#!/usr/bin/env python
# Copyright 2013 the V8 project authors. All rights reserved.
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
#     * Redistributions of source code must retain the above copyright
#       notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above
#       copyright notice, this list of conditions and the following
#       disclaimer in the documentation and/or other materials provided
#       with the distribution.
#     * Neither the name of Google Inc. nor the names of its
#       contributors may be used to endorse or promote products derived
#       from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

import argparse
import sys
import tempfile
import urllib2

from common_includes import *

TRUNKBRANCH = "TRUNKBRANCH"

CONFIG = {
  BRANCHNAME: "prepare-push",
  TRUNKBRANCH: "trunk-push",
  PERSISTFILE_BASENAME: "/tmp/v8-push-to-trunk-tempfile",
  TEMP_BRANCH: "prepare-push-temporary-branch-created-by-script",
  DOT_GIT_LOCATION: ".git",
  VERSION_FILE: "src/version.cc",
  CHANGELOG_FILE: "ChangeLog",
  CHANGELOG_ENTRY_FILE: "/tmp/v8-push-to-trunk-tempfile-changelog-entry",
  PATCH_FILE: "/tmp/v8-push-to-trunk-tempfile-patch-file",
  COMMITMSG_FILE: "/tmp/v8-push-to-trunk-tempfile-commitmsg",
}

PUSH_MESSAGE_SUFFIX = " (based on bleeding_edge revision r%d)"
PUSH_MESSAGE_RE = re.compile(r".* \(based on bleeding_edge revision r(\d+)\)$")


class Preparation(Step):
  MESSAGE = "Preparation."

  def RunStep(self):
    self.InitialEnvironmentChecks()
    self.CommonPrepare()
    self.PrepareBranch()
    self.DeleteBranch(self.Config(TRUNKBRANCH))


class FreshBranch(Step):
  MESSAGE = "Create a fresh branch."

  def RunStep(self):
    self.GitCreateBranch(self.Config(BRANCHNAME), "svn/bleeding_edge")


class PreparePushRevision(Step):
  MESSAGE = "Check which revision to push."

  def RunStep(self):
    if self._options.revision:
      self["push_hash"] = self.GitSVNFindGitHash(self._options.revision)
    else:
      self["push_hash"] = self.GitLog(n=1, format="%H", git_hash="HEAD")
    if not self["push_hash"]:  # pragma: no cover
      self.Die("Could not determine the git hash for the push.")


class DetectLastPush(Step):
  MESSAGE = "Detect commit ID of last push to trunk."

  def RunStep(self):
    last_push = self._options.last_push or self.FindLastTrunkPush()
    while True:
      # Print assumed commit, circumventing git's pager.
      print self.GitLog(n=1, git_hash=last_push)
      if self.Confirm("Is the commit printed above the last push to trunk?"):
        break
      last_push = self.FindLastTrunkPush(parent_hash=last_push)

    if self._options.last_bleeding_edge:
      # Read the bleeding edge revision of the last push from a command-line
      # option.
      last_push_bleeding_edge = self._options.last_bleeding_edge
    else:
      # Retrieve the bleeding edge revision of the last push from the text in
      # the push commit message.
      last_push_title = self.GitLog(n=1, format="%s", git_hash=last_push)
      last_push_be_svn = PUSH_MESSAGE_RE.match(last_push_title).group(1)
      if not last_push_be_svn:  # pragma: no cover
        self.Die("Could not retrieve bleeding edge revision for trunk push %s"
                 % last_push)
      last_push_bleeding_edge = self.GitSVNFindGitHash(last_push_be_svn)
      if not last_push_bleeding_edge:  # pragma: no cover
        self.Die("Could not retrieve bleeding edge git hash for trunk push %s"
                 % last_push)

    # This points to the svn revision of the last push on trunk.
    self["last_push_trunk"] = last_push
    # This points to the last bleeding_edge revision that went into the last
    # push.
    # TODO(machenbach): Do we need a check to make sure we're not pushing a
    # revision older than the last push? If we do this, the output of the
    # current change log preparation won't make much sense.
    self["last_push_bleeding_edge"] = last_push_bleeding_edge


class IncrementVersion(Step):
  MESSAGE = "Increment version number."

