////////////////////////////////////////////////////////////////////////////////
/// @brief V8-vocbase bridge
///
/// @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 "v8-vocbaseprivate.h"
#include "Basics/conversions.h"
#include "Utils/Cursor.h"
#include "Utils/CursorRepository.h"
#include "Utils/transactions.h"
#include "V8/v8-conv.h"
#include "V8Server/v8-voccursor.h"

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

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

////////////////////////////////////////////////////////////////////////////////
/// @brief generates a general cursor from an array
////////////////////////////////////////////////////////////////////////////////

static void JS_CreateCursor (const v8::FunctionCallbackInfo<v8::Value>& args) {
  TRI_V8_TRY_CATCH_BEGIN(isolate);
  v8::HandleScope scope(isolate);

  TRI_vocbase_t* vocbase = GetContextVocBase(isolate);

  if (vocbase == nullptr) {
    TRI_V8_THROW_EXCEPTION(TRI_ERROR_ARANGO_DATABASE_NOT_FOUND);
  }

  if (args.Length() < 1) {
    TRI_V8_THROW_EXCEPTION_USAGE("CREATE_CURSOR(<data>, <batchSize>, <ttl>)");
  }

  if (! args[0]->IsArray()) {
    TRI_V8_THROW_TYPE_ERROR("<data> must be an array");
  }

  // extract objects
  v8::Handle<v8::Array> array = v8::Handle<v8::Array>::Cast(args[0]);
  std::unique_ptr<TRI_json_t> json(TRI_ObjectToJson(isolate, array));

  if (json == nullptr) {
    TRI_V8_THROW_TYPE_ERROR("cannot convert <array> to JSON");
  }

  // maximum number of results to return at once
  uint32_t batchSize = 1000;

  if (args.Length() >= 2) {
    int64_t maxValue = TRI_ObjectToInt64(args[1]);

    if (maxValue > 0 && maxValue < (int64_t) UINT32_MAX) {
      batchSize = static_cast<uint32_t>(maxValue);
    }
  }

  double ttl = 0.0;
  if (args.Length() >= 3) {
    ttl = TRI_ObjectToDouble(args[2]);
  }

  if (ttl <= 0.0) {
    ttl = 30.0; // default ttl
  }

  // create a cursor
  auto cursors = static_cast<triagens::arango::CursorRepository*>(vocbase->_cursorRepository);

  try {
    triagens::arango::Cursor* cursor = cursors->createFromJson(json.get(), static_cast<size_t>(batchSize), nullptr, ttl, true, false);
    json.release();

    TRI_ASSERT(cursor != nullptr);
    cursors->release(cursor);
  
    auto result = V8TickId(isolate, cursor->id());
    TRI_V8_RETURN(result);
  }
  catch (...) {
    TRI_V8_THROW_EXCEPTION_MEMORY();
  }
  TRI_V8_TRY_CATCH_END
}

////////////////////////////////////////////////////////////////////////////////
/// @brief generates a JSON object from the specified cursor
////////////////////////////////////////////////////////////////////////////////

static void JS_JsonCursor (const v8::FunctionCallbackInfo<v8::Value>& args) {
  TRI_V8_TRY_CATCH_BEGIN(isolate);
  v8::HandleScope scope(isolate);

  TRI_vocbase_t* vocbase = GetContextVocBase(isolate);

  if (vocbase == nullptr) {
    TRI_V8_THROW_EXCEPTION(TRI_ERROR_ARANGO_DATABASE_NOT_FOUND);
  }

  if (args.Length() != 1) {
    TRI_V8_THROW_EXCEPTION_USAGE("JSON_CURSOR(<id>)");
  }

  std::string const id = TRI_ObjectToString(args[0]);
  auto cursorId = static_cast<triagens::arango::CursorId>(triagens::basics::StringUtils::uint64(id));

  // find the cursor
  auto cursors = static_cast<triagens::arango::CursorRepository*>(vocbase->_cursorRepository);
  TRI_ASSERT(cursors != nullptr);
  
  bool busy;
  auto cursor = cursors->find(cursorId, busy);

  if (cursor == nullptr) {
    if (busy) {
      TRI_V8_THROW_EXCEPTION(TRI_ERROR_CURSOR_BUSY);
    }

    TRI_V8_THROW_EXCEPTION(TRI_ERROR_CURSOR_NOT_FOUND);
  }

  try {
    auto result = v8::Object::New(isolate);

    // build documents
    auto docs = v8::Array::New(isolate);
    size_t const n = cursor->batchSize();

    for (size_t i = 0; i < n; ++i) {
      if (! cursor->hasNext()) {
        break;
      }

      auto row = cursor->next();

      if (row == nullptr) {
        TRI_V8_THROW_EXCEPTION(TRI_ERROR_OUT_OF_MEMORY);
      }

      docs->Set(static_cast<uint32_t>(i), TRI_ObjectJson(isolate, row));
    }

    result->ForceSet(TRI_V8_ASCII_STRING("result"), docs);

    bool hasCount = cursor->hasCount();
    size_t count = cursor->count();
    bool hasNext = cursor->hasNext();
    TRI_json_t* extra = cursor->extra();
      
    result->ForceSet(TRI_V8_ASCII_STRING("hasMore"), v8::Boolean::New(isolate, hasNext));
    
    if (hasNext) {
      result->ForceSet(TRI_V8_ASCII_STRING("id"), V8TickId(isolate, cursor->id()));
    }

    if (hasCount) {
      result->ForceSet(TRI_V8_ASCII_STRING("count"), v8::Number::New(isolate, static_cast<double>(count)));
    }
    if (extra != nullptr) {
      result->ForceSet(TRI_V8_ASCII_STRING("extra"), TRI_ObjectJson(isolate, extra));
    }

    cursors->release(cursor);

    TRI_V8_RETURN(result);
  }
  catch (...) {
    cursors->release(cursor);
    TRI_V8_THROW_EXCEPTION_MEMORY();
  }
  TRI_V8_TRY_CATCH_END
}

// .............................................................................
// generate the general cursor template
// .............................................................................

void TRI_InitV8cursor (v8::Handle<v8::Context> context,
                       TRI_v8_global_t* v8g) { 
  v8::Isolate* isolate = v8::Isolate::GetCurrent();

  // cursor functions. not intended to be used by end users
  TRI_AddGlobalFunctionVocbase(isolate, context, TRI_V8_ASCII_STRING("CREATE_CURSOR"), JS_CreateCursor, true);
  TRI_AddGlobalFunctionVocbase(isolate, context, TRI_V8_ASCII_STRING("JSON_CURSOR"), JS_JsonCursor, true);
}