/*
 * 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
 *
 *   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 org.apache.pirk.query.wideskies;

import com.google.gson.annotations.Expose;
import org.apache.pirk.schema.query.QuerySchema;
import org.apache.pirk.schema.query.QuerySchemaRegistry;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;

/**
 * Class to hold all of the basic information regarding a query
 * <p>
 * Note that the hash key is specific to the query. If we have hash collisions over our selector set, we will append integers to the key starting with 0 until
 * we no longer have collisions
 */
public class QueryInfo implements Serializable, Cloneable
{
  private static final long serialVersionUID = 1L;

  public static final long queryInfoSerialVersionUID = 1L;

  // So that we can serialize the version number in gson.
  @Expose
  public final long queryInfoVersion = queryInfoSerialVersionUID;

  private static final Logger logger = LoggerFactory.getLogger(QueryInfo.class);

  @Expose
  private UUID identifier; // the identifier of the query

  @Expose
  private int numSelectors = 0; // the number of selectors in the query, given by \floor{paillerBitSize/dataPartitionBitSize}

  @Expose
  private String queryType = null; // QueryType string const

  @Expose
  private int hashBitSize = 0; // Bit size of the keyed hash function

  @Expose
  private String hashKey; // Key for the keyed hash function

  @Expose
  private int numBitsPerDataElement = 0; // total num bits per returned data value - defined relative to query type

  @Expose
  private int dataPartitionBitSize = 0; // num of bits for each partition of an incoming data element, must be < 32 right now

  @Expose
  private int numPartitionsPerDataElement = 0; // num partitions of size dataPartitionBitSize per data element

  @Expose
  private boolean useExpLookupTable = false; // whether or not to generate and use the expLookupTable for encryption, it is very expensive to compute

  @Expose
  private boolean useHDFSExpLookupTable = false; // whether or not to use the expLookupTable stored in HDFS
  // if it doesn't yet exist, it will be created within the cluster and stored in HDFS

  @Expose
  private boolean embedSelector = true; // whether or not to embed the selector in the results - results in a very low

  // false positive rate for variable length selectors and a zero false positive rate
  // for selectors of fixed size < 32 bits
  @Expose
  private QuerySchema qSchema = null;

  public QueryInfo(int numSelectorsInput, int hashBitSizeInput, int dataPartitionBitSizeInput, String queryTypeInput, boolean useExpLookupTableInput, boolean embedSelectorInput, boolean useHDFSExpLookupTableInput)
  {
    this(UUID.randomUUID(), numSelectorsInput, hashBitSizeInput, dataPartitionBitSizeInput, queryTypeInput, useExpLookupTableInput,
        embedSelectorInput, useHDFSExpLookupTableInput);
  }

  public QueryInfo(UUID identifierInput, int numSelectorsInput, int hashBitSizeInput, int dataPartitionBitSizeInput, String queryTypeInput,
      boolean useExpLookupTableInput, boolean embedSelectorInput, boolean useHDFSExpLookupTableInput)
  {
    identifier = identifierInput;
    queryType = queryTypeInput;

    numSelectors = numSelectorsInput;

    hashBitSize = hashBitSizeInput;

    useExpLookupTable = useExpLookupTableInput;
    useHDFSExpLookupTable = useHDFSExpLookupTableInput;
    embedSelector = embedSelectorInput;
    numBitsPerDataElement = QuerySchemaRegistry.get(queryType).getDataElementSize();
    dataPartitionBitSize = dataPartitionBitSizeInput;
    numPartitionsPerDataElement = numBitsPerDataElement / dataPartitionBitSizeInput;

    if (embedSelectorInput)
    {
      numPartitionsPerDataElement += 4; // using a 8-bit partition size and a 32-bit embedded selector
    }

    printQueryInfo();
  }

  /**
   * This constructor is used for deserialization only. The Hash Key should not be set manually in most cases because EncryptQuery
   * will overwrite it with a new random one.
   */
  public QueryInfo(UUID identifierInput, int numSelectorsInput, int hashBitSizeInput, String hashKeyInput, int dataPartitionBitSizeInput, String queryTypeInput,
      boolean useExpLookupTableInput, boolean embedSelectorInput, boolean useHDFSExpLookupTableInput, int numBitsPerDataElementInput,
      QuerySchema querySchemaInput)
  {
    identifier = identifierInput;
    queryType = queryTypeInput;

    numSelectors = numSelectorsInput;

    hashBitSize = hashBitSizeInput;
    hashKey = hashKeyInput;

    useExpLookupTable = useExpLookupTableInput;
    useHDFSExpLookupTable = useHDFSExpLookupTableInput;
    embedSelector = embedSelectorInput;

    numBitsPerDataElement = numBitsPerDataElementInput;
    dataPartitionBitSize = dataPartitionBitSizeInput;
    numPartitionsPerDataElement = numBitsPerDataElement / dataPartitionBitSizeInput;