  def RunStep(self):
    # Retrieve current version from last trunk push.
    self.GitCheckoutFile(self.Config(VERSION_FILE), self["last_push_trunk"])
    self.ReadAndPersistVersion()

    if self.Confirm(("Automatically increment BUILD_NUMBER? (Saying 'n' will "
                     "fire up your EDITOR on %s so you can make arbitrary "
                     "changes. When you're done, save the file and exit your "
                     "EDITOR.)" % self.Config(VERSION_FILE))):
      text = FileToText(self.Config(VERSION_FILE))
      text = MSub(r"(?<=#define BUILD_NUMBER)(?P<space>\s+)\d*$",
                  r"\g<space>%s" % str(int(self["build"]) + 1),
                  text)
      TextToFile(text, self.Config(VERSION_FILE))
    else:
      self.Editor(self.Config(VERSION_FILE))

    # Variables prefixed with 'new_' contain the new version numbers for the
    # ongoing trunk push.
    self.ReadAndPersistVersion("new_")
    self["version"] = "%s.%s.%s" % (self["new_major"],
                                    self["new_minor"],
                                    self["new_build"])


class PrepareChangeLog(Step):
  MESSAGE = "Prepare raw ChangeLog entry."

  def Reload(self, body):
    """Attempts to reload the commit message from rietveld in order to allow
    late changes to the LOG flag. Note: This is brittle to future changes of
    the web page name or structure.
    """
    match = re.search(r"^Review URL: https://codereview\.chromium\.org/(\d+)$",
                      body, flags=re.M)
    if match:
      cl_url = ("https://codereview.chromium.org/%s/description"
                % match.group(1))
      try:
        # Fetch from Rietveld but only retry once with one second delay since
        # there might be many revisions.
        body = self.ReadURL(cl_url, wait_plan=[1])
      except urllib2.URLError:  # pragma: no cover
        pass
    return body

  def RunStep(self):
    self["date"] = self.GetDate()
    output = "%s: Version %s\n\n" % (self["date"], self["version"])
    TextToFile(output, self.Config(CHANGELOG_ENTRY_FILE))
    commits = self.GitLog(format="%H",
        git_hash="%s..%s" % (self["last_push_bleeding_edge"],
                             self["push_hash"]))

    # Cache raw commit messages.
    commit_messages = [
      [
        self.GitLog(n=1, format="%s", git_hash=commit),
        self.Reload(self.GitLog(n=1, format="%B", git_hash=commit)),
        self.GitLog(n=1, format="%an", git_hash=commit),
      ] for commit in commits.splitlines()
    ]

    # Auto-format commit messages.
    body = MakeChangeLogBody(commit_messages, auto_format=True)
    AppendToFile(body, self.Config(CHANGELOG_ENTRY_FILE))

    msg = ("        Performance and stability improvements on all platforms."
           "\n#\n# The change log above is auto-generated. Please review if "
           "all relevant\n# commit messages from the list below are included."
           "\n# All lines starting with # will be stripped.\n#\n")
    AppendToFile(msg, self.Config(CHANGELOG_ENTRY_FILE))

    # Include unformatted commit messages as a reference in a comment.
    comment_body = MakeComment(MakeChangeLogBody(commit_messages))
    AppendToFile(comment_body, self.Config(CHANGELOG_ENTRY_FILE))


class EditChangeLog(Step):
  MESSAGE = "Edit ChangeLog entry."

  def RunStep(self):
    print ("Please press <Return> to have your EDITOR open the ChangeLog "
           "entry, then edit its contents to your liking. When you're done, "
           "save the file and exit your EDITOR. ")
    self.ReadLine(default="")
    self.Editor(self.Config(CHANGELOG_ENTRY_FILE))

    # Strip comments and reformat with correct indentation.
    changelog_entry = FileToText(self.Config(CHANGELOG_ENTRY_FILE)).rstrip()
    changelog_entry = StripComments(changelog_entry)
    changelog_entry = "\n".join(map(Fill80, changelog_entry.splitlines()))
    changelog_entry = changelog_entry.lstrip()

    if changelog_entry == "":  # pragma: no cover
      self.Die("Empty ChangeLog entry.")

