package org.simantics.modeling.mapping;

import java.util.HashMap;
import java.util.Map;

import org.simantics.databoard.Bindings;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.WriteGraph;
import org.simantics.db.WriteOnlyGraph;
import org.simantics.db.common.request.FreshEscapedName;
import org.simantics.db.common.utils.OrderedSetUtils;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.request.PossibleModel;
import org.simantics.diagram.stubs.DiagramResource;
import org.simantics.diagram.stubs.G2DResource;
import org.simantics.graph.db.IImportAdvisor;
import org.simantics.graph.representation.Root;
import org.simantics.layer0.Layer0;
import org.simantics.modeling.ModelingResources;

/**
 * ImportAdvisor for handling Component and Element copies.
 * 
 * The advisor can be configured to copy just component or element.
 * 
 * When copying a component, handling the element many vary:
 * 1. If copied data does not contain element, but the target composite is attached to a diagram, the advisor creates the element.
 * 2. If copied data contains element, but target composite is not attached to a diagram, the advisor deletes the element.  
 * 
 * 
 * @author Marko Luukkainen <marko.luukkainen@vtt.fi>
 *
 */
public class ComponentAndElementPasteImportAdvisor implements IImportAdvisor {
	
	private static boolean DEBUG = false;
	
	protected Resource element;
	protected Resource component;
	
	protected Root elementRoot;
	protected Root componentRoot;
	
	protected Resource composite;
	protected Resource diagram;
	protected Resource model;
	
	protected Map<String, String> nameMappings = new HashMap<String, String>();
	
	protected boolean includeComponent = true;
	protected boolean includeElement = true;
	
	public ComponentAndElementPasteImportAdvisor(ReadGraph graph, Resource composite) throws DatabaseException{
		this.composite = composite;
		this.diagram = graph.getPossibleObject(composite, ModelingResources.getInstance(graph).CompositeToDiagram);
		this.includeElement = diagram != null;
		this.model = graph.sync(new PossibleModel(composite));
	}
	
	public ComponentAndElementPasteImportAdvisor(ReadGraph graph, Resource resource, boolean includeComponent, boolean includeElement) throws DatabaseException{
		if (!includeComponent && !includeElement)
			throw new IllegalArgumentException();
		
		this.includeComponent = includeComponent;
		this.includeElement = includeElement;
		if (includeComponent) {
			this.composite = resource;
			this.diagram = graph.getPossibleObject(composite, ModelingResources.getInstance(graph).CompositeToDiagram);
			if (this.diagram == null)
				this.includeElement = false;
		} else {
			this.diagram = resource;
			this.composite = graph.getPossibleObject(diagram, ModelingResources.getInstance(graph).DiagramToComposite);
		}
		
	}
	
	@Override
	public Resource analyzeRoot(ReadGraph graph, Root root) throws DatabaseException {

		if("%model".equals(root.name)) return model;
		
		DiagramResource DIA = DiagramResource.getInstance(graph);
		String type = root.type;
		
		Resource typeRes = graph.getResource(type);
		if (graph.isInheritedFrom(typeRes, DIA.Element)) {
			elementRoot = root;
			String newName = root.name;
			if (diagram != null)
				newName = newName(graph, diagram, root.name);
			nameMappings.put(root.name, newName);
		} else {
			componentRoot = root;
			String newName = newName(graph, composite, root.name);
			nameMappings.put(root.name, newName);
		}
		
		return null;
		
	}
	
	public String newName(ReadGraph graph, Resource library, String name) throws DatabaseException {
		return graph.syncRequest(new FreshEscapedName(library, Layer0.getInstance(graph).ConsistsOf, name));
	}
	
	public Resource getComponent() {
		return component;
	}
	
	public Resource getElement() {
		return element;
	}
	
	@Override
	public Resource createRoot(WriteOnlyGraph graph, Root root)
			throws DatabaseException {
		Layer0 l0 = graph.getService(Layer0.class);
		if (root == elementRoot) {
			element = graph.newResource();
			String name = root.name;
			String newName = nameMappings.get(name);
			graph.addLiteral(element, l0.HasName, l0.NameOf, l0.String, newName, Bindings.STRING);
			if (DEBUG) System.out.println("CaECopyAdvisor created element " + element + " " + newName);
			return element;
		} else if (root == componentRoot) {
			component = graph.newResource();
			String name = root.name;
			String newName = nameMappings.get(name);
			graph.addLiteral(component, l0.HasName, l0.NameOf, l0.String, newName, Bindings.STRING);
			if (DEBUG) System.out.println("CaECopyAdvisor created component " + component + " " + newName);
			return component;
		}
		throw new DatabaseException("Unknown root " + root);
	}
	
	/**
	 * Attaches pasted component / element to composite / diagram
	 * @param graph
	 * @throws DatabaseException
	 */
	public void attach(WriteGraph graph) throws DatabaseException{
		Layer0 l0 = Layer0.getInstance(graph);
		if (includeComponent) {
			if (component != null)
				graph.claim(composite, l0.ConsistsOf, l0.PartOf, component);
		} else {
			if (component != null)
				graph.deny(component);
		}
		if (!includeElement) {
			// paste target does not need the  element.
			if (element != null) {
				graph.deny(element);
			}
		} else {
			// paste target needs the element.
			boolean created = false;
			if (element == null) {
				// element was not in the copied data, we must create a new one.
				
				ModelingResources MR = ModelingResources.getInstance(graph);
				DiagramResource DIA = DiagramResource.getInstance(graph);
				G2DResource G2D = G2DResource.getInstance(graph);
				
				Resource componentType = graph.getSingleType(component);
				Resource elementType = graph.getSingleObject(componentType, MR.ComponentTypeToSymbol);
				
				element = graph.newResource();
				
				String newName = newName(graph, diagram, "element");
				graph.claimLiteral(element, l0.HasName, newName);
				
				graph.claim(element, l0.InstanceOf, elementType);
				graph.claim(component, MR.ComponentToElement, element);
				
				graph.claimLiteral(element, DIA.HasTransform, G2D.Transform, new double[]{1,0,0,1,0,0});
				
				if (DEBUG) System.out.println("CaECopyAdvisor created deferred element " + element + " " + newName);
				
				created = true;
			}
			graph.claim(diagram, l0.ConsistsOf, l0.PartOf, element);
			OrderedSetUtils.add(graph, diagram, element);
			if (created) {
				createElement(graph, element);
			}
		}

	}
	
	/**
	 * Callback called, if copied data did not contain element, and the advisor had to create the element by itself.
	 * 
	 * Note: default implementation does nothing.
	 * 
	 * @param graph
	 * @param element
	 * @throws DatabaseException
	 */
	public void createElement(WriteGraph graph, Resource element) throws DatabaseException{
		
	}
	

}