package org.simantics.document.linking.ge;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Stack;

import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.widgets.Display;
import org.simantics.Simantics;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.WriteGraph;
import org.simantics.db.common.request.WriteRequest;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.adapter.ActionFactory;
import org.simantics.db.layer0.variable.Variable;
import org.simantics.db.request.Read;
import org.simantics.document.linking.ontology.DocumentLink;
import org.simantics.document.linking.utils.SourceLinkUtil;
import org.simantics.utils.datastructures.Pair;
import org.simantics.utils.ui.ExceptionUtils;

public class FixAllReferencesAction implements ActionFactory {
	
	@Override
	public Runnable create(final Object target) {
		return new Runnable() {
			
			@Override
			public void run() {
				System.out.println(target);
				try {
					Pair<Collection<Resource>, Collection<Resource>> refs = Simantics.getSession()
							.syncRequest(new FindFixable(target));
					String dialogTitle = Messages.FixAllReferencesAction_FixReferences;
					String dialogMessage = NLS.bind(Messages.FixAllReferencesAction_FixOldReferences,
							new Object[] { refs.first.size(), refs.second.size() });
					String dialogButtonLabels[] = new String[] { IDialogConstants.OK_LABEL, IDialogConstants.CANCEL_LABEL };
					int defaultIndex = 0;
					if (refs.first.size() == 0 && refs.second.size() == 0) {
						dialogMessage = Messages.FixAllReferencesAction_NothingToFix;
						dialogButtonLabels = new String[] { IDialogConstants.OK_LABEL };
						MessageDialog dialog = new MessageDialog(Display.getCurrent().getActiveShell(), dialogTitle,
								null, dialogMessage, MessageDialog.CONFIRM, dialogButtonLabels, defaultIndex);
						dialog.open();
						return;
					}
					MessageDialog dialog = new MessageDialog(Display.getCurrent().getActiveShell(), dialogTitle, null,
							dialogMessage, MessageDialog.CONFIRM, dialogButtonLabels, defaultIndex);
					if (dialog.open() != 0)
						return;
					Simantics.getSession().markUndoPoint();
					Simantics.getSession().syncRequest(new FixAll(refs));
				} catch (DatabaseException e) {
					ExceptionUtils.logAndShowError(Messages.FixAllReferencesAction_CannotFixReferences, e);
				}
			}
		};
	}
	
	public static class FindFixable implements Read<Pair<Collection<Resource>, Collection<Resource>>> {
		
		List<Resource> old;
		List<Resource> removed;
		Object target;
		
		public FindFixable(Object target) {
			this.target = target;
		}
		
		@Override
		public Pair<Collection<Resource>, Collection<Resource>> perform(ReadGraph graph) throws DatabaseException {
			old = new ArrayList<Resource>();
			removed = new ArrayList<Resource>();
			
			DocumentLink sl = DocumentLink.getInstance(graph);
			ModelChildRule modelChildRule = new ModelChildRule(graph, sl.ModelViewpointBrowseContext2_ChildRule);
			Stack<Object> stack = new Stack<Object>();
			stack.add(target);
			while (!stack.isEmpty()) {
				Object o = stack.pop();
				@SuppressWarnings("unchecked")
				Collection<Object> children = (Collection<Object>) modelChildRule.getChildren(graph, o);
				
				if (children.size() == 0) {
					if (o instanceof Variable) {
						Variable v = (Variable)o;
						Resource r = v.getPossibleRepresents(graph);
						process(graph, r);
					} else if (o instanceof Resource) {
						Resource r = (Resource)o;
						process(graph, r);
					}
				} else {
					stack.addAll(children);
				}
				
			}
			
			Pair<Collection<Resource>, Collection<Resource>> result =  new Pair<Collection<Resource>, Collection<Resource>>(old, removed);
			old = null;
			removed = null;
			return result;
		}
		
		void process(ReadGraph graph, Resource r) throws DatabaseException{
			if (SourceLinkUtil.isValidSource(graph, r)) {
				if (!SourceLinkUtil.isUpToDateSource(graph, r)) {
					if (!old.contains(r))
						old.add(r);
				}
			} else if (SourceLinkUtil.isSource(graph, r)){
				if (!removed.contains(r))
					removed.add(r);
			}
		}
	}
	
	public static class FixAll extends WriteRequest {
		Pair<Collection<Resource>, Collection<Resource>> refs;
		
		public FixAll(Pair<Collection<Resource>, Collection<Resource>> refs) {
			super();
			this.refs = refs;
		}

		@Override
		public void perform(WriteGraph graph) throws DatabaseException {
			Collection<Resource> old = refs.first;;
			Collection<Resource> removed = refs.second;
			
			for (Resource r : old)
				SourceLinkUtil.updateToLatest(graph, r);
			for (Resource r : removed)
				graph.deny(r);
		}
	}
	
	
	public static class FixAllSilent extends WriteRequest {
		Resource target;
		
		public FixAllSilent(Resource target) {
			this.target = target;
		}
		
		@Override
		public void perform(WriteGraph graph) throws DatabaseException {
			// TODO: using ModelChildRule makes the data processing very slow.
			DocumentLink sl = DocumentLink.getInstance(graph);
			ModelChildRule modelChildRule = new ModelChildRule(graph, sl.ModelViewpointBrowseContext2_ChildRule);
			Stack<Object> stack = new Stack<Object>();
			stack.add(target);
			while (!stack.isEmpty()) {
				Object o = stack.pop();
				@SuppressWarnings("unchecked")
				Collection<Object> children = (Collection<Object>) modelChildRule.getChildren(graph, o);
				
				if (children.size() == 0) {
					if (o instanceof Variable) {
						Variable v = (Variable)o;
						Resource r = v.getPossibleRepresents(graph);
						process(graph, r);
					} else if (o instanceof Resource) {
						Resource r = (Resource)o;
						process(graph, r);
					}
				} else {
					stack.addAll(children);
				}
				
			}
			
		}
		
		void process(WriteGraph graph, Resource r) throws DatabaseException{
			if (SourceLinkUtil.isValidSource(graph, r))
				SourceLinkUtil.updateToLatest(graph, r);
			else
				graph.deny(r);
		}
	}

}