package org.simantics.db.layer0.genericrelation;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Map;
import java.util.TreeMap;

import org.simantics.databoard.Databoard;
import org.simantics.databoard.annotations.Arguments;
import org.simantics.databoard.annotations.Union;
import org.simantics.databoard.binding.Binding;
import org.simantics.databoard.binding.error.BindingConstructionException;
import org.simantics.databoard.serialization.SerializationException;
import org.simantics.databoard.serialization.Serializer;
import org.simantics.databoard.serialization.SerializerConstructionException;
import org.simantics.db.Metadata;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.Session;
import org.simantics.db.common.utils.NameUtils;
import org.simantics.db.exception.DatabaseException;
import org.simantics.layer0.Layer0;

public class DependencyChanges implements Metadata {
    
    public final @Arguments({Resource.class, Change[].class}) TreeMap<Resource, Change[]> modelChanges;
    public final boolean hasUnresolved;
    
    public DependencyChanges(TreeMap<Resource, Change[]> modelChanges, boolean hasUnresolved) {
        this.modelChanges = modelChanges;
        this.hasUnresolved = hasUnresolved;
    }        
    
    public DependencyChanges(Map<Resource, ArrayList<Change>> _modelChanges, boolean hasUnresolved) {
        this(new TreeMap<Resource, Change[]>(), hasUnresolved);
        for(Map.Entry<Resource, ArrayList<Change>> entry : _modelChanges.entrySet()) {
            ArrayList<Change> value = entry.getValue();
            modelChanges.put(entry.getKey(), value.toArray(new Change[value.size()]));
        }
    }
    
    public static enum ChangeType {
        LINK_CHANGE, COMPONENT_ADDITION, COMPONENT_REMOVAL,
        COMPONENT_MODIFICATION
    }
        
    @Union({LinkChange.class,
    	ComponentAddition.class, 
        ComponentRemoval.class, 
        ComponentModification.class})
    public static interface Change {
        ChangeType getType();
        String toString(ReadGraph graph) throws DatabaseException;
    }
    
    public static class LinkChange implements Change {
        public final Resource component;
        public LinkChange(Resource component) {
            this.component = component;
        }
        @Override
        public ChangeType getType() {
            return ChangeType.LINK_CHANGE;
        }
        @Override
        public String toString(ReadGraph graph) throws DatabaseException {
        	return "LinkChange[" + NameUtils.getSafeName(graph, component, true) + "]";
        }
    }

    public static class ComponentAddition implements Change {
        public final Resource component;
        public final Resource parent;
        public ComponentAddition(Resource component, Resource parent) {
            this.component = component;
            this.parent = parent;
        }
        @Override
        public ChangeType getType() {
            return ChangeType.COMPONENT_ADDITION;
        }
        @Override
        public String toString() {
        	return "ComponentAddition[" + component + "]";
        }
        public boolean isValid(ReadGraph graph) throws DatabaseException {
        	return graph.hasStatement(component, Layer0.getInstance(graph).PartOf, parent);
        }
        @Override
        public String toString(ReadGraph graph) throws DatabaseException {
        	return "ComponentAddition[" + NameUtils.getSafeName(graph, component, true) + "]";
        }
    }
    
    public static class ComponentRemoval implements Change {
        public final Resource component;
        public final Resource parent;
        public ComponentRemoval(Resource component, Resource parent) {        
            this.component = component;
            this.parent = parent;
        }
        @Override
        public ChangeType getType() {
            return ChangeType.COMPONENT_REMOVAL;
        }
        public boolean isValid(ReadGraph graph) throws DatabaseException {
        	return !graph.hasStatement(component, Layer0.getInstance(graph).PartOf, parent);
        }
        @Override
        public String toString(ReadGraph graph) throws DatabaseException {
        	return "ComponentRemoval[component=" + NameUtils.getSafeName(graph, component, true) + ", parent=" + NameUtils.getSafeName(graph, parent, true) + "]";
        }
    }
    
    public static class ComponentModification implements Change {
        public final Resource component;
        public ComponentModification(Resource component) {
            this.component = component;
        }
        @Override
        public ChangeType getType() {
            return ChangeType.COMPONENT_MODIFICATION;
        }
        @Override
        public String toString(ReadGraph graph) throws DatabaseException {
        	return "ComponentModification[" + NameUtils.getSafeName(graph, component, true) + "]";
        }
    }
        
    public Change[] get(Resource model) {
        return modelChanges.get(model);
    }
    
    public Map<Resource, Change[]> get() {
    	return modelChanges;
    }
            
    @Override
    public byte[] serialise(Session session) {
        try {
        	Databoard databoard = session.getService( Databoard.class );
        	Binding binding = databoard.getBinding( DependencyChanges.class );
        	Serializer serializer = databoard.getSerializer( binding );
            return serializer.serialize(this);
        } catch (SerializationException e) {
            e.printStackTrace();
        } catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SerializerConstructionException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (BindingConstructionException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
        return new byte[0];
    }
    
    public static DependencyChanges deserialise(Session session, byte[] input) {
        try {
        	Databoard databoard = session.getService( Databoard.class );
        	Binding binding = databoard.getBinding( DependencyChanges.class );
        	Serializer serializer = databoard.getSerializer( binding );
            return (DependencyChanges) serializer.deserialize(input); 
        } catch (SerializationException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (SerializerConstructionException e) {
			e.printStackTrace();
		} catch (BindingConstructionException e) {
			e.printStackTrace();
		}
        return null;
    }
    
    public boolean isEmpty() {
    	return modelChanges.isEmpty() && !hasUnresolved;
    }
    
}