////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 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
////////////////////////////////////////////////////////////////////////////////

#include "v8-shape-conv.h"

#include "Basics/conversions.h"
#include "Logger/Logger.h"
#include "Basics/StringBuffer.h"
#include "Basics/StringUtils.h"
#include "Basics/tri-strings.h"
#include "V8/v8-json.h"
#include "V8/v8-utils.h"
#include "VocBase/VocShaper.h"

using namespace arangodb::basics;

static int FillShapeValueJson(v8::Isolate* isolate, VocShaper* shaper,
                              TRI_shape_value_t* dst,
                              v8::Handle<v8::Value> const json, size_t level,
                              std::set<int>& seenHashes,
                              std::vector<v8::Handle<v8::Object>>& seenObjects,
                              bool create);

static v8::Handle<v8::Value> JsonShapeData(v8::Isolate* isolate,
                                           v8::Handle<v8::Value>&, VocShaper*,
                                           TRI_shape_t const*, char const*,
                                           size_t);

static v8::Handle<v8::Value> JsonShapeData(v8::Isolate* isolate, VocShaper*,
                                           TRI_shape_t const*, char const*,
                                           size_t);

////////////////////////////////////////////////////////////////////////////////
/// @brief shape cache (caches pointer to last shape)
////////////////////////////////////////////////////////////////////////////////

typedef struct shape_cache_s {
  TRI_shape_sid_t _sid;
  TRI_shape_t const* _shape;
} shape_cache_t;

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a null into TRI_shape_value_t
////////////////////////////////////////////////////////////////////////////////

static int FillShapeValueNull(VocShaper* shaper, TRI_shape_value_t* dst) {
  dst->_type = TRI_SHAPE_NULL;
  dst->_sid = BasicShapes::TRI_SHAPE_SID_NULL;
  dst->_fixedSized = true;
  dst->_size = 0;
  dst->_value = nullptr;

  return TRI_ERROR_NO_ERROR;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a boolean into TRI_shape_value_t
////////////////////////////////////////////////////////////////////////////////

static int FillShapeValueBoolean(VocShaper* shaper, TRI_shape_value_t* dst,
                                 v8::Handle<v8::Boolean> const json) {
  TRI_shape_boolean_t* ptr;

  dst->_type = TRI_SHAPE_BOOLEAN;
  dst->_sid = BasicShapes::TRI_SHAPE_SID_BOOLEAN;
  dst->_fixedSized = true;
  dst->_size = sizeof(TRI_shape_boolean_t);
  dst->_value = (char*)(ptr = (TRI_shape_boolean_t*)TRI_Allocate(
                            shaper->memoryZone(), dst->_size, false));

  if (dst->_value == nullptr) {
    return TRI_ERROR_OUT_OF_MEMORY;
  }

  *ptr = json->Value() ? 1 : 0;

  return TRI_ERROR_NO_ERROR;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a boolean into TRI_shape_value_t
////////////////////////////////////////////////////////////////////////////////

static int FillShapeValueBoolean(VocShaper* shaper, TRI_shape_value_t* dst,
                                 v8::Handle<v8::BooleanObject> const json) {
  TRI_shape_boolean_t* ptr;

  dst->_type = TRI_SHAPE_BOOLEAN;
  dst->_sid = BasicShapes::TRI_SHAPE_SID_BOOLEAN;
  dst->_fixedSized = true;
  dst->_size = sizeof(TRI_shape_boolean_t);
  dst->_value = (char*)(ptr = (TRI_shape_boolean_t*)TRI_Allocate(
                            shaper->memoryZone(), dst->_size, false));

  if (dst->_value == nullptr) {
    return TRI_ERROR_OUT_OF_MEMORY;
  }

  *ptr = json->BooleanValue() ? 1 : 0;

  return TRI_ERROR_NO_ERROR;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a number into TRI_shape_value_t
////////////////////////////////////////////////////////////////////////////////

static int FillShapeValueNumber(VocShaper* shaper, TRI_shape_value_t* dst,
                                v8::Handle<v8::Number> const json) {
  TRI_shape_number_t* ptr;

  dst->_type = TRI_SHAPE_NUMBER;
  dst->_sid = BasicShapes::TRI_SHAPE_SID_NUMBER;
  dst->_fixedSized = true;
  dst->_size = sizeof(TRI_shape_number_t);
  dst->_value = (char*)(ptr = (TRI_shape_number_t*)TRI_Allocate(
                            shaper->memoryZone(), dst->_size, false));

  if (dst->_value == nullptr) {
    return TRI_ERROR_OUT_OF_MEMORY;
  }

  *ptr = json->Value();

  return TRI_ERROR_NO_ERROR;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a number into TRI_shape_value_t
////////////////////////////////////////////////////////////////////////////////

static int FillShapeValueNumber(VocShaper* shaper, TRI_shape_value_t* dst,
                                v8::Handle<v8::NumberObject> const json) {
  TRI_shape_number_t* ptr;

  dst->_type = TRI_SHAPE_NUMBER;
  dst->_sid = BasicShapes::TRI_SHAPE_SID_NUMBER;
  dst->_fixedSized = true;
  dst->_size = sizeof(TRI_shape_number_t);
  dst->_value = (char*)(ptr = (TRI_shape_number_t*)TRI_Allocate(
                            shaper->memoryZone(), dst->_size, false));

  if (dst->_value == nullptr) {
    return TRI_ERROR_OUT_OF_MEMORY;
  }

  *ptr = json->NumberValue();

  return TRI_ERROR_NO_ERROR;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a string into TRI_shape_value_t
////////////////////////////////////////////////////////////////////////////////

static int FillShapeValueString(VocShaper* shaper, TRI_shape_value_t* dst,
                                v8::Handle<v8::String> const json) {
  char* ptr;

