package org.simantics.acorn.lru;

import java.util.ArrayList;

import org.simantics.acorn.ClusterManager;
import org.simantics.acorn.exception.AcornAccessVerificationException;
import org.simantics.acorn.exception.IllegalAcornStateException;
import org.simantics.acorn.internal.Change;
import org.simantics.acorn.internal.ClusterChange;
import org.simantics.db.procore.cluster.ClusterTraits;
import org.simantics.db.service.ClusterUID;

import gnu.trove.list.array.TByteArrayList;

public class ClusterChangeSet {

	public enum Type {
		ADD,REMOVE,VALUE
	}
	
	public static class Entry {
		
		final Type type;
		final short subject;
		final short predicate;
		final short object;
		final ClusterUID predicateUID;
		final ClusterUID objectUID;
		final boolean oldValueEx;
		final byte[] oldValue;
		final byte[] newValue;
		
		public Entry(Type type, int subject, ClusterUID predicateUID, int predicate, ClusterUID objectUID, int object) {
			this.type = type;
			this.subject = (short)(subject & 0xFFF);
			this.predicate = (short)predicate;
			this.object = (short)object;
			this.predicateUID = predicateUID;
			this.objectUID = objectUID;
			this.oldValueEx = false;
			this.oldValue = null;
			this.newValue = null;
		}

		public Entry(int subject, boolean oldValueEx, byte[] oldValue, byte[] newValue) throws IllegalAcornStateException {
			if(oldValue == null && newValue == null)
				throw new IllegalAcornStateException("oldValue == null && newValue == null");
			this.type = Type.VALUE;
			this.subject = (short)(subject & 0xFFF);
			this.predicate = 0;
			this.object = 0;
			this.predicateUID = null;
			this.objectUID = null;
			this.oldValueEx = oldValueEx;
			this.oldValue = oldValue;
			this.newValue = newValue;
		}
		
		public void process(ClusterManager clusters, ClusterChange cs, int clusterKey) throws AcornAccessVerificationException {
			
			Entry e = this;
			
			if(e.type == Type.VALUE) {
				
				if(e.oldValue != null) {
					cs.setValue(e.subject, e.oldValue, e.oldValue.length);
				} else {
					Change change = new Change();
					change.addStatementIndex(e.subject, null, ClusterChange.DELETE_OPERATION);
					cs.addChange(change);
				}
				
			} else if(e.type == Type.ADD) {
				
				int s = ClusterTraits.createResourceKeyNoThrow(clusterKey, e.subject);
				int p = clusters.getResourceKey(e.predicateUID, e.predicate);
				int o = clusters.getResourceKey(e.objectUID, e.object);
				Change change = new Change();
				change.addStatementIndex(s, null, ClusterChange.REMOVE_OPERATION);
				change.addStatementIndex(p, e.predicateUID, (byte)0);
				change.addStatementIndex(o, e.objectUID, (byte)0);
				cs.addChange(change);
				
			} else if(e.type == Type.REMOVE) {
				
				int s = ClusterTraits.createResourceKeyNoThrow(clusterKey, e.subject);
				int p = clusters.getResourceKey(e.predicateUID, e.predicate);
				int o = clusters.getResourceKey(e.objectUID, e.object);
				Change change = new Change();
				change.addStatementIndex(s, null, ClusterChange.ADD_OPERATION);
				change.addStatementIndex(p, e.predicateUID, (byte)0);
				change.addStatementIndex(o, e.objectUID, (byte)0);
				cs.addChange(change);
				
			}
			
		}
		
	}
	
	final public String id;
	final public ClusterUID cuid;
	public String chunkKey;
	public int chunkOffset = -1;
	
	public TByteArrayList statementMask = new TByteArrayList();
	public TByteArrayList oldValueEx = new TByteArrayList();
	public ArrayList<byte[]> oldValues = new ArrayList<byte[]>();
	
	public ClusterChangeSet(String id ,ClusterUID cuid) {
		this.id = id;
		this.cuid = cuid;
		String[] ss = id.split("\\.");
		chunkKey = ss[0];
		chunkOffset = Integer.parseInt(ss[1]);
	}
	
	public ClusterStreamChunk getChunk(ClusterManager manager) throws AcornAccessVerificationException {
		return manager.streamLRU.get(chunkKey);
	}

}