/*
 * Copyright DataStax, Inc.
 *
 * 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.
 */
package com.datastax.oss.driver.api.core.servererrors;

import com.datastax.oss.driver.api.core.AllNodesFailedException;
import com.datastax.oss.driver.api.core.ConsistencyLevel;
import com.datastax.oss.driver.api.core.DriverException;
import com.datastax.oss.driver.api.core.cql.ExecutionInfo;
import com.datastax.oss.driver.api.core.metadata.Node;
import com.datastax.oss.driver.api.core.retry.RetryPolicy;
import com.datastax.oss.driver.api.core.session.Request;
import edu.umd.cs.findbugs.annotations.NonNull;
import edu.umd.cs.findbugs.annotations.Nullable;
import java.net.InetAddress;
import java.util.Map;

A non-timeout error during a read query.
This happens when some of the replicas that were contacted by the coordinator replied with an
error.
This exception is processed by RetryPolicy.onErrorResponse(Request, CoordinatorException, int), which will decide if it is rethrown directly to the client or if the request should be retried. If all other tried nodes also fail, this exception will appear in the AllNodesFailedException thrown to the client. /**
 * A non-timeout error during a read query.
 *
 * <p>This happens when some of the replicas that were contacted by the coordinator replied with an
 * error.
 *
 * <p>This exception is processed by {@link RetryPolicy#onErrorResponse(Request,
 * CoordinatorException, int)}, which will decide if it is rethrown directly to the client or if the
 * request should be retried. If all other tried nodes also fail, this exception will appear in the
 * {@link AllNodesFailedException} thrown to the client.
 */
public class ReadFailureException extends QueryConsistencyException {

  private final int numFailures;
  private final boolean dataPresent;
  private final Map<InetAddress, Integer> reasonMap;

  public ReadFailureException(
      @NonNull Node coordinator,
      @NonNull ConsistencyLevel consistencyLevel,
      int received,
      int blockFor,
      int numFailures,
      boolean dataPresent,
      @NonNull Map<InetAddress, Integer> reasonMap) {
    this(
        coordinator,
        String.format(
            "Cassandra failure during read query at consistency %s "
                + "(%d responses were required but only %d replica responded, %d failed)",
            consistencyLevel, blockFor, received, numFailures),
        consistencyLevel,
        received,
        blockFor,
        numFailures,
        dataPresent,
        reasonMap,
        null,
        false);
  }

  private ReadFailureException(
      @NonNull Node coordinator,
      @NonNull String message,
      @NonNull ConsistencyLevel consistencyLevel,
      int received,
      int blockFor,
      int numFailures,
      boolean dataPresent,
      @NonNull Map<InetAddress, Integer> reasonMap,
      @Nullable ExecutionInfo executionInfo,
      boolean writableStackTrace) {
    super(
        coordinator,
        message,
        consistencyLevel,
        received,
        blockFor,
        executionInfo,
        writableStackTrace);
    this.numFailures = numFailures;
    this.dataPresent = dataPresent;
    this.reasonMap = reasonMap;
  }

  
Returns the number of replicas that experienced a failure while executing the request. /** Returns the number of replicas that experienced a failure while executing the request. */
  public int getNumFailures() {
    return numFailures;
  }

  
Whether the actual data was amongst the received replica responses.
During reads, Cassandra doesn't request data from every replica to minimize internal network
traffic. Instead, some replicas are only asked for a checksum of the data. A read failure may
occur even if enough replicas have responded to fulfill the consistency level, if only checksum
responses have been received. This method allows to detect that case.
/**
   * Whether the actual data was amongst the received replica responses.
   *
   * <p>During reads, Cassandra doesn't request data from every replica to minimize internal network
   * traffic. Instead, some replicas are only asked for a checksum of the data. A read failure may
   * occur even if enough replicas have responded to fulfill the consistency level, if only checksum
   * responses have been received. This method allows to detect that case.
   */
  public boolean wasDataPresent() {
    return dataPresent;
  }

  
Returns the a failure reason code for each node that failed.
At the time of writing, the existing reason codes are:

  
0x0000: the error does not have a specific code assigned yet, or the cause is unknown. 
0x0001: The read operation scanned too many tombstones (as defined by 
      tombstone_failure_threshold in cassandra.yaml, causing a 
      TombstoneOverwhelmingException. 
(please refer to the Cassandra documentation for your version for the most up-to-date list of
errors)
This feature is available for protocol v5 or above only. With lower protocol versions, the
map will always be empty.
/**
   * Returns the a failure reason code for each node that failed.
   *
   * <p>At the time of writing, the existing reason codes are:
   *
   * <ul>
   *   <li>{@code 0x0000}: the error does not have a specific code assigned yet, or the cause is
   *       unknown.
   *   <li>{@code 0x0001}: The read operation scanned too many tombstones (as defined by {@code
   *       tombstone_failure_threshold} in {@code cassandra.yaml}, causing a {@code
   *       TombstoneOverwhelmingException}.
   * </ul>
   *
   * (please refer to the Cassandra documentation for your version for the most up-to-date list of
   * errors)
   *
   * <p>This feature is available for protocol v5 or above only. With lower protocol versions, the
   * map will always be empty.
   */
  @NonNull
  public Map<InetAddress, Integer> getReasonMap() {
    return reasonMap;
  }

  @NonNull
  @Override
  public DriverException copy() {
    return new ReadFailureException(
        getCoordinator(),
        getMessage(),
        getConsistencyLevel(),
        getReceived(),
        getBlockFor(),
        numFailures,
        dataPresent,
        reasonMap,
        getExecutionInfo(),
        true);
  }
}