////////////////////////////////////////////////////////////////////////////////
/// @brief console input using linenoise
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2014 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///     http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
/// @author Copyright 2014, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2011-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#include "LinenoiseShell.h"

extern "C" {
#include <linenoise.h>
}

#include "Utilities/Completer.h"
#include "Utilities/LineEditor.h"

using namespace std;
using namespace arangodb;

// -----------------------------------------------------------------------------
// --SECTION--                                                 private functions
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @brief active completer
////////////////////////////////////////////////////////////////////////////////

static Completer* COMPLETER = nullptr;

////////////////////////////////////////////////////////////////////////////////
/// @brief completer generator
////////////////////////////////////////////////////////////////////////////////

static void LinenoiseCompletionGenerator (char const* text, 
                                          linenoiseCompletions* lc) {
  if (COMPLETER) {
    std::vector<string> alternatives = COMPLETER->alternatives(text);
    ShellBase::sortAlternatives(alternatives);

    for (auto& it : alternatives) {
      linenoiseAddCompletion(lc, it.c_str());
    }
  }
}

// -----------------------------------------------------------------------------
// --SECTION--                                              class LinenoiseShell
// -----------------------------------------------------------------------------

// -----------------------------------------------------------------------------
// --SECTION--                                      constructors and destructors
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @brief constructor
////////////////////////////////////////////////////////////////////////////////

LinenoiseShell::LinenoiseShell (std::string const& history, 
                                Completer* completer)
  : ShellBase(history, completer) {
  COMPLETER = completer;
  linenoiseSetCompletionCallback(LinenoiseCompletionGenerator);
  linenoiseInstallWindowChangeHandler();
}

////////////////////////////////////////////////////////////////////////////////
/// @brief destructor
////////////////////////////////////////////////////////////////////////////////

LinenoiseShell::~LinenoiseShell() {
  COMPLETER = nullptr;
}

// -----------------------------------------------------------------------------
// --SECTION--                                                    public methods
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// {@inheritDoc}
////////////////////////////////////////////////////////////////////////////////

bool LinenoiseShell::open (bool) {
  linenoiseHistoryLoad(_historyFilename.c_str());
  _state = STATE_OPENED;
  return true;
}

////////////////////////////////////////////////////////////////////////////////
/// {@inheritDoc}
////////////////////////////////////////////////////////////////////////////////

bool LinenoiseShell::close () {
  // avoid duplicate saving of history
  if (_state != STATE_OPENED) {
    return true;
  }

  _state = STATE_CLOSED;
  auto result = writeHistory();
  linenoiseHistoryFree();
  return result;
}

////////////////////////////////////////////////////////////////////////////////
/// {@inheritDoc}
////////////////////////////////////////////////////////////////////////////////

void LinenoiseShell::addHistory (std::string const& str) {
  if (str.empty()) {
    return;
  }

  linenoiseHistoryAdd(str.c_str());
}

////////////////////////////////////////////////////////////////////////////////
/// {@inheritDoc}
////////////////////////////////////////////////////////////////////////////////

bool LinenoiseShell::writeHistory () {
  linenoiseHistorySave(_historyFilename.c_str());

  return true;
}

////////////////////////////////////////////////////////////////////////////////
/// {@inheritDoc}
////////////////////////////////////////////////////////////////////////////////

std::string LinenoiseShell::getLine (std::string const& prompt, bool& eof) {
  char* line = linenoise(prompt.c_str());

  if (line != nullptr) {
    eof = false;
    std::string const stringValue(line);
    ::free(line);
    return stringValue;
  }

  eof = true;
  return "";
}

// -----------------------------------------------------------------------------
// --SECTION--                                                       END-OF-FILE
// -----------------------------------------------------------------------------