  TRI_Utf8ValueNFC str(TRI_UNKNOWN_MEM_ZONE, json);

  if (*str == nullptr) {
    // empty string
    dst->_type = TRI_SHAPE_SHORT_STRING;
    dst->_sid = BasicShapes::TRI_SHAPE_SID_SHORT_STRING;
    dst->_fixedSized = true;
    dst->_size =
        sizeof(TRI_shape_length_short_string_t) + TRI_SHAPE_SHORT_STRING_CUT;
    dst->_value =
        (ptr = (char*)TRI_Allocate(shaper->memoryZone(), dst->_size, true));

    if (dst->_value == nullptr) {
      return TRI_ERROR_OUT_OF_MEMORY;
    }

    *((TRI_shape_length_short_string_t*)ptr) = 1;
  } else {
    size_t const size = str.length();

    if (size < TRI_SHAPE_SHORT_STRING_CUT) {  // includes '\0'
      dst->_type = TRI_SHAPE_SHORT_STRING;
      dst->_sid = BasicShapes::TRI_SHAPE_SID_SHORT_STRING;
      dst->_fixedSized = true;
      dst->_size =
          sizeof(TRI_shape_length_short_string_t) + TRI_SHAPE_SHORT_STRING_CUT;
      dst->_value =
          (ptr = (char*)TRI_Allocate(shaper->memoryZone(), dst->_size, true));

      if (dst->_value == nullptr) {
        return TRI_ERROR_OUT_OF_MEMORY;
      }

      *((TRI_shape_length_short_string_t*)ptr) =
          (TRI_shape_length_short_string_t)size + 1;
      memcpy(ptr + sizeof(TRI_shape_length_short_string_t), *str, size + 1);
    } else {
      dst->_type = TRI_SHAPE_LONG_STRING;
      dst->_sid = BasicShapes::TRI_SHAPE_SID_LONG_STRING;
      dst->_fixedSized = false;
      dst->_size = sizeof(TRI_shape_length_long_string_t) + size + 1;
      dst->_value =
          (ptr = (char*)TRI_Allocate(shaper->memoryZone(), dst->_size, false));

      if (dst->_value == nullptr) {
        return TRI_ERROR_OUT_OF_MEMORY;
      }

      *((TRI_shape_length_long_string_t*)ptr) =
          (TRI_shape_length_long_string_t)size + 1;
      memcpy(ptr + sizeof(TRI_shape_length_long_string_t), *str, size + 1);
    }
  }

  return TRI_ERROR_NO_ERROR;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a json list into TRI_shape_value_t
////////////////////////////////////////////////////////////////////////////////

static int FillShapeValueList(v8::Isolate* isolate, VocShaper* shaper,
                              TRI_shape_value_t* dst,
                              v8::Handle<v8::Array> const json, size_t level,
                              std::set<int>& seenHashes,
                              std::vector<v8::Handle<v8::Object>>& seenObjects,
                              bool create) {
  size_t total;

  TRI_shape_value_t* values;
  TRI_shape_value_t* p;
  TRI_shape_value_t* e;

  bool hs;
  bool hl;

  TRI_shape_sid_t s;
  TRI_shape_sid_t l;

  TRI_shape_size_t* offsets;
  TRI_shape_size_t offset;

  TRI_shape_t const* found;

  char* ptr;

  // check for special case "empty list"
  uint32_t n = json->Length();

  if (n == 0) {
    dst->_type = TRI_SHAPE_LIST;
    dst->_sid = BasicShapes::TRI_SHAPE_SID_LIST;
    dst->_fixedSized = false;
    dst->_size = sizeof(TRI_shape_length_list_t);
    dst->_value = (ptr = static_cast<char*>(
                       TRI_Allocate(shaper->memoryZone(), dst->_size, false)));

    if (dst->_value == nullptr) {
      return TRI_ERROR_OUT_OF_MEMORY;
    }

    *(TRI_shape_length_list_t*)ptr = 0;

    return TRI_ERROR_NO_ERROR;
  }

  // convert into TRI_shape_value_t array
  p = (values = static_cast<TRI_shape_value_t*>(TRI_Allocate(
           shaper->memoryZone(), sizeof(TRI_shape_value_t) * n, true)));

  if (p == nullptr) {
    return TRI_ERROR_OUT_OF_MEMORY;
  }

  total = 0;
  e = values + n;

  for (uint32_t i = 0; i < n; ++i, ++p) {
    v8::Handle<v8::Value> el = json->Get(i);
    int res = FillShapeValueJson(isolate, shaper, p, el, level + 1, seenHashes,
                                 seenObjects, create);

    if (res != TRI_ERROR_NO_ERROR) {
      for (e = p, p = values; p < e; ++p) {
        if (p->_value != nullptr) {
          TRI_Free(shaper->memoryZone(), p->_value);
        }
      }

      TRI_Free(shaper->memoryZone(), values);
      return res;
    }

    total += static_cast<size_t>(p->_size);
  }

  // check if this list is homoegenous
  hs = true;
  hl = true;

  s = values[0]._sid;
  l = values[0]._size;
  p = values;

  for (; p < e; ++p) {
    if (p->_sid != s) {
      hs = false;
      break;
    }

    if (p->_size != l) {
      hl = false;
    }
  }

  // homogeneous sized
  if (hs && hl) {
    auto shape = static_cast<TRI_homogeneous_sized_list_shape_t*>(
        TRI_Allocate(shaper->memoryZone(),
                     sizeof(TRI_homogeneous_sized_list_shape_t), true));

    if (shape == nullptr) {
      for (p = values; p < e; ++p) {
        if (p->_value != nullptr) {
          TRI_Free(shaper->memoryZone(), p->_value);
        }
      }

