text: #!/usr/bin/env python
  
  #
  # Licensed to the Apache Software Foundation (ASF) under one or more
  # contributor license agreements.  See the NOTICE file distributed with
  # this work for additional information regarding copyright ownership.
  # The ASF licenses this file to You under the Apache License, Version 2.0
  # (the "License"); you may not use this file except in compliance with
  # the License.  You may obtain a copy of the License at
  #
  #    http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  #
  
  # Utility for creating well-formed pull request merges and pushing them to Apache. This script is a modified version
  # of the one created by the Spark project (https://github.com/apache/spark/blob/master/dev/merge_spark_pr.py).
  #
  # Usage: ./bk-merge-pr.py (see config env vars below)
  #
  # This utility assumes you already have local a bookkeeper git folder and that you
  # have added remotes corresponding to both:
  # (i) the github apache bookkeeper mirror and
  # (ii) the apache bookkeeper git repo.
  
  import json
  import os
  import re
  import subprocess
  import sys
  import urllib2
  
  try:
      import jira.client
      JIRA_IMPORTED = True
  except ImportError:
      JIRA_IMPORTED = False
  
  PROJECT_NAME = "bookkeeper"
  
  CAPITALIZED_PROJECT_NAME = "bookkeeper".upper()
  GITHUB_ISSUES_NAME = "issue".upper()
  
  # Location of the local git repository
  REPO_HOME = os.environ.get("%s_HOME" % CAPITALIZED_PROJECT_NAME, os.getcwd())
  # Remote name which points to the GitHub site
  PR_REMOTE_NAME = os.environ.get("PR_REMOTE_NAME", "apache-github")
  # Remote name which points to Apache git
  PUSH_REMOTE_NAME = os.environ.get("PUSH_REMOTE_NAME", "apache")
  # Reference branch name
  DEV_BRANCH_NAME = os.environ.get("DEV_BRANCH_NAME", "master")
  # ASF JIRA username
  JIRA_USERNAME = os.environ.get("JIRA_USERNAME", "")
  # ASF JIRA password
  JIRA_PASSWORD = os.environ.get("JIRA_PASSWORD", "")
  # Github API page size
  GITHUB_PAGE_SIZE = os.environ.get("GH_PAGE_SIZE", "100")
  # OAuth key used for issuing requests against the GitHub API. If this is not defined, then requests
  # will be unauthenticated. You should only need to configure this if you find yourself regularly
  # exceeding your IP's unauthenticated request rate limit. You can create an OAuth key at
  # https://github.com/settings/tokens. This script only requires the "public_repo" scope.
  GITHUB_OAUTH_KEY = os.environ.get("GITHUB_OAUTH_KEY")
  
  GITHUB_USER = os.environ.get("GITHUB_USER", "apache")
  GITHUB_BASE = "https://github.com/%s/%s/pull" % (GITHUB_USER, PROJECT_NAME)
  GITHUB_API_URL  = "https://api.github.com"
  GITHUB_API_BASE = "%s/repos/%s/%s" % (GITHUB_API_URL, GITHUB_USER, PROJECT_NAME)
  JIRA_BASE = "https://issues.apache.org/jira/browse"
  JIRA_API_BASE = "https://issues.apache.org/jira"
  # Prefix added to temporary branches
  TEMP_BRANCH_PREFIX = "PR_TOOL"
  RELEASE_BRANCH_PREFIX = "branch-"
  
  DEFAULT_FIX_VERSION = os.environ.get("DEFAULT_FIX_VERSION", "0.9.1.0")
  
  def get_json(url, preview_api = False):
      try:
          request = urllib2.Request(url)
          if GITHUB_OAUTH_KEY:
              request.add_header('Authorization', 'token %s' % GITHUB_OAUTH_KEY)
          if preview_api:
              request.add_header('Accept', 'application/vnd.github.black-cat-preview+json')
          return json.load(urllib2.urlopen(request))
      except urllib2.HTTPError as e:
          if "X-RateLimit-Remaining" in e.headers and e.headers["X-RateLimit-Remaining"] == '0':
              print "Exceeded the GitHub API rate limit; see the instructions in " + \
                    "bk-merge-pr.py to configure an OAuth token for making authenticated " + \
                    "GitHub requests."
          else:
              print "Unable to fetch URL, exiting: %s" % url
          sys.exit(-1)
  
