////////////////////////////////////////////////////////////////////////////////
/// @brief V8 utility functions
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2004-2012 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 triAGENS GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
/// @author Copyright 2011-2012, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#include "v8-utils.h"

#include <fstream>
#include <locale>

#include "Basics/Dictionary.h"
#include "Basics/StringUtils.h"
#include "BasicsC/conversions.h"
#include "BasicsC/csv.h"
#include "BasicsC/files.h"
#include "BasicsC/logging.h"
#include "BasicsC/process-utils.h"
#include "BasicsC/string-buffer.h"
#include "BasicsC/strings.h"
#include "Rest/SslInterface.h"
#include "V8/v8-conv.h"

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

// -----------------------------------------------------------------------------
// --SECTION--                                                   WEAK DICTIONARY
// -----------------------------------------------------------------------------

// -----------------------------------------------------------------------------
// --SECTION--                                                 private constants
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @addtogroup V8Utils
/// @{
////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////
/// @brief wrapped class for TRI_vocbase_t
////////////////////////////////////////////////////////////////////////////////

static int32_t const WRP_WEAK_DIRECTORY_TYPE = 1000;

////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////

// -----------------------------------------------------------------------------
// --SECTION--                                                     private types
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @addtogroup V8Utils
/// @{
////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////
/// @brief dictionary / key pair
////////////////////////////////////////////////////////////////////////////////

typedef struct {
  void* _dictionary;
  char* _key;
}
wd_key_pair_t;

////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////

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

////////////////////////////////////////////////////////////////////////////////
/// @addtogroup V8Utils
/// @{
////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////
/// @brief weak dictionary callback
////////////////////////////////////////////////////////////////////////////////

static void WeakDictionaryCallback (v8::Persistent<v8::Value> object, void* parameter) {
  typedef Dictionary< v8::Persistent<v8::Value>* > WD;

  WD* dictionary;
  char* key;

  dictionary = (WD*) ((wd_key_pair_t*) parameter)->_dictionary;
  key = ((wd_key_pair_t*) parameter)->_key;

  LOG_TRACE("weak-callback for dictionary called");

  // dispose and clear the persistent handle
  WD::KeyValue const* kv = dictionary->lookup(key);

  if (kv != 0) {
    const_cast<WD::KeyValue*>(kv)->_value->Dispose();
    const_cast<WD::KeyValue*>(kv)->_value->Clear();

    delete const_cast<WD::KeyValue*>(kv)->_value;

    dictionary->erase(key);
  }

  TRI_FreeString(TRI_UNKNOWN_MEM_ZONE, key);
  TRI_Free(TRI_UNKNOWN_MEM_ZONE, parameter);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief invocation callback
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> WeakDictionaryInvocationCallback (v8::Arguments const& args) {
  typedef Dictionary< v8::Persistent<v8::Value>* > WD;
  static uint64_t MIN_SIZE = 100;

  v8::Handle<v8::Object> self = args.Holder();

  if (self->InternalFieldCount() <= 1) {
    return v8::ThrowException(v8::String::New("corrupted weak dictionary"));
  }

  WD* dictionary = new WD(MIN_SIZE);
  v8::Handle<v8::Value> external = v8::Persistent<v8::Value>::New(v8::External::New(dictionary));

  self->SetInternalField(SLOT_CLASS, external);
  self->SetInternalField(SLOT_CLASS_TYPE, v8::Integer::New(WRP_WEAK_DIRECTORY_TYPE));

  return self;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief checks if a property is present
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Integer> PropertyQueryWeakDictionary (v8::Local<v8::String> name,
                                                            const v8::AccessorInfo& info) {
  typedef Dictionary< v8::Persistent<v8::Value>* > WD;

  v8::HandleScope scope;

  // sanity check
  v8::Handle<v8::Object> self = info.Holder();

  // get the dictionary
  WD* dictionary = TRI_UnwrapClass<WD >(self, WRP_WEAK_DIRECTORY_TYPE);

  if (dictionary == 0) {
    return scope.Close(v8::Handle<v8::Integer>());
  }

  // convert the JavaScript string to a string
  string key = TRI_ObjectToString(name);

  if (key == "") {
    return scope.Close(v8::Handle<v8::Integer>());
  }

  // check the dictionary
  WD::KeyValue const* kv = dictionary->lookup(key.c_str());

  if (kv == 0) {
    return scope.Close(v8::Handle<v8::Integer>());
  }

  return scope.Close(v8::Handle<v8::Integer>(v8::Integer::New(v8::None)));
}

////////////////////////////////////////////////////////////////////////////////
/// @brief keys of a dictionary
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Array> KeysOfWeakDictionary (const v8::AccessorInfo& info) {
  typedef Dictionary< v8::Persistent<v8::Value>* > WD;

  v8::HandleScope scope;
  v8::Handle<v8::Array> result = v8::Array::New();

  // sanity check
  v8::Handle<v8::Object> self = info.Holder();

