/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "js/JSON.h"
#include "mozilla/dom/DocumentL10n.h"
#include "mozilla/dom/DocumentL10nBinding.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/Promise.h"
#include "mozilla/dom/PromiseNativeHandler.h"
#include "nsQueryObject.h"
#include "nsISupports.h"
#include "nsContentUtils.h"
#include "xpcprivate.h"

namespace mozilla {
namespace dom {

NS_INTERFACE_MAP_BEGIN(PromiseResolver)
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

NS_IMPL_ADDREF(PromiseResolver)
NS_IMPL_RELEASE(PromiseResolver)

PromiseResolver::PromiseResolver(Promise* aPromise)
{
  mPromise = aPromise;
}

void
PromiseResolver::ResolvedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue)
{
  JS::RootedObject sourceScope(aCx, JS::CurrentGlobalOrNull(aCx));

  AutoEntryScript aes(mPromise->GetParentObject(), "Promise resolution");
  JSContext* cx = aes.cx();
  JS::Rooted<JS::Value> value(cx, aValue);

  xpc::StackScopedCloneOptions options;
  StackScopedClone(cx, options, sourceScope, &value);

  mPromise->MaybeResolve(cx, value);
  mPromise = nullptr;
}

void
PromiseResolver::RejectedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue)
{
  JS::RootedObject sourceScope(aCx, JS::CurrentGlobalOrNull(aCx));

  AutoEntryScript aes(mPromise->GetParentObject(), "Promise rejection");
  JSContext* cx = aes.cx();
  JS::Rooted<JS::Value> value(cx, aValue);

  xpc::StackScopedCloneOptions options;
  StackScopedClone(cx, options, sourceScope, &value);

  mPromise->MaybeReject(cx, value);
  mPromise = nullptr;
}

PromiseResolver::~PromiseResolver()
{
  mPromise = nullptr;
}

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DocumentL10n)
  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  NS_INTERFACE_MAP_ENTRY(nsISupports)
  NS_INTERFACE_MAP_ENTRY(nsIDOMEventListener)
NS_INTERFACE_MAP_END

NS_IMPL_CYCLE_COLLECTING_ADDREF(DocumentL10n)
NS_IMPL_CYCLE_COLLECTING_RELEASE(DocumentL10n)

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DocumentL10n, mDocument, mDOMLocalization, mReady)

DocumentL10n::DocumentL10n(nsIDocument* aDocument)
  : mDocument(aDocument),
    mState(DocumentL10nState::Initialized)
{
}

DocumentL10n::~DocumentL10n()
{
}

bool
DocumentL10n::Init(nsTArray<nsString>& aResourceIds)
{
  nsCOMPtr<mozIDOMLocalization> domL10n = do_CreateInstance("@mozilla.org/intl/domlocalization;1");
  if (NS_WARN_IF(!domL10n)) {
    return false;
  }

  nsIGlobalObject* global = mDocument->GetScopeObject();
  if (!global) {
    return false;
  }

  ErrorResult rv;
  mReady = Promise::Create(global, rv);
  if (rv.Failed()) {
    return false;
  }
  mDOMLocalization = domL10n;

  // The `aEager = true` here allows us to eagerly trigger
  // resource fetching to increase the chance that the l10n
  // resources will be ready by the time the document
  // is ready for localization.
  uint32_t ret;
  mDOMLocalization->AddResourceIds(aResourceIds, true, &ret);

  // Register observers for this instance of
  // mozDOMLocalization to allow it to retranslate
  // the document when locale changes or pseudolocalization
  // gets turned on.
  mDOMLocalization->RegisterObservers();
  return true;
}

JSObject*
DocumentL10n::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
  return DocumentL10n_Binding::Wrap(aCx, this, aGivenProto);
}

already_AddRefed<Promise>
DocumentL10n::MaybeWrapPromise(Promise* aInnerPromise)
{
  // For system principal we don't need to wrap the
  // result promise at all.
  if (nsContentUtils::IsSystemPrincipal(mDocument->NodePrincipal())) {
    return RefPtr<Promise>(aInnerPromise).forget();
  }

  nsIGlobalObject* global = mDocument->GetScopeObject();
  if (!global) {
    return nullptr;
  }

