/*******************************************************************************
 * Copyright (c) 2007, 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.db.layer0.adapter.impl;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.simantics.databoard.Bindings;
import org.simantics.databoard.util.URIStringUtils;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.WriteOnlyGraph;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.util.Layer0Utils;
import org.simantics.db.service.XSupport;
import org.simantics.graph.db.AbstractImportAdvisor2;
import org.simantics.graph.db.ImportAdvisors;
import org.simantics.graph.db.MissingDependencyException;
import org.simantics.graph.db.TransferableGraphImporter;
import org.simantics.graph.representation.Root;
import org.simantics.layer0.Layer0;
import org.simantics.utils.datastructures.Pair;
import org.simantics.utils.datastructures.Triple;

public class SharedOntologyImportAdvisor extends AbstractImportAdvisor2 {

	private Layer0 L0;
	
	private Map<Root, Triple<Resource, Resource, List<String>>> toCreate = new HashMap<Root, Triple<Resource, Resource, List<String>>>();
	private Map<Root, Resource> created = new HashMap<Root, Resource>();

	final private boolean published;

	final private Map<String,Object> context;
	
	public SharedOntologyImportAdvisor(boolean published) {
		this(Collections.<String,Object>emptyMap(), published);
	}

	public SharedOntologyImportAdvisor(Map<String,Object> context, boolean published) {
		this.context = context;
		this.published = published;
	}

	private Resource getNames(ReadGraph graph, String uri, List<String> names) throws DatabaseException {
		
        if("http://".equals(uri) || "http:/".equals(uri)) {
        	return graph.getRootLibrary();
        }
        
        final String[] parts = URIStringUtils.splitURI(uri);
        if(parts != null && parts.length == 2) {
        	Resource base = graph.getPossibleResource(parts[0]);
        	if(base == null) base = getNames(graph, parts[0], names);
        	names.add(parts[1]);
        	return base;
        }
        
        return null;
		
	}
	
	
	@Override
	public Resource analyzeRoot(ReadGraph graph, Root r) throws DatabaseException {

		L0 = Layer0.getInstance(graph);
		
		String uri = r.name;
		Map<String,String> renameMap = (Map<String,String>)context.get(ImportAdvisors.RENAME_MAP);
		if(renameMap != null) {
			String renamed = renameMap.get(uri);
			if(renamed != null) uri = renamed;
		}
		
		Resource existing = graph.getPossibleResource(uri);
		if(existing != null) {
			if(graph.isInstanceOf(existing, L0.ExternalEntity)) {
				created.put(r, existing);
	            addRootInfo(r, r.name, existing);
				return null;
			} else {
				throw new DatabaseException("Shared library " + uri + " exists already.");
			}
		}
		
		Resource type = graph.getPossibleResource(r.type);
		if(type == null) { 
		    Set<String> types = new HashSet<String>();
		    types.add(r.type);
		    throw new MissingDependencyException(types);
		}
		//if(type == null) throw new DatabaseException("Shared library type " + r.type + " was not found.");
		
		List<String> namesToCreate = new ArrayList<String>();
		Resource base = getNames(graph, uri, namesToCreate);
		toCreate.put(r, Triple.make(base, type, namesToCreate));
		
		return null;
		
	}

	@Override
	public Resource getTarget() {
		return null;
	}
	
	@Override
	public Resource createRoot(WriteOnlyGraph graph, Root r) throws DatabaseException {
	    return createRoot(graph, r, null);
	}
	
	@Override
	public Resource createRoot(WriteOnlyGraph graph, Root root, Resource resource) throws DatabaseException {
		return created.get(root);
	}
	
    @Override
    public void beforeWrite(WriteOnlyGraph graph, TransferableGraphImporter process)
            throws DatabaseException {
    	
    	XSupport xs = graph.getService(XSupport.class);

    	Pair<Boolean,Boolean> mode = xs.getServiceMode();
    	
    	try {

	    	graph.markUndoPoint();
	    	
	        if(published) {
	        	xs.setServiceMode(true, true);
	        } else {
		    	xs.setServiceMode(true, mode.second);
	        }
	        
	        graph.setClusterSet4NewResource(graph.getRootLibrary());
	        graph.flushCluster();
	        
	        for(RootInfo info : getRootInfo()) {
	        	// At this stage these are existing L0.ExternalEntity instances that are now being imported.
	        	graph.deny(info.resource, L0.InstanceOf, null, L0.ExternalEntity, null);
	        }
	    	
	        for(Map.Entry<Root, Triple<Resource, Resource, List<String>>> entry : toCreate.entrySet()) {
	        	
	            Triple<Resource, Resource, List<String>> recipe = entry.getValue();
	
	            Resource base = recipe.first;
	            for(int i=0;i<recipe.third.size()-1;i++) {
	                Resource lib = graph.newResource();
	                graph.claim(lib, L0.InstanceOf, null, L0.Library);
	                graph.addLiteral(lib, L0.HasName, L0.NameOf, URIStringUtils.unescape( recipe.third.get(i) ), Bindings.STRING);
	                graph.claim(base, L0.ConsistsOf, L0.PartOf, lib);
	                base = lib;
	            }
	
	            Resource lib = graph.newResource();
	            graph.newClusterSet(lib);
	            graph.setClusterSet4NewResource(lib);
	            graph.claim(lib, L0.InstanceOf, null, recipe.second);
	            String name = URIStringUtils.unescape( recipe.third.get(recipe.third.size()-1) );
	            graph.addLiteral(lib, L0.HasName, L0.NameOf, name, Bindings.STRING);
	            graph.claim(base, L0.ConsistsOf, L0.PartOf, lib);
	
	            addRootInfo(entry.getKey(), name, lib);
	            
	            created.put(entry.getKey(), lib);
	            
	        }
	
	        graph.flushCluster();
	        
    	} finally {

    		xs.setServiceMode(mode.first, mode.second);
    		
    	}
        
    }

    @Override
    public void afterWrite(WriteOnlyGraph graph, TransferableGraphImporter process)
            throws DatabaseException {
        
        String name = getRootInfo().iterator().next().name;
        Resource resource = getRootInfo().iterator().next().resource;
        Layer0Utils.addCommentMetadata(graph, "Imported Shared Ontology " + name + " " + resource);
        
        if(published) {
        	XSupport xs = graph.getService(XSupport.class);
        	xs.setServiceMode(false, false);
        }

        graph.setClusterSet4NewResource(graph.getRootLibrary());
        graph.flushCluster();
        
    }
    
    @Override
    public boolean allowImmutableModifications() {
        return false;
    }
	
    @Override
    public Resource createChild(WriteOnlyGraph graph, TransferableGraphImporter process, Resource parent,
            String name) throws DatabaseException {
        return process.createChild(graph, parent, null, name);
    }
    
    @Override
    public Resource createChild(WriteOnlyGraph graph, TransferableGraphImporter process, Resource parent, Resource child,
            String name) throws DatabaseException {
        return process.createChild(graph, parent, child, name);
    }
    
}