  // get the dictionary
  WD* dictionary = TRI_UnwrapClass<WD >(self, WRP_WEAK_DIRECTORY_TYPE);

  if (dictionary == 0) {
    return scope.Close(result);
  }

  // check the dictionary
  WD::KeyValue const* begin;
  WD::KeyValue const* end;
  WD::KeyValue const* ptr;

  dictionary->range(begin, end);

  size_t count = 0;

  for (ptr = begin;  ptr < end;  ++ptr) {
    if (ptr->_key != 0) {
      result->Set(count++, v8::String::New(ptr->_key));
    }
  }

  return scope.Close(result);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief gets an entry
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> MapGetWeakDictionary (v8::Local<v8::String> name,
                                                   const v8::AccessorInfo& info) {
  typedef Dictionary< v8::Persistent<v8::Value>* > WD;

  v8::HandleScope scope;

  // sanity check
  v8::Handle<v8::Object> self = info.Holder();

  // get the dictionary
  WD* dictionary = TRI_UnwrapClass<WD >(self, WRP_WEAK_DIRECTORY_TYPE);

  if (dictionary == 0) {
    return scope.Close(v8::ThrowException(v8::String::New("corrupted weak dictionary")));
  }

  // convert the JavaScript string to a string
  string key = TRI_ObjectToString(name);

  if (key == "") {
    return scope.Close(v8::Undefined());
  }

  // check the dictionary
  WD::KeyValue const* kv = dictionary->lookup(key.c_str());

  if (kv == 0) {
    return scope.Close(v8::Undefined());
  }

  return scope.Close(*kv->_value);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief gets an entry
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> MapSetWeakDictionary (v8::Local<v8::String> name,
                                                   v8::Local<v8::Value> value,
                                                   const v8::AccessorInfo& info) {
  typedef Dictionary< v8::Persistent<v8::Value>* > WD;

  v8::HandleScope scope;

  // sanity check
  v8::Handle<v8::Object> self = info.Holder();

  // get the dictionary
  WD* dictionary = TRI_UnwrapClass<WD >(self, WRP_WEAK_DIRECTORY_TYPE);

  if (dictionary == 0) {
    return scope.Close(v8::ThrowException(v8::String::New("corrupted weak dictionary")));
  }

  // convert the JavaScript string to a string
  string key = TRI_ObjectToString(name);

  if (key == "") {
    return scope.Close(v8::Undefined());
  }

  char* ckey = TRI_DuplicateStringZ(TRI_UNKNOWN_MEM_ZONE, key.c_str());

  if (ckey == NULL) {
    return scope.Close(v8::ThrowException(v8::String::New("out-of-memory")));
  }

  // create a new weak persistent
  v8::Persistent<v8::Value>* persistent = new v8::Persistent<v8::Value>();
  *persistent = v8::Persistent<v8::Value>::New(value);

  // enter a value into the dictionary
  WD::KeyValue const* kv = dictionary->lookup(ckey);

  if (kv != 0) {
    kv->_value->Dispose();
    kv->_value->Clear();

    delete kv->_value;

    const_cast<WD::KeyValue*>(kv)->_value = persistent;
  }
  else {
    dictionary->insert(ckey, persistent);
  }

  wd_key_pair_t* p = new wd_key_pair_t;
  p->_dictionary = dictionary;
  p->_key = ckey;

  persistent->MakeWeak(p, WeakDictionaryCallback);

  return scope.Close(value);
}

////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////

// -----------------------------------------------------------------------------
// --SECTION--                                                           GENERAL
// -----------------------------------------------------------------------------

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

////////////////////////////////////////////////////////////////////////////////
/// @addtogroup V8Utils
/// @{
////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////
/// @brief reads/execute a file into/in the current context
////////////////////////////////////////////////////////////////////////////////

static bool LoadJavaScriptFile (v8::Handle<v8::Context> context,
                                char const* filename,
                                bool execute) {
  v8::HandleScope handleScope;

  char* content = TRI_SlurpFile(TRI_UNKNOWN_MEM_ZONE, filename);

  if (content == 0) {
    LOG_TRACE("cannot loaded java script file '%s': %s", filename, TRI_last_error());
    return false;
  }

  if (execute) {
    char* contentWrapper = TRI_Concatenate3String("(function() { ",
                                                  content,
                                                  "/* end-of-file */ })()");

    TRI_FreeString(TRI_UNKNOWN_MEM_ZONE, content);

    content = contentWrapper;
  }

  v8::Handle<v8::String> name = v8::String::New(filename);
  v8::Handle<v8::String> source = v8::String::New(content);

  TRI_FreeString(TRI_UNKNOWN_MEM_ZONE, content);

  v8::Handle<v8::Script> script = v8::Script::Compile(source, name);

  // compilation failed, print errors that happened during compilation
  if (script.IsEmpty()) {
    return false;
  }

  // execute script
  v8::Handle<v8::Value> result = script->Run();

  if (result.IsEmpty()) {
    return false;
  }

  LOG_TRACE("loaded java script file: '%s'", filename);
  return true;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief reads all files from a directory into the current context
////////////////////////////////////////////////////////////////////////////////

static bool LoadJavaScriptDirectory (v8::Handle<v8::Context> context, char const* path, bool execute) {
  v8::HandleScope scope;
  TRI_vector_string_t files;
  bool result;
  regex_t re;
  size_t i;

