/**
 * ============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.util.HashSet;
import java.util.List;
import java.util.Set;

import org.onap.aaf.auth.dao.Bytification;
import org.onap.aaf.auth.dao.Cached;
import org.onap.aaf.auth.dao.CassAccess;
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.dao.hl.Question;
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.Split;

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

public class RoleDAO extends CassDAOImpl<AuthzTrans,RoleDAO.Data> {

	public static final String TABLE = "role";
    public static final int CACHE_SEG = 0x40; // yields segment 0x0-0x3F
    
	private final HistoryDAO historyDAO;
	private final CacheInfoDAO infoDAO;

	private PSInfo psChildren, psNS, psName;

	public RoleDAO(AuthzTrans trans, Cluster cluster, String keyspace) throws APIException, IOException {
		super(trans, RoleDAO.class.getSimpleName(),cluster,keyspace,Data.class,TABLE, readConsistency(trans,TABLE), writeConsistency(trans,TABLE));
        // Set up sub-DAOs
        historyDAO = new HistoryDAO(trans, this);
		infoDAO = new CacheInfoDAO(trans,this);
		init(trans);
	}

	public RoleDAO(AuthzTrans trans, HistoryDAO hDAO, CacheInfoDAO ciDAO) {
		super(trans, RoleDAO.class.getSimpleName(),hDAO,Data.class,TABLE, readConsistency(trans,TABLE), writeConsistency(trans,TABLE));
		historyDAO = hDAO;
		infoDAO = ciDAO;
		init(trans);
	}


    //////////////////////////////////////////
    // Data Definition, matches Cassandra DM
    //////////////////////////////////////////
    private static final int KEYLIMIT = 2;
    /**
     * Data class that matches the Cassandra Table "role"
     * @author Jonathan
     */
	public static class Data extends CacheableData implements Bytification {
    	public String		ns;
		public String		name;
		public Set<String>  perms;
		public String		description;

        ////////////////////////////////////////
        // Getters
		public Set<String> perms(boolean mutable) {
			if (perms == null) {
				perms = new HashSet<String>();
			} else if (mutable && !(perms instanceof HashSet)) {
				perms = new HashSet<String>(perms);
			}
			return perms;
		}
		
		public static Data create(NsDAO.Data ns, String name) {
			NsSplit nss = new NsSplit(ns,name);		
			RoleDAO.Data rv = new Data();
			rv.ns = nss.ns;
			rv.name=nss.name;
			return rv;
		}
		
		public String fullName() {
			return ns + '.' + name;
		}
		
		public String encode() {
			return ns + '|' + name;
		}
		
		/**
		 * Decode Perm String, including breaking into appropriate Namespace
		 * 
		 * @param trans
		 * @param q
		 * @param r
		 * @return
		 */
		public static Result<Data> decode(AuthzTrans trans, Question q, String r) {
			String[] ss = Split.splitTrim('|', r,2);
			Data data = new Data();
			if(ss[1]==null) { // older 1 part encoding must be evaluated for NS
				Result<NsSplit> nss = q.deriveNsSplit(trans, ss[0]);
				if(nss.notOK()) {
					return Result.err(nss);
				}
				data.ns=nss.value.ns;
				data.name=nss.value.name;
			} else { // new 4 part encoding
				data.ns=ss[0];
				data.name=ss[1];
			}
			return Result.ok(data);
		}

		/**
		 * Decode from UserRole Data
		 * @param urdd
		 * @return
		 */
		public static RoleDAO.Data decode(UserRoleDAO.Data urdd) {
			RoleDAO.Data rd = new RoleDAO.Data();
			rd.ns = urdd.ns;
			rd.name = urdd.rname;
			return rd;
		}


		/**
		 * Decode Perm String, including breaking into appropriate Namespace
		 * 
		 * @param trans
		 * @param q
		 * @param p
		 * @return
		 */
		public static Result<String[]> decodeToArray(AuthzTrans trans, Question q, String p) {
			String[] ss = Split.splitTrim('|', p,2);
			if(ss[1]==null) { // older 1 part encoding must be evaluated for NS
				Result<NsSplit> nss = q.deriveNsSplit(trans, ss[0]);
				if(nss.notOK()) {
					return Result.err(nss);
				}
				ss[0] = nss.value.ns;
				ss[1] = nss.value.name;
			}
			return Result.ok(ss);
		}
		
		@Override
		public int[] invalidate(Cached<?,?> cache) {
			return new int[] {
				seg(cache,ns,name),
				seg(cache,ns),
				seg(cache,name),
			};
		}

		@Override
		public ByteBuffer bytify() throws IOException {
			ByteArrayOutputStream baos = new ByteArrayOutputStream();
			RoleLoader.deflt.marshal(this,new DataOutputStream(baos));
			return ByteBuffer.wrap(baos.toByteArray());
		}
		
		@Override
		public void reconstitute(ByteBuffer bb) throws IOException {
			RoleLoader.deflt.unmarshal(this, toDIS(bb));
		}

		@Override
		public String toString() {
			return ns + '.' + name;
		}
    }

    private static class RoleLoader extends Loader<Data> implements Streamer<Data> {
		public static final int MAGIC=923577343;
    	public static final int VERSION=1;
    	public static final int BUFF_SIZE=96;

    	public static final RoleLoader deflt = new RoleLoader(KEYLIMIT);
    	
		public RoleLoader(int keylimit) {
			super(keylimit);
		}
		
		@Override
		public Data load(Data data, Row row) {
			// Int more efficient
			data.ns = row.getString(0);
			data.name = row.getString(1);
			data.perms = row.getSet(2,String.class);
			data.description = row.getString(3);
			return data;
		}