  def post_json(url, data):
      try:
          request = urllib2.Request(url, data, { 'Content-Type': 'application/json' })
          if GITHUB_OAUTH_KEY:
              request.add_header('Authorization', 'token %s' % GITHUB_OAUTH_KEY)
          return json.load(urllib2.urlopen(request))
      except urllib2.HTTPError as e:
          if "X-RateLimit-Remaining" in e.headers and e.headers["X-RateLimit-Remaining"] == '0':
              print "Exceeded the GitHub API rate limit; see the instructions in " + \
                    "bk-merge-pr.py to configure an OAuth token for making authenticated " + \
                    "GitHub requests."
          else:
              print "Unable to fetch URL, exiting: %s - %s" % (url, e)
          sys.exit(-1)
  
  def fail(msg):
      print msg
      clean_up()
      sys.exit(-1)
  
  
  def run_cmd(cmd):
      print cmd
      if isinstance(cmd, list):
          return subprocess.check_output(cmd)
      else:
          return subprocess.check_output(cmd.split(" "))
  
  
  def continue_maybe(prompt):
      result = raw_input("\n%s (y/n): " % prompt)
      if result.lower() != "y":
          fail("Okay, exiting")
  
  def clean_up():
      if original_head != get_current_branch():
          print "Restoring head pointer to %s" % original_head
          run_cmd("git checkout %s" % original_head)
  
      branches = run_cmd("git branch").replace(" ", "").split("\n")
  
      for branch in filter(lambda x: x.startswith(TEMP_BRANCH_PREFIX), branches):
          print "Deleting local branch %s" % branch
          run_cmd("git branch -D %s" % branch)
  
  def get_current_branch():
      return run_cmd("git rev-parse --abbrev-ref HEAD").replace("\n", "")
  
  def get_milestones():
      return get_json("https://api.github.com/repos/%s/%s/milestones?state=open&sort=due_on&direction=asc" % (GITHUB_USER, PROJECT_NAME))
  
  def get_all_labels():
      result = get_json("https://api.github.com/repos/%s/%s/labels?per_page=%s" % (GITHUB_USER, PROJECT_NAME, GITHUB_PAGE_SIZE))
      return map(lambda x: x['name'], result)
  
  # merge the requested PR and return the merge hash
  def merge_pr(pr_num, target_ref, title, body, default_pr_reviewers, pr_repo_desc):
      pr_branch_name = "%s_MERGE_PR_%s" % (TEMP_BRANCH_PREFIX, pr_num)
      target_branch_name = "%s_MERGE_PR_%s_%s" % (TEMP_BRANCH_PREFIX, pr_num, target_ref.upper())
      run_cmd("git fetch %s pull/%s/head:%s" % (PR_REMOTE_NAME, pr_num, pr_branch_name))
      run_cmd("git fetch %s %s:%s" % (PUSH_REMOTE_NAME, target_ref, target_branch_name))
      run_cmd("git checkout %s" % target_branch_name)
  
      had_conflicts = False
      try:
          run_cmd(['git', 'merge', pr_branch_name, '--squash'])
      except Exception as e:
          msg = "Error merging: %s\nWould you like to manually fix-up this merge?" % e
          continue_maybe(msg)
          msg = "Okay, please fix any conflicts and 'git add' conflicting files... Finished?"
          continue_maybe(msg)
          had_conflicts = True
  
      # Offer to run unit tests before committing
      result = raw_input('Do you want to validate unit tests after the merge? (y/n): ')
      if result.lower() == 'y':
          test_res = subprocess.call('mvn clean install'.split())
          if test_res == 0:
              print('Unit tests execution succeeded')
          else:
              continue_maybe("Unit tests execution FAILED. Do you want to continue with the merge anyway?")
  
      # Offer to run spotbugs and rat before committing
      result = raw_input('Do you want to validate spotbugs and rat after the merge? (y/n): ')
      if result.lower() == 'y':
          test_res = subprocess.call('mvn clean install -DskipTests spotbugs:check apache-rat:check'.split())
          if test_res == 0:
              print('QA tests execution succeeded')
          else:
              continue_maybe("QA tests execution FAILED. Do you want to continue with the merge anyway?")
  