  LOG_TRACE("loading JavaScript directory: '%s'", path);

  files = TRI_FilesDirectory(path);

  regcomp(&re, "^(.*)\\.js$", REG_ICASE | REG_EXTENDED);

  result = true;

  for (i = 0;  i < files._length;  ++i) {
    v8::TryCatch tryCatch;
    bool ok;
    char const* filename;
    char* full;

    filename = files._buffer[i];

    if (! regexec(&re, filename, 0, 0, 0) == 0) {
      continue;
    }

    full = TRI_Concatenate2File(path, filename);
    ok = LoadJavaScriptFile(context, full, execute);
    TRI_FreeString(TRI_CORE_MEM_ZONE, full);

    result = result && ok;

    if (! ok) {
      TRI_LogV8Exception(&tryCatch);
    }
  }

  TRI_DestroyVectorString(&files);
  regfree(&re);

  return result;
}

////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////

// -----------------------------------------------------------------------------
// --SECTION--                                                      JS functions
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @addtogroup V8Utils
/// @{
////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////
/// @brief executes a script
///
/// @FUN{internal.execute(@FA{script}, @FA{sandbox}, @FA{filename})}
///
/// Executes the @FA{script} with the @FA{sandbox} as context. Global variables
/// assigned inside the @FA{script}, will be visible in the @FA{sandbox} object
/// after execution. The @FA{filename} is used for displaying error
/// messages.
///
/// If @FA{sandbox} is undefined, then @FN{execute} uses the current context.
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_Execute (v8::Arguments const& argv) {
  v8::HandleScope scope;
  size_t i;

  // extract arguments
  if (argv.Length() != 3) {
    return scope.Close(v8::ThrowException(v8::String::New("usage: execute(<script>, <sandbox>, <filename>)")));
  }

  v8::Handle<v8::Value> source = argv[0];
  v8::Handle<v8::Value> sandboxValue = argv[1];
  v8::Handle<v8::Value> filename = argv[2];

  if (! source->IsString()) {
    return scope.Close(v8::ThrowException(v8::String::New("<script> must be a string")));
  }

  bool useSandbox = sandboxValue->IsObject();
  v8::Handle<v8::Object> sandbox;
  v8::Handle<v8::Context> context;

  if (useSandbox) {
    sandbox = sandboxValue->ToObject();

    // create new context
    context = v8::Context::New();
    context->Enter();

    // copy sandbox into context
    v8::Handle<v8::Array> keys = sandbox->GetPropertyNames();

    for (i = 0; i < keys->Length(); i++) {
      v8::Handle<v8::String> key = keys->Get(v8::Integer::New(i))->ToString();
      v8::Handle<v8::Value> value = sandbox->Get(key);

      if (TRI_IsTraceLogging(__FILE__)) {
        v8::String::Utf8Value keyName(key);

        if (*keyName != 0) {
          LOG_TRACE("copying key '%s' from sandbox to context", *keyName);
        }
      }

      if (value == sandbox) {
        value = context->Global();
      }

      context->Global()->Set(key, value);
    }
  }

  // execute script inside the context
  v8::Handle<v8::Script> script = v8::Script::Compile(source->ToString(), filename);

  // compilation failed, print errors that happened during compilation
  if (script.IsEmpty()) {
    if (useSandbox) {
      context->DetachGlobal();
      context->Exit();
    }

    return scope.Close(v8::Undefined());
  }

  // compilation succeeded, run the script
  v8::Handle<v8::Value> result = script->Run();

  if (result.IsEmpty()) {
    if (useSandbox) {
      context->DetachGlobal();
      context->Exit();
    }

    return scope.Close(v8::Undefined());
  }

  // copy result back into the sandbox
  if (useSandbox) {
    v8::Handle<v8::Array> keys = context->Global()->GetPropertyNames();

    for (i = 0; i < keys->Length(); i++) {
      v8::Handle<v8::String> key = keys->Get(v8::Integer::New(i))->ToString();
      v8::Handle<v8::Value> value = context->Global()->Get(key);

      if (TRI_IsTraceLogging(__FILE__)) {
        v8::String::Utf8Value keyName(key);

        if (*keyName != 0) {
          LOG_TRACE("copying key '%s' from context to sandbox", *keyName);
        }
      }

      if (value == context->Global()) {
        value = sandbox;
      }

      sandbox->Set(key, value);
    }

    context->DetachGlobal();
    context->Exit();
  }

  if (useSandbox) {
    return scope.Close(v8::True());
  }
  else {
    return scope.Close(result);
  }
}

////////////////////////////////////////////////////////////////////////////////
/// @brief checks if a file of any type or directory exists
///
/// @FUN{fs.exists(@FA{filename})}
///
/// Returns true if a file (of any type) or a directory exists at a given
/// path. If the file is a broken symbolic link, returns false.
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_Exists (v8::Arguments const& argv) {
  v8::HandleScope scope;

  // extract arguments
  if (argv.Length() != 1) {
    return scope.Close(v8::ThrowException(v8::String::New("usage: exists(<filename>)")));
  }

  string filename = TRI_ObjectToString(argv[0]);

  return scope.Close(TRI_ExistsFile(filename.c_str()) ? v8::True() : v8::False());;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief reads in a line from stdin
///
/// @FUN{console.getline()}
///
/// Reads in a line from the console.
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_Getline (v8::Arguments const& argv) {
  v8::HandleScope scope;

  string line;
  getline(cin, line);

  return scope.Close(v8::String::New(line.c_str(), line.size()));
}

////////////////////////////////////////////////////////////////////////////////
/// @brief reads a file and executes it
///
/// @FUN{internal.load(@FA{filename})}
///
/// Reads in a files and executes the contents in the current context.
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_Load (v8::Arguments const& argv) {
  v8::HandleScope scope;