    # Safe new change log for adding it later to the trunk patch.
    TextToFile(changelog_entry, self.Config(CHANGELOG_ENTRY_FILE))


class StragglerCommits(Step):
  MESSAGE = ("Fetch straggler commits that sneaked in since this script was "
             "started.")

  def RunStep(self):
    self.GitSVNFetch()
    self.GitCheckout("svn/bleeding_edge")


class SquashCommits(Step):
  MESSAGE = "Squash commits into one."

  def RunStep(self):
    # Instead of relying on "git rebase -i", we'll just create a diff, because
    # that's easier to automate.
    TextToFile(self.GitDiff("svn/trunk", self["push_hash"]),
               self.Config(PATCH_FILE))

    # Convert the ChangeLog entry to commit message format.
    text = FileToText(self.Config(CHANGELOG_ENTRY_FILE))

    # Remove date and trailing white space.
    text = re.sub(r"^%s: " % self["date"], "", text.rstrip())

    # Retrieve svn revision for showing the used bleeding edge revision in the
    # commit message.
    self["svn_revision"] = self.GitSVNFindSVNRev(self["push_hash"])
    suffix = PUSH_MESSAGE_SUFFIX % int(self["svn_revision"])
    text = MSub(r"^(Version \d+\.\d+\.\d+)$", "\\1%s" % suffix, text)

    # Remove indentation and merge paragraphs into single long lines, keeping
    # empty lines between them.
    def SplitMapJoin(split_text, fun, join_text):
      return lambda text: join_text.join(map(fun, text.split(split_text)))
    strip = lambda line: line.strip()
    text = SplitMapJoin("\n\n", SplitMapJoin("\n", strip, " "), "\n\n")(text)

    if not text:  # pragma: no cover
      self.Die("Commit message editing failed.")
    TextToFile(text, self.Config(COMMITMSG_FILE))


class NewBranch(Step):
  MESSAGE = "Create a new branch from trunk."

  def RunStep(self):
    self.GitCreateBranch(self.Config(TRUNKBRANCH), "svn/trunk")


class ApplyChanges(Step):
  MESSAGE = "Apply squashed changes."

  def RunStep(self):
    self.ApplyPatch(self.Config(PATCH_FILE))
    Command("rm", "-f %s*" % self.Config(PATCH_FILE))


class AddChangeLog(Step):
  MESSAGE = "Add ChangeLog changes to trunk branch."

  def RunStep(self):
    # The change log has been modified by the patch. Reset it to the version
    # on trunk and apply the exact changes determined by this PrepareChangeLog
    # step above.
    self.GitCheckoutFile(self.Config(CHANGELOG_FILE), "svn/trunk")
    changelog_entry = FileToText(self.Config(CHANGELOG_ENTRY_FILE))
    old_change_log = FileToText(self.Config(CHANGELOG_FILE))
    new_change_log = "%s\n\n\n%s" % (changelog_entry, old_change_log)
    TextToFile(new_change_log, self.Config(CHANGELOG_FILE))
    os.remove(self.Config(CHANGELOG_ENTRY_FILE))


class SetVersion(Step):
  MESSAGE = "Set correct version for trunk."

  def RunStep(self):
    # The version file has been modified by the patch. Reset it to the version
    # on trunk and apply the correct version.
    self.GitCheckoutFile(self.Config(VERSION_FILE), "svn/trunk")
    output = ""
    for line in FileToText(self.Config(VERSION_FILE)).splitlines():
      if line.startswith("#define MAJOR_VERSION"):
        line = re.sub("\d+$", self["new_major"], line)
      elif line.startswith("#define MINOR_VERSION"):
        line = re.sub("\d+$", self["new_minor"], line)
      elif line.startswith("#define BUILD_NUMBER"):
        line = re.sub("\d+$", self["new_build"], line)
      elif line.startswith("#define PATCH_LEVEL"):
        line = re.sub("\d+$", "0", line)
      elif line.startswith("#define IS_CANDIDATE_VERSION"):
        line = re.sub("\d+$", "0", line)
      output += "%s\n" % line
    TextToFile(output, self.Config(VERSION_FILE))


class CommitTrunk(Step):
  MESSAGE = "Commit to local trunk branch."