      commit_authors = run_cmd(['git', 'log', 'HEAD..%s' % pr_branch_name,
                               '--pretty=format:%an <%ae>']).split("\n")
      distinct_authors = sorted(set(commit_authors),
                                key=lambda x: commit_authors.count(x), reverse=True)
      primary_author = raw_input(
          "Enter primary author in the format of \"name <email>\" [%s]: " %
          distinct_authors[0])
      if primary_author == "":
          primary_author = distinct_authors[0]
  
      reviewers = raw_input("Enter reviewers [%s]: " % default_pr_reviewers).strip()
      if reviewers == '':
          reviewers = default_pr_reviewers
  
      commits = run_cmd(['git', 'log', 'HEAD..%s' % pr_branch_name,
                        '--pretty=format:%h [%an] %s']).split("\n")
      
      if len(commits) > 1:
          result = raw_input("List pull request commits in squashed commit message? (y/n): ")
          if result.lower() == "y":
            should_list_commits = True
          else:
            should_list_commits = False
      else:
          should_list_commits = False
  
      merge_message_flags = []
  
      merge_message_flags += ["-m", title]
      if body is not None:
          # We remove @ symbols from the body to avoid triggering e-mails
          # to people every time someone creates a public fork of the project.
          merge_message_flags += ["-m", body.replace("@", "")]
  
      authors = "\n".join(["Author: %s" % a for a in distinct_authors])
  
      merge_message_flags += ["-m", authors]
  
      if (reviewers != ""):
          merge_message_flags += ["-m", "Reviewers: %s" % reviewers]
  
      if had_conflicts:
          committer_name = run_cmd("git config --get user.name").strip()
          committer_email = run_cmd("git config --get user.email").strip()
          message = "This patch had conflicts when merged, resolved by\nCommitter: %s <%s>" % (
              committer_name, committer_email)
          merge_message_flags += ["-m", message]
  
      # The string "Closes #%s" string is required for GitHub to correctly close the PR
      close_line = "This closes #%s from %s" % (pr_num, pr_repo_desc)
      # Find the github issues to close
      github_issues = re.findall("#[0-9]{3,6}", title)
  
      if len(github_issues) != 0:
          for issue_id in github_issues:
              close_line += ", closes %s" % (issue_id)
  
      if should_list_commits:
          close_line += " and squashes the following commits:"
      merge_message_flags += ["-m", close_line]
  
      if should_list_commits:
          merge_message_flags += ["-m", "\n".join(commits)]
  
      run_cmd(['git', 'commit', '--author="%s"' % primary_author] + merge_message_flags)
  
      continue_maybe("Merge complete (local ref %s). Push to %s?" % (
          target_branch_name, PUSH_REMOTE_NAME))
  
      try:
          run_cmd('git push %s %s:%s' % (PUSH_REMOTE_NAME, target_branch_name, target_ref))
      except Exception as e:
          clean_up()
          fail("Exception while pushing: %s" % e)
  
      merge_hash = run_cmd("git rev-parse %s" % target_branch_name)[:8]
      merge_log = run_cmd("git show --format=fuller -q %s" % target_branch_name)
      clean_up()
      print("Pull request #%s merged!" % pr_num)
      print("Merge hash: %s" % merge_hash)
      return merge_hash, merge_log
  
  def ask_for_branch(default_branch):
      pick_ref = raw_input("Enter a branch name [%s]: " % default_branch)
      if pick_ref == "":
          pick_ref = default_branch
      return pick_ref
  
  def cherry_pick(pr_num, merge_hash, pick_ref):
      pick_branch_name = "%s_PICK_PR_%s_%s" % (TEMP_BRANCH_PREFIX, pr_num, pick_ref.upper())
  
      run_cmd("git fetch %s %s:%s" % (PUSH_REMOTE_NAME, pick_ref, pick_branch_name))
      run_cmd("git checkout %s" % pick_branch_name)
  
      try:
          run_cmd("git cherry-pick -sx %s" % merge_hash)
      except Exception as e:
          msg = "Error cherry-picking: %s\nWould you like to manually fix-up this merge?" % e
          continue_maybe(msg)
          msg = "Okay, please fix any conflicts and finish the cherry-pick. Finished?"
          continue_maybe(msg)
  
      continue_maybe("Pick complete (local ref %s). Push to %s?" % (
          pick_branch_name, PUSH_REMOTE_NAME))
  
      try:
          run_cmd('git push %s %s:%s' % (PUSH_REMOTE_NAME, pick_branch_name, pick_ref))
      except Exception as e:
          clean_up()
          fail("Exception while pushing: %s" % e)
  
      pick_hash = run_cmd("git rev-parse %s" % pick_branch_name)[:8]
      clean_up()
  
      print("Pull request #%s picked into %s!" % (pr_num, pick_ref))
      print("Pick hash: %s" % pick_hash)
      return pick_ref
  
