,
                message=message), diff

    def update_task_branch_uri(self, staging_remote_refname):
        summary = ""
        remote_uri = None
        if staging_remote_refname and self.task:
            remote_uri = "%s#%s" % (self.staging_url, staging_remote_refname)
        elif self.remote and self.task:
            try:
                branch = self.get_wip_branch()
                remote = self.repo.remote(self.remote)
                if self.prompt('Push HEAD to %s/%s?' % (remote, branch)):
                    info = remote.push('HEAD:refs/heads/' + branch,
                                       force=True)[0]
                    if not info.flags & info.ERROR:
                        summary += "  * Branch pushed to %s/%s\n" % (remote,
                                                                     branch)
                    else:
                        print("-> Could not push branch %s/%s: %s" % (
                            remote, branch, info.summary))

                remote_uri = "%s#%s" % (self.remote_url, branch)
            except Exception as e:
                summary += "  * Failed: push wip branch: %s\n" % e

        if remote_uri:
            try:
                self.phabricator.maniphest.update(
                    id=int(self.task[1:]),
                    auxiliary={"std:maniphest:git:uri-branch": remote_uri})
            except:
                print("-> Failed to set std:maniphest:git:uri-branch to %s"
                      % remote_uri)

        return summary

    @stash
    def do_attach(self):
        # If we are in branch "T123" and user does "git phab attach -t T456",
        # that's suspicious. Better stop before doing a mistake.
        if self.branch_task and self.branch_task != self.task:
            self.die("Your current branch name suggests task %s but you're "
                     "going to attach to task %s. Aborting."
                     % (self.branch_task, self.task))

        self.ensure_project_phids()
        self.remove_ourself_from_reviewers()

        summary = ""

        # Oldest commit is last in the list; if there is only one commit, we
        # are trying to attach the first commit in the repository, so avoid
        # trying to get its parent.
        commits = self.get_commits(self.revision_range)
        if len(commits[-1].parents) > 0:
            s = commits[-1].hexsha + "^..HEAD"
            all_commits = list(self.repo.iter_commits(s))
        else:
            s = commits[-1].hexsha + ".."
            all_commits = list(self.repo.iter_commits(s))
            all_commits.append(commits[-1])

        # Sanity checks
        for c in commits:
            if c not in all_commits:
                self.die("'%s' is not in current tree. Aborting." % c.hexsha)
            if len(c.parents) > 1:
                self.die("'%s' is a merge commit. Aborting." % c.hexsha)

        self.filter_already_proposed_commits(commits, all_commits)
        if not commits:
            print("-> Everything has already been proposed")
            return

        # Ask confirmation before doing any harm
        self.print_commits(commits)

        if self.arcconfig.get('git-phab.force-tasks') and not self.task:
            self.task = "T"

        if self.task == "T":
            agreed = self.prompt("Attach above commits "
                                 "and create a new task ?")
        elif self.task:
            agreed = self.prompt("Attach above commits to task %s?" %
                                 self.task)
        else:
            agreed = self.prompt("Attach above commits?")

        if not agreed:
            print("-> Aborting")
            sys.exit(0)

        if self.task == "T":
            try:
                self.task = self.create_task(commits)["objectName"]
                summary += "  * New: task %s\n" % self.task
            except KeyError:
                self.die("Could not create task.")

        orig_commit = self.repo.head.commit
        orig_branch = self.repo.head.reference

        patch_attachement_failure = False
        staging_remote_refname = None
        try:
            # Detach HEAD from the branch; this gives a cleaner reflog for the
            # branch
            if len(commits[-1].parents) > 0:
                self.repo.head.reference = commits[-1].parents[0]
            else:
                self.repo.head.reference = commits[-1]
            self.repo.head.reset(index=True, working_tree=True)

            for commit in reversed(all_commits):
                if len(commit.parents) > 0:
                    self.repo.git.cherry_pick(commit.hexsha)

                if not patch_attachement_failure and commit in commits:
                    print("-> Attaching %s:" % self.format_commit(commit))
                    try:
                        new, revision, diff = self.attach_commit(
                            commit, all_commits)
                    except Exception as e:
                        logging.exception("Failed proposing patch. "
                                          "Finnish rebuilding branch "
                                          "without proposing further patches")
                        sys.stdout.flush()
                        patch_attachement_failure = True
                        summary += "  * Failed proposing: %s -- " \
                            "NO MORE PATCH PROPOSED\n" % self.format_commit(
                                self.repo.head.commit)
                        continue

                    msg = self.strip_updates(commit.message)