  ErrorResult result;
  RefPtr<Promise> docPromise = Promise::Create(global, result);
  if (result.Failed()) {
    return nullptr;
  }

  RefPtr<PromiseResolver> resolver = new PromiseResolver(docPromise);
  aInnerPromise->AppendNativeHandler(resolver);
  return docPromise.forget();
}

NS_IMETHODIMP
DocumentL10n::HandleEvent(Event* aEvent)
{
#ifdef DEBUG
  nsAutoString eventType;
  aEvent->GetType(eventType);
  MOZ_ASSERT(eventType.EqualsLiteral("MozBeforeInitialXULLayout"));
#endif

  TriggerInitialDocumentTranslation();

  return NS_OK;
}

uint32_t
DocumentL10n::AddResourceIds(nsTArray<nsString>& aResourceIds)
{
  uint32_t ret = 0;
  mDOMLocalization->AddResourceIds(aResourceIds, false, &ret);
  return ret;
}

uint32_t
DocumentL10n::RemoveResourceIds(nsTArray<nsString>& aResourceIds)
{
  // We need to guard against a scenario where the
  // mDOMLocalization has been unlinked, but the elements
  // are only now removed from DOM.
  if (!mDOMLocalization) {
    return 0;
  }
  uint32_t ret = 0;
  mDOMLocalization->RemoveResourceIds(aResourceIds, &ret);
  return ret;
}

already_AddRefed<Promise>
DocumentL10n::FormatMessages(JSContext* aCx, const Sequence<L10nKey>& aKeys, ErrorResult& aRv)
{
  nsTArray<JS::Value> jsKeys;
  SequenceRooter<JS::Value> rooter(aCx, &jsKeys);
  for (auto& key : aKeys) {
    JS::RootedValue jsKey(aCx);
    if (!ToJSValue(aCx, key, &jsKey)) {
      aRv.NoteJSContextException(aCx);
      return nullptr;
    }
    jsKeys.AppendElement(jsKey);
  }

  RefPtr<Promise> promise;
  aRv = mDOMLocalization->FormatMessages(jsKeys, getter_AddRefs(promise));
  if (aRv.Failed()) {
    return nullptr;
  }

  return MaybeWrapPromise(promise);
}

already_AddRefed<Promise>
DocumentL10n::FormatValues(JSContext* aCx, const Sequence<L10nKey>& aKeys, ErrorResult& aRv)
{
  nsTArray<JS::Value> jsKeys;
  SequenceRooter<JS::Value> rooter(aCx, &jsKeys);
  for (auto& key : aKeys) {
    JS::RootedValue jsKey(aCx);
    if (!ToJSValue(aCx, key, &jsKey)) {
      aRv.NoteJSContextException(aCx);
      return nullptr;
    }
    jsKeys.AppendElement(jsKey);
  }

  RefPtr<Promise> promise;
  aRv = mDOMLocalization->FormatValues(jsKeys, getter_AddRefs(promise));
  if (aRv.Failed()) {
    return nullptr;
  }

  return MaybeWrapPromise(promise);
}

already_AddRefed<Promise>
DocumentL10n::FormatValue(JSContext* aCx, const nsAString& aId, const Optional<JS::Handle<JSObject*>>& aArgs, ErrorResult& aRv)
{
  JS::Rooted<JS::Value> args(aCx);

  if (aArgs.WasPassed()) {
    args = JS::ObjectValue(*aArgs.Value());
  } else {
    args = JS::UndefinedValue();
  }

  RefPtr<Promise> promise;
  nsresult rv = mDOMLocalization->FormatValue(aId, args, getter_AddRefs(promise));
  if (NS_FAILED(rv)) {
    aRv.Throw(rv);
    return nullptr;
  }
  return MaybeWrapPromise(promise);
}