      TRI_Free(shaper->memoryZone(), values);
      return TRI_ERROR_OUT_OF_MEMORY;
    }

    shape->base._size = sizeof(TRI_homogeneous_sized_list_shape_t);
    shape->base._type = TRI_SHAPE_HOMOGENEOUS_SIZED_LIST;
    shape->base._dataSize = TRI_SHAPE_SIZE_VARIABLE;
    shape->_sidEntry = s;
    shape->_sizeEntry = l;

    found = shaper->findShape(&shape->base, create);

    if (found == nullptr) {
      for (p = values; p < e; ++p) {
        if (p->_value != nullptr) {
          TRI_Free(shaper->memoryZone(), p->_value);
        }
      }

      TRI_Free(shaper->memoryZone(), values);
      TRI_Free(shaper->memoryZone(), shape);

      LOG(TRACE) << "shaper failed to find shape of type " << shape->base._type;

      if (!create) {
        return TRI_RESULT_ELEMENT_NOT_FOUND;
      }

      return TRI_ERROR_INTERNAL;
    }

    TRI_ASSERT(found != nullptr);

    dst->_type = found->_type;
    dst->_sid = found->_sid;

    dst->_fixedSized = false;
    dst->_size = sizeof(TRI_shape_length_list_t) + total;
    dst->_value = (ptr = static_cast<char*>(
                       TRI_Allocate(shaper->memoryZone(), dst->_size, false)));

    if (dst->_value == nullptr) {
      for (p = values; p < e; ++p) {
        if (p->_value != nullptr) {
          TRI_Free(shaper->memoryZone(), p->_value);
        }
      }

      TRI_Free(shaper->memoryZone(), values);

      return TRI_ERROR_OUT_OF_MEMORY;
    }

    // copy sub-objects into data space
    *(TRI_shape_length_list_t*)ptr = (TRI_shape_length_list_t)n;
    ptr += sizeof(TRI_shape_length_list_t);

    for (p = values; p < e; ++p) {
      TRI_ASSERT(p->_value != nullptr || p->_size == 0);
      if (p->_value != nullptr) {
        memcpy(ptr, p->_value, static_cast<size_t>(p->_size));
      }
      ptr += p->_size;
    }
  }

  // homogeneous
  else if (hs) {
    auto shape = static_cast<TRI_homogeneous_list_shape_t*>(TRI_Allocate(
        shaper->memoryZone(), sizeof(TRI_homogeneous_list_shape_t), true));

    if (shape == nullptr) {
      for (p = values; p < e; ++p) {
        if (p->_value != nullptr) {
          TRI_Free(shaper->memoryZone(), p->_value);
        }
      }

      TRI_Free(shaper->memoryZone(), values);

      return TRI_ERROR_OUT_OF_MEMORY;
    }

    shape->base._size = sizeof(TRI_homogeneous_list_shape_t);
    shape->base._type = TRI_SHAPE_HOMOGENEOUS_LIST;
    shape->base._dataSize = TRI_SHAPE_SIZE_VARIABLE;
    shape->_sidEntry = s;

    // if found returns non-NULL, it will free the shape!!
    found = shaper->findShape(&shape->base, create);

    if (found == nullptr) {
      for (p = values; p < e; ++p) {
        if (p->_value != nullptr) {
          TRI_Free(shaper->memoryZone(), p->_value);
        }
      }

      LOG(TRACE) << "shaper failed to find shape " << shape->base._type;

      TRI_Free(shaper->memoryZone(), values);
      TRI_Free(shaper->memoryZone(), shape);

      if (!create) {
        return TRI_RESULT_ELEMENT_NOT_FOUND;
      }

      return TRI_ERROR_INTERNAL;
    }

    TRI_ASSERT(found != nullptr);

    dst->_type = found->_type;
    dst->_sid = found->_sid;

    offset =
        sizeof(TRI_shape_length_list_t) + (n + 1) * sizeof(TRI_shape_size_t);

    dst->_fixedSized = false;
    dst->_size = offset + total;
    dst->_value = (ptr = static_cast<char*>(
                       TRI_Allocate(shaper->memoryZone(), dst->_size, true)));

    if (dst->_value == nullptr) {
      for (p = values; p < e; ++p) {
        if (p->_value != nullptr) {
          TRI_Free(shaper->memoryZone(), p->_value);
        }
      }

      TRI_Free(shaper->memoryZone(), values);

      return TRI_ERROR_OUT_OF_MEMORY;
    }

    // copy sub-objects into data space
    *(TRI_shape_length_list_t*)ptr = (TRI_shape_length_list_t)n;
    ptr += sizeof(TRI_shape_length_list_t);

    offsets = (TRI_shape_size_t*)ptr;
    ptr += (n + 1) * sizeof(TRI_shape_size_t);

    for (p = values; p < e; ++p) {
      *offsets++ = offset;
      offset += p->_size;

      TRI_ASSERT(p->_value != nullptr || p->_size == 0);
      if (p->_value != nullptr) {
        memcpy(ptr, p->_value, static_cast<size_t>(p->_size));
      }
      ptr += p->_size;
    }

    *offsets = offset;
  }

  // in-homogeneous
  else {
    dst->_type = TRI_SHAPE_LIST;
    dst->_sid = BasicShapes::TRI_SHAPE_SID_LIST;

    offset = sizeof(TRI_shape_length_list_t) + n * sizeof(TRI_shape_sid_t) +
             (n + 1) * sizeof(TRI_shape_size_t);

    dst->_fixedSized = false;
    dst->_size = offset + total;
    dst->_value =
        (ptr = (char*)TRI_Allocate(shaper->memoryZone(), dst->_size, true));

    if (dst->_value == nullptr) {
      for (p = values; p < e; ++p) {
        if (p->_value != nullptr) {
          TRI_Free(shaper->memoryZone(), p->_value);
        }
      }

      TRI_Free(shaper->memoryZone(), values);
      return TRI_ERROR_OUT_OF_MEMORY;
    }

    // copy sub-objects into data space
    *(TRI_shape_length_list_t*)ptr = (TRI_shape_length_list_t)n;
    ptr += sizeof(TRI_shape_length_list_t);

