#
# Copyright (C) 2008 The Android Open Source Project
#
# Licensed 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.

from optparse import SUPPRESS_HELP
import os
import re
import subprocess
import sys

from git_command import GIT
from command import Command, MirrorSafeCommand
from error import RepoChangedException, GitError
from project import R_HEADS

class Sync(Command, MirrorSafeCommand):
  common = True
  helpSummary = "Update working tree to the latest revision"
  helpUsage = """
%prog [<project>...]
"""
  helpDescription = """
The '%prog' command synchronizes local project directories
with the remote repositories specified in the manifest.  If a local
project does not yet exist, it will clone a new local directory from
the remote repository and set up tracking branches as specified in
the manifest.  If the local project already exists, '%prog'
will update the remote branches and rebase any new local changes
on top of the new remote changes.

'%prog' will synchronize all projects listed at the command
line.  Projects can be specified either by name, or by a relative
or absolute path to the project's local directory. If no projects
are specified, '%prog' will synchronize all projects listed in
the manifest.

The -d/--detach option can be used to switch specified projects
back to the manifest revision.  This option is especially helpful
if the project is currently on a topic branch, but the manifest
revision is temporarily needed.
"""

  def _Options(self, p):
    p.add_option('-n','--network-only',
                 dest='network_only', action='store_true',
                 help="fetch only, don't update working tree")
    p.add_option('-d','--detach',
                 dest='detach_head', action='store_true',
                 help='detach projects back to manifest revision')

    p.add_option('--no-repo-verify',
                 dest='no_repo_verify', action='store_true',
                 help='do not verify repo source code')
    p.add_option('--repo-upgraded',
                 dest='repo_upgraded', action='store_true',
                 help=SUPPRESS_HELP)

  def _Fetch(self, *projects):
    fetched = set()
    for project in projects:
      if project.Sync_NetworkHalf():
        fetched.add(project.gitdir)
      else:
        print >>sys.stderr, 'error: Cannot fetch %s' % project.name
        sys.exit(1)
    return fetched

  def Execute(self, opt, args):
    if opt.network_only and opt.detach_head:
      print >>sys.stderr, 'error: cannot combine -n and -d'
      sys.exit(1)

    rp = self.manifest.repoProject
    rp.PreSync()

    mp = self.manifest.manifestProject
    mp.PreSync()

    if opt.repo_upgraded:
      for project in self.manifest.projects.values():
        if project.Exists:
          project.PostRepoUpgrade()

    all = self.GetProjects(args, missing_ok=True)
    fetched = self._Fetch(rp, mp, *all)

    if rp.HasChanges:
      print >>sys.stderr, 'info: A new version of repo is available'
      print >>sys.stderr, ''
      if opt.no_repo_verify or _VerifyTag(rp):
        if not rp.Sync_LocalHalf():
          sys.exit(1)
        print >>sys.stderr, 'info: Restarting repo with latest version'
        raise RepoChangedException(['--repo-upgraded'])
      else:
        print >>sys.stderr, 'warning: Skipped upgrade to unverified version'

    if opt.network_only:
      # bail out now; the rest touches the working tree
      return

    if mp.HasChanges:
      if not mp.Sync_LocalHalf():
        sys.exit(1)

      self.manifest._Unload()
      all = self.GetProjects(args, missing_ok=True)
      missing = []
      for project in all:
        if project.gitdir not in fetched:
          missing.append(project)
      self._Fetch(*missing)

    for project in all:
      if project.worktree:
        if not project.Sync_LocalHalf(
            detach_head=opt.detach_head):
          sys.exit(1)


def _VerifyTag(project):
  gpg_dir = os.path.expanduser('~/.repoconfig/gnupg')
  if not os.path.exists(gpg_dir):
    print >>sys.stderr,\
"""warning: GnuPG was not available during last "repo init"
warning: Cannot automatically authenticate repo."""
    return True

  remote = project.GetRemote(project.remote.name)
  ref = remote.ToLocal(project.revision)

  try:
    cur = project.bare_git.describe(ref)
  except GitError:
    cur = None

  if not cur \
     or re.compile(r'^.*-[0-9]{1,}-g[0-9a-f]{1,}$').match(cur):
    rev = project.revision
    if rev.startswith(R_HEADS):
      rev = rev[len(R_HEADS):]

    print >>sys.stderr
    print >>sys.stderr,\
      "warning: project '%s' branch '%s' is not signed" \
      % (project.name, rev)
    return False

  env = dict(os.environ)
  env['GIT_DIR'] = project.gitdir
  env['GNUPGHOME'] = gpg_dir

  cmd = [GIT, 'tag', '-v', cur]
  proc = subprocess.Popen(cmd,
                          stdout = subprocess.PIPE,
                          stderr = subprocess.PIPE,
                          env = env)
  out = proc.stdout.read()
  proc.stdout.close()

  err = proc.stderr.read()
  proc.stderr.close()

  if proc.wait() != 0:
    print >>sys.stderr
    print >>sys.stderr, out
    print >>sys.stderr, err
    print >>sys.stderr
    return False
  return True