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
  # Spark.
  #   usage: ./merge_spark_pr.py    (see config env vars below)
  #
  # This utility assumes you already have a local Spark git folder and that you
  # have added remotes corresponding to both (i) the github apache Spark
  # mirror and (ii) the apache 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
  
  # Location of your Spark git development area
  SPARK_HOME = os.environ.get("SPARK_HOME", os.getcwd())
  # Remote name which points to the Gihub 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")
  # ASF JIRA username
  JIRA_USERNAME = os.environ.get("JIRA_USERNAME", "")
  # ASF JIRA password
  JIRA_PASSWORD = os.environ.get("JIRA_PASSWORD", "")
  # 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_BASE = "https://github.com/apache/spark/pull"
  GITHUB_API_BASE = "https://api.github.com/repos/apache/spark"
  JIRA_BASE = "https://issues.apache.org/jira/browse"
  JIRA_API_BASE = "https://issues.apache.org/jira"
  # Prefix added to temporary branches
  BRANCH_PREFIX = "PR_TOOL"
  
  
  def get_json(url):
      try:
          request = urllib2.Request(url)
          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 " +
                    "dev/merge_spark_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 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():
      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(BRANCH_PREFIX), branches):
          print("Deleting local branch %s" % branch)
          run_cmd("git branch -D %s" % branch)
  
  
  # merge the requested PR and return the merge hash
  def merge_pr(pr_num, target_ref, title, body, pr_repo_desc):
      pr_branch_name = "%s_MERGE_PR_%s" % (BRANCH_PREFIX, pr_num)
      target_branch_name = "%s_MERGE_PR_%s_%s" % (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
  
      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]
  
      commits = run_cmd(['git', 'log', 'HEAD..%s' % pr_branch_name,
                        '--pretty=format:%h [%an] %s']).split("\n\n")
  
      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 Spark.
          merge_message_flags += ["-m", body.replace("@", "")]
  
      authors = "\n".join(["Author: %s" % a for a in distinct_authors])
  
      merge_message_flags += ["-m", authors]
  
      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
      merge_message_flags += ["-m", "Closes #%s from %s." % (pr_num, pr_repo_desc)]
  
      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]
      clean_up()
      print("Pull request #%s merged!" % pr_num)
      print("Merge hash: %s" % merge_hash)
      return merge_hash
  
  
  def cherry_pick(pr_num, merge_hash, default_branch):
      pick_ref = raw_input("Enter a branch name [%s]: " % default_branch)
      if pick_ref == "":
          pick_ref = default_branch
  
      pick_branch_name = "%s_PICK_PR_%s_%s" % (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 == "master":
          return versions[0]
      else:
          branch_ver = branch.replace("branch-", "")
          return filter(lambda x: x.name.startswith(branch_ver), versions)[-1]
  
  
  def resolve_jira_issue(merge_branches, comment, default_jira_id=""):
      asf_jira = jira.client.JIRA({'server': JIRA_API_BASE},
                                  basic_auth=(JIRA_USERNAME, JIRA_PASSWORD))
  
      jira_id = raw_input("Enter a JIRA id [%s]: " % default_jira_id)
      if jira_id == "":
          jira_id = default_jira_id
  
      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 = choose_jira_assignee(issue, asf_jira)
      # Check again, we might not have chosen an 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("SPARK")
      versions = sorted(versions, key=lambda x: x.name, reverse=True)
      versions = filter(lambda x: x.raw['released'] is False, versions)
      # Consider only x.y.z versions
      versions = filter(lambda x: re.match('\d+\.\d+\.\d+', x.name), versions)
  
      default_fix_versions = map(lambda x: fix_version_from_branch(x, versions).name, merge_branches)
      for v in default_fix_versions:
          # Handles the case where we have forked a release branch but not yet made the release.
          # In this case, if the PR is committed to the master branch and the release branch, we
          # only consider the release branch to be the fix version. E.g. it is not valid to have
          # both 1.1.0 and 1.0.0 as fix versions.
          (major, minor, patch) = v.split(".")
          if patch == "0":
              previous = "%s.%s.%s" % (major, int(minor) - 1, 0)
              if previous in default_fix_versions:
                  default_fix_versions = filter(lambda x: x != v, 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 choose_jira_assignee(issue, asf_jira):
      """
      Prompt the user to choose who to assign the issue to in jira, given a list of candidates,
      including the original reporter and all commentors
      """
      reporter = issue.fields.reporter
      commentors = map(lambda x: x.author, issue.fields.comment.comments)
      candidates = set(commentors)
      candidates.add(reporter)
      candidates = list(candidates)
      print("JIRA is unassigned, choose assignee")
      for idx, author in enumerate(candidates):
          annotations = ["Reporter"] if author == reporter else []
          if author in commentors:
              annotations.append("Commentor")
          print("[%d] %s (%s)" % (idx, author.displayName, ",".join(annotations)))
      assignee = raw_input("Enter number of user to assign to (blank to leave unassigned):")
      if assignee == "":
          return None
      else:
          assignee = candidates[int(assignee)]
          asf_jira.assign_issue(issue.key, assignee.key)
          return assignee
  
  
  def resolve_jira_issues(title, merge_branches, comment):
      jira_ids = re.findall("SPARK-[0-9]{4,5}", title)
  
      if len(jira_ids) == 0:
          resolve_jira_issue(merge_branches, comment)
      for jira_id in jira_ids:
          resolve_jira_issue(merge_branches, comment, jira_id)
  
  
  def standardize_jira_ref(text):
      """
      Standardize the [SPARK-XXXXX] [MODULE] prefix
      Converts "[SPARK-XXX][mllib] Issue", "[MLLib] SPARK-XXX. Issue" or "SPARK XXX [MLLIB]: Issue" to
      "[SPARK-XXX][MLLIB] Issue"
  