                    # Add the "Differential Revision:" line.
                    if new:
                        msg = msg + '\nDifferential Revision: ' + revision.uri
                        summary += "  * New: "
                    else:
                        summary += "  * Updated: %s " % revision.uri

                    self.repo.git.commit("-n", amend=True, message=msg)
                    self.update_local_commit_info(diff, self.repo.head.object)
                    staging_remote_refname = self.push_diff_to_staging(
                        diff, self.repo.head.object)
                    print("%s-> OK%s" % (Colors.OKGREEN, Colors.ENDC))

                    summary += self.format_commit(self.repo.head.commit) + "\n"
                else:
                    print("-> pick " + commit.hexsha)
                    summary += "  * Picked: %s\n" % self.format_commit(commit)

            orig_branch.commit = self.repo.head.commit
            self.repo.head.reference = orig_branch
        except:
            print("-> Cleaning up back to original state on error")
            self.repo.head.commit = orig_commit
            orig_branch.commit = orig_commit
            self.repo.head.reference = orig_branch
            self.repo.head.reset(index=True, working_tree=True)
            raise

        if not patch_attachement_failure:
            summary += self.update_task_branch_uri(staging_remote_refname)

        if self.task and not self.branch_task:
            # Check if we already have a branch for this task
            branch = None
            for b in self.repo.branches:
                if self.task_from_branchname(b.name) == self.task:
                    branch = b
                    break

            if branch:
                # There is a branch corresponding to our task, but it's not the
                # current branch. It's weird case that should rarely happen.
                if self.prompt('Reset branch %s to what has just been sent '
                               'to phabricator?' % branch.name):
                    branch.commit = self.repo.head.commit
                    summary += "  * Branch %s reset to %s\n" % \
                               (branch.name, branch.commit)
            else:
                new_bname = self.branch_name_with_task()
                if self.in_feature_branch():
                    if self.prompt("Rename current branch to '%s'?" %
                                   new_bname):
                        self.repo.head.reference.rename(new_bname)
                        summary += "  * Branch renamed to %s\n" % new_bname
                else:
                    # Current branch is probably something like 'master' or
                    # 'gnome-3-18', better create a new branch than renaming.
                    if self.prompt("Create and checkout a new branch called: "
                                   "'%s'?" % new_bname):
                        new_branch = self.repo.create_head(new_bname)
                        tracking = self.repo.head.reference.tracking_branch()
                        if tracking:
                            new_branch.set_tracking_branch(tracking)
                        new_branch.checkout()

                        summary += "  * Branch %s created and checked out\n" \
                            % new_bname

        print("\n\nSummary:")
        print(summary)

    def has_been_applied(self, revision):
        did = int(revision['id'])

        for c in self.repo.iter_commits():
            i = self.get_differential_id(c)
            if i == did:
                return True
        return False

    def move_to_output_directory(self, revision, diff, filename, n=0):
        assert self.output_directory
        os.makedirs(self.output_directory, exist_ok=True)

        name = "{:04d}-{}.patch".format(
            n, revision['title'].replace(" ", "_").replace("/", "_"))
        target = os.path.join(self.output_directory, name)
        shutil.copy(filename, target)
        print(target)

    def get_diff_phid(self, phid):
        # Convert diff phid to a name
        reply = self.phabricator.phid.query(phids=[phid])

        assert(len(reply) == 1)

        # Convert name to a diff json object
        response = reply[phid]
        assert(response['type'] == "DIFF")

        d = response['name'].strip("Diff ")
        reply = self.phabricator.differential.querydiffs(ids=[d])
        assert(len(reply) == 1)

        response = reply[d]

        return response

    def get_revision_and_diff(self, diff=None, phid=None):
        if diff is not None:
            reply = self.phabricator.differential.query(ids=[diff])
        else:
            reply = self.phabricator.differential.query(phids=[phid])

        assert(len(reply) == 1)

        revision = reply[0]
        diff = self.get_diff_phid(revision['activeDiffPHID'])

        return revision, diff

    def write_patch_file(self, revision, diff):
        date = datetime.utcfromtimestamp(int(diff['dateModified']))

        handle, filename = tempfile.mkstemp(".patch", "git-phab-")
        f = os.fdopen(handle, "w")

