/*
    * Copyright (c) 2005, The K-Wf Grid Consortium
    * Fraunhofer Institute for Computer Architecture and Software Technology
    * See http://www.kwfgrid.eu and http://www.first.fraunhofer.de for more details.
    */
   package net.kwfgrid.gwui.graphview;
   
   import net.kwfgrid.gworkflowdl.structure.*;
   import net.kwfgrid.gwui.graphviz.*;
  import net.kwfgrid.gwui.graphview.*;
  import net.kwfgrid.gwui.GWUI;
  
  import de.fzi.wim.guibase.graphview.layout.*;
  import de.fzi.wim.guibase.graphview.graph.Node;
  import de.fzi.wim.guibase.graphview.graph.Graph;
  import de.fzi.wim.guibase.graphview.view.JGraphPane;
  
  import java.util.*;
  
  import org.apache.log4j.Logger;
  
  /***
     A layout strategy which uses a remote graphviz instance to layout the graph.
   */
  public class DOTLayoutStrategy implements LayoutStrategy {
      private static final Logger logger = Logger.getLogger(DOTLayoutStrategy.class);
  
      private static final int MAX_TIMER = 16;
  
      private WorkflowGraph _graph;
      private boolean _valid;
      private JGraphPane _view;
      private HashMap _knownelements;
      private String _knownworkflowid;
      private int _timer;
  
      public DOTLayoutStrategy(JGraphPane view, WorkflowGraph graph) {
  	logger.debug("Constructed new DOTLayoutStrategy for graph "+graph);
  
  	_timer = MAX_TIMER;
  	_graph = graph;
  	_view = view;
  	_valid = false;
  	_knownelements = new HashMap();
  	_knownworkflowid = null;
      }
      
      public boolean shouldExecuteStep() {
  	return !_valid;
      }
  
      public void executeGraphLayoutStep() {
  	if (_timer == MAX_TIMER) {
  	    Iterator nodes = _graph.getNodes().iterator(); while (nodes.hasNext()) {
  		Node n = (Node)nodes.next();
  		n.setLocation(-20000, -20000);
  	    }
  	    Iterator edges = _graph.getEdges().iterator(); while (edges.hasNext()) {
  		ArcEdge e = (ArcEdge)edges.next();
  		e.setControlPoints(null);
  		e.setLabelPosition(null);
  		e.setPointOfArrowAtStart(null);
  		e.setPointOfArrowAtEnd(null);
  	    }
          _timer--;
      } else if (_timer == 0) {
  	    if (_graph.getEdges().size() > 0 && _graph.getNodes().size() > 0) {
  		logger.debug("Executing graphviz layouter.");
  		
  		_knownworkflowid = new String(_graph.getWorkflow().getID());
  		
  		try {
  		    GraphViz gviz = GWUI.getInstance().getGraphVizWS(_graph.getWorkflow().getID());
  		    
  		    // construct converter for gworkflowdl and create input dot
  		    WorkflowGraph2DOTConverter builder = new WorkflowGraph2DOTConverter(_view);
  		    ConversionDirector director = new ConversionDirector(_graph, builder, new ElementIterator(_graph));
  		    director.build();
  		    String dot = builder.getDOT();
  		    
  		    logger.debug("Input dot=\n"+dot);
  		    
  		    // run graphviz
  		    String annotateddot = new String(gviz.dot("-Tdot", dot));
  		    
  		    logger.debug("Output dot=\n"+annotateddot);
  		    
  		    // apply layout to graph
  		    (new DOTLayout2WorkflowGraph(annotateddot, _graph)).run();
  		    