  def RunStep(self):
    self.GitCommit(file_name = self.Config(COMMITMSG_FILE))
    Command("rm", "-f %s*" % self.Config(COMMITMSG_FILE))


class SanityCheck(Step):
  MESSAGE = "Sanity check."

  def RunStep(self):
    # TODO(machenbach): Run presubmit script here as it is now missing in the
    # prepare push process.
    if not self.Confirm("Please check if your local checkout is sane: Inspect "
        "%s, compile, run tests. Do you want to commit this new trunk "
        "revision to the repository?" % self.Config(VERSION_FILE)):
      self.Die("Execution canceled.")  # pragma: no cover


class CommitSVN(Step):
  MESSAGE = "Commit to SVN."

  def RunStep(self):
    result = self.GitSVNDCommit()
    if not result:  # pragma: no cover
      self.Die("'git svn dcommit' failed.")
    result = filter(lambda x: re.search(r"^Committed r[0-9]+", x),
                    result.splitlines())
    if len(result) > 0:
      self["trunk_revision"] = re.sub(r"^Committed r([0-9]+)", r"\1",result[0])

    # Sometimes grepping for the revision fails. No idea why. If you figure
    # out why it is flaky, please do fix it properly.
    if not self["trunk_revision"]:
      print("Sorry, grepping for the SVN revision failed. Please look for it "
            "in the last command's output above and provide it manually (just "
            "the number, without the leading \"r\").")
      self.DieNoManualMode("Can't prompt in forced mode.")
      while not self["trunk_revision"]:
        print "> ",
        self["trunk_revision"] = self.ReadLine()


class TagRevision(Step):
  MESSAGE = "Tag the new revision."

  def RunStep(self):
    self.GitSVNTag(self["version"])


class CleanUp(Step):
  MESSAGE = "Done!"

  def RunStep(self):
    print("Congratulations, you have successfully created the trunk "
          "revision %s. Please don't forget to roll this new version into "
          "Chromium, and to update the v8rel spreadsheet:"
          % self["version"])
    print "%s\ttrunk\t%s" % (self["version"], self["trunk_revision"])

    self.CommonCleanup()
    if self.Config(TRUNKBRANCH) != self["current_branch"]:
      self.GitDeleteBranch(self.Config(TRUNKBRANCH))


class PushToTrunk(ScriptsBase):
  def _PrepareOptions(self, parser):
    group = parser.add_mutually_exclusive_group()
    group.add_argument("-f", "--force",
                      help="Don't prompt the user.",
                      default=False, action="store_true")
    group.add_argument("-m", "--manual",
                      help="Prompt the user at every important step.",
                      default=False, action="store_true")
    parser.add_argument("-b", "--last-bleeding-edge",
                        help=("The git commit ID of the last bleeding edge "
                              "revision that was pushed to trunk. This is "
                              "used for the auto-generated ChangeLog entry."))
    parser.add_argument("-l", "--last-push",
                        help="The git commit ID of the last push to trunk.")
    parser.add_argument("-R", "--revision",
                        help="The svn revision to push (defaults to HEAD).")

  def _ProcessOptions(self, options):  # pragma: no cover
    if not options.manual and not options.reviewer:
      print "A reviewer (-r) is required in (semi-)automatic mode."
      return False
    if not options.manual and not options.author:
      print "Specify your chromium.org email with -a in (semi-)automatic mode."
      return False
    if options.revision and not int(options.revision) > 0:
      print("The --revision flag must be a positiv integer pointing to a "
            "valid svn revision.")
      return False

    options.tbr_commit = not options.manual
    return True

  def _Steps(self):
    return [
      Preparation,
      FreshBranch,
      PreparePushRevision,
      DetectLastPush,
      IncrementVersion,
      PrepareChangeLog,
      EditChangeLog,
      StragglerCommits,
      SquashCommits,
      NewBranch,
      ApplyChanges,
      AddChangeLog,
      SetVersion,
      CommitTrunk,
      SanityCheck,
      CommitSVN,
      TagRevision,
      CleanUp,
    ]


if __name__ == "__main__":  # pragma: no cover
  sys.exit(PushToTrunk(CONFIG).Run())