      >>> standardize_jira_ref(
      ...     "[SPARK-5821] [SQL] ParquetRelation2 CTAS should check if delete is successful")
      '[SPARK-5821][SQL] ParquetRelation2 CTAS should check if delete is successful'
      >>> standardize_jira_ref(
      ...     "[SPARK-4123][Project Infra][WIP]: Show new dependencies added in pull requests")
      '[SPARK-4123][PROJECT INFRA][WIP] Show new dependencies added in pull requests'
      >>> standardize_jira_ref("[MLlib] Spark  5954: Top by key")
      '[SPARK-5954][MLLIB] Top by key'
      >>> standardize_jira_ref("[SPARK-979] a LRU scheduler for load balancing in TaskSchedulerImpl")
      '[SPARK-979] a LRU scheduler for load balancing in TaskSchedulerImpl'
      >>> standardize_jira_ref(
      ...     "SPARK-1094 Support MiMa for reporting binary compatibility accross versions.")
      '[SPARK-1094] Support MiMa for reporting binary compatibility accross versions.'
      >>> standardize_jira_ref("[WIP]  [SPARK-1146] Vagrant support for Spark")
      '[SPARK-1146][WIP] Vagrant support for Spark'
      >>> standardize_jira_ref(
      ...     "SPARK-1032. If Yarn app fails before registering, app master stays aroun...")
      '[SPARK-1032] If Yarn app fails before registering, app master stays aroun...'
      >>> standardize_jira_ref(
      ...     "[SPARK-6250][SPARK-6146][SPARK-5911][SQL] Types are now reserved words in DDL parser.")
      '[SPARK-6250][SPARK-6146][SPARK-5911][SQL] Types are now reserved words in DDL parser.'
      >>> standardize_jira_ref("Additional information for users building from source code")
      'Additional information for users building from source code'
      """
      jira_refs = []
      components = []
  
      # If the string is compliant, no need to process any further
      if (re.search(r'^\[SPARK-[0-9]{3,6}\](\[[A-Z0-9_\s,]+\] )+\S+', text)):
          return text
  
      # Extract JIRA ref(s):
      pattern = re.compile(r'(SPARK[-\s]*[0-9]{3,6})+', 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 spark 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)
      clean_text = ''.join(jira_refs).strip() + ''.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
  
  
  def get_current_ref():
      ref = run_cmd("git rev-parse --abbrev-ref HEAD").strip()
      if ref == 'HEAD':
          # The current ref is a detached HEAD, so grab its SHA.
          return run_cmd("git rev-parse HEAD").strip()
      else:
          return ref
  
  
  def main():
      global original_head
  
      os.chdir(SPARK_HOME)
      original_head = get_current_ref()
  
      branches = get_json("%s/branches" % GITHUB_API_BASE)
      branch_names = filter(lambda x: x.startswith("branch-"), [x['name'] for x in branches])
      # Assumes branch names can be sorted lexicographically
      latest_branch = sorted(branch_names, reverse=True)[0]
  
      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))
  
      url = pr["url"]
  
      # Decide whether to use the modified title or not
      modified_title = standardize_jira_ref(pr["title"])
      if modified_title != pr["title"]:
          print("I've re-written the title as follows to match the standard format:")
          print("Original: %s" % pr["title"])
          print("Modified: %s" % modified_title)
          result = raw_input("Would you like to use the modified title? (y/n): ")
          if result.lower() == "y":
              title = modified_title
              print("Using modified title:")
          else:
              title = pr["title"]
              print("Using original title:")
          print(title)
      else:
          title = pr["title"]
  
      body = pr["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)
  
      # 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, 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("title\t%s\nsource\t%s\ntarget\t%s\nurl\t%s" %
            (title, pr_repo_desc, target_ref, url))
      continue_maybe("Proceed with merging pull request #%s?" % pr_num)
  
      merged_refs = [target_ref]
  
      merge_hash = merge_pr(pr_num, target_ref, title, body, 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":
          merged_refs = merged_refs + [cherry_pick(pr_num, merge_hash, latest_branch)]
  
      if JIRA_IMPORTED:
          if JIRA_USERNAME and JIRA_PASSWORD:
              continue_maybe("Would you like to update an associated JIRA?")
              jira_comment = "Issue resolved by pull request %s\n[%s/%s]" % \
                             (pr_num, GITHUB_BASE, pr_num)
              resolve_jira_issues(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)
      try:
          main()
      except:
          clean_up()
          raise
  