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

		@Override
		protected void body(Data data, int _idx, Object[] obj) {
		    	int idx = _idx;
			obj[idx]=data.perms;
			obj[++idx]=data.description;
		}

		@Override
		public void marshal(Data data, DataOutputStream os) throws IOException {
			writeHeader(os,MAGIC,VERSION);
			writeString(os, data.ns);
			writeString(os, data.name);
			writeStringSet(os,data.perms);
			writeString(os, data.description);
		}

		@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.ns = readString(is, buff);
			data.name = readString(is,buff);
			data.perms = readStringSet(is,buff);
			data.description = readString(is,buff);
		}
    };

	private void init(AuthzTrans trans) {
		String[] helpers = setCRUD(trans, TABLE, Data.class, RoleLoader.deflt);
		
		psNS = new PSInfo(trans, SELECT_SP + helpers[FIELD_COMMAS] + " FROM " + TABLE +
				" WHERE ns = ?", new RoleLoader(1),readConsistency);

		psName = new PSInfo(trans, SELECT_SP + helpers[FIELD_COMMAS] + " FROM " + TABLE +
				" WHERE name = ?", new RoleLoader(1),readConsistency);

		psChildren = new PSInfo(trans, SELECT_SP +  helpers[FIELD_COMMAS] +  " FROM " + TABLE + 
				" WHERE ns=? AND name > ? AND name < ?", 
				new RoleLoader(3) {
			@Override
			protected void key(Data data, int _idx, Object[] obj) {
			    	int idx = _idx;
				obj[idx] = data.ns;
				obj[++idx]=data.name + DOT;
				obj[++idx]=data.name + DOT_PLUS_ONE;
			}
		},readConsistency);
		
	}

	public Result<List<Data>> readNS(AuthzTrans trans, String ns) {
		return psNS.read(trans, R_TEXT + " NS " + ns, new Object[]{ns});
	}

	public Result<List<Data>> readName(AuthzTrans trans, String name) {
		return psName.read(trans, R_TEXT + name, new Object[]{name});
	}

	public Result<List<Data>> readChildren(AuthzTrans trans, String ns, String role) {
		if(role.length()==0 || "*".equals(role)) {
			return psChildren.read(trans, R_TEXT, new Object[]{ns, FIRST_CHAR, LAST_CHAR}); 
		} else {
			return psChildren.read(trans, R_TEXT, new Object[]{ns, role+DOT, role+DOT_PLUS_ONE});
		}
	}

	/**
	 * Add a single Permission to the Role's Permission Collection
	 * 
	 * @param trans
	 * @param role
	 * @param perm
	 * @param type
	 * @param action
	 * @return
	 */
	public Result<Void> addPerm(AuthzTrans trans, RoleDAO.Data role, PermDAO.Data perm) {
		// Note: Prepared Statements for Collection updates aren't supported
		String pencode = perm.encode();
		try {
			getSession(trans).execute(UPDATE_SP + TABLE + " SET perms = perms + {'" + 
				pencode + "'} WHERE " +
				"ns = '" + role.ns + "' AND name = '" + role.name + "';");
		} catch (DriverException | APIException | IOException e) {
			reportPerhapsReset(trans,e);
			return Result.err(Result.ERR_Backend, CassAccess.ERR_ACCESS_MSG);
		}

		wasModified(trans, CRUD.update, role, "Added permission " + pencode + " to role " + role.fullName());
		return Result.ok();
	}

	/**
	 * Remove a single Permission from the Role's Permission Collection
	 * @param trans
	 * @param role
	 * @param perm
	 * @param type
	 * @param action
	 * @return
	 */
	public Result<Void> delPerm(AuthzTrans trans, RoleDAO.Data role, PermDAO.Data perm) {
		// Note: Prepared Statements for Collection updates aren't supported

		String pencode = perm.encode();
		
		//ResultSet rv =
		try {
			getSession(trans).execute(UPDATE_SP + TABLE + " SET perms = perms - {'" + 
				pencode	+ "'} WHERE " +
				"ns = '" + role.ns + "' AND name = '" + role.name + "';");
		} catch (DriverException | APIException | IOException e) {
			reportPerhapsReset(trans,e);
			return Result.err(Result.ERR_Backend, CassAccess.ERR_ACCESS_MSG);
		}

		//TODO how can we tell when it doesn't?
		wasModified(trans, CRUD.update, role, "Removed permission " + pencode + " from role " + role.fullName() );
		return Result.ok();
	}
	
	/**
	 * Add description to role
	 * 
	 * @param trans
	 * @param ns
	 * @param name
	 * @param description
	 * @return
	 */
	public Result<Void> addDescription(AuthzTrans trans, String ns, String name, String description) {
		try {
			getSession(trans).execute(UPDATE_SP + TABLE + " SET description = '" 
				+ description + "' WHERE ns = '" + ns + "' AND name = '" + name + "';");
		} catch (DriverException | APIException | IOException e) {
			reportPerhapsReset(trans,e);
			return Result.err(Result.ERR_Backend, CassAccess.ERR_ACCESS_MSG);
		}

		Data data = new Data();
		data.ns=ns;
		data.name=name;
		wasModified(trans, CRUD.update, data, "Added description " + description + " to role " + data.fullName(), null );
		return Result.ok();
	}
	
	
    /**
     * 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.fullName();
        hd.memo = memo ? override[0] : (data.fullName() + " was "  + modified.name() + 'd' );
		if(modified==CRUD.delete) {
			try {
				hd.reconstruct = data.bytify();
			} catch (IOException e) {
				trans.error().log(e,"Could not serialize RoleDAO.Data");
			}
		}

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

    
}