  
  def fix_version_from_branch(branch, versions):
      # Note: Assumes this is a sorted (newest->oldest) list of un-released versions
      if branch == DEV_BRANCH_NAME:
          versions = filter(lambda x: x == DEFAULT_FIX_VERSION, versions)
          if len(versions) > 0:
              return versions[0]
          else:
              return None
      else:
          versions = filter(lambda x: x.startswith(branch), versions)
          if len(versions) > 0:
              return versions[-1]
          else:
              return None
  
  
  def resolve_jira_issue(merge_branches, comment, jira_id):
      asf_jira = jira.client.JIRA({'server': JIRA_API_BASE},
                                  basic_auth=(JIRA_USERNAME, JIRA_PASSWORD))
  
      result = raw_input("Resolve JIRA %s ? (y/n): " % jira_id)
      if result.lower() != "y":
          return
  
      try:
          issue = asf_jira.issue(jira_id)
      except Exception as e:
          fail("ASF JIRA could not find %s\n%s" % (jira_id, e))
  
      cur_status = issue.fields.status.name
      cur_summary = issue.fields.summary
      cur_assignee = issue.fields.assignee
      if cur_assignee is None:
          cur_assignee = "NOT ASSIGNED!!!"
      else:
          cur_assignee = cur_assignee.displayName
  
      if cur_status == "Resolved" or cur_status == "Closed":
          fail("JIRA issue %s already has status '%s'" % (jira_id, cur_status))
      print ("=== JIRA %s ===" % jira_id)
      print ("summary\t\t%s\nassignee\t%s\nstatus\t\t%s\nurl\t\t%s/%s\n" % (
          cur_summary, cur_assignee, cur_status, JIRA_BASE, jira_id))
  
      versions = asf_jira.project_versions(CAPITALIZED_PROJECT_NAME)
      versions = sorted(versions, key=lambda x: x.name, reverse=True)
      versions = filter(lambda x: x.raw['released'] is False, versions)
  
      version_names = map(lambda x: x.name, versions)
      default_fix_versions = map(lambda x: fix_version_from_branch(x, version_names), merge_branches)
      default_fix_versions = filter(lambda x: x != None, default_fix_versions)
      default_fix_versions = ",".join(default_fix_versions)
  
      fix_versions = raw_input("Enter comma-separated fix version(s) [%s]: " % default_fix_versions)
      if fix_versions == "":
          fix_versions = default_fix_versions
      fix_versions = fix_versions.replace(" ", "").split(",")
  
      def get_version_json(version_str):
          return filter(lambda v: v.name == version_str, versions)[0].raw
  
      jira_fix_versions = map(lambda v: get_version_json(v), fix_versions)
  
      resolve = filter(lambda a: a['name'] == "Resolve Issue", asf_jira.transitions(jira_id))[0]
      resolution = filter(lambda r: r.raw['name'] == "Fixed", asf_jira.resolutions())[0]
      asf_jira.transition_issue(
          jira_id, resolve["id"], fixVersions = jira_fix_versions,
          comment = comment, resolution = {'id': resolution.raw['id']})
  
      print "Successfully resolved %s with fixVersions=%s!" % (jira_id, fix_versions)
  
  
  def resolve_jira_issues(title, merge_branches, comment):
      jira_ids = re.findall("%s-[0-9]{3,6}" % CAPITALIZED_PROJECT_NAME, title)
  
      if len(jira_ids) == 0:
          print "No JIRA issue found to update"
      for jira_id in jira_ids:
          resolve_jira_issue(merge_branches, comment, jira_id)
  
  
  def standardize_jira_ref(text):
      """
      Standardize the jira reference commit message prefix to "PROJECT_NAME-XXX: Issue"
  
      'BOOKKEEPER-877: Script for generating patch for reviews'
      'ISSUE #376: Script for generating patch for reviews'
      """
      jira_refs = []
      github_issue_refs = []
      github_issue_ids = []
      components = []
  
      # Extract JIRA ref(s):
      pattern = re.compile(r'(%s[-\s]*[0-9]{3,6})+' % CAPITALIZED_PROJECT_NAME, re.IGNORECASE)
      for ref in pattern.findall(text):
          # Add brackets, replace spaces with a dash, & convert to uppercase
          jira_refs.append(re.sub(r'\s+', '-', ref.upper()))
          text = text.replace(ref, '')
  