    TRI_shape_sid_t* sids = (TRI_shape_sid_t*)ptr;
    ptr += n * sizeof(TRI_shape_sid_t);

    offsets = (TRI_shape_size_t*)ptr;
    ptr += (n + 1) * sizeof(TRI_shape_size_t);

    for (p = values; p < e; ++p) {
      *sids++ = p->_sid;

      *offsets++ = offset;
      offset += p->_size;

      TRI_ASSERT(p->_value != nullptr || p->_size == 0);
      if (p->_value != nullptr) { 
        memcpy(ptr, p->_value, static_cast<size_t>(p->_size));
      }
      ptr += p->_size;
    }

    *offsets = offset;
  }

  // free TRI_shape_value_t array
  for (p = values; p < e; ++p) {
    if (p->_value != nullptr) {
      TRI_Free(shaper->memoryZone(), p->_value);
    }
  }

  TRI_Free(shaper->memoryZone(), values);
  return TRI_ERROR_NO_ERROR;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a json array into TRI_shape_value_t
////////////////////////////////////////////////////////////////////////////////

static int FillShapeValueArray(v8::Isolate* isolate, VocShaper* shaper,
                               TRI_shape_value_t* dst,
                               v8::Handle<v8::Object> const json, size_t level,
                               std::set<int>& seenHashes,
                               std::vector<v8::Handle<v8::Object>>& seenObjects,
                               bool create) {
  v8::HandleScope scope(isolate);
  TRI_shape_value_t* values;
  TRI_shape_value_t* p;
  TRI_shape_value_t* e;

  TRI_array_shape_t* a;

  TRI_shape_sid_t* sids;
  TRI_shape_aid_t* aids;
  TRI_shape_size_t* offsetsF;
  TRI_shape_size_t* offsetsV;
  TRI_shape_size_t offset;

  TRI_shape_t const* found;

  char* ptr;

  // number of attributes
  v8::Handle<v8::Array> names = json->GetOwnPropertyNames();
  uint32_t n = names->Length();

  // convert into TRI_shape_value_t array
  p = (values = static_cast<TRI_shape_value_t*>(TRI_Allocate(
           shaper->memoryZone(), n * sizeof(TRI_shape_value_t), true)));

  if (p == nullptr) {
    return TRI_ERROR_OUT_OF_MEMORY;
  }

  size_t total = 0;

  size_t f = 0;
  size_t v = 0;

  for (uint32_t i = 0; i < n; ++i, ++p) {
    v8::Handle<v8::Value> key = names->Get(i);

    // first find an identifier for the name
    TRI_Utf8ValueNFC keyStr(TRI_UNKNOWN_MEM_ZONE, key);

    if (*keyStr == 0 || keyStr.length() == 0) {
      --p;
      continue;
    }

    if ((*keyStr)[0] == '_' && level == 0) {
      // on top level, strip reserved attributes before shaping
      char const* k = (*keyStr);
      if (strcmp(k, "_key") == 0 || strcmp(k, "_rev") == 0 ||
          strcmp(k, "_id") == 0 || strcmp(k, "_from") == 0 ||
          strcmp(k, "_to") == 0) {
        // found a reserved attribute - discard it
        --p;
        continue;
      }
    }

    if (create) {
      p->_aid = shaper->findOrCreateAttributeByName(*keyStr);
    } else {
      p->_aid = shaper->lookupAttributeByName(*keyStr);
    }

    int res;

    // convert value
    if (p->_aid == 0) {
      if (create) {
        res = TRI_ERROR_INTERNAL;
      } else {
        res = TRI_RESULT_ELEMENT_NOT_FOUND;
      }
    } else {
      v8::Handle<v8::Value> val = json->Get(key);
      res = FillShapeValueJson(isolate, shaper, p, val, level + 1, seenHashes,
                               seenObjects, create);
    }

    if (res != TRI_ERROR_NO_ERROR) {
      for (e = p, p = values; p < e; ++p) {
        if (p->_value != nullptr) {
          TRI_Free(shaper->memoryZone(), p->_value);
        }
      }

      TRI_Free(shaper->memoryZone(), values);
      return res;
    }

    total += static_cast<size_t>(p->_size);

    // count fixed and variable sized values
    if (p->_fixedSized) {
      ++f;
    } else {
      ++v;
    }
  }

  // adjust n
  n = (uint32_t)(f + v);

  // add variable offset table size
  total += (v + 1) * sizeof(TRI_shape_size_t);

  // now sort the shape entries
  if (n > 1) {
    TRI_SortShapeValues(values, (size_t)n);
  }

#ifdef DEBUG_JSON_SHAPER
  printf("shape values\n------------\ntotal: %u, fixed: %u, variable: %u\n",
         (unsigned int)n, (unsigned int)f, (unsigned int)v);
  TRI_PrintShapeValues(values, n);
  printf("\n");
#endif

  // generate shape structure
  size_t const totalSize =
      sizeof(TRI_array_shape_t) + n * sizeof(TRI_shape_sid_t) +
      n * sizeof(TRI_shape_aid_t) + (f + 1) * sizeof(TRI_shape_size_t);

  a = (TRI_array_shape_t*)(ptr = (char*)TRI_Allocate(shaper->memoryZone(),
                                                     totalSize, true));

  if (ptr == nullptr) {
    e = values + n;

    for (p = values; p < e; ++p) {
      if (p->_value != nullptr) {
        TRI_Free(shaper->memoryZone(), p->_value);
      }
    }

    TRI_Free(shaper->memoryZone(), values);

    return TRI_ERROR_OUT_OF_MEMORY;
  }

  a->base._type = TRI_SHAPE_ARRAY;
  a->base._size = (TRI_shape_size_t)totalSize;
  a->base._dataSize = (v == 0) ? total : TRI_SHAPE_SIZE_VARIABLE;

  a->_fixedEntries = f;
  a->_variableEntries = v;

  ptr += sizeof(TRI_array_shape_t);