  // extract arguments
  if (argv.Length() != 1) {
    return scope.Close(v8::ThrowException(v8::String::New("usage: load(<filename>)")));
  }

  v8::String::Utf8Value name(argv[0]);

  if (*name == 0) {
    return scope.Close(v8::ThrowException(v8::String::New("<filename> must be a string")));
  }

  char* content = TRI_SlurpFile(TRI_UNKNOWN_MEM_ZONE, *name);

  if (content == 0) {
    return scope.Close(v8::ThrowException(v8::String::New(TRI_last_error())));
  }

  TRI_ExecuteJavaScriptString(v8::Context::GetCurrent(), v8::String::New(content), argv[0], false);
  TRI_FreeString(TRI_UNKNOWN_MEM_ZONE, content);

  return scope.Close(v8::Undefined());
}

////////////////////////////////////////////////////////////////////////////////
/// @brief logs a message
///
/// @FUN{internal.log(@FA{level}, @FA{message})}
///
/// Logs the @FA{message} at the given log @FA{level}.
///
/// Valid log-level are:
///
/// - fatal
/// - error
/// - warning
/// - info
/// - debug
/// - trace
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_Log (v8::Arguments const& argv) {
  v8::HandleScope scope;

  if (argv.Length() != 2) {
    return scope.Close(v8::ThrowException(v8::String::New("usage: log(<level>, <message>)")));
  }

  v8::String::Utf8Value level(argv[0]);

  if (*level == 0) {
    return scope.Close(v8::ThrowException(v8::String::New("<level> must be a string")));
  }

  v8::String::Utf8Value message(argv[1]);

  if (*message == 0) {
    return scope.Close(v8::ThrowException(v8::String::New("<message> must be a string")));
  }

  if (TRI_CaseEqualString(*level, "fatal")) {
    LOG_FATAL("%s", *message);
  }
  else if (TRI_CaseEqualString(*level, "error")) {
    LOG_ERROR("%s", *message);
  }
  else if (TRI_CaseEqualString(*level, "warning")) {
    LOG_WARNING("%s", *message);
  }
  else if (TRI_CaseEqualString(*level, "info")) {
    LOG_INFO("%s", *message);
  }
  else if (TRI_CaseEqualString(*level, "debug")) {
    LOG_DEBUG("%s", *message);
  }
  else if (TRI_CaseEqualString(*level, "trace")) {
    LOG_TRACE("%s", *message);
  }
  else {
    LOG_ERROR("(unknown log level '%s') %s", *level, *message);
  }

  return scope.Close(v8::Undefined());
}

////////////////////////////////////////////////////////////////////////////////
/// @brief gets or sets the log-level
///
/// @FUN{internal.logLevel()}
///
/// Returns the current log-level as string.
///
/// @verbinclude fluent37
///
/// @FUN{internal.logLevel(@FA{level})}
///
/// Changes the current log-level. Valid log-level are:
///
/// - fatal
/// - error
/// - warning
/// - info
/// - debug
/// - trace
///
/// @verbinclude fluent38
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_LogLevel (v8::Arguments const& argv) {
  v8::HandleScope scope;

  if (1 <= argv.Length()) {
    v8::String::Utf8Value str(argv[0]);

    TRI_SetLogLevelLogging(*str);
  }

  return scope.Close(v8::String::New(TRI_LogLevelLogging()));
}

////////////////////////////////////////////////////////////////////////////////
/// @brief renames a file
///
/// @FUN{fs.move(@FA{source}, @FA{destination})}
///
/// Moves @FA{source} to @FA{destination}. Failure to move the file, or
/// specifying a directory for target when source is a file will throw an
/// exception.
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_Move (v8::Arguments const& argv) {
  v8::HandleScope scope;

  // extract two arguments
  if (argv.Length() != 2) {
    return scope.Close(v8::ThrowException(v8::String::New("usage: move(<source>, <destination>)")));
  }

  string source = TRI_ObjectToString(argv[0]);
  string destination = TRI_ObjectToString(argv[1]);

  int res = TRI_RenameFile(source.c_str(), destination.c_str());

  if (res != TRI_ERROR_NO_ERROR) {
    return scope.Close(v8::ThrowException(TRI_CreateErrorObject(res, "cannot move file")));
  }

  return scope.Close(v8::Undefined());;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief outputs the arguments
///
/// @FUN{internal.output(@FA{string1}, @FA{string2}, @FA{string3}, ...)}
///
/// Outputs the arguments to standard output.
///
/// @verbinclude fluent39
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_Output (v8::Arguments const& argv) {
  for (int i = 0; i < argv.Length(); i++) {
    v8::HandleScope scope;

    // extract the next argument
    v8::Handle<v8::Value> val = argv[i];