    if (embedSelectorInput)
    {
      numPartitionsPerDataElement += 4; // using a 8-bit partition size and a 32-bit embedded selector
    }

    addQuerySchema(querySchemaInput);

    printQueryInfo();
  }

  public QueryInfo(Map queryInfoMap)
  {
    // The Storm Config serializes the map as a json and reads back in with numeric values as longs.
    // So numerics need to be cast as a long and call .intValue. However, in PirkHashScheme the map contains ints.
    identifier = UUID.fromString((String) queryInfoMap.get("uuid"));
    queryType = (String) queryInfoMap.get("queryType");
    hashKey = (String) queryInfoMap.get("hashKey");
    useExpLookupTable = (boolean) queryInfoMap.get("useExpLookupTable");
    useHDFSExpLookupTable = (boolean) queryInfoMap.get("useHDFSExpLookupTable");
    embedSelector = (boolean) queryInfoMap.get("embedSelector");
    try
    {
      numSelectors = ((Long) queryInfoMap.get("numSelectors")).intValue();
      hashBitSize = ((Long) queryInfoMap.get("hashBitSize")).intValue();
      numBitsPerDataElement = ((Long) queryInfoMap.get("numBitsPerDataElement")).intValue();
      numPartitionsPerDataElement = ((Long) queryInfoMap.get("numPartitionsPerDataElement")).intValue();
      dataPartitionBitSize = ((Long) queryInfoMap.get("dataPartitionsBitSize")).intValue();
    } catch (ClassCastException e)
    {
      numSelectors = (int) queryInfoMap.get("numSelectors");
      hashBitSize = (int) queryInfoMap.get("hashBitSize");
      numBitsPerDataElement = (int) queryInfoMap.get("numBitsPerDataElement");
      numPartitionsPerDataElement = (int) queryInfoMap.get("numPartitionsPerDataElement");
      dataPartitionBitSize = (int) queryInfoMap.get("dataPartitionsBitSize");
    }
  }

  public UUID getIdentifier()
  {
    return identifier;
  }

  public String getQueryType()
  {
    return queryType;
  }

  public int getNumSelectors()
  {
    return numSelectors;
  }

  public int getHashBitSize()
  {
    return hashBitSize;
  }

  public String getHashKey()
  {
    return hashKey;
  }

  public void setHashKey(String hashKey)
  {
    this.hashKey = hashKey;
  }

  public int getNumBitsPerDataElement()
  {
    return numBitsPerDataElement;
  }

  public int getNumPartitionsPerDataElement()
  {
    return numPartitionsPerDataElement;
  }

  public int getDataPartitionBitSize()
  {
    return dataPartitionBitSize;
  }

  public boolean useExpLookupTable()
  {
    return useExpLookupTable;
  }

  public boolean useHDFSExpLookupTable()
  {
    return useHDFSExpLookupTable;
  }

  public boolean getEmbedSelector()
  {
    return embedSelector;
  }

  public Map toMap()
  {
    Map<String,Object> queryInfo = new HashMap<String,Object>();
    queryInfo.put("uuid", identifier.toString());
    queryInfo.put("queryType", queryType);
    queryInfo.put("numSelectors", numSelectors);
    queryInfo.put("hashBitSize", hashBitSize);
    queryInfo.put("hashKey", hashKey);
    queryInfo.put("numBitsPerDataElement", numBitsPerDataElement);
    queryInfo.put("numPartitionsPerDataElement", numPartitionsPerDataElement);
    queryInfo.put("dataPartitionsBitSize", dataPartitionBitSize);
    queryInfo.put("useExpLookupTable", useExpLookupTable);
    queryInfo.put("useHDFSExpLookupTable", useHDFSExpLookupTable);
    queryInfo.put("embedSelector", embedSelector);

    return queryInfo;
  }

  public void addQuerySchema(QuerySchema qSchemaIn)
  {
    qSchema = qSchemaIn;
  }

  public QuerySchema getQuerySchema()
  {
    return qSchema;
  }

  public void printQueryInfo()
  {
    logger.info("identifier = " + identifier + " numSelectors = " + numSelectors + " hashBitSize = " + hashBitSize + " hashKey = " + hashKey
        + " dataPartitionBitSize = " + dataPartitionBitSize + " numBitsPerDataElement = " + numBitsPerDataElement + " numPartitionsPerDataElement = "
        + numPartitionsPerDataElement + " queryType = " + queryType + " useExpLookupTable = " + useExpLookupTable + " useHDFSExpLookupTable = "
        + useHDFSExpLookupTable + " embedSelector = " + embedSelector);
  }

  @Override
  public QueryInfo clone()
  {
    try
    {
      return (QueryInfo) super.clone();
    } catch (CloneNotSupportedException e)
    {
      throw new RuntimeException(e);
    }
  }
}