        commit_hash = None
        local_commits = {}
        if isinstance(diff["properties"], dict):
            local_commits = diff["properties"]["local:commits"]
        try:
            keys = [k for k in local_commits.keys()]
        except TypeError:
            keys = []

        if len(keys) > 1:
            self.die("%sRevision %s names several commits, "
                     "in git-phab workflow, 1 revision == 1 commit."
                     " We can't cherry-pick that revision.%s"
                     % (Colors.FAIL, revision.id, Colors.ENDC))

        if keys:
            local_infos = local_commits[keys[0]]

            raw_commit = local_infos.get("raw_commit")
            # Use the raw_commit as set by git-phab when providing the patch
            if raw_commit:
                f.write(raw_commit)
                f.close()
                return filename

            # Try to rebuild the commit
            commit_hash = local_infos.get("commit")
            if commit_hash:
                f.write("From: %s Mon Sep 17 00:00:00 2001\n" % commit_hash)

        authorname = diff.get("authorName")
        email = diff.get("authorEmail")
        if not authorname:
            # getting author name from phabricator itself
            authorname = self.phabricator.user.query(
                phids=[revision['authorPHID']])[0]["realName"]

            author = self.format_user(authorname)
            if not author:
                self.die("%sNo author email for %s%s"
                         % (Colors.FAIL, authorname, Colors.ENDC))
        else:
            author = "%s <%s>" % (authorname, email)

        f.write("From: %s\n" % author)
        f.write("Date: {} +0000\n".format(date))
        f.write("Subject: {}\n\n".format(revision['title']))

        # Drop the arc insert Depends on Dxxxx line if needed
        summary = re.sub(re.compile("^\s*Depends on D\d+\n?", re.M), "",
                         revision['summary'])
        f.write("{}\n".format(summary))
        f.write("Differential Revision: {}/D{}\n\n".format(
            self.phabricator_uri, revision['id']))

        diffid = self.get_diff_phid(revision['activeDiffPHID'])["id"]
        output = self.phabricator.differential.getrawdiff(diffID=diffid)

        f.write(output.response)

        f.close()

        return filename

    def am_patch(self, filename, base_commit):
        try:
            # Pass --keep-cr to avoid breaking on patches for code which uses
            # CRLF line endings, due to automatically removing them before
            # applying the patch. See
            # http://stackoverflow.com/a/16144559/2931197
            self.repo.git.am(filename, keep_cr=True)
            return
        except git.exc.GitCommandError as e:
            self.repo.git.am("--abort")
            if not base_commit:
                print(e)
                self.die("{}git am failed, aborting{}".format(
                    Colors.FAIL, Colors.ENDC))

        cbranch = self.repo.head.reference

        # Checkout base commit to apply patch on
        try:
            self.repo.head.reference = self.repo.commit(base_commit)
        except (gitdb.exc.BadObject, ValueError):
            self.die("%sCould not apply patch %s from %s (even on base commit"
                     " %s), aborting%s" % (
                         Colors.FAIL, filename, self.differential, base_commit,
                         Colors.ENDC))
        self.repo.head.reset(index=True, working_tree=True)

        # Apply the patch on it
        self.repo.git.am(filename)
        new_commit = self.repo.head.commit

        # Go back to previous branch
        self.repo.head.reference = cbranch
        self.repo.head.reset(index=True, working_tree=True)

        # And try to cherry pick on patch
        self.repo.git.cherry_pick(new_commit.hexsha)

    def fetch_staging_commits(self, diff):
        if not self.staging_url:
            print("No staging URL")
            return False

        try:
            self.repo.git.fetch(self.staging_url,
                                self.get_diff_staging_ref(diff["id"]))
        except git.exc.GitCommandError as e:
            print(e)
            return False

        return True

    def cherry_pick(self):
        if self.repo.is_dirty():
            self.die("Repository is dirty. Aborting.")