  // array of shape identifiers
  sids = (TRI_shape_sid_t*)ptr;
  ptr += n * sizeof(TRI_shape_sid_t);

  // array of attribute identifiers
  aids = (TRI_shape_aid_t*)ptr;
  ptr += n * sizeof(TRI_shape_aid_t);

  // array of offsets for fixed part (within the shape)
  offset = (v + 1) * sizeof(TRI_shape_size_t);
  offsetsF = (TRI_shape_size_t*)ptr;

  // fill destination (except sid)
  dst->_type = TRI_SHAPE_ARRAY;

  dst->_fixedSized = true;
  dst->_size = total;
  dst->_value = (ptr = static_cast<char*>(
                     TRI_Allocate(shaper->memoryZone(), dst->_size, true)));

  if (ptr == nullptr) {
    e = values + n;

    for (p = values; p < e; ++p) {
      if (p->_value != nullptr) {
        TRI_Free(shaper->memoryZone(), p->_value);
      }
    }

    TRI_Free(shaper->memoryZone(), values);
    TRI_Free(shaper->memoryZone(), a);

    return TRI_ERROR_OUT_OF_MEMORY;
  }

  // array of offsets for variable part (within the value)
  offsetsV = (TRI_shape_size_t*)ptr;
  ptr += (v + 1) * sizeof(TRI_shape_size_t);

  // and fill in attributes
  e = values + n;

  for (p = values; p < e; ++p) {
    *aids++ = p->_aid;
    *sids++ = p->_sid;

    TRI_ASSERT(p->_value != nullptr || p->_size == 0);
    if (p->_value != nullptr) {
      memcpy(ptr, p->_value, static_cast<size_t>(p->_size));
    }
    ptr += p->_size;

    dst->_fixedSized &= p->_fixedSized;

    if (p->_fixedSized) {
      *offsetsF++ = offset;
      offset += p->_size;
      *offsetsF = offset;
    } else {
      *offsetsV++ = offset;
      offset += p->_size;
      *offsetsV = offset;
    }
  }

  // free TRI_shape_value_t array
  for (p = values; p < e; ++p) {
    if (p->_value != nullptr) {
      TRI_Free(shaper->memoryZone(), p->_value);
    }
  }

  TRI_Free(shaper->memoryZone(), values);

  // lookup this shape
  found = shaper->findShape(&a->base, create);

  if (found == nullptr) {
    LOG(TRACE) << "shaper failed to find shape " << a->base._type;
    TRI_Free(shaper->memoryZone(), dst->_value);
    TRI_Free(shaper->memoryZone(), a);

    if (!create) {
      return TRI_RESULT_ELEMENT_NOT_FOUND;
    }

    return TRI_ERROR_INTERNAL;
  }

  // and finally add the sid
  dst->_sid = found->_sid;
  return TRI_ERROR_NO_ERROR;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a json object into TRI_shape_value_t
////////////////////////////////////////////////////////////////////////////////

static int FillShapeValueJson(v8::Isolate* isolate, VocShaper* shaper,
                              TRI_shape_value_t* dst,
                              v8::Handle<v8::Value> const json, size_t level,
                              std::set<int>& seenHashes,
                              std::vector<v8::Handle<v8::Object>>& seenObjects,
                              bool create) {
  v8::HandleScope scope(isolate);

  if (json->IsRegExp() || json->IsFunction() || json->IsExternal()) {
    LOG(TRACE) << "shaper failed because regexp/function/external/date object cannot be converted";
    return TRI_ERROR_BAD_PARAMETER;
  }

  if (json->IsNull() || json->IsUndefined()) {
    return FillShapeValueNull(shaper, dst);
  }

  if (json->IsBoolean()) {
    return FillShapeValueBoolean(shaper, dst, json->ToBoolean());
  }

  if (json->IsBooleanObject()) {
    return FillShapeValueBoolean(shaper, dst,
                                 v8::Handle<v8::BooleanObject>::Cast(json));
  }

  if (json->IsNumber()) {
    return FillShapeValueNumber(shaper, dst, json->ToNumber());
  }

  if (json->IsNumberObject()) {
    return FillShapeValueNumber(shaper, dst,
                                v8::Handle<v8::NumberObject>::Cast(json));
  }

  if (json->IsString()) {
    return FillShapeValueString(shaper, dst, json->ToString());
  }

  if (json->IsStringObject()) {
    return FillShapeValueString(
        shaper, dst, v8::Handle<v8::StringObject>::Cast(json)->ValueOf());
  }

  else if (json->IsArray()) {
    return FillShapeValueList(isolate, shaper, dst,
                              v8::Handle<v8::Array>::Cast(json), level,
                              seenHashes, seenObjects, create);
  }

  if (json->IsObject()) {
    v8::Handle<v8::Object> o = json->ToObject();
    v8::Handle<v8::String> toJsonString = TRI_V8_PAIR_STRING("toJSON", 6);
    if (o->Has(toJsonString)) {
      v8::Handle<v8::Value> func = o->Get(toJsonString);
      if (func->IsFunction()) {
        v8::Handle<v8::Function> toJson = v8::Handle<v8::Function>::Cast(func);

        v8::Handle<v8::Value> args;
        v8::Handle<v8::Value> result = toJson->Call(o, 0, &args);

        if (!result.IsEmpty()) {
          return FillShapeValueString(shaper, dst, result->ToString());
        }
      }
    }

    // fall-through intentional

    // check for cycles
    int hash = o->GetIdentityHash();

    if (seenHashes.find(hash) != seenHashes.end()) {
      for (auto const& seenObject : seenObjects) {
        if (json->StrictEquals(seenObject)) {
          return TRI_ERROR_ARANGO_SHAPER_FAILED;
        }
      }
    } else {
      seenHashes.insert(hash);
    }

    seenObjects.push_back(o);
    int res = FillShapeValueArray(isolate, shaper, dst, json->ToObject(), level,
                                  seenHashes, seenObjects, create);
    seenObjects.pop_back();
    // cannot remove hash value from seenHashes because multiple objects might
    // have the same
    // hash values (collisions)
    return res;
  }

