////////////////////////////////////////////////////////////////////////////////
/// @brief V8 job
///
/// @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, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#include "V8Job.h"

#include "Basics/json.h"
#include "Basics/logging.h"
#include "Dispatcher/DispatcherQueue.h"
#include "V8/v8-conv.h"
#include "V8/v8-utils.h"
#include "V8Server/ApplicationV8.h"
#include "VocBase/vocbase.h"

using namespace std;
using namespace triagens::basics;
using namespace triagens::rest;
using namespace triagens::arango;

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

////////////////////////////////////////////////////////////////////////////////
/// @brief constructs a new V8 job
////////////////////////////////////////////////////////////////////////////////

V8Job::V8Job (TRI_vocbase_t* vocbase,
              ApplicationV8* v8Dealer,
              std::string const& command,
              TRI_json_t const* parameters,
              bool allowUseDatabase)
  : Job("V8 Job"),
    _vocbase(vocbase),
    _v8Dealer(v8Dealer),
    _command(command),
    _parameters(nullptr),
    _canceled(0),
    _allowUseDatabase(allowUseDatabase) {

  if (parameters != nullptr) {
    // create our own copy of the parameters
    _parameters = TRI_CopyJson(TRI_UNKNOWN_MEM_ZONE, parameters);
  }
}

////////////////////////////////////////////////////////////////////////////////
/// @brief destroys a V8 job
////////////////////////////////////////////////////////////////////////////////

V8Job::~V8Job () {
  if (_parameters != nullptr) {
    TRI_FreeJson(TRI_UNKNOWN_MEM_ZONE, _parameters);
  }
}

// -----------------------------------------------------------------------------
// --SECTION--                                                       Job methods
// -----------------------------------------------------------------------------

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

Job::status_t V8Job::work () {
  if (_canceled) {
    return status_t(JOB_DONE);
  }

  ApplicationV8::V8Context* context = _v8Dealer->enterContext(_vocbase, _allowUseDatabase);

  // note: the context might be 0 in case of shut-down
  if (context == nullptr) {
    return status_t(JOB_DONE);
  }

  // now execute the function within this context
  {
    auto isolate = context->isolate;
    v8::HandleScope scope(isolate);

    // get built-in Function constructor (see ECMA-262 5th edition 15.3.2)
    auto current = isolate->GetCurrentContext()->Global();
    auto ctor = v8::Local<v8::Function>::Cast(current->Get(TRI_V8_ASCII_STRING("Function")));

    // Invoke Function constructor to create function with the given body and no arguments
    v8::Handle<v8::Value> args[2] = { TRI_V8_ASCII_STRING("params"), TRI_V8_STD_STRING(_command) };
    v8::Local<v8::Object> function = ctor->NewInstance(2, args);

    v8::Handle<v8::Function> action = v8::Local<v8::Function>::Cast(function);

    if (! action.IsEmpty()) {
      // only go in here if action is a function
      v8::Handle<v8::Value> fArgs;

      if (_parameters != nullptr) {
        fArgs = TRI_ObjectJson(isolate, _parameters);
      }
      else {
        fArgs = v8::Undefined(isolate);
      }

      // call the function within a try/catch
      try {
        v8::TryCatch tryCatch;

        action->Call(current, 1, &fArgs);

        if (tryCatch.HasCaught()) {
          if (tryCatch.CanContinue()) {
            TRI_LogV8Exception(isolate, &tryCatch);
          }
          else {
            TRI_GET_GLOBALS();

            v8g->_canceled = true;
            LOG_WARNING("caught non-catchable exception (aka termination) in periodic job");
          }
        }
      }
      catch (triagens::basics::Exception const& ex) {
        LOG_ERROR("caught exception in V8 job: %s %s", TRI_errno_string(ex.code()), ex.what());
      }
      catch (std::bad_alloc const&) {
        LOG_ERROR("caught exception in V8 job: %s", TRI_errno_string(TRI_ERROR_OUT_OF_MEMORY));
      }
      catch (...) {
        LOG_ERROR("caught unknown exception in V8 job");
      }
    }
  }

  _v8Dealer->exitContext(context);

  return status_t(JOB_DONE);
}

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

bool V8Job::cancel () {
  _canceled = 1;
  return true;
}

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

void V8Job::cleanup (DispatcherQueue* queue) {
  queue->removeJob(this);
  delete this;
}

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

void V8Job::handleError (Exception const& ex) {
}

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

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