        print("Checking revision:", self.differential)
        did = self.differential.strip("D")

        if not did.isdigit():
            self.die("Invalid diff ID ‘{}’".format(self.differential))

        revision, diff = self.get_revision_and_diff(diff=did)

        if self.fetch_staging_commits(diff):
            self.repo.git.cherry_pick("FETCH_HEAD")
            return

        if self.has_been_applied(revision):
            self.die("{} was already applied\n".format(self.differential))

        filename = self.write_patch_file(revision, diff)
        if self.output_directory:
            self.move_to_output_directory(revision, diff, filename)
        else:
            self.am_patch(filename, diff.get("sourceControlBaseRevision"))
        os.unlink(filename)

    def get_differentials_to_apply_for_revision(self):
        print("Checking revision:", self.differential)
        did = self.differential.strip("D")

        revision, diff = self.get_revision_and_diff(diff=did)
        dq = [(revision, diff)]
        pq = []

        while dq != []:
            top = dq.pop()
            pq.append(top)
            depends = top[0]['auxiliary']['phabricator:depends-on']
            for p in depends:
                revision, diff = self.get_revision_and_diff(phid=p)

                if revision.get('statusName') == 'Abandoned':
                    continue

                if self.has_been_applied(revision):
                    continue

                dq.append((revision, diff))
        return pq

    def apply_differential_with_dependencies(self):
        pq = self.get_differentials_to_apply_for_revision()
        n = 0
        while pq != []:
            (r, d) = pq.pop()

            filename = self.write_patch_file(r, d)
            if self.output_directory:
                self.move_to_output_directory(r, d, filename, n)
            else:
                print("Applying D{}".format(r['id']))
                self.am_patch(filename, d.get("sourceControlBaseRevision"))
            os.unlink(filename)
            n += 1

    @stash
    def do_apply(self):
        if not self.differential and not self.task:
            self.die("No task or revision provided. Aborting.")

        if self.differential:
            if self.no_dependencies:
                self.cherry_pick()
            else:
                self.apply_differential_with_dependencies()

            return

        commit_info = self.fetch_from_task()
        if self.no_dependencies:
            if commit_info[0]:
                self.repo.git.cherry_pick(commit_info[0].hexsha)
                return
            else:
                self.die("Can not apply revisions from a task"
                         " without its dependencies as the task"
                         " might refer to several revisions.")

        starting_commit = self.repo.head.commit
        try:
            common_ancestor = self.repo.merge_base(commit_info[0],
                                                   starting_commit)
        except git.exc.GitCommandError:
            self.die("No common ancestor found between Task commit"
                     " and the current repository.")

        for commit in reversed(list(self.repo.iter_commits(
                common_ancestor[0].hexsha + '^..' + commit_info[0].hexsha))):
            try:
                self.repo.git.cherry_pick(commit.hexsha)
            except git.exc.GitCommandError as e:
                stderr = e.stderr.decode("utf-8")
                if "The previous cherry-pick is now empty," \
                        " possibly due to conflict resolution." \
                        in stderr:
                    self.repo.git.reset()
                elif stderr.startswith("error: could not apply"):
                    self.die("%s\\nnWhen the conflict are fixed run"
                             " `git phab apply %s` again." % (
                                 stderr, self.task))
                else:
                    raise e

    def do_log(self):
        commits = self.get_commits(self.revision_range)
        self.print_commits(commits)

    def fetch_from_task(self):
        reply = self.phabricator.maniphest.query(ids=[int(self.task[1:])])
        if not reply:
            self.die("Not task found for ID: %s" % self.task)

        props = list(reply.values())[0]
        auxiliary = props['auxiliary']
        if not auxiliary or not auxiliary.get('std:maniphest:git:uri-branch'):
            # FIXME: There is currently no way to retrieve revisions
            # associated with a task from the conduit API
            self.die("%sCan not apply revisions from a task"
                     " if no 'remote branch' has been set for it.%s\n"
                     "INFO: You need to find what revisions are"
                     " associated with the tasks and apply them."
                     % (Colors.FAIL, Colors.ENDC))

        uri = auxiliary['std:maniphest:git:uri-branch']
        remote, branch = uri.split('#')

        self.repo.git.fetch(remote, "%s" % branch)
        commit = self.repo.commit('FETCH_HEAD')

        return (commit, remote, branch)

    def checkout_base_revision(self, diff):
        base_commit = diff.get("sourceControlBaseRevision")
        if base_commit:
            try:
                self.repo.git.checkout(base_commit)
            except git.exc.GitCommandError:
                print("Could not get base commit %s" % base_commit)
                base_commit = None

        if not base_commit:
            print("%sWARNING: Building `fake fetch` from"
                  " current commit (%s)\nas we do not have"
                  " information or access to the base commit"
                  " the revision has been proposed from%s" % (
                      Colors.WARNING, self.repo.head.commit.hexsha,
                      Colors.ENDC))
            self.repo.git.checkout(self.repo.head.commit.hexsha)