  LOG(TRACE) << "shaper failed to convert object";
  return TRI_ERROR_BAD_PARAMETER;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a data null blob into a json object
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JsonShapeDataNull(v8::Isolate* isolate,
                                               VocShaper* shaper,
                                               TRI_shape_t const* shape,
                                               char const* data, size_t size) {
  return v8::Null(isolate);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a data boolean blob into a json object
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JsonShapeDataBoolean(v8::Isolate* isolate,
                                                  VocShaper* shaper,
                                                  TRI_shape_t const* shape,
                                                  char const* data,
                                                  size_t size) {
  bool v = (*(TRI_shape_boolean_t const*)data) != 0;

  return v8::Boolean::New(isolate, v);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a data number blob into a json object
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JsonShapeDataNumber(v8::Isolate* isolate,
                                                 VocShaper* shaper,
                                                 TRI_shape_t const* shape,
                                                 char const* data,
                                                 size_t size) {
  TRI_shape_number_t v = *(TRI_shape_number_t const*)data;

  return v8::Number::New(isolate, v);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a data short string blob into a json object
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JsonShapeDataShortString(v8::Isolate* isolate,
                                                      VocShaper* shaper,
                                                      TRI_shape_t const* shape,
                                                      char const* data,
                                                      size_t size) {
  TRI_shape_length_short_string_t l =
      *(TRI_shape_length_short_string_t const*)data;
  data += sizeof(TRI_shape_length_short_string_t);

  return TRI_V8_PAIR_STRING(data, l - 1);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a data long string blob into a json object
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JsonShapeDataLongString(v8::Isolate* isolate,
                                                     VocShaper* shaper,
                                                     TRI_shape_t const* shape,
                                                     char const* data,
                                                     size_t size) {
  TRI_shape_length_long_string_t l =
      *(TRI_shape_length_long_string_t const*)data;
  data += sizeof(TRI_shape_length_long_string_t);

  return TRI_V8_PAIR_STRING(data, l - 1);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief merges a data array blob into an existing json object
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JsonShapeDataArray(v8::Isolate* isolate,
                                                v8::Handle<v8::Value>& value,
                                                VocShaper* shaper,
                                                TRI_shape_t const* shape,
                                                char const* data, size_t size) {
  v8::EscapableHandleScope scope(isolate);
  TRI_array_shape_t const* s;
  TRI_shape_aid_t const* aids;
  TRI_shape_sid_t const* sids;
  TRI_shape_size_t const* offsetsF;
  TRI_shape_size_t const* offsetsV;
  TRI_shape_size_t f;
  TRI_shape_size_t i;
  TRI_shape_size_t n;
  TRI_shape_size_t v;
  shape_cache_t shapeCache;
  char const* qtr;

  v8::Handle<v8::Object> array = v8::Handle<v8::Object>::Cast(value);

  s = (TRI_array_shape_t const*)shape;
  f = s->_fixedEntries;
  v = s->_variableEntries;
  n = f + v;

  qtr = (char const*)shape;

  qtr += sizeof(TRI_array_shape_t);

  sids = (TRI_shape_sid_t const*)qtr;
  qtr += n * sizeof(TRI_shape_sid_t);

  aids = (TRI_shape_aid_t const*)qtr;
  qtr += n * sizeof(TRI_shape_aid_t);

  offsetsF = (TRI_shape_size_t const*)qtr;
  shapeCache._sid = 0;
  shapeCache._shape = 0;

  for (i = 0; i < f; ++i, ++sids, ++aids, ++offsetsF) {
    TRI_shape_sid_t sid = *sids;

    TRI_shape_t const* subshape;
    if (sid == shapeCache._sid && shapeCache._sid > 0) {
      subshape = shapeCache._shape;
    } else {
      shapeCache._shape = subshape = shaper->lookupShapeId(sid);
      shapeCache._sid = sid;
    }

    if (subshape == nullptr) {
      LOG(WARN) << "cannot find shape #" << sid;
      continue;
    }

    TRI_shape_aid_t aid = *aids;
    char const* name = shaper->lookupAttributeId(aid);

    if (name == nullptr) {
      LOG(WARN) << "cannot find attribute #" << aid;
      continue;
    }

    const TRI_shape_size_t offset = *offsetsF;
    v8::Handle<v8::Value> element =
        JsonShapeData(isolate, shaper, subshape, data + offset,
                      static_cast<size_t>(offsetsF[1] - offset));
    array->ForceSet(TRI_V8_STRING(name), element);
  }

  offsetsV = (TRI_shape_size_t const*)data;

  for (i = 0; i < v; ++i, ++sids, ++aids, ++offsetsV) {
    TRI_shape_sid_t sid = *sids;

    TRI_shape_t const* subshape;
    if (sid == shapeCache._sid && shapeCache._sid > 0) {
      subshape = shapeCache._shape;
    } else {
      shapeCache._shape = subshape = shaper->lookupShapeId(sid);
      shapeCache._sid = sid;
    }

    if (subshape == nullptr) {
      LOG(WARN) << "cannot find shape #" << sid;
      continue;
    }

