/**
 * ============LICENSE_START====================================================
 * org.onap.aaf
 * ===========================================================================
 * Copyright (c) 2018 AT&T Intellectual Property. All rights reserved.
 * ===========================================================================
 * 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.
 * ============LICENSE_END====================================================
 *
 */

package org.onap.aaf.auth.dao.cass;

import java.nio.ByteBuffer;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.UUID;

import org.onap.aaf.auth.dao.AbsCassDAO;
import org.onap.aaf.auth.dao.CassDAOImpl;
import org.onap.aaf.auth.dao.Loader;
import org.onap.aaf.auth.env.AuthzTrans;
import org.onap.aaf.auth.layer.Result;

import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.ConsistencyLevel;
import com.datastax.driver.core.ResultSet;
import com.datastax.driver.core.Row;

/**
 * History
 * 
 * Originally written PE3617
 * @author Jonathan
 * 
 * History is a special case, because we don't want Updates or Deletes...  Too likely to mess up history.
 * 
 * Jonathan 9-9-2013 - Found a problem with using "Prepare".  You cannot prepare anything with a "now()" in it, as
 * it is evaluated once during the prepare, and kept.  That renders any use of "now()" pointless.  Therefore
 * the Create function needs to be run fresh everytime.
 * 
 * Fixed in Cassandra 1.2.6 https://issues.apache.org/jira/browse/CASSANDRA-5616
 *
 */
public class HistoryDAO extends CassDAOImpl<AuthzTrans, HistoryDAO.Data> {
    private static final String TABLE = "history";

    private String[] helpers;

    private HistLoader defLoader;

    private AbsCassDAO<AuthzTrans, Data>.PSInfo readByUser, readBySubject, readByYRMN;

    public HistoryDAO(AuthzTrans trans, Cluster cluster, String keyspace) {
        super(trans, HistoryDAO.class.getSimpleName(),cluster,keyspace,Data.class,TABLE,ConsistencyLevel.LOCAL_ONE,ConsistencyLevel.ANY);
        init(trans);
    }

    public HistoryDAO(AuthzTrans trans, AbsCassDAO<AuthzTrans,?> aDao) {
        super(trans, HistoryDAO.class.getSimpleName(),aDao,Data.class,TABLE,ConsistencyLevel.LOCAL_ONE,ConsistencyLevel.ANY);
        init(trans);
    }


    private static final int KEYLIMIT = 1;
    public static class Data {
        public UUID id;
        public int    yr_mon;
        public String user;
        public String action;
        public String target;
        public String subject;
        public String  memo;
        public ByteBuffer reconstruct;
    }
    
    private static class HistLoader extends Loader<Data> {
        public HistLoader(int keylimit) {
            super(keylimit);
        }

        @Override
        public Data load(Data data, Row row) {
            data.id = row.getUUID(0);
            data.yr_mon = row.getInt(1);
            data.user = row.getString(2);
            data.action = row.getString(3);
            data.target = row.getString(4);
            data.subject = row.getString(5);
            data.memo = row.getString(6);
            data.reconstruct = row.getBytes(7);
            return data;
        }

        @Override
        protected void key(Data data, int idx, Object[] obj) {
            obj[idx]=data.id;
        }

        @Override
        protected void body(Data data, int _idx, Object[] obj) {
                int idx = _idx;
            obj[idx]=data.yr_mon;
            obj[++idx]=data.user;
            obj[++idx]=data.action;
            obj[++idx]=data.target;
            obj[++idx]=data.subject;
            obj[++idx]=data.memo;
//            obj[++idx]=data.detail;
            obj[++idx]=data.reconstruct;        
        }
    };
    
    private void init(AuthzTrans trans) {
        // Loader must match fields order
        defLoader = new HistLoader(KEYLIMIT);
        helpers = setCRUD(trans, TABLE, Data.class, defLoader);