    // convert it into a string
    v8::String::Utf8Value utf8(val);

    if (*utf8 == 0) {
      continue;
    }

    // print the argument
    char const* ptr = *utf8;
    size_t len = utf8.length();

    while (0 < len) {
      ssize_t n = write(1, ptr, len);

      if (n < 0) {
        return v8::Undefined();
      }

      len -= n;
      ptr += n;
    }
  }

  return v8::Undefined();
}

////////////////////////////////////////////////////////////////////////////////
/// @brief returns the current process information
///
/// @FUN{internal.processStat()}
///
/// Returns information about the current process:
///
/// - minorPageFaults: The number of minor faults the process has made
///   which have not required loading a memory page from disk.
///
/// - majorPageFaults: The number of major faults the process has made
///   which have required loading a memory page from disk.
///
/// - userTime: Amount of time that this process has been scheduled in
///   user mode, measured in clock ticks.
///
/// - systemTime: Amount of time that this process has been scheduled
///   in kernel mode, measured in clock ticks.
///
/// - numberThreads: Number of threads in this process.
///
/// - residentSize: Resident Set Size: number of pages the process has
///   in real memory.  This is just the pages which count toward text,
///   data, or stack space.  This does not include pages which have
///   not been demand-loaded in, or which are swapped out.
///
/// - virtualSize: Virtual memory size in bytes.
///
/// @verbinclude system1
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_ProcessStat (v8::Arguments const& argv) {
  v8::HandleScope scope;

  v8::Handle<v8::Object> result = v8::Object::New();

  TRI_process_info_t info = TRI_ProcessInfoSelf();

  result->Set(v8::String::New("minorPageFaults"), v8::Number::New((double) info._minorPageFaults));
  result->Set(v8::String::New("majorPageFaults"), v8::Number::New((double) info._majorPageFaults));
  result->Set(v8::String::New("userTime"), v8::Number::New((double) info._userTime / (double) info._scClkTck));
  result->Set(v8::String::New("systemTime"), v8::Number::New((double) info._systemTime / (double) info._scClkTck));
  result->Set(v8::String::New("numberThreads"), v8::Number::New((double) info._numberThreads));
  result->Set(v8::String::New("residentSize"), v8::Number::New((double) info._residentSize));
  result->Set(v8::String::New("virtualSize"), v8::Number::New((double) info._virtualSize));

  return scope.Close(result);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief reads in a file
///
/// @FUN{internal.read(@FA{filename})}
///
/// Reads in a files and returns the content as string.
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_Read (v8::Arguments const& argv) {
  v8::HandleScope scope;

  if (argv.Length() != 1) {
    return scope.Close(v8::ThrowException(v8::String::New("usage: read(<filename>)")));
  }

  v8::String::Utf8Value name(argv[0]);

  if (*name == 0) {
    return scope.Close(v8::ThrowException(v8::String::New("<filename> must be a string")));
  }

  char* content = TRI_SlurpFile(TRI_UNKNOWN_MEM_ZONE, *name);

  if (content == 0) {
    return scope.Close(v8::ThrowException(v8::String::New(TRI_last_error())));
  }

  v8::Handle<v8::String> result = v8::String::New(content);

  TRI_FreeString(TRI_UNKNOWN_MEM_ZONE, content);

  return scope.Close(result);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief removes a file
///
/// @FUN{fs.remove(@FA{filename})}
///
/// Removes the file @FA{filename} at the given path. Throws an exception if the
/// path corresponds to anything that is not a file or a symbolic link. If
/// "path" refers to a symbolic link, removes the symbolic link.
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_Remove (v8::Arguments const& argv) {
  v8::HandleScope scope;

  // extract two arguments
  if (argv.Length() != 1) {
    return scope.Close(v8::ThrowException(v8::String::New("usage: remove(<filename>)")));
  }

  string filename = TRI_ObjectToString(argv[1]);

  int res = TRI_UnlinkFile(filename.c_str());

  if (res != TRI_ERROR_NO_ERROR) {
    return scope.Close(v8::ThrowException(TRI_CreateErrorObject(res, "cannot remove file")));
  }

  return scope.Close(v8::Undefined());;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief formats the arguments
///
/// @FUN{internal.sprintf(@FA{format}, @FA{argument1}, ...)}
///
/// Formats the arguments according to the format string @FA{format}.
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_SPrintF (v8::Arguments const& argv) {
  v8::HandleScope scope;

  size_t len = argv.Length();

  if (len == 0) {
    return scope.Close(v8::String::New(""));
  }

  v8::String::Utf8Value format(argv[0]);

  if (*format == 0) {
    return scope.Close(v8::ThrowException(v8::String::New("<format> must be a string")));
  }

  string result;

  size_t p = 1;

  for (char const* ptr = *format;  *ptr;  ++ptr) {
    if (*ptr == '%') {
      ++ptr;

      switch (*ptr) {
        case '%':
          result += '%';
          break;

        case 'd':
        case 'f':
        case 'i': {
          if (len <= p) {
            return scope.Close(v8::ThrowException(v8::String::New("not enough arguments")));
          }

          bool e;
          double f = TRI_ObjectToDouble(argv[p], e);

          if (e) {
            string msg = StringUtils::itoa(p) + ".th argument must be a number";
            return scope.Close(v8::ThrowException(v8::String::New(msg.c_str())));
          }

          char b[1024];

          if (*ptr == 'f') {
            snprintf(b, sizeof(b), "%f", f);
          }
          else {
            snprintf(b, sizeof(b), "%ld", (long) f);
          }