    def create_fake_fetch(self, revision, diff):
        current_branch = self.repo.active_branch
        pq = self.get_differentials_to_apply_for_revision()

        checkout_base_revision = True
        if pq:
            n = 0
            while pq != []:
                (r, d) = pq.pop()
                if checkout_base_revision:
                    self.checkout_base_revision(d)
                    checkout_base_revision = False

                filename = self.write_patch_file(r, d)
                print("Applying D{}".format(r['id']))

                self.am_patch(filename, None)
                os.unlink(filename)
                n += 1

        branch_name = self.clean_phab_branch_name(revision.get('branch'),
                                                  self.differential)

        remote = "file://" + self.repo.working_dir
        with open(os.path.join(self.repo.working_dir, ".git",
                               "FETCH_HEAD"),
                  "w") as fetch_head_file:
            fetch_head_file.write("%s		branch '%s' of %s" % (
                self.repo.head.commit.hexsha, branch_name, remote))

        current_branch.checkout()
        commit = self.repo.commit('FETCH_HEAD')

        return commit, remote, branch_name

    def do_fetch(self):
        if not self.differential and not self.task:
            self.die("No task or revision provided. Aborting.")

        if self.differential:
            commit, remote, branch_name = self.fetch_from_revision()
        else:
            commit, remote, branch_name = self.fetch_from_task()

        if not self.checkout:
            print("From %s\n"
                  " * branch    %s -> FETCH_HEAD" % (
                      remote, branch_name))
            return

        self.checkout_branch(commit, remote, branch_name)

    def clean_phab_branch_name(self, branch_name, default):
        if not branch_name or branch_name in ['master']:
            return default

        revision = self.revision_from_branchname(branch_name)
        if revision:
            return branch_name[len(revision + '-'):]

        task = self.task_from_branchname(branch_name)
        if task:
            return branch_name[len(task + '-'):]

        return branch_name

    def fetch_from_revision(self):
        did = self.differential.strip("D")

        revision, diff = self.get_revision_and_diff(diff=did)

        if not self.fetch_staging_commits(diff):
            return self.create_fake_fetch(revision, diff)

        return (self.repo.rev_parse("FETCH_HEAD"), self.staging_url,
                self.clean_phab_branch_name(revision['branch'],
                                            self.differential))

    def checkout_branch(self, commit, remote, remote_branch_name):
        if self.differential:
            branchname_match_method = self.revision_from_branchname
            branch_name = self.differential
        else:
            branchname_match_method = self.task_from_branchname
            branch_name = self.task

        # Lookup for an existing branch for this task
        branch = None
        for b in self.repo.branches:
            if branchname_match_method(b.name) == branch_name:
                branch = b
                break

        if branch:
            if not self.prompt("Do you want to reset branch %s to %s?" %
                               (branch.name, commit.hexsha)):
                self.die("Aborting")
            branch.commit = commit
            print("Branch %s has been reset." % branch.name)
        else:
            name = remote_branch_name[remote_branch_name.rfind('/') + 1:]
            branch = self.repo.create_head(name, commit=commit)
            print("New branch %s has been created." % branch.name)

        branch.checkout()

    def do_browse(self):
        urls = []
        if not self.objects:
            if not self.task:
                self.die("Could not figure out a task from branch name")
            self.objects = [self.task]

        for obj in self.objects:
            if re.fullmatch('(T|D)[0-9]+', obj):
                urls.append(self.phabricator_uri + "/" + obj)
                continue

            try:
                commit = self.repo.rev_parse(obj)
            except git.BadName:
                self.die("Wrong commit hash: %s" % obj)

            uri = self.get_differential_link(commit)
            if not uri:
                print("Could not find a differential for %s" % obj)
                continue
            urls.append(uri)

        for url in urls:
            print("Openning: %s" % url)
            subprocess.check_call(["xdg-open", url],
                                  stdout=subprocess.DEVNULL,
                                  stderr=subprocess.DEVNULL)

    def do_clean(self):
        branch_task = []
        self.repo.git.prune()
        for r in self.repo.references:
            if r.is_remote() and r.remote_name != self.remote:
                continue

            task = self.task_from_branchname(r.name)
            if task:
                branch_task.append((r, task))

        task_ids = [t[1:] for b, t in branch_task]
        reply = self.phabricator.maniphest.query(ids=task_ids)

        for tphid, task in reply.items():
            if not task["isClosed"]:
                continue

            for branch, task_name in branch_task:
                if task["objectName"] != task_name:
                    continue

                if self.prompt("Task '%s' has been closed, do you want to "
                               "delete branch '%s'?" % (task_name, branch)):
                    if branch.is_remote():
                        try:
                            self.repo.git.push(self.remote,
                                               ":" + branch.remote_head)
                        except git.exc.GitCommandError:
                            pass
                    else:
                        self.repo.delete_head(branch, force=True)

                    print("  -> Branch %s was deleted" % branch.name)

