/**
 * ============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.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.security.SecureRandom;
import java.util.Date;
import java.util.List;

import org.onap.aaf.auth.dao.Bytification;
import org.onap.aaf.auth.dao.CIDAO;
import org.onap.aaf.auth.dao.Cached;
import org.onap.aaf.auth.dao.CassDAOImpl;
import org.onap.aaf.auth.dao.Loader;
import org.onap.aaf.auth.dao.Streamer;
import org.onap.aaf.auth.env.AuthzTrans;
import org.onap.aaf.auth.layer.Result;
import org.onap.aaf.misc.env.APIException;
import org.onap.aaf.misc.env.util.Chrono;

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

/**
 * CredDAO manages credentials. 
 * @author Jonathan
 * Date: 7/19/13
 */
public class CredDAO extends CassDAOImpl<AuthzTrans,CredDAO.Data> {
    public static final String TABLE = "cred";
    public static final int CACHE_SEG = 0x40; // yields segment 0x0-0x3F
    public static final int RAW = -1;
    public static final int NONE = 0;
    public static final int FQI = 10;
    public static final int BASIC_AUTH = 1;
    public static final int BASIC_AUTH_SHA256 = 2;
    public static final int CERT_SHA256_RSA =200;
    public static final SecureRandom srand = new SecureRandom();
    
    private HistoryDAO historyDAO;
    private CIDAO<AuthzTrans> infoDAO;
    private PSInfo psNS;
    private PSInfo psID;
    
    public CredDAO(AuthzTrans trans, Cluster cluster, String keyspace) throws APIException, IOException {
        super(trans, CredDAO.class.getSimpleName(),cluster, keyspace, Data.class,TABLE, readConsistency(trans,TABLE), writeConsistency(trans,TABLE));
        init(trans);
    }

    public CredDAO(AuthzTrans trans, HistoryDAO hDao, CacheInfoDAO ciDao) throws APIException, IOException {
        super(trans, CredDAO.class.getSimpleName(),hDao, Data.class,TABLE, readConsistency(trans,TABLE), writeConsistency(trans,TABLE));
        historyDAO = hDao;
        infoDAO = ciDao;
        init(trans);
    }

    public static final int KEYLIMIT = 3;
    public static class Data extends CacheableData implements Bytification {
        
        public String                   id;
        public Integer                  type;
        public Date                     expires;
        public Integer                  other;
        public String                   ns;
        public String					tag;
        public String					notes;
        public ByteBuffer               cred;  //   this is a blob in cassandra


        @Override
        public int[] invalidate(Cached<?,?> cache) {
            return new int[] {
                seg(cache,id) // cache is for all entities
            };
        }
        
        @Override
        public ByteBuffer bytify() throws IOException {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            CredLoader.deflt.marshal(this,new DataOutputStream(baos));
            return ByteBuffer.wrap(baos.toByteArray());
        }
        
        @Override
        public void reconstitute(ByteBuffer bb) throws IOException {
            CredLoader.deflt.unmarshal(this, toDIS(bb));
        }

        public String toString() {
            return id + ' ' + type + ' ' + Chrono.dateTime(expires);
        }
    }

    public static class CredLoader extends Loader<Data> implements Streamer<Data>{
        public static final int MAGIC=153323443;
        public static final int VERSION=2;
        public static final int BUFF_SIZE=48; // Note: 

        public static final CredLoader deflt = new CredLoader(KEYLIMIT);
        public CredLoader(int keylimit) {
            super(keylimit);
        }

        @Override
        public Data load(Data data, Row row) {
            data.id = row.getString(0);
            data.type = row.getInt(1);    // NOTE: in datastax driver,  If the int value is NULL, 0 is returned!
            data.expires = row.getTimestamp(2);
            data.other = row.getInt(3);
            data.ns = row.getString(4);     
            data.tag = row.getString(5);
            data.notes = row.getString(6);
            data.cred = row.getBytesUnsafe(7);            
            return data;
        }

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

            obj[idx] = data.id;
            obj[++idx] = data.type;
            obj[++idx] = data.expires;
        }

        @Override
        protected void body(Data data, int idx, Object[] obj) {
            int i;
            obj[i=idx] = data.other;
            obj[++i] = data.ns;
            obj[++i] = data.tag;
            obj[++i] = data.notes;
            obj[++i] = data.cred;
        }