          ++p;

          result += b;

          break;
        }

        case 'o':
        case 's': {
          if (len <= p) {
            return scope.Close(v8::ThrowException(v8::String::New("not enough arguments")));
          }

          v8::String::Utf8Value text(argv[p]);

          if (*text == 0) {
            string msg = StringUtils::itoa(p) + ".th argument must be a string";
            return scope.Close(v8::ThrowException(v8::String::New(msg.c_str())));
          }

          ++p;

          result += *text;

          break;
        }

        default: {
          string msg = "found illegal format directive '" + string(1, *ptr) + "'";
          return scope.Close(v8::ThrowException(v8::String::New(msg.c_str())));
        }
      }
    }
    else {
      result += *ptr;
    }
  }

  for (size_t i = p;  i < len;  ++i) {
    v8::String::Utf8Value text(argv[i]);

    if (*text == 0) {
      string msg = StringUtils::itoa(i) + ".th argument must be a string";
      return scope.Close(v8::ThrowException(v8::String::New(msg.c_str())));
    }

    result += " ";
    result += *text;
  }

  return scope.Close(v8::String::New(result.c_str()));
}

////////////////////////////////////////////////////////////////////////////////
/// @brief sha256 sum
///
/// @FUN{internal.sha256(@FA{text})}
///
/// Computes a sha256 for the @FA{text}.
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_Sha256 (v8::Arguments const& argv) {
  v8::HandleScope scope;

  // extract arguments
  if (argv.Length() != 1) {
    return scope.Close(v8::ThrowException(v8::String::New("usage: sha256(<text>)")));
  }

  string key = TRI_ObjectToString(argv[0]);

  // create sha256
  char* hash = 0;
  size_t hashLen;

  SslInterface::sslSHA256(key.c_str(), key.size(), hash, hashLen);

  // as hex
  char* hex = 0;
  size_t hexLen;

  SslInterface::sslHEX(hash, hashLen, hex, hexLen);

  delete[] hash;

  // and return
  v8::Handle<v8::String> hashStr = v8::String::New(hex, hexLen);

  delete[] hex;

  return scope.Close(hashStr);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief returns the current time
///
/// @FUN{internal.time()}
///
/// Returns the current time in seconds.
///
/// @verbinclude fluent36
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_Time (v8::Arguments const& argv) {
  v8::HandleScope scope;

  return scope.Close(v8::Number::New(TRI_microtime()));
}

////////////////////////////////////////////////////////////////////////////////
/// @brief returns the current time
///
/// @FUN{internal.wait(<seconds>)}
///
/// Wait for <seconds>, call the garbage collection.
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JS_Wait (v8::Arguments const& argv) {
  v8::HandleScope scope;

  // extract arguments
  if (argv.Length() != 1) {
    return scope.Close(v8::ThrowException(v8::String::New("usage: wait(<seconds>)")));
  }

  double n = TRI_ObjectToDouble(argv[0]);
  double until = TRI_microtime() + n;

  while(! v8::V8::IdleNotification()) {
  }

  while (TRI_microtime() < until) {
    while(! v8::V8::IdleNotification()) {
    }

    usleep(100);
  }

  return scope.Close(v8::Undefined());
}

////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////

// -----------------------------------------------------------------------------
// --SECTION--                                                  public functions
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @addtogroup V8Utils
/// @{
////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////
/// @brief adds attributes to array
////////////////////////////////////////////////////////////////////////////////

void TRI_AugmentObject (v8::Handle<v8::Value> value, TRI_json_t const* json) {
  v8::HandleScope scope;

  if (! value->IsObject()) {
    return;
  }

  if (json->_type != TRI_JSON_ARRAY) {
    return;
  }

  v8::Handle<v8::Object> object = value->ToObject();

  size_t n = json->_value._objects._length;

  for (size_t i = 0;  i < n;  i += 2) {
    TRI_json_t* key = (TRI_json_t*) TRI_AtVector(&json->_value._objects, i);

    if (key->_type != TRI_JSON_STRING) {
      continue;
    }

    TRI_json_t* j = (TRI_json_t*) TRI_AtVector(&json->_value._objects, i + 1);
    v8::Handle<v8::Value> val = TRI_ObjectJson(j);

    object->Set(v8::String::New(key->_value._string.data), val);
  }
}

////////////////////////////////////////////////////////////////////////////////
/// @brief reports an exception
////////////////////////////////////////////////////////////////////////////////

string TRI_StringifyV8Exception (v8::TryCatch* tryCatch) {
  v8::HandleScope handle_scope;

  v8::String::Utf8Value exception(tryCatch->Exception());
  const char* exceptionString = *exception;
  v8::Handle<v8::Message> message = tryCatch->Message();
  string result;