    @stash
    def do_land(self):
        if self.task:
            commit, remote, remote_branch_name = self.fetch_from_task()
            branch = self.repo.active_branch
            if not self.prompt("Do you want to reset branch %s to %s?" %
                               (branch.name, commit.hexsha)):
                self.die("Aborting")

            branch.commit = commit

        # Collect commits that will be pushed
        output = self.repo.git.push(dry_run=True, porcelain=True)
        m = re.search('[0-9a-z]+\.\.[0-9a-z]+', output)
        commits = self.get_commits(m.group(0)) if m else []

        # Sanity checks
        if len(commits) == 0:
            self.die("No commits to push. Aborting.")
        if commits[0] != self.repo.head.commit:
            self.die("Top commit to push is not HEAD.")
        for c in commits:
            if len(c.parents) > 1:
                self.die("'%s' is a merge commit. Aborting." % c.hexsha)

        orig_commit = self.repo.head.commit
        orig_branch = self.repo.head.reference
        all_tasks = []
        try:
            # Detach HEAD from the branch; this gives a cleaner reflog for the
            # branch
            self.repo.head.reference = commits[-1].parents[0]
            self.repo.head.reset(index=True, working_tree=True)
            for commit in reversed(commits):
                self.repo.git.cherry_pick(commit.hexsha)

                reviewers, tasks = self.get_reviewers_and_tasks(commit)
                all_tasks += tasks

                # Rewrite commit message:
                # - Add "Reviewed-by:" line
                # - Ensure body doesn't contain blacklisted words
                # - Ensure phabricator fields are last to make its parser happy
                # - Discard updates/discussion of previous patch revisions
                subject, body, git_fields, phab_fields, updates = \
                    self.parse_commit_msg(self.repo.head.commit.message)

                for r in reviewers:
                    field = "Reviewed-by: " + r
                    if field not in git_fields:
                        git_fields.append(field)

                msg = self.format_commit_msg(subject, body, git_fields,
                                             phab_fields, True)
                self.repo.git.commit(amend=True, message=msg)

            orig_branch.commit = self.repo.head.commit
            self.repo.head.reference = orig_branch
        except:
            print("Cleaning up back to original state on error")
            self.repo.head.commit = orig_commit
            orig_branch.commit = orig_commit
            self.repo.head.reference = orig_branch
            self.repo.head.reset(index=True, working_tree=True)
            raise

        self.print_commits(commits)
        if self.no_push:
            return

        # Ask confirmation
        if not self.prompt("Do you want to push above commits?"):
            print("Aborting")
            exit(0)

        # Do the real push
        self.repo.git.push()

        # Propose to close tasks
        for task in set(all_tasks):
            if self.prompt("Do you want to close '%s'?" % task):
                self.phabricator.maniphest.update(id=int(task[1:]),
                                                  status='resolved')

    def run(self):
        self.validate_args()
        method = 'do_' + self.subparser_name.replace('-', '_')
        getattr(self, method)()


def DisabledCompleter(prefix, **kwargs):
    return []


def check_dependencies_versions():
    required_pygit_version = '2.0'
    if git.__version__ < required_pygit_version:
        print("%sPythonGit >= %s required %s found%s"
              % (Colors.FAIL, required_pygit_version,
                 git.__version__, Colors.ENDC))
        exit(1)


if __name__ == '__main__':
    check_dependencies_versions()
    parser = argparse.ArgumentParser(description='Phabricator integration.')
    subparsers = parser.add_subparsers(dest='subparser_name')
    subparsers.required = True

    parser.add_argument('--arcrc', help="arc configuration file")