void
DocumentL10n::SetAttributes(JSContext* aCx, Element& aElement, const nsAString& aId, const Optional<JS::Handle<JSObject*>>& aArgs, ErrorResult& aRv)
{
  aElement.SetAttribute(NS_LITERAL_STRING("data-l10n-id"), aId, aRv);
  if (aRv.Failed()) {
    return;
  }
  if (aArgs.WasPassed()) {
    nsAutoString data;
    JS::Rooted<JS::Value> val(aCx, JS::ObjectValue(*aArgs.Value()));
    if (!nsContentUtils::StringifyJSON(aCx, &val, data)) {
      aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
      return;
    }
    aElement.SetAttribute(NS_LITERAL_STRING("data-l10n-args"), data, aRv);
  } else {
    aElement.RemoveAttribute(NS_LITERAL_STRING("data-l10n-args"), aRv);
  }
}

void
DocumentL10n::GetAttributes(JSContext* aCx, Element& aElement, L10nKey& aResult, ErrorResult& aRv)
{
  nsAutoString l10nId;
  nsAutoString l10nArgs;

  aElement.GetAttr(kNameSpaceID_None, nsGkAtoms::datal10nid, l10nId);
  aResult.mId = l10nId;

  aElement.GetAttr(kNameSpaceID_None, nsGkAtoms::datal10nargs, l10nArgs);
  if (!l10nArgs.IsEmpty()) {
    JS::Rooted<JS::Value> json(aCx);
    if (!JS_ParseJSON(aCx, l10nArgs.get(), l10nArgs.Length(), &json)) {
      aRv.NoteJSContextException(aCx);
      return;
    } else if (!json.isObject()) {
      aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
      return;
    }
    aResult.mArgs.Construct();
    aResult.mArgs.Value() = &json.toObject();
  }
}

already_AddRefed<Promise>
DocumentL10n::TranslateFragment(nsINode& aNode, ErrorResult& aRv)
{
  RefPtr<Promise> promise;
  nsresult rv = mDOMLocalization->TranslateFragment(&aNode, getter_AddRefs(promise));
  if (NS_FAILED(rv)) {
    aRv.Throw(rv);
    return nullptr;
  }
  return MaybeWrapPromise(promise);
}

already_AddRefed<Promise>
DocumentL10n::TranslateElements(const Sequence<OwningNonNull<Element>>& aElements, ErrorResult& aRv)
{
  AutoTArray<RefPtr<Element>, 10> elements;
  elements.SetCapacity(aElements.Length());
  for (auto& element : aElements) {
    elements.AppendElement(element);
  }
  RefPtr<Promise> promise;
  aRv = mDOMLocalization->TranslateElements(
      elements, getter_AddRefs(promise));
  if (aRv.Failed()) {
    return nullptr;
  }
  return MaybeWrapPromise(promise);
}

class L10nReadyHandler final : public PromiseNativeHandler
{
public:
  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_CYCLE_COLLECTION_CLASS(L10nReadyHandler)

  explicit L10nReadyHandler(Promise* aPromise)
    : mPromise(aPromise)
  {
  }

  void
  ResolvedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue) override
  {
    mPromise->MaybeResolveWithUndefined();
  }

  void
  RejectedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue) override
  {
    mPromise->MaybeRejectWithUndefined();
  }

private:
  ~L10nReadyHandler() = default;

  RefPtr<Promise> mPromise;
};

NS_IMPL_CYCLE_COLLECTION(L10nReadyHandler, mPromise)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(L10nReadyHandler)
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

NS_IMPL_CYCLE_COLLECTING_ADDREF(L10nReadyHandler)
NS_IMPL_CYCLE_COLLECTING_RELEASE(L10nReadyHandler)

void
DocumentL10n::TriggerInitialDocumentTranslation()
{
  if (mState == DocumentL10nState::InitialTranslationTriggered) {
    return;
  }

  mState = DocumentL10nState::InitialTranslationTriggered;

  Element* elem = mDocument->GetDocumentElement();
  if (elem) {
    mDOMLocalization->ConnectRoot(elem);
  }

  RefPtr<Promise> promise;
  mDOMLocalization->TranslateRoots(getter_AddRefs(promise));
  RefPtr<PromiseNativeHandler> l10nReadyHandler = new L10nReadyHandler(mReady);
  promise->AppendNativeHandler(l10nReadyHandler);
}

Promise*
DocumentL10n::Ready()
{
  return mReady;
}

} // namespace dom
} // namespace mozilla