// Copyright (C) 2019-2020 Zilliz. All rights reserved.
//
// 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.

#include "PayloadStream.h"

namespace wrapper {

PayloadOutputStream::PayloadOutputStream() {
  buffer_.reserve(1024 * 1024);
  closed_ = false;
}

PayloadOutputStream::~PayloadOutputStream() noexcept {

}

arrow::Status PayloadOutputStream::Close() {
  closed_ = true;
  return arrow::Status::OK();
}

arrow::Result<int64_t> PayloadOutputStream::Tell() const {
  return arrow::Result<int64_t>(buffer_.size());
}

bool PayloadOutputStream::closed() const {
  return closed_;
}

arrow::Status PayloadOutputStream::Write(const void *data, int64_t nbytes) {
  if (nbytes <= 0) return arrow::Status::OK();
  auto size = buffer_.size();
  buffer_.resize(size + nbytes);
  std::memcpy(buffer_.data() + size, data, nbytes);
  return arrow::Status::OK();
}

arrow::Status PayloadOutputStream::Flush() {
  return arrow::Status::OK();
}

const std::vector<uint8_t> &PayloadOutputStream::Buffer() const {
  return buffer_;
}

PayloadInputStream::PayloadInputStream(const uint8_t *data, int64_t size) :
    data_(data), size_(size), tell_(0), closed_(false) {
}

PayloadInputStream::~PayloadInputStream() noexcept {

}

arrow::Status PayloadInputStream::Close() {
  closed_ = true;
  return arrow::Status::OK();
}

bool PayloadInputStream::closed() const {
  return closed_;
}

arrow::Result<int64_t> PayloadInputStream::Tell() const {
  return arrow::Result<int64_t>(tell_);
}

arrow::Status PayloadInputStream::Seek(int64_t position) {
  if (position < 0 || position >= size_) return arrow::Status::IOError("invalid position");
  tell_ = position;
  return arrow::Status::OK();
}

arrow::Result<int64_t> PayloadInputStream::Read(int64_t nbytes, void *out) {
  auto remain = size_ - tell_;
  if (nbytes > remain) nbytes = remain;
  std::memcpy(out, data_ + tell_, nbytes);
  tell_ += nbytes;
  return arrow::Result<int64_t>(nbytes);
}

arrow::Result<std::shared_ptr<arrow::Buffer>> PayloadInputStream::Read(int64_t nbytes) {
  auto remain = size_ - tell_;
  if (nbytes > remain) nbytes = remain;
  auto buf = std::make_shared<arrow::Buffer>(data_ + tell_, nbytes);
  tell_ += nbytes;
  return arrow::Result<std::shared_ptr<arrow::Buffer>>(buf);
}

arrow::Result<int64_t> PayloadInputStream::GetSize() {
  return arrow::Result<int64_t>(size_);
}

}