/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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
 *
 *   https://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 org.apache.accumulo.core.data.constraints;

import java.util.ArrayList;
import java.util.List;

import org.apache.accumulo.core.data.ColumnUpdate;
import org.apache.accumulo.core.data.Key;
import org.apache.accumulo.core.data.Mutation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A constraints that limits the size of keys to 1mb.
 *
 * <p>
 * This was moved from the org.apache.accumulo.core.constraints package since 2.1.0
 *
 * @since 2.1.0
 */
public class DefaultKeySizeConstraint implements Constraint {

  private static final Logger LOG = LoggerFactory.getLogger(DefaultKeySizeConstraint.class);
  protected static final short MAX__KEY_SIZE_EXCEEDED_VIOLATION = 1;
  protected static final long maxSize = 1048576; // 1MB default size

  @Override
  public String getViolationDescription(short violationCode) {

    if (violationCode == MAX__KEY_SIZE_EXCEEDED_VIOLATION) {
      return "Key was larger than 1MB";
    }
    return null;

  }

  static final List<Short> NO_VIOLATIONS = new ArrayList<>();

  @Override
  public List<Short> check(Environment env, Mutation mutation) {

    // fast size check
    if (mutation.numBytes() < maxSize) {
      return NO_VIOLATIONS;
    }

    List<Short> violations = new ArrayList<>();

    for (ColumnUpdate cu : mutation.getUpdates()) {
      int size = mutation.getRow().length;
      size += cu.getColumnFamily().length;
      size += cu.getColumnQualifier().length;
      size += cu.getColumnVisibility().length;

      if (size > maxSize) {
        violations.add(MAX__KEY_SIZE_EXCEEDED_VIOLATION);
        Key k = new Key(mutation.getRow(), cu.getColumnFamily(), cu.getColumnQualifier(),
            cu.getColumnVisibility(), cu.getTimestamp(), cu.isDeleted());
        LOG.debug("Constraint violation. Key {} (size = {}) larger than 1MB", k, size);
      }
    }

    return violations;
  }
}