        // Need a specialty Creator to handle the "now()"
        // 9/9/2013 - Jonathan - Just great... now() is evaluated once on Client side, invalidating usage (what point is a now() from a long time in the past?
        // Unless this is fixed, we're putting in non-prepared statement
        // Solved in Cassandra.  Make sure you are running 1.2.6 Cassandra or later. https://issues.apache.org/jira/browse/CASSANDRA-5616    
        replace(CRUD.create, new PSInfo(trans, "INSERT INTO history (" +  helpers[FIELD_COMMAS] +
                    ") VALUES(now(),?,?,?,?,?,?,?)", 
                    new HistLoader(0) {
                        @Override
                        protected void key(Data data, int idx, Object[] obj) {
                        }
                    },writeConsistency)
                );
//        disable(CRUD.Create);
        
        replace(CRUD.read, new PSInfo(trans, SELECT_SP +  helpers[FIELD_COMMAS] +
                " FROM history WHERE id = ?", defLoader,readConsistency) 
//                new HistLoader(2) {
//                    @Override
//                    protected void key(Data data, int idx, Object[] obj) {
//                        obj[idx]=data.yr_mon;
//                        obj[++idx]=data.id;
//                    }
//                })
            );
        disable(CRUD.update);
        disable(CRUD.delete);
        
        readByUser = new PSInfo(trans, SELECT_SP + helpers[FIELD_COMMAS] + 
                " FROM history WHERE user = ?", defLoader,readConsistency);
        readBySubject = new PSInfo(trans, SELECT_SP + helpers[FIELD_COMMAS] + 
                " FROM history WHERE subject = ? and target = ? ALLOW FILTERING", defLoader,readConsistency);
        readByYRMN = new PSInfo(trans, SELECT_SP + helpers[FIELD_COMMAS] + 
                " FROM history WHERE yr_mon = ?", defLoader,readConsistency);
        async(true); //TODO dropping messages with Async
    }

    public static Data newInitedData() {
        Data data = new Data();
        Date now = new Date();
        // Sonar claims that SimpleDateFormat is not thread safe, so we can't be static
        data.yr_mon = Integer.parseInt(new SimpleDateFormat("yyyyMM").format(now));
        // data.day_time = Integer.parseInt(dayTimeFormat.format(now));
        return data;        
    }

    public Result<List<Data>> readByYYYYMM(AuthzTrans trans, int yyyymm) {
        Result<ResultSet> rs = readByYRMN.exec(trans, "yr_mon", yyyymm);
        if (rs.notOK()) {
            return Result.err(rs);
        }
        return extract(defLoader,rs.value,null,dflt);
    }

    /**
     * Gets the history for a user in the specified year and month
     * year - the year in yyyy format
     * month -  the month in a year ...values 1 - 12
     **/
    public Result<List<Data>> readByUser(AuthzTrans trans, String user, int ... yyyymm) {
        if (yyyymm.length==0) {
            return Result.err(Status.ERR_BadData, "No or invalid yyyymm specified");
        }
        Result<ResultSet> rs = readByUser.exec(trans, "user", user);
        if (rs.notOK()) {
            return Result.err(rs);
        }
        return extract(defLoader,rs.value,null,yyyymm.length>0?new YYYYMM(yyyymm):dflt);
    }
    
    public Result<List<Data>> readBySubject(AuthzTrans trans, String subject, String target, int ... yyyymm) {
        if (yyyymm.length==0) {
            return Result.err(Status.ERR_BadData, "No or invalid yyyymm specified");
        }
        Result<ResultSet> rs = readBySubject.exec(trans, "subject", subject, target);
        if (rs.notOK()) {
            return Result.err(rs);
        }
        return extract(defLoader,rs.value,null,yyyymm.length>0?new YYYYMM(yyyymm):dflt);
    }
    
    private class YYYYMM implements Accept<Data> {
        private int[] yyyymm;
        public YYYYMM(int yyyymm[]) {
            this.yyyymm = yyyymm;
        }
        @Override
        public boolean ok(Data data) {
            int dym = data.yr_mon;
            for (int ym:yyyymm) {
                if (dym==ym) {
                    return true;
                }
            }
            return false;
        }
        
    };
    
}