#!/usr/bin/env python
#
# Copyright (C) 2011, 2012  Chiel ten Brinke <ctenbrinke@gmail.com>
#                           Strahinja Val Markovic <val@markovic.io>
#
# 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/>.

import os
from sys import platform
import glob
from ycm.completers.threaded_completer import ThreadedCompleter
from ycm.server import responses
from ycm import utils
import urllib2
import urllib
import urlparse
import json
import subprocess
import logging


SERVER_NOT_FOUND_MSG = ( 'OmniSharp server binary not found at {0}. ' +
'Did you compile it? You can do so by running ' +
'"./install.sh --omnisharp-completer".' )

class CsharpCompleter( ThreadedCompleter ):
  """
  A Completer that uses the Omnisharp server as completion engine.
  """

  def __init__( self, user_options ):
    super( CsharpCompleter, self ).__init__( user_options )
    self._omnisharp_port = None
    self._logger = logging.getLogger( __name__ )

    if self.user_options[ 'auto_start_csharp_server' ]:
      self._StartServer()


  def Shutdown( self ):
    if ( self.user_options[ 'auto_start_csharp_server' ] and
         self._ServerIsRunning() ):
      self._StopServer()


  def SupportedFiletypes( self ):
    """ Just csharp """
    return [ 'cs' ]


  def ComputeCandidates( self, request_data ):
    return [ responses.BuildCompletionData(
                completion[ 'CompletionText' ],
                completion[ 'DisplayText' ],
                completion[ 'Description' ] )
             for completion in self._GetCompletions( request_data ) ]


  def DefinedSubcommands( self ):
    return [ 'StartServer',
             'StopServer',
             'RestartServer',
             'GoToDefinition',
             'GoToDeclaration',
             'GoToDefinitionElseDeclaration' ]


  def OnUserCommand( self, arguments, request_data ):
    if not arguments:
      raise ValueError( self.UserCommandsHelpMessage() )

    command = arguments[ 0 ]
    if command == 'StartServer':
      self._StartServer( request_data )
    elif command == 'StopServer':
      self._StopServer()
    elif command == 'RestartServer':
      if self._ServerIsRunning():
        self._StopServer()
      self._StartServer( request_data )
    elif command in [ 'GoToDefinition',
                      'GoToDeclaration',
                      'GoToDefinitionElseDeclaration' ]:
      return self._GoToDefinition( request_data )
    raise ValueError( self.UserCommandsHelpMessage() )


  def DebugInfo( self ):
    if self._ServerIsRunning():
      return 'Server running at: {}\nLogfiles:\n{}\n{}'.format(
        self._PortToHost(), self._filename_stdout, self._filename_stderr )
    else:
      return 'Server is not running'


  def _StartServer( self, request_data ):
    """ Start the OmniSharp server """
    self._omnisharp_port = self._FindFreePort()
    solutionfiles, folder = _FindSolutionFiles( request_data[ 'filepath' ] )

    if len( solutionfiles ) == 0:
      raise RuntimeError(
        'Error starting OmniSharp server: no solutionfile found' )
    elif len( solutionfiles ) == 1:
      solutionfile = solutionfiles[ 0 ]
    else:
      raise RuntimeError(
        'Found multiple solution files instead of one!\n{}'.format(
          solutionfiles ) )

    omnisharp = os.path.join(
      os.path.abspath( os.path.dirname( __file__ ) ),
      'OmniSharpServer/OmniSharp/bin/Debug/OmniSharp.exe' )

    if not os.path.isfile( omnisharp ):
      raise RuntimeError( SERVER_NOT_FOUND_MSG.format( omnisharp ) )

    if not platform.startswith( 'win' ):
      omnisharp = 'mono ' + omnisharp

    path_to_solutionfile = os.path.join( folder, solutionfile )
    # command has to be provided as one string for some reason
    command = [ omnisharp + ' -p ' + str( self._omnisharp_port ) + ' -s ' +
                path_to_solutionfile ]

    filename_format = os.path.join( utils.PathToTempDir(),
                                   'omnisharp_{port}_{sln}_{std}.log' )

    self._filename_stdout = filename_format.format(
        port=self._omnisharp_port, sln=solutionfile, std='stdout' )
    self._filename_stderr = filename_format.format(
        port=self._omnisharp_port, sln=solutionfile, std='stderr' )

    with open( self._filename_stderr, 'w' ) as fstderr:
      with open( self._filename_stdout, 'w' ) as fstdout:
        subprocess.Popen( command, stdout=fstdout, stderr=fstderr, shell=True )

    self._logger.info( 'Starting OmniSharp server' )


  def _StopServer( self ):
    """ Stop the OmniSharp server """
    self._GetResponse( '/stopserver' )
    self._omnisharp_port = None
    self._logger.info( 'Stopping OmniSharp server' )


  def _GetCompletions( self, request_data ):
    """ Ask server for completions """
    completions = self._GetResponse( '/autocomplete',
                                     self._DefaultParameters( request_data ) )
    return completions if completions != None else []


  def _GoToDefinition( self, request_data ):
    """ Jump to definition of identifier under cursor """
    definition = self._GetResponse( '/gotodefinition',
                                    self._DefaultParameters( request_data ) )
    if definition[ 'FileName' ] != None:
      return responses.BuildGoToResponse( definition[ 'FileName' ],
                                          definition[ 'Line' ],
                                          definition[ 'Column' ] )
    else:
      raise RuntimeError( 'Can\'t jump to definition' )


  def _DefaultParameters( self, request_data ):
    """ Some very common request parameters """
    parameters = {}
    parameters[ 'line' ] = request_data[ 'line_num' ] + 1
    parameters[ 'column' ] = request_data[ 'column_num' ] + 1
    filepath = request_data[ 'filepath' ]
    parameters[ 'buffer' ] = request_data[ 'file_data' ][ filepath ][
      'contents' ]
    parameters[ 'filename' ] = filepath
    return parameters


  def _ServerIsRunning( self ):
    """ Check if our OmniSharp server is running """
    return  ( self._omnisharp_port != None and
        self._GetResponse( '/checkalivestatus', silent=True ) != None )


  def _FindFreePort( self ):
    """ Find port without an OmniSharp server running on it """
    port = self.user_options[ 'csharp_server_port' ]
    while self._GetResponse( '/checkalivestatus',
        silent=True,
        port=port ) != None:
      port += 1
    return port


  def _PortToHost( self, port=None ):
    if port == None:
      port = self._omnisharp_port
    return 'http://localhost:' + str( port )


  def _GetResponse( self, endPoint, parameters={}, silent=False, port=None ):
    """ Handle communication with server """
    # TODO: Replace usage of urllib with Requests
    target = urlparse.urljoin( self._PortToHost( port ), endPoint )
    parameters = urllib.urlencode( parameters )
    response = urllib2.urlopen( target, parameters )
    return json.loads( response.read() )


def _FindSolutionFiles( filepath ):
  """ Find solution files by searching upwards in the file tree """
  folder = os.path.dirname( filepath )
  solutionfiles = glob.glob1( folder, '*.sln' )
  while not solutionfiles:
    lastfolder = folder
    folder = os.path.dirname( folder )
    if folder == lastfolder:
      break
    solutionfiles = glob.glob1( folder, '*.sln' )
  return solutionfiles, folder