      # Extract Github Issue ref(s)
      pattern = re.compile(r'(%s[-\s]*([0-9]{3,6}))+' % GITHUB_ISSUES_NAME, re.IGNORECASE)
      for ref in pattern.findall(text):
          # Add brackets, replace spaces or a dash with ' #', & convert to uppercase
          github_issue_refs.append(re.sub(r'[-\s]+', ' #', ref[0].upper()))
          text = text.replace(ref[0], '')
          github_issue_ids.append(ref[1].upper())
  
      # Extract project name component(s):
      # Look for alphanumeric chars, spaces, dashes, periods, and/or commas
      pattern = re.compile(r'(\[[\w\s,-\.]+\])', re.IGNORECASE)
      for component in pattern.findall(text):
          components.append(component.upper())
          text = text.replace(component, '')
  
      # Cleanup any remaining symbols:
      pattern = re.compile(r'^\W+(.*)', re.IGNORECASE)
      if (pattern.search(text) is not None):
          text = pattern.search(text).groups()[0]
  
      # Assemble full text (JIRA ref(s), module(s), remaining text)
      prefix = ''
      jira_prefix = ' '.join(jira_refs).strip()
      if jira_prefix:
          prefix = jira_prefix + ": "
      github_prefix = ' '.join(github_issue_refs).strip()
      if github_prefix:
          prefix = github_prefix + ": "
      clean_text = prefix + ' '.join(components).strip() + " " + text.strip()
  
      # Replace multiple spaces with a single space, e.g. if no jira refs and/or components were included
      clean_text = re.sub(r'\s+', ' ', clean_text.strip())
  
      return clean_text, github_issue_ids
  
  def get_reviewers(pr_num):
      """
      Get a candidate list of reviewers that have commented on the PR with '+1' or 'LGTM'
      """
      approval_msgs = ['+1', 'lgtm']
  
      pr_comments = get_json("%s/issues/%s/comments" % (GITHUB_API_BASE, pr_num))
  
      reviewers_ids = set()
      for comment in pr_comments:
          for approval_msg in approval_msgs:
              if approval_msg in comment['body'].lower():
                  reviewers_ids.add(comment['user']['login'])
  
      approval_review_states = ['approved']
      pr_reviews = get_json('{0}/pulls/{1}/reviews?per_page=100'.format(GITHUB_API_BASE, pr_num), True)
      for review in pr_reviews:
          for approval_state in approval_review_states:
              if approval_state in review['state'].lower():
                  reviewers_ids.add(review['user']['login'])
  
      if len(reviewers_ids) == 0:
          fail("No approvals found in this pull request")
  
      reviewers_emails = []
      for reviewer_id in reviewers_ids:
          username = None
          useremail = None
          user = get_json("%s/users/%s" % (GITHUB_API_URL, reviewer_id))
          if user['email']:
              useremail = user['email'].strip()
          if user['name']:
              username = user['name'].strip()
          if username is None:
              continue
          reviewers_emails.append('{0} <{1}>'.format(username.encode('utf8'), useremail))
      return ', '.join(reviewers_emails)
  
  def check_ci_status(pr):
      ci_status = get_json("%s/commits/%s/status" % (GITHUB_API_BASE, pr["head"]["sha"]))
      state = ci_status["state"]
      if state != "success":
          comments = get_json(pr["comments_url"])
          ignore_ci_comments = [c for c in comments if c["body"].upper() == "IGNORE CI"]
          if len(ignore_ci_comments) > 0:
              print "\n\nWARNING: The PR has not passed CI (state is %s)" % (state) \
                  + ", but this has been overridden by %s. \n" % (ignore_ci_comments[0]["user"]["login"]) \
                  + "Proceed at your own peril!\n\n"
          else:
              check_individual_ci_status(ci_status, comments)
  
  
  def check_individual_ci_status(ci_status, comments):
      postcommit_java9_success = False
      postcommit_java8_success = False
      integration_tests_success = False
      travis_success = False
      for status in ci_status["statuses"]:
          if status["context"] == u"Jenkins: Maven clean install (Java 9)":
              postcommit_java9_success = status["state"] == "success"
          elif status["context"] == u"Jenkins: Maven clean install (Java 8)": 
              postcommit_java8_success = status["state"] == "success"
          elif status["context"] == u"Jenkins: Integration Tests": 
              integration_tests_success = status["state"] == "success"
          elif status["context"] == u"continuous-integration/travis-ci/pr":
              travis_success = status["state"] == "success"
  