    TRI_shape_aid_t aid = *aids;
    char const* name = shaper->lookupAttributeId(aid);

    if (name == nullptr) {
      LOG(WARN) << "cannot find attribute #" << aid;
      continue;
    }

    const TRI_shape_size_t offset = *offsetsV;
    v8::Handle<v8::Value> element =
        JsonShapeData(isolate, shaper, subshape, data + offset,
                      static_cast<size_t>(offsetsV[1] - offset));
    array->ForceSet(TRI_V8_STRING(name), element);
  }

  return scope.Escape<v8::Value>(array);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a data array blob into a new json object
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JsonShapeDataArray(v8::Isolate* isolate,
                                                VocShaper* shaper,
                                                TRI_shape_t const* shape,
                                                char const* data, size_t size) {
  v8::EscapableHandleScope scope(isolate);
  TRI_array_shape_t const* s;
  TRI_shape_aid_t const* aids;
  TRI_shape_sid_t const* sids;
  TRI_shape_size_t const* offsetsF;
  TRI_shape_size_t const* offsetsV;
  TRI_shape_size_t f;
  TRI_shape_size_t i;
  TRI_shape_size_t n;
  TRI_shape_size_t v;
  shape_cache_t shapeCache;
  char const* qtr;

  v8::Handle<v8::Object> array;

  s = (TRI_array_shape_t const*)shape;
  f = s->_fixedEntries;
  v = s->_variableEntries;
  n = f + v;

  qtr = (char const*)shape;
  array = v8::Object::New(isolate);

  qtr += sizeof(TRI_array_shape_t);

  sids = (TRI_shape_sid_t const*)qtr;
  qtr += n * sizeof(TRI_shape_sid_t);

  aids = (TRI_shape_aid_t const*)qtr;
  qtr += n * sizeof(TRI_shape_aid_t);

  offsetsF = (TRI_shape_size_t const*)qtr;
  shapeCache._sid = 0;
  shapeCache._shape = 0;

  for (i = 0; i < f; ++i, ++sids, ++aids, ++offsetsF) {
    TRI_shape_sid_t sid = *sids;

    TRI_shape_t const* subshape;
    if (sid == shapeCache._sid && shapeCache._sid > 0) {
      subshape = shapeCache._shape;
    } else {
      shapeCache._shape = subshape = shaper->lookupShapeId(sid);
      shapeCache._sid = sid;
    }

    if (subshape == nullptr) {
      LOG(WARN) << "cannot find shape #" << sid;
      continue;
    }

    TRI_shape_aid_t aid = *aids;
    char const* name = shaper->lookupAttributeId(aid);

    if (name == nullptr) {
      LOG(WARN) << "cannot find attribute #" << aid;
      continue;
    }

    const TRI_shape_size_t offset = *offsetsF;
    v8::Handle<v8::Value> element =
        JsonShapeData(isolate, shaper, subshape, data + offset,
                      static_cast<size_t>(offsetsF[1] - offset));
    array->ForceSet(TRI_V8_STRING(name), element);
  }

  offsetsV = (TRI_shape_size_t const*)data;

  for (i = 0; i < v; ++i, ++sids, ++aids, ++offsetsV) {
    TRI_shape_sid_t sid = *sids;

    TRI_shape_t const* subshape;
    if (sid == shapeCache._sid && shapeCache._sid > 0) {
      subshape = shapeCache._shape;
    } else {
      shapeCache._shape = subshape = shaper->lookupShapeId(sid);
      shapeCache._sid = sid;
    }

    if (subshape == nullptr) {
      LOG(WARN) << "cannot find shape #" << sid;
      continue;
    }

    TRI_shape_aid_t aid = *aids;
    char const* name = shaper->lookupAttributeId(aid);

    if (name == nullptr) {
      LOG(WARN) << "cannot find attribute #" << aid;
      continue;
    }

    const TRI_shape_size_t offset = *offsetsV;
    v8::Handle<v8::Value> element =
        JsonShapeData(isolate, shaper, subshape, data + offset,
                      static_cast<size_t>(offsetsV[1] - offset));
    array->ForceSet(TRI_V8_STRING(name), element);
  }

  return scope.Escape<v8::Value>(array);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a data list blob into a json object
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JsonShapeDataList(v8::Isolate* isolate,
                                               VocShaper* shaper,
                                               TRI_shape_t const* shape,
                                               char const* data, size_t size) {
  v8::EscapableHandleScope scope(isolate);
  TRI_shape_length_list_t i;
  TRI_shape_length_list_t l;
  TRI_shape_sid_t const* sids;
  TRI_shape_size_t const* offsets;
  shape_cache_t shapeCache;
  char const* ptr;

  ptr = data;
  l = *(TRI_shape_length_list_t const*)ptr;

  if (l == 0) {
    return scope.Escape<v8::Value>(v8::Array::New(isolate, 0));
  }

  shapeCache._sid = 0;
  shapeCache._shape = 0;
  v8::Handle<v8::Array> list = v8::Array::New(isolate, l);

  ptr += sizeof(TRI_shape_length_list_t);
  sids = (TRI_shape_sid_t const*)ptr;

  ptr += l * sizeof(TRI_shape_sid_t);
  offsets = (TRI_shape_size_t const*)ptr;

  for (i = 0; i < l; ++i, ++sids, ++offsets) {
    TRI_shape_sid_t sid = *sids;

    TRI_shape_t const* subshape;
    if (sid == shapeCache._sid && shapeCache._sid > 0) {
      subshape = shapeCache._shape;
    } else {
      shapeCache._shape = subshape = shaper->lookupShapeId(sid);
      shapeCache._sid = sid;
    }

    if (subshape == nullptr) {
      LOG(WARN) << "cannot find shape #" << sid;
      continue;
    }

    const TRI_shape_size_t offset = *offsets;
    v8::Handle<v8::Value> element =
        JsonShapeData(isolate, shaper, subshape, data + offset,
                      static_cast<size_t>(offsets[1] - offset));
    list->Set((uint32_t)i, element);
  }

  return scope.Escape<v8::Value>(list);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a data homogeneous list blob into a json object
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JsonShapeDataHomogeneousList(
    v8::Isolate* isolate, VocShaper* shaper, TRI_shape_t const* shape,
    char const* data, size_t size) {
  v8::EscapableHandleScope scope(isolate);
  TRI_homogeneous_list_shape_t const* s;
  TRI_shape_length_list_t i;
  TRI_shape_length_list_t l;
  TRI_shape_sid_t sid;
  TRI_shape_size_t const* offsets;
  char const* ptr;
  TRI_shape_t const* subshape;

