/*
 * 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.tuscany.nosqldatastore.hbase;

import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.client.*;
import org.apache.tuscany.nosqldatastore.Group;
import org.apache.tuscany.nosqldatastore.exception.DuplicateEntryException;
import org.apache.tuscany.nosqldatastore.exception.EntryNotFoundException;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class HBaseGroup implements Group {

    private HTable table;
    private String cf;

    HBaseGroup(HTable table, String cf){
        this.table = table;
        this.cf = cf;
    }

    public void addEntry(String key, String value) throws DuplicateEntryException {
        if(get(key) == null){
            Put put = new Put(key.getBytes());
            put.add(cf.getBytes(),key.getBytes(),value.getBytes());
            try {
                table.put(put);
                table.flushCommits();
            } catch (IOException e) {
                System.out.println("Error: Adding the entry for the Key "+key);
                e.printStackTrace();
            }
        } else {
            throw new DuplicateEntryException("Duplicate entry for key "+key);
        }
    }

    public void updateEntry(String key, String value) throws EntryNotFoundException {
        if(get(key) != null){
            Put put = new Put(key.getBytes());
            put.add(cf.getBytes(),key.getBytes(),value.getBytes());
            try {
                table.put(put);
                table.flushCommits();
            } catch (IOException e) {
                System.out.println("Error: Adding the entry for the Key "+key);
                e.printStackTrace();
            }
        } else {
            throw new EntryNotFoundException("Entry does not exist for key "+key);
        }
    }

    public void deleteEntry(String key) throws EntryNotFoundException {
        if(get(key) != null){
            Delete delete = new Delete(key.getBytes());
            delete.deleteColumn(cf.getBytes(), key.getBytes());
            try {
                table.delete(delete);
                table.flushCommits();
            } catch (IOException e) {
                System.out.println("Error: Deleting the entry for the Key "+key);
                e.printStackTrace();
            }
        } else {
            throw new EntryNotFoundException("Entry does not exist for key "+key);
        }
    }

    public String getEntry(String key) throws EntryNotFoundException {
        byte[] b;
        if((b = get(key)) != null){
            return new String(b);
        } else {
            throw new EntryNotFoundException("Entry does not exist for key "+key);
        }
    }

    private byte[] get(String key){
        Result result = null;
        Get get = new Get(key.getBytes());
        try {
            result = table.get(get);
        } catch (IOException e) {
            System.out.println("Error: Getting the entry for the Key "+key);
            e.printStackTrace();
        }
        return result.getValue(cf.getBytes(),key.getBytes());
    }
}