#!/usr/bin/env python
#
# Copyright (C) 2011, 2012  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 vim

def CurrentLineAndColumn():
  """Returns the 0-based current line and 0-based current column."""
  # See the comment in CurrentColumn about the calculation for the line and
  # column number
  line, column = vim.current.window.cursor
  line -= 1
  return line, column


def CurrentColumn():
  """Returns the 0-based current column. Do NOT access the CurrentColumn in
  vim.current.line. It doesn't exist yet.  Only the chars before the current
  column exist in vim.current.line."""

  # vim's columns are 1-based while vim.current.line columns are 0-based
  # ... but vim.current.window.cursor (which returns a (line, column) tuple)
  # columns are 0-based, while the line from that same tuple is 1-based.
  # vim.buffers buffer objects OTOH have 0-based lines and columns.
  # Pigs have wings and I'm a loopy purple duck. Everything makes sense now.
  return vim.current.window.cursor[ 1 ]


def GetUnsavedBuffers():
  def BufferModified( buffer_number ):
    to_eval = 'getbufvar({0}, "&mod")'.format( buffer_number )
    return GetBoolValue( to_eval )

  return ( x for x in vim.buffers if BufferModified( x.number ) )


# Both |line| and |column| need to be 1-based
def JumpToLocation( filename, line, column ):
  # Add an entry to the jumplist
  vim.command( "normal m'" )

  if filename != vim.current.buffer.name:
    # We prefix the command with 'keepjumps' so that opening the file is not
    # recorded in the jumplist. So when we open the file and move the cursor to
    # a location in it, the user can use CTRL-O to jump back to the original
    # location, not to the start of the newly opened file.
    # Sadly this fails on random occasions and the undesired jump remains in the
    # jumplist.
    vim.command( 'keepjumps edit {0}'.format( filename ) )
  vim.current.window.cursor = ( line, column - 1 )

  # Center the screen on the jumped-to location
  vim.command( 'normal! zz' )


def NumLinesInBuffer( buffer ):
  # This is actually less than obvious, that's why it's wrapped in a function
  return len( buffer )


def PostVimMessage( message ):
  vim.command( "echohl WarningMsg | echomsg '{0}' | echohl None"
               .format( EscapeForVim( message ) ) )


def PresentDialog( message, choices, default_choice_index = 0 ):
  """Presents the user with a dialog where a choice can be made.
  This will be a dialog for gvim users or a question in the message buffer
  for vim users or if `set guioptions+=c` was used.

  choices is list of alternatives.
  default_choice_index is the 0-based index of the default element
  that will get choosen if the user hits <CR>. Use -1 for no default.

  PresentDialog will return a 0-based index into the list
  or -1 if the dialog was dismissed by using <Esc>, Ctrl-C, etc.

  See also:
    :help confirm() in vim (Note that vim uses 1-based indexes)

  Example call:
    PresentDialog("Is this a nice example?", ["Yes", "No", "May&be"])
      Is this a nice example?
      [Y]es, (N)o, May(b)e:"""
  to_eval = "confirm('{0}', '{1}', {2})".format( EscapeForVim( message ),
    EscapeForVim( "\n" .join( choices ) ), default_choice_index + 1 )
  return int( vim.eval( to_eval ) ) - 1


def Confirm( message ):
  return bool( PresentDialog( message, [ "Ok", "Cancel" ] ) == 0 )


def EchoText( text ):
  def EchoLine( text ):
    vim.command( "echom '{0}'".format( EscapeForVim( text ) ) )

  for line in text.split( '\n' ):
    EchoLine( line )


def EscapeForVim( text ):
  return text.replace( "'", "''" )


def CurrentFiletypes():
  ft_string = vim.eval( "&filetype" )
  return ft_string.split( '.' )


def FiletypesForBuffer( buffer_object ):
  # NOTE: Getting &ft for other buffers only works when the buffer has been
  # visited by the user at least once, which is true for modified buffers
  ft_string = vim.eval( 'getbufvar({0}, "&ft")'.format( buffer_object.number ) )
  return ft_string.split( '.' )


def GetVariableValue( variable ):
  return vim.eval( variable )


def GetBoolValue( variable ):
  return bool( int( vim.eval( variable ) ) )