YouCompleteMe/python/ycm/client/completion_request.py

# Copyright (C) 2013  Google Inc.
#
# This file is part of YouCompleteMe.
#
# YouCompleteMe is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# YouCompleteMe is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.

from __future__ import unicode_literals
from __future__ import print_function
from __future__ import division
from __future__ import absolute_import
# Not installing aliases from python-future; it's unreliable and slow.
from builtins import *  # noqa

from future.utils import iteritems
from ycmd.utils import ToUnicode
from ycm.client.base_request import ( BaseRequest, JsonFromFuture,
                                      HandleServerException,
                                      MakeServerException )
from ycm import vimsupport


class CompletionRequest( BaseRequest ):
  def __init__( self, request_data ):
    super( CompletionRequest, self ).__init__()
    self.request_data = request_data
    self._response_future = None
    self._response = { 'completions': [], 'completion_start_column': -1 }
    self._complete_done_hooks = {
      'cs': self._OnCompleteDone_Csharp,
      'java': self._OnCompleteDone_Java,
    }


  def Start( self ):
    self._response_future = self.PostDataToHandlerAsync( self.request_data,
                                                         'completions' )


  def Done( self ):
    return bool( self._response_future ) and self._response_future.done()


  def RawResponse( self ):
    if not self._response_future:
      return self._response

    with HandleServerException( truncate = True ):
      self._response = JsonFromFuture( self._response_future )

      # Vim may not be able to convert the 'errors' entry to its internal format
      # so we remove it from the response.
      errors = self._response.pop( 'errors', [] )
      for e in errors:
        with HandleServerException( truncate = True ):
          raise MakeServerException( e )

    return self._response


  def Response( self ):
    response = self.RawResponse()
    response[ 'completions' ] = _ConvertCompletionDatasToVimDatas(
        response[ 'completions' ] )
    return response


  def OnCompleteDone( self ):
    if not self.Done():
      return

    complete_done_actions = self._GetCompleteDoneHooks()
    for action in complete_done_actions:
      action()


  def _GetCompleteDoneHooks( self ):
    filetypes = vimsupport.CurrentFiletypes()
    for key, value in iteritems( self._complete_done_hooks ):
      if key in filetypes:
        yield value


  def _GetCompletionsUserMayHaveCompleted( self ):
    completed_item = vimsupport.GetVariableValue( 'v:completed_item' )
    completions = self.RawResponse()[ 'completions' ]

    if 'user_data' in completed_item and completed_item[ 'user_data' ]:
      # Vim supports user_data (8.0.1493) or later, so we actually know the
      # _exact_ element that was selected, having put its index in the
      # user_data field.
      return [ completions[ int( completed_item[ 'user_data' ] ) ] ]

    # Otherwise, we have to guess by matching the values in the completed item
    # and the list of completions. Sometimes this returns multiple
    # possibilities, which is essentially unresolvable.

    result = _FilterToMatchingCompletions( completed_item, completions, True )
    result = list( result )

    if result:
      return result

    if _HasCompletionsThatCouldBeCompletedWithMoreText( completed_item,
                                                        completions ):
      # Since the way that YCM works leads to CompleteDone called on every
      # character, return blank if the completion might not be done. This won't
      # match if the completion is ended with typing a non-keyword character.
      return []

    result = _FilterToMatchingCompletions( completed_item, completions, False )

    return list( result )


  def _OnCompleteDone_Csharp( self ):
    completions = self._GetCompletionsUserMayHaveCompleted()
    namespaces = [ _GetRequiredNamespaceImport( c ) for c in completions ]
    namespaces = [ n for n in namespaces if n ]
    if not namespaces:
      return

    if len( namespaces ) > 1:
      choices = [ "{0} {1}".format( i + 1, n )
                  for i, n in enumerate( namespaces ) ]
      choice = vimsupport.PresentDialog( "Insert which namespace:", choices )
      if choice < 0:
        return
      namespace = namespaces[ choice ]
    else:
      namespace = namespaces[ 0 ]

    vimsupport.InsertNamespace( namespace )


  def _OnCompleteDone_Java( self ):
    completions = self._GetCompletionsUserMayHaveCompleted()
    fixit_completions = [ _GetFixItCompletion( c ) for c in completions ]
    fixit_completions = [ f for f in fixit_completions if f ]
    if not fixit_completions:
      return

