/*
 * 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;

Thrown when the coordinator knows there is not enough replicas alive to perform a query with the
requested consistency level.
This exception is processed by RetryPolicy.onUnavailable(Request, ConsistencyLevel, int, int, 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. /**
 * Thrown when the coordinator knows there is not enough replicas alive to perform a query with the
 * requested consistency level.
 *
 * <p>This exception is processed by {@link RetryPolicy#onUnavailable(Request, ConsistencyLevel,
 * int, int, 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 UnavailableException extends QueryExecutionException {
  private final ConsistencyLevel consistencyLevel;
  private final int required;
  private final int alive;

  public UnavailableException(
      @NonNull Node coordinator,
      @NonNull ConsistencyLevel consistencyLevel,
      int required,
      int alive) {
    this(
        coordinator,
        String.format(
            "Not enough replicas available for query at consistency %s (%d required but only %d alive)",
            consistencyLevel, required, alive),
        consistencyLevel,
        required,
        alive,
        null,
        false);
  }

  private UnavailableException(
      @NonNull Node coordinator,
      @NonNull String message,
      @NonNull ConsistencyLevel consistencyLevel,
      int required,
      int alive,
      ExecutionInfo executionInfo,
      boolean writableStackTrace) {
    super(coordinator, message, executionInfo, writableStackTrace);
    this.consistencyLevel = consistencyLevel;
    this.required = required;
    this.alive = alive;
  }

  
The consistency level of the operation triggering this exception. /** The consistency level of the operation triggering this exception. */
  @NonNull
  public ConsistencyLevel getConsistencyLevel() {
    return consistencyLevel;
  }

  
The number of replica acknowledgements/responses required to perform the operation (with its
required consistency level).
/**
   * The number of replica acknowledgements/responses required to perform the operation (with its
   * required consistency level).
   */
  public int getRequired() {
    return required;
  }

  
The number of replicas that were known to be alive by the coordinator node when it tried to
execute the operation.
/**
   * The number of replicas that were known to be alive by the coordinator node when it tried to
   * execute the operation.
   */
  public int getAlive() {
    return alive;
  }

  @NonNull
  @Override
  public DriverException copy() {
    return new UnavailableException(
        getCoordinator(),
        getMessage(),
        consistencyLevel,
        required,
        alive,
        getExecutionInfo(),
        true);
  }
}