  s = (TRI_homogeneous_list_shape_t const*)shape;
  sid = s->_sidEntry;

  ptr = data;
  l = *(TRI_shape_length_list_t const*)ptr;

  ptr += sizeof(TRI_shape_length_list_t);
  offsets = (TRI_shape_size_t const*)ptr;

  subshape = shaper->lookupShapeId(sid);

  if (subshape == nullptr) {
    LOG(WARN) << "cannot find shape #" << sid;
    return scope.Escape<v8::Value>(v8::Array::New(isolate));
  }

  v8::Handle<v8::Array> list = v8::Array::New(isolate, l);

  for (i = 0; i < l; ++i, ++offsets) {
    TRI_shape_size_t offset = *offsets;
    v8::Handle<v8::Value> element =
        JsonShapeData(isolate, shaper, subshape, data + offset,
                      static_cast<size_t>(offsets[1] - offset));

    list->Set((uint32_t)i, element);
  }

  return scope.Escape<v8::Value>(list);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a data homogeneous sized list blob into a json object
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JsonShapeDataHomogeneousSizedList(
    v8::Isolate* isolate, VocShaper* shaper, TRI_shape_t const* shape,
    char const* data, size_t size) {
  v8::EscapableHandleScope scope(isolate);
  TRI_homogeneous_sized_list_shape_t const* s;
  TRI_shape_length_list_t i;
  TRI_shape_length_list_t l;
  TRI_shape_sid_t sid;
  TRI_shape_size_t length;
  char const* ptr;
  TRI_shape_t const* subshape;

  s = (TRI_homogeneous_sized_list_shape_t const*)shape;

  ptr = data;
  l = *(TRI_shape_length_list_t const*)ptr;

  if (l == 0) {
    return scope.Escape<v8::Value>(v8::Array::New(isolate));
  }

  sid = s->_sidEntry;
  length = s->_sizeEntry;

  subshape = shaper->lookupShapeId(sid);

  if (subshape == nullptr) {
    LOG(WARN) << "cannot find shape #" << sid;
    return scope.Escape<v8::Value>(v8::Array::New(isolate));
  }

  TRI_shape_size_t offset = sizeof(TRI_shape_length_list_t);

  v8::Handle<v8::Array> list = v8::Array::New(isolate, l);

  for (i = 0; i < l; ++i, offset += length) {
    v8::Handle<v8::Value> element = JsonShapeData(
        isolate, shaper, subshape, data + offset, static_cast<size_t>(length));
    list->Set((uint32_t)i, element);
  }

  return scope.Escape<v8::Value>(list);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief merges a data blob into an existing json object
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JsonShapeData(v8::Isolate* isolate,
                                           v8::Handle<v8::Value>& value,
                                           VocShaper* shaper,
                                           TRI_shape_t const* shape,
                                           char const* data, size_t size) {
  if (shape == nullptr) {
    v8::EscapableHandleScope scope(isolate);
    return scope.Escape<v8::Value>(v8::Null(isolate));
  }

  TRI_ASSERT(shape->_type == TRI_SHAPE_ARRAY);
  return JsonShapeDataArray(isolate, value, shaper, shape, data, size);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a data blob into a new json object
////////////////////////////////////////////////////////////////////////////////

static v8::Handle<v8::Value> JsonShapeData(v8::Isolate* isolate,
                                           VocShaper* shaper,
                                           TRI_shape_t const* shape,
                                           char const* data, size_t size) {
  if (shape == nullptr) {
    v8::EscapableHandleScope scope(isolate);
    return scope.Escape<v8::Value>(v8::Null(isolate));
  }

  switch (shape->_type) {
    case TRI_SHAPE_NULL:
      return JsonShapeDataNull(isolate, shaper, shape, data, size);

    case TRI_SHAPE_BOOLEAN:
      return JsonShapeDataBoolean(isolate, shaper, shape, data, size);

    case TRI_SHAPE_NUMBER:
      return JsonShapeDataNumber(isolate, shaper, shape, data, size);

    case TRI_SHAPE_SHORT_STRING:
      return JsonShapeDataShortString(isolate, shaper, shape, data, size);

    case TRI_SHAPE_LONG_STRING:
      return JsonShapeDataLongString(isolate, shaper, shape, data, size);

    case TRI_SHAPE_ARRAY:
      return JsonShapeDataArray(isolate, shaper, shape, data, size);

    case TRI_SHAPE_LIST:
      return JsonShapeDataList(isolate, shaper, shape, data, size);

    case TRI_SHAPE_HOMOGENEOUS_LIST:
      return JsonShapeDataHomogeneousList(isolate, shaper, shape, data, size);

    case TRI_SHAPE_HOMOGENEOUS_SIZED_LIST:
      return JsonShapeDataHomogeneousSizedList(isolate, shaper, shape, data,
                                               size);
  }

  {
    v8::EscapableHandleScope scope(isolate);
    return scope.Escape<v8::Value>(v8::Null(isolate));
  }
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a TRI_shaped_json_t into an existing V8 object
////////////////////////////////////////////////////////////////////////////////

v8::Handle<v8::Value> TRI_JsonShapeData(v8::Isolate* isolate,
                                        v8::Handle<v8::Value> value,
                                        VocShaper* shaper,
                                        TRI_shape_t const* shape,
                                        char const* data, size_t size) {
  return JsonShapeData(isolate, value, shaper, shape, data, size);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief converts a TRI_shaped_json_t into a new V8 object
////////////////////////////////////////////////////////////////////////////////

v8::Handle<v8::Value> TRI_JsonShapeData(v8::Isolate* isolate, VocShaper* shaper,
                                        TRI_shape_t const* shape,
                                        char const* data, size_t size) {
  return JsonShapeData(isolate, shaper, shape, data, size);
}