// Copyright (C) 2011, 2012  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/>.

#include "standard.h"
#include "Candidate.h"
#include "Result.h"
#include <cctype>
#include <boost/algorithm/string.hpp>

using boost::algorithm::all;
using boost::algorithm::is_lower;

namespace YouCompleteMe {

namespace {

LetterNode *FirstUppercaseNode( const std::list< LetterNode *> &list ) {
  LetterNode *node = NULL;
  foreach( LetterNode * current_node, list ) {
    if ( current_node->LetterIsUppercase() ) {
      node = current_node;
      break;
    }
  }
  return node;
}

} // unnamed namespace

std::string GetWordBoundaryChars( const std::string &text ) {
  std::string result;

  for ( uint i = 0; i < text.size(); ++i ) {
    bool is_first_char_but_not_underscore = i == 0 && text[ i ] != '_';
    bool is_good_uppercase = i > 0 &&
                             IsUppercase( text[ i ] ) &&
                             !IsUppercase( text[ i - 1 ] );
    bool is_alpha_after_underscore = i > 0 &&
                                     text[ i - 1 ] == '_' &&
                                     isalpha( text[ i ] );

    if ( is_first_char_but_not_underscore ||
         is_good_uppercase ||
         is_alpha_after_underscore ) {
      result.push_back( tolower( text[ i ] ) );
    }
  }

  return result;
}


Bitset LetterBitsetFromString( const std::string &text ) {
  Bitset letter_bitset;
  foreach ( char letter, text ) {
    letter_bitset.set( IndexForChar( letter ) );
  }

  return letter_bitset;
}


Candidate::Candidate( const std::string &text )
  :
  text_( text ),
  word_boundary_chars_( GetWordBoundaryChars( text ) ),
  text_is_lowercase_( all( text, is_lower() ) ),
  letters_present_( LetterBitsetFromString( text ) ),
  root_node_( new LetterNode( text ) ) {
}


Result Candidate::QueryMatchResult( const std::string &query,
                                    bool case_sensitive ) const {
  LetterNode *node = root_node_.get();
  int index_sum = 0;

  foreach ( char letter, query ) {
    const std::list< LetterNode *> *list = node->NodeListForLetter( letter );

    if ( !list )
      return Result( false );

    if ( case_sensitive ) {
      // When the query letter is uppercase, then we force an uppercase match
      // but when the query letter is lowercase, then it can match both an
      // uppercase and a lowercase letter. This is by design and it's much
      // better than forcing lowercase letter matches.
      node = IsUppercase( letter ) ?
             FirstUppercaseNode( *list ) :
             list->front();

      if ( !node )
        return Result( false );
    } else {
      node = list->front();
    }

    index_sum += node->Index();
  }

  return Result( true, &text_, text_is_lowercase_, index_sum,
                 word_boundary_chars_, query );
}

} // namespace YouCompleteMe