  // V8 didn't provide any extra information about this error; just print the exception.
  if (message.IsEmpty()) {
    if (exceptionString == 0) {
      result = "JavaScript exception\n";
    }
    else {
      result = "JavaScript exception: " + string(exceptionString) + "\n";
    }
  }
  else {
    v8::String::Utf8Value filename(message->GetScriptResourceName());
    const char* filenameString = *filename;
    int linenum = message->GetLineNumber();
    int start = message->GetStartColumn() + 1;
    int end = message->GetEndColumn();

    if (filenameString == 0) {
      if (exceptionString == 0) {
        result = "JavaScript exception\n";
      }
      else {
        result = "JavaScript exception: " + string(exceptionString) + "\n";
      }
    }
    else {
      if (exceptionString == 0) {
        result = "JavaScript exception in file '" + string(filenameString) + "' at "
               + StringUtils::itoa(linenum) + "," + StringUtils::itoa(start) + "\n";
      }
      else {
        result = "JavaScript exception in file '" + string(filenameString) + "' at "
               + StringUtils::itoa(linenum) + "," + StringUtils::itoa(start)
               + ": " + exceptionString + "\n";
      }
    }

    v8::String::Utf8Value sourceline(message->GetSourceLine());

    if (*sourceline) {
      string l = *sourceline;

      result += "!" + l + "\n";

      if (1 < start) {
        l = string(start - 1, ' ');
      }
      else {
        l = "";
      }

      l += string((size_t)(end - start + 1), '^');

      result += "!" + l + "\n";
    }

    v8::String::Utf8Value stacktrace(tryCatch->StackTrace());

    if (*stacktrace && stacktrace.length() > 0) {
      result += "stacktrace: " + string(*stacktrace) + "\n";
    }
  }

  return result;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief prints an exception and stacktrace
////////////////////////////////////////////////////////////////////////////////

void TRI_LogV8Exception (v8::TryCatch* tryCatch) {
  v8::HandleScope handle_scope;

  v8::String::Utf8Value exception(tryCatch->Exception());
  const char* exceptionString = *exception;
  v8::Handle<v8::Message> message = tryCatch->Message();

  // V8 didn't provide any extra information about this error; just print the exception.
  if (message.IsEmpty()) {
    if (exceptionString == 0) {
      LOG_ERROR("JavaScript exception");
    }
    else {
      LOG_ERROR("JavaScript exception: %s", exceptionString);
    }
  }
  else {
    v8::String::Utf8Value filename(message->GetScriptResourceName());
    const char* filenameString = *filename;
    int linenum = message->GetLineNumber();
    int start = message->GetStartColumn() + 1;
    int end = message->GetEndColumn();

    if (filenameString == 0) {
      if (exceptionString == 0) {
        LOG_ERROR("JavaScript exception");
      }
      else {
        LOG_ERROR("JavaScript exception: %s", exceptionString);
      }
    }
    else {
      if (exceptionString == 0) {
        LOG_ERROR("JavaScript exception in file '%s' at %d,%d", filenameString, linenum, start);
      }
      else {
        LOG_ERROR("JavaScript exception in file '%s' at %d,%d: %s", filenameString, linenum, start, exceptionString);
      }
    }

    v8::String::Utf8Value sourceline(message->GetSourceLine());

    if (*sourceline) {
      string l = *sourceline;

      LOG_ERROR("!%s", l.c_str());

      if (1 < start) {
        l = string(start - 1, ' ');
      }
      else {
        l = "";
      }

      l += string((size_t)(end - start + 1), '^');

      LOG_ERROR("!%s", l.c_str());
    }

    v8::String::Utf8Value stacktrace(tryCatch->StackTrace());

    if (*stacktrace && stacktrace.length() > 0) {
      LOG_ERROR("stacktrace: %s", *stacktrace);
    }
  }
}

////////////////////////////////////////////////////////////////////////////////
/// @brief reads a file into the current context
////////////////////////////////////////////////////////////////////////////////

bool TRI_LoadJavaScriptFile (v8::Handle<v8::Context> context, char const* filename) {
  return LoadJavaScriptFile(context, filename, false);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief reads all files from a directory into the current context
////////////////////////////////////////////////////////////////////////////////

bool TRI_LoadJavaScriptDirectory (v8::Handle<v8::Context> context, char const* path) {
  return LoadJavaScriptDirectory(context, path, false);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief executes a file in the current context
////////////////////////////////////////////////////////////////////////////////

bool TRI_ExecuteJavaScriptFile (v8::Handle<v8::Context> context, char const* filename) {
  return LoadJavaScriptFile(context, filename, true);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief executes all files from a directory in the current context
////////////////////////////////////////////////////////////////////////////////

bool TRI_ExecuteJavaScriptDirectory (v8::Handle<v8::Context> context, char const* path) {
  return LoadJavaScriptDirectory(context, path, true);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief executes a string within a V8 context, optionally print the result
////////////////////////////////////////////////////////////////////////////////

v8::Handle<v8::Value> TRI_ExecuteJavaScriptString (v8::Handle<v8::Context> context,
                                                   v8::Handle<v8::String> source,
                                                   v8::Handle<v8::Value> name,
                                                   bool printResult) {
  v8::HandleScope scope;

  v8::Handle<v8::Value> result;
  v8::Handle<v8::Script> script = v8::Script::Compile(source, name);

  // compilation failed, print errors that happened during compilation
  if (script.IsEmpty()) {
    return scope.Close(result);
  }

