/**
 * Copyright (c) 2021 OceanBase
 * OceanBase CE is licensed under Mulan PubL v2.
 * You can use this software according to the terms and conditions of the Mulan PubL v2.
 * You may obtain a copy of Mulan PubL v2 at:
 *          http://license.coscl.org.cn/MulanPubL-2.0
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 * See the Mulan PubL v2 for more details.
 */

#define USING_LOG_PREFIX SQL_DAS
#include "ob_das_extra_data.h"
namespace oceanbase
{
namespace sql
{
ObDASExtraData::ObDASExtraData()
  : output_exprs_(nullptr),
    eval_ctx_(nullptr),
    task_id_(0),
    timeout_ts_(0),
    result_addr_(),
    rpc_proxy_(),
    result_(),
    result_iter_(),
    has_more_(false),
    need_check_output_datum_(false)
{
}

int ObDASExtraData::init(const int64_t task_id,
                         const int64_t timeout_ts,
                         const common::ObAddr &result_addr,
                         rpc::frame::ObReqTransport *transport)
{
  int ret = OB_SUCCESS;
  if (OB_FAIL(rpc_proxy_.init(transport))) {
    LOG_WARN("init rpc proxy failed", KR(ret));
  } else {
    task_id_ = task_id;
    timeout_ts_ = timeout_ts;
    result_addr_ = result_addr;
    has_more_ = false;
    need_check_output_datum_ = false;
  }
  return ret;
}

int ObDASExtraData::fetch_result()
{
  int ret = OB_SUCCESS;
  FLTSpanGuard(fetch_das_extra_result);
  ObDASDataFetchReq req;
  int64_t tenant_id = MTL_ID();
  int64_t timeout = timeout_ts_ - ObTimeUtility::current_time();
  result_.get_datum_store().reset();
  if (OB_UNLIKELY(timeout <= 0)) {
    ret = OB_TIMEOUT;
    LOG_WARN("das extra data fetch result timeout", KR(ret), K(timeout_ts_), K(timeout));
  } else if (OB_FAIL(req.init(tenant_id, task_id_))) {
    LOG_WARN("init das data fetch request failed", KR(ret));
  } else if (OB_FAIL(rpc_proxy_
                     .to(result_addr_)
                     .by(tenant_id)
                     .timeout(timeout)
                     .sync_fetch_das_result(req, result_))) {
    LOG_WARN("rpc sync fetch das result failed", KR(ret));
  } else if (OB_FAIL(result_.get_datum_store().begin(result_iter_))) {
    LOG_WARN("begin result iter failed", KR(ret));
  } else {
    LOG_TRACE("das fetch task result", KR(ret), K(req), K(result_));
    has_more_ = result_.has_more();
  }
  return ret;
}

int ObDASExtraData::get_next_row()
{
  int ret = OB_SUCCESS;
  bool got_row = false;
  if (!result_iter_.is_valid()) {
    // hasn't fetched any data yet
    if (OB_FAIL(fetch_result())) {
      LOG_WARN("fetch result failed", KR(ret));
    }
  }
  while (!got_row && OB_SUCC(ret)) {
    if (OB_FAIL(result_iter_.get_next_row<false>(*eval_ctx_, *output_exprs_))) {
      if (OB_ITER_END != ret) {
        LOG_WARN("get next row from result iter failed", KR(ret));
      } else if (has_more_) {
        ret = OB_SUCCESS;
        if (OB_FAIL(fetch_result())) {
          LOG_WARN("fetch result failed", KR(ret));
        }
      }
    } else {
      got_row = true;
      LOG_DEBUG("get next row from result iter", KR(ret),
                "output", ROWEXPR2STR(*eval_ctx_, *output_exprs_));
    }
  }
  return ret;
}

int ObDASExtraData::get_next_rows(int64_t &count, int64_t capacity)
{
  int ret = OB_SUCCESS;
  bool got_row = false;
  if (!result_iter_.is_valid()) {
    // hasn't fetched any data yet
    if (OB_FAIL(fetch_result())) {
      LOG_WARN("fetch result failed", KR(ret));
    }
  }
  while (!got_row && OB_SUCC(ret)) {
    if (OB_UNLIKELY(need_check_output_datum_)) {
      ret = result_iter_.get_next_batch<true>(*output_exprs_, *eval_ctx_,
                                                         capacity, count);
    } else {
      ret = result_iter_.get_next_batch<false>(*output_exprs_, *eval_ctx_,
                                                          capacity, count);
    }
    if (OB_FAIL(ret)) {
      if (OB_ITER_END != ret) {
        LOG_WARN("get next batch from result iter failed", KR(ret));
      } else if (has_more_) {
        ret = OB_SUCCESS;
        if (OB_FAIL(fetch_result())) {
          LOG_WARN("fetch result failed", KR(ret));
        }
      }
    } else {
      got_row = true;
      PRINT_VECTORIZED_ROWS(SQL, DEBUG, *eval_ctx_, *output_exprs_, count, KR(ret));
    }
  }
  return ret;
}

void ObDASExtraData::erase_task_result()
{
  int ret = OB_SUCCESS;
  if (result_iter_.is_valid() && !has_more_) {
    // we have fetched all results, nothing to erase
  } else {
    ObDASDataEraseReq req;
    int64_t tenant_id = MTL_ID();
    int64_t timeout = timeout_ts_ - ObTimeUtility::current_time();
    if (OB_UNLIKELY(timeout < 0)) {
      ret = OB_TIMEOUT;
      LOG_WARN("das extra data erase result timeout", KR(ret), K(timeout_ts_), K(timeout));
    } else if (OB_FAIL(req.init(tenant_id, task_id_))) {
      LOG_WARN("init das data erase request failed", KR(ret));
    } else if (OB_FAIL(rpc_proxy_
                       .to(result_addr_)
                       .by(tenant_id)
                       .timeout(timeout)
                       .async_erase_das_result(req, nullptr))) {
      LOG_WARN("rpc async erase das result failed", KR(ret));
    }
  }
}
}  // namespace sql
}  // namespace oceanbase