    # If we have user_data in completions (8.0.1493 or later), then we would
    # only ever return max. 1 completion here. However, if we had to guess, it
    # is possible that we matched multiple completion items (e.g. for overloads,
    # or similar classes in multiple packages). In any case, rather than
    # prompting the user and disturbing her workflow, we just apply the first
    # one. This might be wrong, but the solution is to use a (very) new version
    # of Vim which supports user_data on completion items
    fixit_completion = fixit_completions[ 0 ]

    for fixit in fixit_completion:
      vimsupport.ReplaceChunks( fixit[ 'chunks' ], silent=True )


def _GetRequiredNamespaceImport( completion ):
  if ( 'extra_data' not in completion
       or 'required_namespace_import' not in completion[ 'extra_data' ] ):
    return None
  return completion[ 'extra_data' ][ 'required_namespace_import' ]


def _GetFixItCompletion( completion ):
  if ( 'extra_data' not in completion
       or 'fixits' not in completion[ 'extra_data' ] ):
    return None

  return completion[ 'extra_data' ][ 'fixits' ]


def _FilterToMatchingCompletions( completed_item,
                                  completions,
                                  full_match_only ):
  """Filter to completions matching the item Vim said was completed"""
  match_keys = ( [ 'word', 'abbr', 'menu', 'info' ] if full_match_only
                  else [ 'word' ] )

  for index, completion in enumerate( completions ):
    item = _ConvertCompletionDataToVimData( index, completion )

    def matcher( key ):
      return ( ToUnicode( completed_item.get( key, "" ) ) ==
               ToUnicode( item.get( key, "" ) ) )

    if all( [ matcher( i ) for i in match_keys ] ):
      yield completion


def _HasCompletionsThatCouldBeCompletedWithMoreText( completed_item,
                                                     completions ):
  if not completed_item:
    return False

  completed_word = ToUnicode( completed_item[ 'word' ] )
  if not completed_word:
    return False

  # Sometimes CompleteDone is called after the next character is inserted.
  # If so, use inserted character to filter possible completions further.
  text = vimsupport.TextBeforeCursor()
  reject_exact_match = True
  if text and text[ -1 ] != completed_word[ -1 ]:
    reject_exact_match = False
    completed_word += text[ -1 ]

  for index, completion in enumerate( completions ):
    word = ToUnicode(
        _ConvertCompletionDataToVimData( index, completion )[ 'word' ] )
    if reject_exact_match and word == completed_word:
      continue
    if word.startswith( completed_word ):
      return True
  return False


def _ConvertCompletionDataToVimData( completion_identifier, completion_data ):
  # see :h complete-items for a description of the dictionary fields
  vim_data = {
    'word'  : '',
    'dup'   : 1,
    'empty' : 1,
  }

  if ( 'extra_data' in completion_data and
       'doc_string' in completion_data[ 'extra_data' ] ):
    doc_string = completion_data[ 'extra_data' ][ 'doc_string' ]
  else:
    doc_string = ""

  if 'insertion_text' in completion_data:
    vim_data[ 'word' ] = completion_data[ 'insertion_text' ]
  if 'menu_text' in completion_data:
    vim_data[ 'abbr' ] = completion_data[ 'menu_text' ]
  if 'extra_menu_info' in completion_data:
    vim_data[ 'menu' ] = completion_data[ 'extra_menu_info' ]
  if 'kind' in completion_data:
    kind = ToUnicode( completion_data[ 'kind' ] )
    if kind:
      vim_data[ 'kind' ] = kind[ 0 ].lower()
  if 'detailed_info' in completion_data:
    vim_data[ 'info' ] = completion_data[ 'detailed_info' ]
    if doc_string:
      vim_data[ 'info' ] += '\n' + doc_string
  elif doc_string:
    vim_data[ 'info' ] = doc_string

  # We store the completion item index as a string in the completion user_data.
  # This allows us to identify the _exact_ item that was completed in the
  # CompleteDone handler, by inspecting this item from v:completed_item
  #
  # We convert to string because completion user data items must be strings.
  #
  # Note: Not all versions of Vim support this (added in 8.0.1483), but adding
  # the item to the dictionary is harmless in earlier Vims.
  vim_data[ 'user_data' ] = str( completion_identifier )

  return vim_data


def _ConvertCompletionDatasToVimDatas( response_data ):
  return [ _ConvertCompletionDataToVimData( i, x )
           for i, x in enumerate( response_data ) ]