#!/usr/bin/python

# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""A command line interface to the ChromeOS gerrit instances

Internal Note:
To expose a function directly to the command line interface, name your function
with the prefix "UserAct".
"""

import inspect
import os
import re

from chromite.buildbot import constants
from chromite.lib import commandline
from chromite.lib import cros_build_lib
from chromite.lib import gerrit
from chromite.lib import terminal


COLOR = None

# Map the internal names to the ones we normally show on the web ui.
GERRIT_APPROVAL_MAP = {
    'COMR': ['CQ', 'Commit Queue',],
    'CRVW': ['CR', 'Code Review ',],
    'SUBM': ['S ', 'Submitted   ',],
    'VRIF': ['V ', 'Verified    ',],
}

# Order is important -- matches the web ui.  This also controls the short
# entries that we summarize in non-verbose mode.
GERRIT_SUMMARY_CATS = ('CR', 'CQ', 'V',)


def red(s):
  return COLOR.Color(terminal.Color.RED, s)


def green(s):
  return COLOR.Color(terminal.Color.GREEN, s)


def blue(s):
  return COLOR.Color(terminal.Color.BLUE, s)


def limits(cls):
  """Given a dict of fields, calculate the longest string lengths

  This allows you to easily format the output of many results so that the
  various cols all line up correctly.
  """
  lims = {}
  for cl in cls:
    for k in cl.keys():
      lims[k] = max(lims.get(k, 0), len(str(cl[k])))
  return lims


def GetApprovalSummary(_opts, cls):
  """Return a dict of the most important approvals"""
  approvs = dict([(x, '') for x in GERRIT_SUMMARY_CATS])
  if 'approvals' in cls['currentPatchSet']:
    for approver in cls['currentPatchSet']['approvals']:
      cats = GERRIT_APPROVAL_MAP.get(approver['type'])
      if not cats:
        cros_build_lib.Warning('unknown gerrit approval type: %s',
                               approver['type'])
        continue
      cat = cats[0].strip()
      val = int(approver['value'])
      if not cat in approvs:
        # Ignore the extended categories in the summary view.
        continue
      elif approvs[cat] is '':
        approvs[cat] = val
      elif val < 0:
        approvs[cat] = min(approvs[cat], val)
      else:
        approvs[cat] = max(approvs[cat], val)
  return approvs


def PrintCl(opts, cls, lims, show_approvals=True):
  """Pretty print a single result"""
  if not lims:
    lims = {'url': 0, 'project': 0}

  status = ''
  if show_approvals and not opts.verbose:
    approvs = GetApprovalSummary(opts, cls)
    for cat in GERRIT_SUMMARY_CATS:
      if approvs[cat] is '':
        functor = lambda x: x
      elif approvs[cat] < 0:
        functor = red
      else:
        functor = green
      status += functor('%s:%2s ' % (cat, approvs[cat]))

  print '%s %s%-*s %s' % (blue('%-*s' % (lims['url'], cls['url'])), status,
                          lims['project'], cls['project'], cls['subject'])

  if show_approvals and opts.verbose:
    for approver in cls['currentPatchSet'].get('approvals', []):
      functor = red if int(approver['value']) < 0 else green
      n = functor('%2s' % approver['value'])
      t = GERRIT_APPROVAL_MAP.get(approver['type'], [approver['type'],
                                                     approver['type']])[1]
      print '      %s %s %s' % (n, t, approver['by']['email'])


def _MyUserInfo():
  username = os.environ['USER']
  emails = ['%s@%s' % (username, domain)
            for domain in ('google.com', 'chromium.org')]
  reviewers = ['reviewer:%s' % x for x in emails]
  owners = ['owner:%s' % x for x in emails]
  return emails, reviewers, owners


def FilteredQuery(opts, query):
  """Query gerrit and filter/clean up the results"""
  ret = []

  for cl in opts.gerrit.Query(query, raw=True):
    # Gerrit likes to return a stats record too.
    if not 'project' in cl:
      continue

    # Strip off common leading names since the result is still
    # unique over the whole tree.
    if not opts.verbose:
      for pfx in ('chromeos', 'chromiumos', 'overlays', 'platform'):
        if cl['project'].startswith('%s/' % pfx):
          cl['project'] = cl['project'][len(pfx) + 1:]

    ret.append(cl)

  if opts.sort in ('number',):
    key = lambda x: int(x[opts.sort])
  else:
    key = lambda x: x[opts.sort]
  return sorted(ret, key=key)


def ChangeNumberToCommit(opts, idx):
  """Given a gerrit CL #, return the revision info

  This is the form that the gerrit ssh interface expects.
  """
  cl = opts.gerrit.QuerySingleRecord(idx, raw=True)
  return cl['currentPatchSet']['revision']


def ReviewCommand(opts, idx, command):
  """Shortcut to run `gerrit --review |command|` on a specific CL"""
  rev = ChangeNumberToCommit(opts, idx)
  cmd = opts.gerrit.GetGerritReviewCommand([rev] + command)
  cros_build_lib.RunCommand(cmd, print_cmd=opts.debug)


def IsApprover(cl, users):
  """See if the approvers in |cl| is listed in |users|"""
  # See if we are listed in the approvals list.  We have to parse
  # this by hand as the gerrit query system doesn't support it :(
  # http://code.google.com/p/gerrit/issues/detail?id=1235
  if 'approvals' not in cl['currentPatchSet']:
    return False

  if isinstance(users, basestring):
    users = (users,)

  for approver in cl['currentPatchSet']['approvals']:
    if approver['by']['email'] in users:
      return True

