/* 
 * 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 parquet.hadoop.metadata;

import java.util.Arrays;
import java.util.Set;

import parquet.column.Encoding;
import parquet.schema.PrimitiveType.PrimitiveTypeName;

public class ColumnChunkProperties {

    private static Canonicalizer<ColumnChunkProperties> properties = new Canonicalizer<ColumnChunkProperties>();

    public static ColumnChunkProperties get(ColumnPath path, PrimitiveTypeName type, CompressionCodecName codec, Set<Encoding> encodings) {
        return properties.canonicalize(new ColumnChunkProperties(codec, path, type, encodings));
    }

    private final CompressionCodecName codec;
    private final ColumnPath path;
    private final PrimitiveTypeName type;
    private final Set<Encoding> encodings;

    private ColumnChunkProperties(CompressionCodecName codec,
                                  ColumnPath path,
                                  PrimitiveTypeName type,
                                  Set<Encoding> encodings) {
        super();
        this.codec = codec;
        this.path = path;
        this.type = type;
        this.encodings = encodings;
    }

    public CompressionCodecName getCodec() {
        return codec;
    }

    public ColumnPath getPath() {
        return path;
    }

    public PrimitiveTypeName getType() {
        return type;
    }

    public Set<Encoding> getEncodings() {
        return encodings;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj instanceof ColumnChunkProperties) {
            ColumnChunkProperties other = (ColumnChunkProperties) obj;
            return other.codec == codec && other.path.equals(path) && other.type == type && equals(other.encodings, encodings);
        }
        return false;
    }

    private boolean equals(Set<Encoding> a, Set<Encoding> b) {
        return a.size() == b.size() && a.containsAll(b);
    }

    @Override
    public int hashCode() {
        return codec.hashCode() ^ path.hashCode() ^ type.hashCode() ^ Arrays.hashCode(encodings.toArray());
    }

    @Override
    public String toString() {
        return codec + " " + path + " " + type + "  " + encodings;
    }
}