  		    // remember layouted nodes.
  		    _knownelements.clear();
  		    Iterator i = _graph.getNodes().iterator(); while (i.hasNext()) {
  			Node node = (Node)i.next();
  			if (node instanceof PlaceNode) {
  			    _knownelements.put(((PlaceNode)node).getPlace().getID(), node);
  			} else if (node instanceof TransitionNode) {
  			    _knownelements.put(((TransitionNode)node).getTransition().getID(), node);
  			}
 		    }
 		    i = _graph.getEdges().iterator(); while (i.hasNext()) {
 			ArcEdge edge = (ArcEdge)i.next();
 			_knownelements.put(edgeID(edge), edge);
 		    }
 		    _valid = true;
 		} catch (GraphVizException x) {
 		    logger.error("Could not apply graphviz layout.", x);
 		    _timer = MAX_TIMER;
 		}
 	    }
 	} else {
 	    _timer--;
 	}
     }
 
     private String edgeID(ArcEdge edge) {
     if (edge instanceof ReadEdge) {
         return edgeID(edge.getPlace(), edge.getTransition());
     } else if (edge instanceof InEdge) {
 	    return edgeID(edge.getPlace(), edge.getTransition());
 	} else {
 	    return edgeID(edge.getTransition(), edge.getPlace());
 	}
     }
 
     private String edgeID(PlaceNode from, TransitionNode to) {
 	return from.getPlace().getID()+"->"+to.getTransition().getID();
     }
 
     private String edgeID(TransitionNode from, PlaceNode to) {
 	return from.getTransition().getID()+"->"+to.getPlace().getID();
     }
 
     public Graph getGraph() {
 	return _graph;
     }
 
     public void elementsAdded(Collection nodes, Collection edges) {
 	logger.debug("Elements added: "+(nodes!=null?nodes.size():0)+" Nodes and "+(edges!=null?edges.size():0)+" Edges.");
 
 	if (_valid) {
 	    Workflow wf = _graph.getWorkflow();
 	    
 	    logger.debug("Workflow is "+wf);
 	    
 	    String ID = wf.getID();
 	    
 	    logger.debug("ID is "+ID+", known ID is "+_knownworkflowid+".");
 	    
 	    _valid = ID.equals(_knownworkflowid);
 	    
 	    logger.debug("After ID check layout is valid? "+_valid);
 	    
 	    if (nodes != null) {
 		Iterator i = nodes.iterator(); while (i.hasNext()) {
 		    Node node = (Node)i.next();
 		    Node knownnode = null;
 		    if (node instanceof PlaceNode) {
 			knownnode = (Node)_knownelements.get(((PlaceNode)node).getPlace().getID());
 		    } else if (node instanceof TransitionNode) {
 			knownnode = (Node)_knownelements.get(((TransitionNode)node).getTransition().getID());
 		    }	    
 		    if (knownnode!=null) {
 			node.setLocation(knownnode.getX(), knownnode.getY());
 		    } else {
 			_valid = false;
 			node.setLocation(-20000, -20000);
 		    }
 		}
 	    }
 	    
 	    logger.debug("After node check layout is valid? "+_valid);
 	    
 	    if (edges != null) {
 		Iterator i = edges.iterator(); while (i.hasNext() && _valid) {
 		    ArcEdge edge = (ArcEdge)i.next();
 		    ArcEdge knownedge = (ArcEdge)_knownelements.get(edgeID(edge));
 		    if (knownedge!=null) {
 			edge.setControlPoints(knownedge.getControlPoints());
 			edge.setLabelPosition(knownedge.getLabelPosition());
 			edge.setPointOfArrowAtStart(knownedge.getPointOfArrowAtStart());
 			edge.setPointOfArrowAtEnd(knownedge.getPointOfArrowAtEnd());
 		    } else {
 			_valid = false;			
 		    }
 		}
 	    }
 
 	    logger.debug("After edge check layout is valid? "+_valid);
 	}
 
 	if (!_valid) _timer = MAX_TIMER;
     }
 
     public void elementsRemoved(Collection nodes, Collection edges) {
 	// _valid = false;
     }
 
     public void graphContentsChanged() {
 	// _valid = false;
     }
 
     public void notifyGraphLayoutUpdated() {
 	// _valid = false;
     }
 }