  return False


def UserActTodo(opts):
  """List CLs needing your review"""
  emails, reviewers, owners = _MyUserInfo()
  cls = FilteredQuery(opts, '( %s ) status:open NOT ( %s )' %
                            (' OR '.join(reviewers), ' OR '.join(owners)))
  cls = [x for x in cls if not IsApprover(x, emails)]
  lims = limits(cls)
  for cl in cls:
    PrintCl(opts, cl, lims)


def UserActMine(opts):
  """List your CLs with review statuses"""
  _, _, owners = _MyUserInfo()
  cls = FilteredQuery(opts, '( %s ) status:new' % (' OR '.join(owners),))
  lims = limits(cls)
  for cl in cls:
    PrintCl(opts, cl, lims)


def UserActInspect(opts, idx):
  """Inspect CL number <n>"""
  PrintCl(opts, FilteredQuery(opts, idx)[0], None)


def UserActReview(opts, idx, num):
  """Mark CL <n> with code review status [-2,-1,0,1,2]"""
  ReviewCommand(opts, idx, ['--code-review', str(num)])


def UserActVerify(opts, idx, num):
  """Mark CL <n> with verify status [-1,0,1]"""
  ReviewCommand(opts, idx, ['--verified', str(num)])


def UserActReady(opts, idx, num):
  """Mark CL <n> with ready status [-1,0,1]"""
  ReviewCommand(opts, idx, ['--commit-queue', str(num)])


def UserActSubmit(opts, idx):
  """Submit CL <n>"""
  ReviewCommand(opts, idx, ['--submit'])


def UserActAbandon(opts, idx):
  """Abandon CL <n>"""
  ReviewCommand(opts, idx, ['--abandon'])


def UserActRestore(opts, idx):
  """Restore CL <n> that was abandoned"""
  ReviewCommand(opts, idx, ['--submit'])


def UserActReviewers(opts, idx, *emails):
  """Add/remove reviewers' emails for CL <n> (prepend with '~' to remove)"""

  # Allow for optional leading '~'.
  email_validator = re.compile(r'^[~]?%s$' % constants.EMAIL_REGEX)
  add_list, remove_list, invalid_list = [], [], []

  for x in emails:
    if not email_validator.match(x):
      invalid_list.append(x)
    elif x[0] == '~':
      remove_list.append(x[1:])
    else:
      add_list.append(x)

  if invalid_list:
    cros_build_lib.Die(
        'Invalid email address(es): %s' % ', '.join(invalid_list))

  if add_list or remove_list:
    opts.gerrit.SetReviewers(idx, add=add_list, remove=remove_list)


def main(argv):
  # Locate actions that are exposed to the user.  All functions that start
  # with "UserAct" are fair game.
  act_pfx = 'UserAct'
  actions = [x for x in globals() if x.startswith(act_pfx)]

  usage = """%prog [options] <action> [action args]

There is no support for doing line-by-line code review via the command line.
This helps you manage various bits and CL status.

Example:
  $ gerrit todo             # List all the CLs that await your review.
  $ gerrit mine             # List all of your open CLs.
  $ gerrit inspect 28123    # Inspect CL 28123 on the public gerrit.
  $ gerrit inspect *28123   # Inspect CL 28123 on the internal gerrit.
  $ gerrit verify 28123 1   # Mark CL 28123 as verified (+1).

Actions:"""
  indent = max([len(x) - len(act_pfx) for x in actions])
  for a in sorted(actions):
    usage += '\n  %-*s: %s' % (indent, a[len(act_pfx):].lower(),
                               globals()[a].__doc__)

  parser = commandline.OptionParser(usage=usage)
  parser.add_option('-i', '--internal', default=None, action='store_true',
                    help='Query gerrit-int')
  parser.add_option('-e', '--external', dest='internal', action='store_false',
                    help='Query gerrit (default)')
  parser.add_option('--sort', default='number', help='Key to sort on '
                                                     '(number, project)')
  parser.add_option('-v', '--verbose', default=False, action='store_true',
                    help='Be more verbose in output')
  opts, args = parser.parse_args(argv)
  if not args:
    parser.error('missing action')

  # pylint: disable=W0603
  global COLOR
  COLOR = terminal.Color(enabled=opts.color)

  # TODO: This sucks.  We assume that all actions which take an argument are
  # a CL #.  Or at least, there's no other reason for it to start with a *.
  # We do this to automatically select internal vs external gerrit as this
  # convention is encoded in much of our system.  However, the rest of this
  # script doesn't expect (or want) the leading *.
  if len(args) > 1:
    if args[1][0] == '*':
      if opts.internal is None:
        opts.internal = True
      args[1] = args[1][1:]

  opts.gerrit = gerrit.GetGerritHelper(
      constants.INTERNAL_REMOTE if opts.internal else constants.EXTERNAL_REMOTE,
      print_cmd=opts.debug)

  # Now look up the requested user action and run it.
  cmd = args[0].lower()
  args = args[1:]
  functor = globals().get(act_pfx + cmd.capitalize())
  if functor:
    argspec = inspect.getargspec(functor)
    if argspec.varargs:
      if len(args) < len(argspec.args):
        parser.error('incorrect number of args: %s expects at least %s' %
                     (cmd, len(argspec.args)))
    elif len(argspec.args) - 1 != len(args):
      parser.error('incorrect number of args: %s expects %s' %
                   (cmd, len(argspec.args) - 1))
    try:
      functor(opts, *args)
    except (cros_build_lib.RunCommandError, gerrit.GerritException) as e:
      cros_build_lib.Die(e.message)
  else:
    parser.error('unknown action: %s' % (cmd,))