#include "node_errors.h"
#include "util-inl.h"
#include "base_object-inl.h"

namespace node {
namespace util {

using v8::ALL_PROPERTIES;
using v8::Array;
using v8::ArrayBufferView;
using v8::Boolean;
using v8::Context;
using v8::Function;
using v8::FunctionCallbackInfo;
using v8::FunctionTemplate;
using v8::Global;
using v8::IndexFilter;
using v8::Integer;
using v8::Isolate;
using v8::KeyCollectionMode;
using v8::Local;
using v8::Object;
using v8::ONLY_CONFIGURABLE;
using v8::ONLY_ENUMERABLE;
using v8::ONLY_WRITABLE;
using v8::Private;
using v8::Promise;
using v8::PropertyFilter;
using v8::Proxy;
using v8::SKIP_STRINGS;
using v8::SKIP_SYMBOLS;
using v8::String;
using v8::Uint32;
using v8::Value;

static void GetOwnNonIndexProperties(
    const FunctionCallbackInfo<Value>& args) {
  Environment* env = Environment::GetCurrent(args);
  Local<Context> context = env->context();

  CHECK(args[0]->IsObject());
  CHECK(args[1]->IsUint32());

  Local<Object> object = args[0].As<Object>();

  Local<Array> properties;

  PropertyFilter filter =
    static_cast<PropertyFilter>(args[1].As<Uint32>()->Value());

  if (!object->GetPropertyNames(
        context, KeyCollectionMode::kOwnOnly,
        filter,
        IndexFilter::kSkipIndices)
          .ToLocal(&properties)) {
    return;
  }
  args.GetReturnValue().Set(properties);
}

static void GetConstructorName(
    const FunctionCallbackInfo<Value>& args) {
  CHECK(args[0]->IsObject());

  Local<Object> object = args[0].As<Object>();
  Local<String> name = object->GetConstructorName();

  args.GetReturnValue().Set(name);
}

static void GetPromiseDetails(const FunctionCallbackInfo<Value>& args) {
  // Return undefined if it's not a Promise.
  if (!args[0]->IsPromise())
    return;

  auto isolate = args.GetIsolate();

  Local<Promise> promise = args[0].As<Promise>();

  int state = promise->State();
  Local<Value> values[2] = { Integer::New(isolate, state) };
  size_t number_of_values = 1;
  if (state != Promise::PromiseState::kPending)
    values[number_of_values++] = promise->Result();
  Local<Array> ret = Array::New(isolate, values, number_of_values);
  args.GetReturnValue().Set(ret);
}

static void GetProxyDetails(const FunctionCallbackInfo<Value>& args) {
  // Return undefined if it's not a proxy.
  if (!args[0]->IsProxy())
    return;

  Local<Proxy> proxy = args[0].As<Proxy>();

  Local<Value> ret[] = {
    proxy->GetTarget(),
    proxy->GetHandler()
  };

  args.GetReturnValue().Set(
      Array::New(args.GetIsolate(), ret, arraysize(ret)));
}

static void PreviewEntries(const FunctionCallbackInfo<Value>& args) {
  if (!args[0]->IsObject())
    return;

  Environment* env = Environment::GetCurrent(args);
  bool is_key_value;
  Local<Array> entries;
  if (!args[0].As<Object>()->PreviewEntries(&is_key_value).ToLocal(&entries))
    return;
  // Fast path for WeakMap and WeakSet.
  if (args.Length() == 1)
    return args.GetReturnValue().Set(entries);

  Local<Value> ret[] = {
    entries,
    Boolean::New(env->isolate(), is_key_value)
  };
  return args.GetReturnValue().Set(
      Array::New(env->isolate(), ret, arraysize(ret)));
}

inline Local<Private> IndexToPrivateSymbol(Environment* env, uint32_t index) {
#define V(name, _) &Environment::name,
  static Local<Private> (Environment::*const methods[])() const = {
    PER_ISOLATE_PRIVATE_SYMBOL_PROPERTIES(V)
  };
#undef V
  CHECK_LT(index, arraysize(methods));
  return (env->*methods[index])();
}

static void GetHiddenValue(const FunctionCallbackInfo<Value>& args) {
  Environment* env = Environment::GetCurrent(args);

