// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "bindings/core/v8/JSONValuesForV8.h"

#include "bindings/core/v8/ExceptionState.h"
#include "bindings/core/v8/ScriptState.h"
#include "bindings/core/v8/V8Binding.h"

namespace blink {

static String coreString(v8::Local<v8::String> v8String) {
  int length = v8String->Length();
  UChar* buffer;
  String result = String::createUninitialized(length, buffer);
  v8String->Write(reinterpret_cast<uint16_t*>(buffer), 0, length);
  return result;
}

std::unique_ptr<JSONValue> toJSONValue(v8::Local<v8::Context> context,
                                       v8::Local<v8::Value> value,
                                       int maxDepth) {
  if (value.IsEmpty()) {
    ASSERT_NOT_REACHED();
    return nullptr;
  }

  if (!maxDepth)
    return nullptr;
  maxDepth--;

  if (value->IsNull() || value->IsUndefined())
    return JSONValue::null();
  if (value->IsBoolean())
    return JSONBasicValue::create(value.As<v8::Boolean>()->Value());
  if (value->IsNumber())
    return JSONBasicValue::create(value.As<v8::Number>()->Value());
  if (value->IsString())
    return JSONString::create(coreString(value.As<v8::String>()));
  if (value->IsArray()) {
    v8::Local<v8::Array> array = value.As<v8::Array>();
    std::unique_ptr<JSONArray> inspectorArray = JSONArray::create();
    uint32_t length = array->Length();
    for (uint32_t i = 0; i < length; i++) {
      v8::Local<v8::Value> value;
      if (!array->Get(context, i).ToLocal(&value))
        return nullptr;
      std::unique_ptr<JSONValue> element =
          toJSONValue(context, value, maxDepth);
      if (!element)
        return nullptr;
      inspectorArray->pushValue(std::move(element));
    }
    return std::move(inspectorArray);
  }
  if (value->IsObject()) {
    std::unique_ptr<JSONObject> jsonObject = JSONObject::create();
    v8::Local<v8::Object> object = v8::Local<v8::Object>::Cast(value);
    v8::Local<v8::Array> propertyNames;
    if (!object->GetPropertyNames(context).ToLocal(&propertyNames))
      return nullptr;
    uint32_t length = propertyNames->Length();
    for (uint32_t i = 0; i < length; i++) {
      v8::Local<v8::Value> name;
      if (!propertyNames->Get(context, i).ToLocal(&name))
        return nullptr;
      // FIXME(yurys): v8::Object should support GetOwnPropertyNames
      if (name->IsString()) {
        v8::Maybe<bool> hasRealNamedProperty = object->HasRealNamedProperty(
            context, v8::Local<v8::String>::Cast(name));
        if (!hasRealNamedProperty.IsJust() || !hasRealNamedProperty.FromJust())
          continue;
      }
      v8::Local<v8::String> propertyName;
      if (!name->ToString(context).ToLocal(&propertyName))
        continue;
      v8::Local<v8::Value> property;
      if (!object->Get(context, name).ToLocal(&property))
        return nullptr;
      std::unique_ptr<JSONValue> propertyValue =
          toJSONValue(context, property, maxDepth);
      if (!propertyValue)
        return nullptr;
      jsonObject->setValue(coreString(propertyName), std::move(propertyValue));
    }
    return std::move(jsonObject);
  }
  ASSERT_NOT_REACHED();
  return nullptr;
}

v8::Local<v8::Value> fromJSONString(ScriptState* scriptState,
                                    const String& stringifiedJSON,
                                    ExceptionState& exceptionState) {
  v8::Isolate* isolate = scriptState->isolate();
  v8::Local<v8::Value> parsed;
  v8::TryCatch tryCatch(isolate);
  if (!v8Call(v8::JSON::Parse(isolate, v8String(isolate, stringifiedJSON)),
              parsed, tryCatch)) {
    if (tryCatch.HasCaught())
      exceptionState.rethrowV8Exception(tryCatch.Exception());
  }

  return parsed;
}

}  // namespace blink