      if postcommit_java8_success and postcommit_java9_success and travis_success and not integration_tests_success:
          # all ci passed except integration tests
          ignore_it_ci_comments = [c for c in comments if c["body"].upper() == "IGNORE IT CI"]
          if len(ignore_it_ci_comments) > 0:
              print "\n\nWARNING: The PR has not passed integration tests CI" \
                  + ", but this has been overridden by %s. \n" % (ignore_it_ci_comments[0]["user"]["login"]) \
                  + "Proceed at your own peril!\n\n"
          else:
              fail("The PR has not passed integration tests CI")
      else:
          fail("The PR has not passed CI:\n" \
              + "\t Travis: %s\n" % travis_success \
              + "\t PostCommit (Java 8): %s\n" % postcommit_java8_success \
              + "\t PostCommit (Java 9): %s\n" % postcommit_java9_success \
              + "\t Integration Tests: %s\n" % integration_tests_success)
  
  def ask_release_for_github_issues(branch, labels):
      print "=== Add release to github issues ==="
      while True:
          fix_releases = ask_for_labels("release/%s" % branch, labels, [])
          if len(fix_releases) != 1:
              print "Please choose only one release to add for branch '%s'." % branch
              continue
  
          print "=== Apply following releases to github issues ==" 
          print "Fix Releases: %s" % ', '.join(fix_releases)
          print ""
  
          if raw_input("Would you like to add these releases to github issues? (y/n): ") == "y":
              break
      return fix_releases
  
  def ask_updates_for_github_issues(milestones, labels, issue_labels):
      while True:
          fix_milestone, fix_milestone_number, fix_areas, fix_types = \
              get_updates_for_github_issues(milestones, labels, issue_labels)
  
          print "=== Apply following milestone, area, type to github issues ==" 
          print "Fix Types: %s" % ', '.join(fix_types)
          print "Fix Areas: %s" % ', '.join(fix_areas)
          print "Fix Milestone: %s" % fix_milestone
          print ""
  
          if raw_input("Would you like to update github issues with these labels? (y/n): ") == "y":
              break
  
      return fix_milestone, fix_milestone_number, fix_areas, fix_types
  
  def get_updates_for_github_issues(milestones, labels, issue_labels):
      # get milestone
      default_milestone_name = milestones[0]['title']
      milestone_list = map(lambda x: x['title'], milestones)
      milestone_map = dict((milestone['title'], milestone['number']) for milestone in milestones)
      fix_milestone = ""
      while True:
          fix_milestone = raw_input("Choose fix milestone : options are [%s] - default: [%s]: " % (', '.join(milestone_list).strip(), default_milestone_name))
          fix_milestone = fix_milestone.strip()
          if fix_milestone == "":
              fix_milestone = default_milestone_name
              break
          elif fix_milestone in milestone_map:
              break
          else:
              print "Invalid milestone: %s." % fix_milestone
  
      # get area
      fix_areas = ask_for_labels("area/", labels, issue_labels)
      
      # get types
      fix_types = ask_for_labels("type/", labels, issue_labels) 
  
      return fix_milestone, milestone_map[fix_milestone], fix_areas, fix_types
  
  def ask_for_labels(prefix, labels, issue_labels):
      issue_filtered_labels = map(lambda l: l.split('/')[1], filter(lambda x: x.startswith(prefix), issue_labels))
      filtered_labels = map(lambda l: l.split('/')[1], filter(lambda x: x.startswith(prefix), labels))
      while True:
          fix_labels = raw_input("Choose label '%s' - options are: [%s] - default: [%s] (comma separated): "
              % (prefix, ', '.join(filtered_labels).strip(), ', '.join(issue_filtered_labels).strip()))
          if fix_labels == "":
              if not issue_filtered_labels:
                  print "Please specify a '%s' label to close the issue!" % prefix
                  continue
              else:
                  fix_labels = issue_filtered_labels
                  break
          fix_labels = fix_labels.replace(" ", "").split(",")
          if not fix_labels:
              print "Please specify a '%s' label to close the issue!" % prefix
              continue
          invalid_label = False
          for label in fix_labels:
              if label not in filtered_labels:
                  print "Invalid '%s' label: %s." % (prefix, label)
                  invalid_label = True
                  break
          if invalid_label:
              continue
          else:
              break
      return fix_labels
  
  def get_github_issue_url(github_issue_id):
      return "https://api.github.com/repos/%s/%s/issues/%s" % (GITHUB_USER, PROJECT_NAME, github_issue_id) 
  
  def get_assignees_url(github_issue_id):
      return "https://api.github.com/repos/%s/%s/issues/%s/assignees" % (GITHUB_USER, PROJECT_NAME, github_issue_id) 
  