        @Override
        public void marshal(Data data, DataOutputStream os) throws IOException {
            writeHeader(os,MAGIC,VERSION);
            writeString(os, data.id);
            os.writeInt(data.type);    
            os.writeLong(data.expires==null?-1:data.expires.getTime());
            os.writeInt(data.other==null?0:data.other);
            writeString(os, data.ns);
            writeString(os, data.tag);
            writeString(os, data.notes);
            if (data.cred==null) {
                os.writeInt(-1);
            } else {
                int l = data.cred.limit()-data.cred.position();
                os.writeInt(l);
                os.write(data.cred.array(),data.cred.position(),l);
            }
        }

        @Override
        public void unmarshal(Data data, DataInputStream is) throws IOException {
            /*int version = */readHeader(is,MAGIC,VERSION);
            // If Version Changes between Production runs, you'll need to do a switch Statement, and adequately read in fields
            byte[] buff = new byte[BUFF_SIZE];
            data.id = readString(is,buff);
            data.type = is.readInt();
            
            long l = is.readLong();
            data.expires = l<0?null:new Date(l);
            data.other = is.readInt();
            data.ns = readString(is,buff);
            data.tag = readString(is,buff);
            data.notes = readString(is,buff);
            
            int i = is.readInt();
            data.cred=null;
            if (i>=0) {
                byte[] bytes = new byte[i]; // a bit dangerous, but lessened because of all the previous sized data reads
                int read = is.read(bytes);
                if (read>0) {
                    data.cred = ByteBuffer.wrap(bytes);
                }
            }
        }
    }

    private void init(AuthzTrans trans) throws APIException, IOException {
        // Set up sub-DAOs
        if (historyDAO==null) {
            historyDAO = new HistoryDAO(trans,this);
        }
        if (infoDAO==null) {
            infoDAO = new CacheInfoDAO(trans,this);
        }
        

        String[] helpers = setCRUD(trans, TABLE, Data.class, CredLoader.deflt);
        
        psNS = new PSInfo(trans, SELECT_SP + helpers[FIELD_COMMAS] + " FROM " + TABLE +
                " WHERE ns = ?", CredLoader.deflt,readConsistency);
        
        psID = new PSInfo(trans, SELECT_SP + helpers[FIELD_COMMAS] + " FROM " + TABLE +
                " WHERE id = ?", CredLoader.deflt,readConsistency);
    }
    
	/* (non-Javadoc)
	 * @see org.onap.aaf.auth.dao.CassDAOImpl#create(org.onap.aaf.misc.env.TransStore, java.lang.Object)
	 */
	@Override
	public Result<Data> create(AuthzTrans trans, Data data) {
		if(data.tag == null) {
			if(data.type==0) {
				data.tag="PlaceHolder";
			} else {
				long l = srand.nextLong();
				data.tag = Long.toHexString(l);
			}
		}
		return super.create(trans, data);
	}

	public Result<List<Data>> readNS(AuthzTrans trans, String ns) {
        return psNS.read(trans, R_TEXT, new Object[]{ns});
    }
    
    public Result<List<Data>> readID(AuthzTrans trans, String id) {
        return psID.read(trans, R_TEXT, new Object[]{id});
    }
    
    /**
     * Log Modification statements to History
     *
     * @param modified        which CRUD action was done
     * @param data            entity data that needs a log entry
     * @param overrideMessage if this is specified, we use it rather than crafting a history message based on data
     */
    @Override
    protected void wasModified(AuthzTrans trans, CRUD modified, Data data, String ... override) {
        boolean memo = override.length>0 && override[0]!=null;
        boolean subject = override.length>1 && override[1]!=null;

        HistoryDAO.Data hd = HistoryDAO.newInitedData();
        hd.user = trans.user();
        hd.action = modified.name();
        hd.target = TABLE;
        hd.subject = subject?override[1]: data.id;
        hd.memo = memo
                ? String.format("%s by %s", override[0], hd.user)
                : (modified.name() + "d credential for " + data.id);
        // Detail?
           if (modified==CRUD.delete) {
                    try {
                        hd.reconstruct = data.bytify();
                    } catch (IOException e) {
                        trans.error().log(e,"Could not serialize CredDAO.Data");
                    }
                }

        if (historyDAO.create(trans, hd).status!=Status.OK) {
            trans.error().log("Cannot log to History");
        }
        if (infoDAO.touch(trans, TABLE,data.invalidate(cache)).status!=Status.OK) {
            trans.error().log("Cannot touch Cred");
        }
    }
}