  CHECK(args[0]->IsObject());
  CHECK(args[1]->IsUint32());

  Local<Object> obj = args[0].As<Object>();
  auto index = args[1]->Uint32Value(env->context()).FromJust();
  auto private_symbol = IndexToPrivateSymbol(env, index);
  auto maybe_value = obj->GetPrivate(env->context(), private_symbol);

  args.GetReturnValue().Set(maybe_value.ToLocalChecked());
}

static void SetHiddenValue(const FunctionCallbackInfo<Value>& args) {
  Environment* env = Environment::GetCurrent(args);

  CHECK(args[0]->IsObject());
  CHECK(args[1]->IsUint32());

  Local<Object> obj = args[0].As<Object>();
  auto index = args[1]->Uint32Value(env->context()).FromJust();
  auto private_symbol = IndexToPrivateSymbol(env, index);
  auto maybe_value = obj->SetPrivate(env->context(), private_symbol, args[2]);

  args.GetReturnValue().Set(maybe_value.FromJust());
}

void ArrayBufferViewHasBuffer(const FunctionCallbackInfo<Value>& args) {
  CHECK(args[0]->IsArrayBufferView());
  args.GetReturnValue().Set(args[0].As<ArrayBufferView>()->HasBuffer());
}

class WeakReference : public BaseObject {
 public:
  WeakReference(Environment* env, Local<Object> object, Local<Object> target)
    : BaseObject(env, object) {
    MakeWeak();
    target_.Reset(env->isolate(), target);
    target_.SetWeak();
  }

  static void New(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
    CHECK(args.IsConstructCall());
    CHECK(args[0]->IsObject());
    new WeakReference(env, args.This(), args[0].As<Object>());
  }

  static void Get(const FunctionCallbackInfo<Value>& args) {
    WeakReference* weak_ref = Unwrap<WeakReference>(args.Holder());
    Isolate* isolate = args.GetIsolate();
    if (!weak_ref->target_.IsEmpty())
      args.GetReturnValue().Set(weak_ref->target_.Get(isolate));
  }

  static void IncRef(const FunctionCallbackInfo<Value>& args) {
    WeakReference* weak_ref = Unwrap<WeakReference>(args.Holder());
    if (weak_ref->reference_count_ == 0) weak_ref->target_.ClearWeak();
    weak_ref->reference_count_++;
  }

  static void DecRef(const FunctionCallbackInfo<Value>& args) {
    WeakReference* weak_ref = Unwrap<WeakReference>(args.Holder());
    CHECK_GE(weak_ref->reference_count_, 1);
    weak_ref->reference_count_--;
    if (weak_ref->reference_count_ == 0) weak_ref->target_.SetWeak();
  }

  SET_MEMORY_INFO_NAME(WeakReference)
  SET_SELF_SIZE(WeakReference)
  SET_NO_MEMORY_INFO()

 private:
  Global<Object> target_;
  uint64_t reference_count_ = 0;
};

static void GuessHandleType(const FunctionCallbackInfo<Value>& args) {
  Environment* env = Environment::GetCurrent(args);
  int fd;
  if (!args[0]->Int32Value(env->context()).To(&fd)) return;
  CHECK_GE(fd, 0);

  uv_handle_type t = uv_guess_handle(fd);
  const char* type = nullptr;

  switch (t) {
    case UV_TCP:
      type = "TCP";
      break;
    case UV_TTY:
      type = "TTY";
      break;
    case UV_UDP:
      type = "UDP";
      break;
    case UV_FILE:
      type = "FILE";
      break;
    case UV_NAMED_PIPE:
      type = "PIPE";
      break;
    case UV_UNKNOWN_HANDLE:
      type = "UNKNOWN";
      break;
    default:
      ABORT();
  }

  args.GetReturnValue().Set(OneByteString(env->isolate(), type));
}

void Initialize(Local<Object> target,
                Local<Value> unused,
                Local<Context> context,
                void* priv) {
  Environment* env = Environment::GetCurrent(context);

