package org.simantics.databoard.serialization.impl;

import gnu.trove.map.hash.TObjectIntHashMap;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.List;
import java.util.TreeSet;

import org.simantics.databoard.binding.MapBinding;
import org.simantics.databoard.binding.error.BindingException;
import org.simantics.databoard.binding.util.IsReferableQuery;
import org.simantics.databoard.binding.util.Result;
import org.simantics.databoard.serialization.SerializationException;
import org.simantics.databoard.serialization.Serializer;
import org.simantics.databoard.serialization.Serializer.CompositeSerializer;

public class MapSerializer extends CompositeSerializer {

	Integer fixedSizeOfKey, fixedSizeOfValue, fixedSizeOfEntry;
	public Serializer keySerializer, valueSerializer;
	MapBinding binding;
	
	/**
	 * 
	 * @param binding
	 * @param keySerializer (optional) can be set later
	 * @param valueSerializer (optional) can be set later
	 */
	public MapSerializer(MapBinding binding, Serializer keySerializer, Serializer valueSerializer) {
		super( IsReferableQuery.isReferable( binding.type() ) != Result.No );
		this.keySerializer = keySerializer;
		this.valueSerializer = valueSerializer;
		this.binding = binding;
		
	}
	
	@Override
	public void finalizeConstruction() {
		fixedSizeOfKey = keySerializer.getConstantSize();
		fixedSizeOfValue = valueSerializer.getConstantSize();
		fixedSizeOfEntry = (fixedSizeOfKey!=null && fixedSizeOfValue!=null) ? (fixedSizeOfKey+fixedSizeOfValue) : null; 
	}

	@Override
	public Object deserialize(DataInput in, List<Object> identities) throws IOException{
		try {
			int length = in.readInt();
			if (length<0) throw new SerializationException("Cannot use negative array length");
			assertRemainingBytes(in, (long)length*((long)keySerializer.getMinSize()+(long)valueSerializer.getMinSize()));
			
			Object keys[] = new Object[length];
			Object values[] = new Object[length];
						
			for(int i=0;i<length;++i) {
				keys[i] = keySerializer.deserialize(in, identities);
				values[i] = valueSerializer.deserialize(in, identities);				
			}
			return binding.create(keys, values);
		} catch (BindingException e) {
			throw new IOException( e ); 
		}			
	}
	
	@Override
	public void deserializeTo(DataInput in, List<Object> identities, Object obj) throws IOException {
		try {
			TreeSet<Object> oldKeys = new TreeSet<Object>( binding.getKeyBinding() );
			binding.getKeys(obj, oldKeys);
			
			int length = in.readInt();
			if (length<0) throw new SerializationException("Cannot use negative array length");
			assertRemainingBytes(in, (long)length*((long)keySerializer.getMinSize()+(long)valueSerializer.getMinSize()));
			
			for(int i=0;i<length;++i) {
				Object key = keySerializer.deserialize(in, identities);
				Object value = valueSerializer.deserialize(in, identities);
				binding.put(obj, key, value);
				oldKeys.remove(key);
			}
			
			// remove unused keys
			for (Object key : oldKeys)
				binding.remove(obj, key);
		} catch (BindingException e) {
			throw new IOException( e ); 
		}
			
	}
	
	@Override
	public void skip(DataInput in, List<Object> identities)
	throws IOException, SerializationException {
		int length = in.readInt();
		if (fixedSizeOfEntry!=null) {
			in.skipBytes( length * fixedSizeOfEntry );
			return;
		}
		for(int i=0;i<length;++i) {
			if (fixedSizeOfKey!=null) {
				in.skipBytes(fixedSizeOfKey);
			} else {
				keySerializer.skip(in, identities);
			}
			
			if (fixedSizeOfValue!=null) {
				in.skipBytes(fixedSizeOfValue);
			} else {
				valueSerializer.skip(in, identities);
			}
		}
	}

	@Override
	public void serialize(DataOutput out, TObjectIntHashMap<Object> identities, Object map) throws IOException {
		try {
			int length = binding.size(map);
			//if (binding.isOrderedMap(map)) 
			{
				Object[] keys = new Object[length];
				Object[] values = new Object[length];
				binding.getAll(map, keys, values);
				out.writeInt(length);
				for(int i=0;i<length;++i) {
					Object key = keys[i];
					Object value = values[i];
					keySerializer.serialize(out, identities, key);
					valueSerializer.serialize(out, identities, value);				
				}
			}
			/*
			else {
				// Sort keys by putting into a treemap
				TreeMap<Object, Object> copyMap = new TreeMap<Object, Object>(binding.getKeyBinding());
				binding.getAll(map, copyMap);
				Iterator<Entry<Object, Object>> iter = copyMap.entrySet().iterator();
				putLength(out, length);
				while (iter.hasNext()) {
					Entry<Object, Object> e = iter.next();
					Object key = e.getKey();
					Object value = e.getValue();
					keySerializer.serialize(out, identities, key);
					valueSerializer.serialize(out, identities, value);				
				}
			}*/
		} catch (BindingException e) {
			throw new IOException( e ); 
		}
	}

	@Override
	public Integer getConstantSize() {
		return null;
	}

	@Override
	public int getSize(Object obj, TObjectIntHashMap<Object> identities) throws IOException {
		try {
			int length = binding.size(obj);
			if (fixedSizeOfEntry!=null)
				return 4 + fixedSizeOfEntry * length;
			int result = 4;
			Object keys[] = binding.getKeys(obj);
			for(int i=0;i<length;++i) {
				Object key = keys[i];
				Object value = binding.get(obj, key);
				result += keySerializer.getSize(key, identities);
				result += valueSerializer.getSize(value, identities);
			}
			return result;
		} catch (BindingException e) {
			throw new IOException( e ); 
		}
	}

	@Override
	public int getMinSize() {
		return 4;
	}
	
}