  def get_github_issue_labels(github_issue_id):
      url = "https://api.github.com/repos/%s/%s/issues/%s/labels" % (GITHUB_USER, PROJECT_NAME, github_issue_id) 
      result = get_json(url)
      return map(lambda x: x["name"], result)
  
  def add_release_to_github_issues(github_issue_ids, labels, fix_release):
      for github_issue_id in github_issue_ids:
          labels = add_release_to_github_issue(github_issue_id, labels, fix_release)
      return labels
  
  def add_release_to_github_issue(github_issue_id, labels, fix_release):
      url = get_github_issue_url(github_issue_id)
      labels = ["release/%s" % fix_release] + labels
      data = json.dumps({
          'labels': labels
      })
      post_json(url, data)
      return labels
  
  def update_github_issue(github_issue_id, fix_milestone_number, fix_milestone, fix_areas, fix_types, other_labels):
      url = get_github_issue_url(github_issue_id)
      labels = other_labels + map(lambda x: "area/%s" % x, fix_areas)
      labels = labels + map(lambda x: "type/%s" % x, fix_types)
      labels.append("release/%s" % fix_milestone)
      data = json.dumps({
          'milestone': int(fix_milestone_number),
          'labels': labels,
      })
      post_json(url, data)
      return labels
  
  def update_github_issues(github_issue_ids, fix_milestone_number, fix_milestone, fix_areas, fix_types, other_labels):
      for github_issue_id in github_issue_ids:
          labels = update_github_issue(github_issue_id, fix_milestone_number, fix_milestone, fix_areas, fix_types, other_labels)
      return labels
  
  def add_assignees_to_github_issues(github_issue_ids, assignees):
      for github_issue_id in github_issue_ids:
          add_assignees_to_github_issue(github_issue_id, assignees)
  
  def add_assignees_to_github_issue(github_issue_id, assignees):
      url = get_assignees_url(github_issue_id)
      data = json.dumps({
          "assignees": assignees
      })
      post_json(url, data)
  
  def main():
      global original_head
  
      if not GITHUB_OAUTH_KEY:
          print "OAuth key is needed for merging bookkeeper pull requests."
          print "If environment variable 'GITHUB_OAUTH_KEY' is not defined,"
          print "then requests will be unauthenticated."
          print "You can create an OAuth key at https://github.com/settings/tokens"
          print "and set it to the environment variable 'GITHUB_OAUTH_KEY'."
          print "(This token only needs the 'public_repo' scope permissions)"
          exit(-1)
  
      # 0. get the current state so we can go back
      original_head = get_current_branch()
  
      # 1. retrieve milestones, labels, branches
      milestones = get_milestones()
      labels = get_all_labels()
      branches = get_json("%s/branches" % GITHUB_API_BASE)
      branch_names = filter(lambda x: x.startswith(RELEASE_BRANCH_PREFIX), [x['name'] for x in branches])
      # Assumes branch names can be sorted lexicographically
      latest_branch = sorted(branch_names, reverse=True)[0]
  
      # 2. retrieve the details for a given pull request
      pr_num = raw_input("Which pull request would you like to merge? (e.g. 34): ")
      pr = get_json("%s/pulls/%s" % (GITHUB_API_BASE, pr_num))
      pr_events = get_json("%s/issues/%s/events" % (GITHUB_API_BASE, pr_num))
      pr_reviewers = get_reviewers(pr_num)
      check_ci_status(pr)
  
      url = pr["url"]
  
      # 3. repair the title for commit message
      pr_title = pr["title"]
      commit_title = raw_input("Commit title [%s]: " % pr_title.encode("utf-8")).decode("utf-8")
      if commit_title == "":
          commit_title = pr_title
  
      # Decide whether to use the modified title or not
      modified_title, github_issue_ids = standardize_jira_ref(commit_title)
      if modified_title != commit_title:
          print "I've re-written the title as follows to match the standard format:"
          print "Original: %s" % commit_title
          print "Modified: %s" % modified_title
          result = raw_input("Would you like to use the modified title? (y/n): ")
          if result.lower() == "y":
              commit_title = modified_title
              print "Using modified title:"
          else:
              print "Using original title:"
          print commit_title
  
      body = pr["body"]
      modified_body = ""
      for line in body.split('\n'):
          if line.startswith('>'):
              continue
          modified_body = modified_body + line + "\n"
      if modified_body != body:
          print "I've re-written the body as follows to match the standard formats:"
          print "Original: "
          print body
          print "Modified: "
          print modified_body
          result = raw_input("Would you like to use the modified body? (y/n): ")
          if result.lower() == "y":
              body = modified_body
              print "Using modified body."
          else:
              print "Using original body."
  
