/*******************************************************************************
 *  Copyright (c) 2010 Association for Decentralized Information Management in
 *  Industry THTH ry.
 *  All rights reserved. This program and the accompanying materials
 *  are made available under the terms of the Eclipse Public License v1.0
 *  which accompanies this distribution, and is available at
 *  http://www.eclipse.org/legal/epl-v10.html
 *
 *  Contributors:
 *      VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.databoard.binding.reflection;

import java.lang.reflect.Array;
import java.util.Iterator;

import org.simantics.databoard.Bindings;
import org.simantics.databoard.adapter.AdaptException;
import org.simantics.databoard.adapter.Adapter;
import org.simantics.databoard.adapter.AdapterConstructionException;
import org.simantics.databoard.binding.ArrayBinding;
import org.simantics.databoard.binding.Binding;
import org.simantics.databoard.binding.error.BindingException;
import org.simantics.databoard.binding.error.UnsupportedOperationException;
import org.simantics.databoard.type.ArrayType;

/**
 * ReflectionArrayBinding binds T[] 
 *
 * @author Toni Kalajainen <toni.kalajainen@vtt.fi>
 */
public class GenericArrayBinding extends ArrayBinding {
	
	Class<?> clazz;
	Class<?> componentClass;

	public GenericArrayBinding(Class<?> clazz, ArrayType type, Binding componentBinding) {
		super(type, componentBinding);
		this.clazz = clazz;
		this.type = type;		
		this.componentClass = clazz.getComponentType();		
	}

	@Override
	public Object create() {
		return Array.newInstance(componentClass, 0);
	}
	
	@Override
	public Object create(int length, Iterator<Object> values) {
		Object result = Array.newInstance(componentClass, length);
		for (int i=0; i<length; i++) 
			Array.set(result, i, values.next());
		return result;
	}
	
	@Override
	public Object create(Object[] array) throws BindingException {
		int length = array.length;
		Object result = Array.newInstance(componentClass, length);
		System.arraycopy(array, 0, result, 0, length);
		return result;
	}
	
	@Override
	public void readFrom(Binding srcBinding, Object src, Object dst)
			throws BindingException {
		try {
			ArrayBinding sb = (ArrayBinding) srcBinding;
			Binding scb = sb.getComponentBinding();
			Binding dcb = getComponentBinding();
			Adapter cloner = dcb.isImmutable() ? Bindings.adapterFactory.getAdapter(scb, dcb, false, true) : null;
			int length = Array.getLength(dst);
			if (length != sb.size(src)) throw new BindingException(clazz.getName()+" is length immutable");
		
			for (int i=0; i<length; i++) {
				if (dcb.isImmutable()) {
					Object sc = sb.get(src, i);
					Object dc = cloner.adapt(sc);
					set(dst, i, dc);					
				} else {
					Object dc = Array.get(dst, i);
					Object sc = sb.get(src, i);
					dc = dcb.readFromTry(scb, sc, dc);
					Array.set(dst, i, dc);
				}
			}
		} catch (AdaptException e) {
			throw new BindingException(e);
		} catch (AdapterConstructionException e) {
			throw new BindingException(e);
		}
	}
	
	@Override
	public Object readFromTry(Binding srcBinding, Object src, Object dst)
			throws BindingException {
		try {
			ArrayBinding sb = (ArrayBinding) srcBinding;
			Binding scb = sb.getComponentBinding();
			Binding dcb = getComponentBinding();
			Adapter cloner = Bindings.adapterFactory.getAdapter(scb, dcb, false, true);
			int length = Array.getLength(dst);
			int srcSize = sb.size(src);
			Object d = dst;
			if (length != srcSize || dcb.isImmutable()) {
				d = Array.newInstance(componentClass, srcSize);
				if (dcb.isImmutable()) {
					for (int i=0; i<srcSize; i++) {
						Object sc = sb.get(src, i);
						Object dc = cloner.adapt(sc);
						set(d, i, dc);
					}
				} else {
					int X = Math.min(Array.getLength(dst), srcSize);				
					for (int i=0; i<X; i++) {
						Object dc = Array.get(dst, i);
						Object sc = sb.get(src, i);
						dc = dcb.readFromTry(scb, sc, dc);
						Array.set(d, i, dc);
					}
					for (int i=X; i<srcSize; i++) {
						Object sc = sb.get(src, i);
						Object dc = cloner.adapt(sc);
						set(d, i, dc);
					}
				}
				
			} else {
				if (dcb.isImmutable()) {
					for (int i=0; i<length; i++) {
						Object sc = sb.get(src, i);
						Object dc = cloner.adapt(sc);
						set(d, i, dc);
					}
				} else {
					for (int i=0; i<length; i++) {
						Object dc = Array.get(dst, i);
						Object sc = sb.get(src, i);
						dc = dcb.readFromTry(scb, sc, dc);
						Array.set(d, i, dc);
					}
				}
			}
			
			return d;
		} catch (AdaptException e) {
			throw new BindingException(e);
		} catch (AdapterConstructionException e) {
			throw new BindingException(e);
		}
	}	
	
	@Override
	public Object get(Object array, int index) throws BindingException {
		if (!isInstance(array)) throw new BindingException("Unexpected class "+array.getClass().getSimpleName()+", "+clazz.getSimpleName()+" expected");
		return Array.get(array, index);
	}
	
	@Override
	public void getAll(Object array, Object[] result) throws BindingException {
		int length = Array.getLength(array);
		System.arraycopy(array, 0, result, 0, length);
	}
	
	@Override
	public void set(Object array, int index, Object value)
			throws BindingException {
		if (index<0 || index>Array.getLength(array))
			throw new BindingException("Index out of bounds");
		Array.set(array, index, value);
	}
	
	@Override
	public int size(Object array) throws BindingException {
		if (!isInstance(array)) {
			if(array == null)
				throw new BindingException("Tried to calculate the size of a null array.");
			throw new BindingException("Unexpected class "+array.getClass().getSimpleName()+", "+clazz.getSimpleName()+" expected");
		}
		return Array.getLength(array);
	}
	@Override
	public boolean isInstance(Object obj) {
		return clazz.isInstance(obj);
	}				   

	@Override
	public boolean isImmutable() {
		return false;
	}
	
	@Override
	public void add(Object array, int index, Object element)
			throws BindingException, IndexOutOfBoundsException {
		throw new UnsupportedOperationException();
	}
	
	@Override
	public void remove(Object array, int index, int count) 
	throws BindingException, IndexOutOfBoundsException {
		throw new UnsupportedOperationException();
	}

	@Override
	public void setSize(Object array, int newSize) throws BindingException {
		int oldSize = Array.getLength(array);
		if (oldSize==newSize) return;
		throw new BindingException(clazz.getName()+" is length immutable");
	}	

	@Override
	public boolean isResizable() {
		return false;
	}
	
	@Override
	protected boolean baseEquals(Object obj) {
		return super.baseEquals(obj) && ((GenericArrayBinding)obj).clazz.equals(clazz);
	}
	
	@Override
	public int baseHashCode() {
		return super.baseHashCode() + 13 * clazz.hashCode();
	}
}