  // compilation succeeded, run the script
  result = script->Run();

  if (result.IsEmpty()) {
    return scope.Close(result);
  }
  else {

    // if all went well and the result wasn't undefined then print the returned value
    if (printResult && ! result->IsUndefined()) {
      v8::TryCatch tryCatch;

      v8::Handle<v8::String> printFuncName = v8::String::New("print");
      v8::Handle<v8::Function> print = v8::Handle<v8::Function>::Cast(context->Global()->Get(printFuncName));

      v8::Handle<v8::Value> args[] = { result };
      print->Call(print, 1, args);

      if (tryCatch.HasCaught()) {
        TRI_LogV8Exception(&tryCatch);
      }
    }

    return scope.Close(result);
  }
}

////////////////////////////////////////////////////////////////////////////////
/// @brief creates an error in a javascript object
////////////////////////////////////////////////////////////////////////////////

v8::Handle<v8::Object> TRI_CreateErrorObject (int errorNumber, string const& message) {
  TRI_v8_global_t* v8g;
  v8::HandleScope scope;

  v8g = (TRI_v8_global_t*) v8::Isolate::GetCurrent()->GetData();

  string msg;
  if (message.size()) {
    msg = message;
  }
  else {
    msg = TRI_errno_string(errorNumber) + string(": ") + message;
  }
  v8::Handle<v8::String> errorMessage = v8::String::New(msg.c_str());

  v8::Handle<v8::Object> errorObject = v8::Exception::Error(errorMessage)->ToObject();
  v8::Handle<v8::Value> proto = v8g->ErrorTempl->NewInstance();

  errorObject->Set(v8::String::New("errorNum"), v8::Number::New(errorNumber));
  errorObject->Set(v8::String::New("errorMessage"), errorMessage);

  if (! proto.IsEmpty()) {
    errorObject->SetPrototype(proto);
  }

  return errorObject;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief stores the V8 utils functions inside the global variable
////////////////////////////////////////////////////////////////////////////////

void TRI_InitV8Utils (v8::Handle<v8::Context> context, string const& path) {
  v8::HandleScope scope;

  v8::Handle<v8::FunctionTemplate> ft;
  v8::Handle<v8::ObjectTemplate> rt;

  // check the isolate
  v8::Isolate* isolate = v8::Isolate::GetCurrent();
  TRI_v8_global_t* v8g = (TRI_v8_global_t*) isolate->GetData();

  if (v8g == 0) {
    v8g = new TRI_v8_global_t;
    isolate->SetData(v8g);
  }

  // .............................................................................
  // create the Dictionary constructor
  // .............................................................................

  ft = v8::FunctionTemplate::New(WeakDictionaryInvocationCallback);
  ft->SetClassName(v8::String::New("WeakDictionary"));

  rt = ft->InstanceTemplate();
  rt->SetInternalFieldCount(2);

  rt->SetNamedPropertyHandler(MapGetWeakDictionary,        // NamedPropertyGetter
                              MapSetWeakDictionary,        // NamedPropertySetter
                              PropertyQueryWeakDictionary, // NamedPropertyQuery,
                              0,                           // NamedPropertyDeleter deleter = 0,
                              KeysOfWeakDictionary         // NamedPropertyEnumerator,
                                                           // Handle<Value> data = Handle<Value>());
                              );

  v8g->DictionaryTempl = v8::Persistent<v8::ObjectTemplate>::New(rt);

  // must come after SetInternalFieldCount
  context->Global()->Set(v8::String::New("WeakDictionary"), ft->GetFunction());

  // .............................................................................
  // create the global functions
  // .............................................................................

  context->Global()->Set(v8::String::New("SYS_EXECUTE"),
                         v8::FunctionTemplate::New(JS_Execute)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("FS_EXISTS"),
                         v8::FunctionTemplate::New(JS_Exists)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("SYS_GETLINE"),
                         v8::FunctionTemplate::New(JS_Getline)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("SYS_LOAD"),
                         v8::FunctionTemplate::New(JS_Load)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("SYS_LOG"),
                         v8::FunctionTemplate::New(JS_Log)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("SYS_LOG_LEVEL"),
                         v8::FunctionTemplate::New(JS_LogLevel)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("FS_MOVE"),
                         v8::FunctionTemplate::New(JS_Move)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("FS_REMOVE"),
                         v8::FunctionTemplate::New(JS_Remove)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("SYS_OUTPUT"),
                         v8::FunctionTemplate::New(JS_Output)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("SYS_PROCESS_STAT"),
                         v8::FunctionTemplate::New(JS_ProcessStat)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("SYS_READ"),
                         v8::FunctionTemplate::New(JS_Read)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("SYS_SHA256"),
                         v8::FunctionTemplate::New(JS_Sha256)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("SYS_SPRINTF"),
                         v8::FunctionTemplate::New(JS_SPrintF)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("SYS_TIME"),
                         v8::FunctionTemplate::New(JS_Time)->GetFunction(),
                         v8::ReadOnly);

  context->Global()->Set(v8::String::New("SYS_WAIT"),
                         v8::FunctionTemplate::New(JS_Wait)->GetFunction(),
                         v8::ReadOnly);

  // .............................................................................
  // create the global variables
  // .............................................................................

  vector<string> paths = StringUtils::split(path, ";:");

  v8::Handle<v8::Array> modulesPaths = v8::Array::New();

  for (uint32_t i = 0;  i < (uint32_t) paths.size();  ++i) {
    modulesPaths->Set(i, v8::String::New(paths[i].c_str()));
  }

  context->Global()->Set(v8::String::New("MODULES_PATH"), modulesPaths);
}

////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////

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