////////////////////////////////////////////////////////////////////////////////
/// @brief implementation of the base class
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2014-2015 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 2014-2015, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2011-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#include "ShellBase.h"

#include "Basics/StringUtils.h"
#include "Basics/files.h"
#include "Utilities/Completer.h"
#include "Utilities/DummyShell.h"

#if defined(TRI_HAVE_LINENOISE)
#include "Utilities/LinenoiseShell.h"
#endif

using namespace std;
using namespace arangodb;
using namespace triagens::basics;

// -----------------------------------------------------------------------------
// --SECTION--                                                   class ShellBase
// -----------------------------------------------------------------------------

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

////////////////////////////////////////////////////////////////////////////////
/// @brief creates a shell
////////////////////////////////////////////////////////////////////////////////

ShellBase* ShellBase::buildShell (std::string const& history,
                                  Completer* completer) {

  // no keyboard input. use low-level shell without fancy color codes 
  // and with proper pipe handling

  if (! isatty(STDIN_FILENO)) {
    return new DummyShell(history, completer);
  }
  else {
#if defined(TRI_HAVE_LINENOISE)
    return new LinenoiseShell(history, completer);
#else
    return new DummyShell(history, completer); // last resort!
#endif
  }
}

////////////////////////////////////////////////////////////////////////////////
/// @brief sort the alternatives results vector
////////////////////////////////////////////////////////////////////////////////

void ShellBase::sortAlternatives (vector<string>& completions) {
  std::sort(completions.begin(), completions.end(),
    [](std::string const& l, std::string const& r) -> bool {
      int res = strcasecmp(l.c_str(), r.c_str());
      return (res < 0);
    }
  );
}

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

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

ShellBase::ShellBase (string const& history, Completer* completer)
  : _current(),
    _historyFilename(),
    _state(STATE_NONE),
    _completer(completer) {

  // construct the complete history path
  string path;
  char* p = TRI_HomeDirectory();

  if (p != nullptr) {
    path.append(p);
    TRI_Free(TRI_CORE_MEM_ZONE, p);

    if (! path.empty() && path[path.size() - 1] != TRI_DIR_SEPARATOR_CHAR) {
      path.push_back(TRI_DIR_SEPARATOR_CHAR);
    }
  }

  path.append(history);

  _historyFilename = path;
}

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

ShellBase::~ShellBase () {
  delete _completer;
}

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

////////////////////////////////////////////////////////////////////////////////
/// @brief handle a signal
////////////////////////////////////////////////////////////////////////////////

void ShellBase::signal () {
  // do nothing special
}

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

////////////////////////////////////////////////////////////////////////////////
/// @brief shell prompt
////////////////////////////////////////////////////////////////////////////////

string ShellBase::prompt (const string& prompt,
                          const string& plain,
                          bool& eof) {
  size_t lineno = 0;
  string dotdot = "...> ";
  string p = prompt;
  string sep = "";
  string line;

  eof = false;

  while (true) {

    // calling concrete implementation of the shell
    line = getLine(p, eof);
    p = dotdot;

    if (eof) {

      // give up, if the user pressed control-D on the top-most level
      if (_current.empty()) {
        return "";
      }

      // otherwise clear current content
      _current.clear();
      eof = false;
      break;
    }

    _current += sep;
    sep = "\n";
    ++lineno;

    // remove any prompt at the beginning of the line
    size_t pos = string::npos;

    if (StringUtils::isPrefix(line, plain)) {
      pos = line.find('>');
    }
    else if (StringUtils::isPrefix(line, "...")) {
      pos = line.find('>');
    }

    if (pos != string::npos) {
      pos = line.find_first_not_of(" \t", pos + 1);

      if (pos != string::npos) {
        line = line.substr(pos);
      }
      else {
        line.clear();
      }
    }

    // extend line and check
    _current += line;

    // stop if line is complete
    bool ok = _completer->isComplete(_current, lineno);

    if (ok) {
      break;
    }
  }

  // clear current line
  line = _current;
  _current.clear();

  return line;
}

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