#define V(name, _)                                                            \
  target->Set(context,                                                        \
              FIXED_ONE_BYTE_STRING(env->isolate(), #name),                   \
              Integer::NewFromUnsigned(env->isolate(), index++)).Check();
  {
    uint32_t index = 0;
    PER_ISOLATE_PRIVATE_SYMBOL_PROPERTIES(V)
  }
#undef V

#define V(name)                                                               \
  target->Set(context,                                                        \
              FIXED_ONE_BYTE_STRING(env->isolate(), #name),                   \
              Integer::New(env->isolate(), Promise::PromiseState::name))      \
    .FromJust()
  V(kPending);
  V(kFulfilled);
  V(kRejected);
#undef V

  env->SetMethodNoSideEffect(target, "getHiddenValue", GetHiddenValue);
  env->SetMethod(target, "setHiddenValue", SetHiddenValue);
  env->SetMethodNoSideEffect(target, "getPromiseDetails", GetPromiseDetails);
  env->SetMethodNoSideEffect(target, "getProxyDetails", GetProxyDetails);
  env->SetMethodNoSideEffect(target, "previewEntries", PreviewEntries);
  env->SetMethodNoSideEffect(target, "getOwnNonIndexProperties",
                                     GetOwnNonIndexProperties);
  env->SetMethodNoSideEffect(target, "getConstructorName", GetConstructorName);

  env->SetMethod(target, "arrayBufferViewHasBuffer", ArrayBufferViewHasBuffer);
  Local<Object> constants = Object::New(env->isolate());
  NODE_DEFINE_CONSTANT(constants, ALL_PROPERTIES);
  NODE_DEFINE_CONSTANT(constants, ONLY_WRITABLE);
  NODE_DEFINE_CONSTANT(constants, ONLY_ENUMERABLE);
  NODE_DEFINE_CONSTANT(constants, ONLY_CONFIGURABLE);
  NODE_DEFINE_CONSTANT(constants, SKIP_STRINGS);
  NODE_DEFINE_CONSTANT(constants, SKIP_SYMBOLS);
  target->Set(context,
              FIXED_ONE_BYTE_STRING(env->isolate(), "propertyFilter"),
              constants).Check();

  Local<String> should_abort_on_uncaught_toggle =
      FIXED_ONE_BYTE_STRING(env->isolate(), "shouldAbortOnUncaughtToggle");
  CHECK(target
            ->Set(env->context(),
                  should_abort_on_uncaught_toggle,
                  env->should_abort_on_uncaught_toggle().GetJSArray())
            .FromJust());

  Local<String> weak_ref_string =
      FIXED_ONE_BYTE_STRING(env->isolate(), "WeakReference");
  Local<FunctionTemplate> weak_ref =
      env->NewFunctionTemplate(WeakReference::New);
  weak_ref->InstanceTemplate()->SetInternalFieldCount(1);
  weak_ref->SetClassName(weak_ref_string);
  env->SetProtoMethod(weak_ref, "get", WeakReference::Get);
  env->SetProtoMethod(weak_ref, "incRef", WeakReference::IncRef);
  env->SetProtoMethod(weak_ref, "decRef", WeakReference::DecRef);
  target->Set(context, weak_ref_string,
              weak_ref->GetFunction(context).ToLocalChecked()).Check();

  env->SetMethod(target, "guessHandleType", GuessHandleType);
}

}  // namespace util
}  // namespace node

NODE_MODULE_CONTEXT_AWARE_INTERNAL(util, node::util::Initialize)