      target_ref = pr["base"]["ref"]
      user_login = pr["user"]["login"]
      base_ref = pr["head"]["ref"]
      pr_repo_desc = "%s/%s" % (user_login, base_ref)
  
      # append pr num to the github issues - we need to attach label and milestone to them
      github_issue_ids.append(pr_num)
  
      #
      # 4. attach milestone, area, type and release to github issues
      #
  
      # get issue labels
      issue_labels = get_github_issue_labels(pr_num)
      # ask for fix milestone, area and type
      fix_milestone, fix_milestone_number, fix_areas, fix_types = \
          ask_updates_for_github_issues(milestones, labels, issue_labels)
      # update issues with fix milestone, are and type
      other_labels = filter(lambda x: not x.startswith("area"), issue_labels)
      all_issue_labels = update_github_issues( \
          github_issue_ids, \
          fix_milestone_number, \
          fix_milestone, \
          fix_areas, \
          fix_types, \
          other_labels)
      # add the pr author to the assignees
      add_assignees_to_github_issues(github_issue_ids, [ user_login ])
  
      #
      # 5. Process the merge
      #
  
      # Merged pull requests don't appear as merged in the GitHub API;
      # Instead, they're closed by asfgit.
      merge_commits = \
          [e for e in pr_events if e["actor"]["login"] == "asfgit" and e["event"] == "closed"]
  
      if merge_commits:
          merge_hash = merge_commits[0]["commit_id"]
          message = get_json("%s/commits/%s" % (GITHUB_API_BASE, merge_hash))["commit"]["message"]
  
          print "Pull request %s has already been merged, assuming you want to backport" % pr_num
          commit_is_downloaded = run_cmd(['git', 'rev-parse', '--quiet', '--verify',
                                      "%s^{commit}" % merge_hash]).strip() != ""
          if not commit_is_downloaded:
              fail("Couldn't find any merge commit for #%s, you may need to update HEAD." % pr_num)
  
          print "Found commit %s:\n%s" % (merge_hash, message)
          
          cherry_pick(pr_num, merge_hash, ask_for_branch(latest_branch))
          sys.exit(0)
  
      if not bool(pr["mergeable"]):
          msg = "Pull request %s is not mergeable in its current form.\n" % pr_num + \
              "Continue? (experts only!)"
          continue_maybe(msg)
  
      print ("\n=== Pull Request #%s ===" % pr_num)
      print ("PR title\t%s\nCommit title\t%s\nSource\t\t%s\nTarget\t\t%s\nURL\t\t%s" % (
          pr_title, commit_title, pr_repo_desc, target_ref, url))
      continue_maybe("Proceed with merging pull request #%s?" % pr_num)
  
      merged_refs = [target_ref]
      # proceed with the merge
      merge_hash, merge_commit_log = merge_pr(pr_num, target_ref, commit_title, body, pr_reviewers, pr_repo_desc)
  
      pick_prompt = "Would you like to pick %s into another branch?" % merge_hash
      while raw_input("\n%s (y/n): " % pick_prompt).lower() == "y":
          pick_ref = ask_for_branch(latest_branch) 
          branch_version = pick_ref.split('-')[1]
          # add releases
          fix_releases = ask_release_for_github_issues(branch_version, labels)
          if len(fix_releases) > 0:
              all_issue_labels = add_release_to_github_issues(github_issue_ids, all_issue_labels, fix_releases[0])
          merged_refs = merged_refs + [cherry_pick(pr_num, merge_hash, pick_ref)]
  
      if JIRA_IMPORTED:
          if JIRA_USERNAME and JIRA_PASSWORD:
              jira_comment = '''Issue resolved by merging pull request %s
              [%s/%s]
  
              {noformat}
              %s
              {noformat}
              ''' % (pr_num, GITHUB_BASE, pr_num, merge_commit_log)
              resolve_jira_issues(commit_title, merged_refs, jira_comment)
          else:
              print "JIRA_USERNAME and JIRA_PASSWORD not set"
              print "Exiting without trying to close the associated JIRA."
      else:
          print "Could not find jira-python library. Run 'sudo pip install jira' to install."
          print "Exiting without trying to close the associated JIRA."
  
  if __name__ == "__main__":
      import doctest
      (failure_count, test_count) = doctest.testmod()
      if (failure_count):
          exit(-1)
  
      main()
  