/* 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 "mozilla/dom/TextEncoder.h"

#include "mozilla/ErrorResult.h"
#include "nsReadableUtils.h"

namespace mozilla::dom {

void TextEncoder::Encode(JSContext* aCx, JS::Handle<JSObject*> aObj,
                         const nsACString& aUtf8String,
                         JS::MutableHandle<JSObject*> aRetval,
                         ErrorResult& aRv) {
  JSAutoRealm ar(aCx, aObj);
  JSObject* outView = Uint8Array::Create(aCx, aUtf8String, aRv);
  if (aRv.Failed()) {
    return;
  }

  aRetval.set(outView);
}

void TextEncoder::EncodeInto(JSContext* aCx, JS::Handle<JSString*> aSrc,
                             const Uint8Array& aDst,
                             TextEncoderEncodeIntoResult& aResult,
                             OOMReporter& aError) {
  DebugOnly<size_t> dstLength = 0;
  auto maybe = aDst.ProcessData(
      [&](const Span<uint8_t>& aData, JS::AutoCheckCannotGC&&) {
        dstLength = aData.Length();
        return JS_EncodeStringToUTF8BufferPartial(aCx, aSrc,
                                                  AsWritableChars(aData));
      });
  if (!maybe) {
    aError.ReportOOM();
    return;
  }
  size_t read;
  size_t written;
  std::tie(read, written) = *maybe;
  MOZ_ASSERT(written <= dstLength);
  aResult.mRead.Construct() = read;
  aResult.mWritten.Construct() = written;
}

void TextEncoder::GetEncoding(nsACString& aEncoding) {
  aEncoding.AssignLiteral("utf-8");
}

}  // namespace mozilla::dom