    attach_parser = subparsers.add_parser(
        'attach', help="Generate a Differential for each commit")
    attach_parser.add_argument(
        '--reviewers', '-r', metavar='<username1,#project2,...>',
        help="A list of reviewers") \
        .completer = DisabledCompleter
    attach_parser.add_argument(
        '--cc', '--subscribers', metavar='<username1,#project2,...>',
        help="A list of subscribers") \
        .completer = DisabledCompleter
    attach_parser.add_argument(
        '--message', '-m', metavar='<message>',
        help=("When updating a revision, use the specified message instead of "
              "prompting")) \
        .completer = DisabledCompleter
    attach_parser.add_argument(
        '--task', '-t', metavar='<T123>',
        nargs="?", const="T",
        help=("Set the task this Differential refers to")) \
        .completer = DisabledCompleter
    attach_parser.add_argument(
        '--remote', metavar='<remote>',
        help=("A remote repository to push to. "
              "Overrides 'phab.remote' configuration.")) \
        .completer = DisabledCompleter
    attach_parser.add_argument(
        '--assume-yes', '-y', dest="assume_yes", action="store_true",
        help="Assume `yes` as answer to all prompts.") \
        .completer = DisabledCompleter
    attach_parser.add_argument(
        '--projects', '-p', dest="projects",
        metavar='<project1,project2,...>',
        help="A list of `extra` projects (they will be added to"
        "any project(s) configured in .arcconfig)") \
        .completer = DisabledCompleter
    attach_parser.add_argument(
        'revision_range', metavar='<revision range>',
        nargs='?', default=None,
        help="commit or revision range to attach. When not specified, "
             "the tracking branch is used") \
        .completer = DisabledCompleter
    attach_parser.add_argument(
        '--autostash', action="store_true",
        help="Automatically stash not committed changes."
        " You can also `git config [--global] phab.autostash true` "
        "to make it permanent") \
        .completer = DisabledCompleter

    apply_parser = subparsers.add_parser(
        'apply', help="Apply a revision and its dependencies"
        " on the current tree")
    apply_parser.add_argument(
        '--output-directory', '-o',
        metavar='<directory>',
        help="Directory to put patches in")
    apply_parser.add_argument(
        'task_or_revision', metavar='<(T|D)123>', nargs='?',
        help="The task or revision to fetch") \
        .completer = DisabledCompleter
    apply_parser.add_argument(
        '--no-dependencies', "-n", action="store_true",
        help="Do not apply dependencies of a revision.") \
        .completer = DisabledCompleter
    apply_parser.add_argument(
        '--autostash', action="store_true",
        help="Automatically stash not committed changes."
        " You can also `git config [--global] phab.autostash true` "
        "to make it always happen") \
        .completer = DisabledCompleter

    log_parser = subparsers.add_parser(
        'log', help="Show commit logs with their differential ID")
    log_parser.add_argument(
        'revision_range', metavar='<revision range>',
        nargs='?', default=None,
        help="commit or revision range to show. When not specified, "
             "the tracking branch is used") \
        .completer = DisabledCompleter

    fetch_parser = subparsers.add_parser(
        'fetch', help="Fetch a task's branch")
    fetch_parser.add_argument(
        'task_or_revision', metavar='<(T|D)123>', nargs='?',
        help="The task or revision to fetch") \
        .completer = DisabledCompleter
    fetch_parser.add_argument(
        '--checkout', "-c", action="store_true",
        help="Also checks out the commits in a branch.") \
        .completer = DisabledCompleter

    browse_parser = subparsers.add_parser(
        'browse', help="Open the task of the current "
        "branch in web browser")
    browse_parser.add_argument(
        'objects', nargs='*', default=[],
        help="The 'objects' to browse. It can either be a task ID, "
             "a revision ID, a commit hash or empty to open current branch's "
             "task.") \
        .completer = DisabledCompleter

    clean_parser = subparsers.add_parser(
        'clean', help="Clean all branches for which the associated task"
        " has been closed")

    land_parser = subparsers.add_parser(
        'land', help="Run 'git push' but also close related tasks")
    land_parser.add_argument(
        '--no-push', action="store_true",
        help="Only rewrite commit messages but do not push.") \
        .completer = DisabledCompleter
    land_parser.add_argument(
        'task', metavar='<T123>', nargs='?',
        help="The task to land") \
        .completer = DisabledCompleter
    land_parser.add_argument(
        '--autostash', action="store_true",
        help="Automatically stash not committed changes."
        " You can also `git config [--global] phab.autostash true` "
        "to make it always happen") \
        .completer = DisabledCompleter

    argcomplete.autocomplete(parser)

    obj = GitPhab()
    parser.parse_args(namespace=obj)
    obj.run()