package org.simantics.document.linking.function;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.eclipse.core.runtime.IProgressMonitor;
import org.simantics.databoard.Bindings;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.common.utils.Logger;
import org.simantics.db.common.utils.NameUtils;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.adapter.Instances;
import org.simantics.db.layer0.genericrelation.Dependencies;
import org.simantics.document.linking.ontology.DocumentLink;
import org.simantics.document.linking.utils.SourceLinkUtil;
import org.simantics.scl.runtime.function.FunctionImpl5;
import org.simantics.workbench.search.NamedResource;
import org.simantics.workbench.search.SearchQuery;
import org.simantics.workbench.search.SearchResult;
import org.simantics.workbench.search.SearchResultColumn;
import org.simantics.workbench.search.SearchResultRow;
import org.simantics.workbench.search.StringUtil;

public class SearchFunction extends FunctionImpl5<IProgressMonitor, ReadGraph, Resource, SearchQuery, Integer, SearchResult> {

	public static List<SearchResultColumn> columns;
	
	static {
		columns = new ArrayList<SearchResultColumn>();
		columns.add(new SearchResultColumn("Name")); //$NON-NLS-1$
		columns.add(new SearchResultColumn("Comment")); //$NON-NLS-1$
		columns.add(new SearchResultColumn("Part Of")); //$NON-NLS-1$
	}
	
	@Override
	public SearchResult apply(IProgressMonitor monitor, ReadGraph graph, Resource model, SearchQuery query, Integer maxResults) {
		 try {
			 	DocumentLink sl = DocumentLink.getInstance(graph);
			  	Instances instancesQuery = graph.adapt(sl.Source, Instances.class);
		        Collection<Resource> found = instancesQuery.find(graph, model);
		        return generateSearchResults(graph, found,query);
	        } catch (DatabaseException e) {
	            Logger.defaultLogError(e);
	        }
	        return null;
	}
	
	
	public static class NameComparator {
		private String name;
		int type = 0;
		
		public NameComparator(String query) {
	        String parts[] = query.split(" OR "); //$NON-NLS-1$
	        for (String s : parts) {
	        	if (s.startsWith("Name:")) { //$NON-NLS-1$
	        		 name = s.substring(5);
	        	}
	        }
	        if (name == null)
	        	return;
	        name = name.trim();
	        boolean freeStart = false;
	        boolean freeEnd = false;
	        if (name.endsWith("*")) { //$NON-NLS-1$
	        	name = name.substring(0,name.length()-1);
	        	freeEnd = true;
	        }
	        if (name.startsWith("*")) { //$NON-NLS-1$
	        	name = name.substring(1,name.length());
	        	freeStart = true;
	        }
	        if (freeStart && freeEnd)
	        	type = 1;
	        else if (freeStart)
	        	type = 2;
	        else if (freeEnd)
	        	type = 3;
	        name = name.toLowerCase();
		}
		
		public boolean compare(String s) {
			switch (type) {
			case 0:
				return s.toLowerCase().equals(name);
			case 1:
				return s.toLowerCase().contains(name);
			case 2:
				return s.toLowerCase().endsWith(name);
			case 3:
				return s.toLowerCase().startsWith(name);
			}
			return false;
		}
	}
	
    public static final SearchResult generateSearchResults(ReadGraph graph,
    		Collection<Resource> results, SearchQuery query) throws DatabaseException {
        DocumentLink sl = DocumentLink.getInstance(graph);

        SearchResult result = new SearchResult(columns);
        Set<Resource> processed = new HashSet<Resource>();

        NameComparator c = new NameComparator(query.getQuery(Dependencies.FIELD_NAME_SEARCH));

        for (Resource source : results) {
        	  // Prevent index corruption from producing duplicate results.
            if (!processed.add(source))
                continue;
            
            Resource reference = SourceLinkUtil.getReferredDocument(graph, source);
            if (!SourceLinkUtil.isValidReference(graph, reference)) {
            	// TODO: searching removed references
            	continue;
            }

            Resource parent = (Resource) graph.getSingleObject(source, sl.hasSource_Inverse);
            String name = NameUtils.getSafeLabel(graph,reference);
            if (name.length() == 0)
            	name = NameUtils.getSafeName(graph, reference);
       
            if (!c.compare(name))
            	continue;
            
            String parentName = NameUtils.getSafeLabel(graph, parent);
            if (parentName.length() == 0)
            	parentName = NameUtils.getSafeName(graph, parent);
            
            if (graph.isInstanceOf(source, sl.FunctionalSource)) {
            	Resource relation = graph.getSingleObject(source, sl.consernsRelation);
            	String relationName = NameUtils.getSafeLabel(graph, relation);
            	if (relationName.length() == 0)
            		relationName = NameUtils.getSafeName(graph, relation);
            	parentName = parentName +"#"+relationName; //$NON-NLS-1$
            }
            
            DocumentLinkRow rst = new DocumentLinkRow();
            rst.resource = NamedResource.of(graph, reference, name);
            rst.parent = NamedResource.of(graph, parent,parentName);
            rst.comment = graph.getPossibleRelatedValue(source, sl.hasSourceComment,Bindings.STRING);

//          Collection<Resource> typeResources = graph.getTypes(reference);
//            Collection<Resource> principalTypeResources = graph.getPrincipalTypes(reference);
//            if (!typeResources.isEmpty()) {
//                rst.types = new ArrayList<NamedResource>(typeResources.size());
//                rst.principalTypes = new ArrayList<NamedResource>(principalTypeResources.size());
//                for (Resource t : typeResources) {
//                    String oname = NameUtils.getSafeLabel(graph, t);
//                    NamedResource nr = NamedResource.of(graph, t, oname);
//                    rst.types.add(nr);
//                    if (principalTypeResources.contains(t))
//                        rst.principalTypes.add(nr);
//                }
//            }

            result.addRow(rst);
        }
        return result;
    }
    
    private static class DocumentLinkRow implements SearchResultRow {
    	public NamedResource             resource;
    	public NamedResource             parent;
    	public String comment;
    	@Override
    	public String getContent(int column) {
    		switch (column) {
    		case 0:
    			return "<a class=\"small\" href=\"resource:"+ resource.getResource() +"\"" + (resource.getUri() == null ? "" : " title=\""+resource.getUri()+"\">")+StringUtil.escape(resource.getName())+"</a>"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$ //$NON-NLS-6$
    		case 1:
    			if (comment != null)
    				return comment;
    			return ""; //$NON-NLS-1$
    		case 2:
    			if (parent != null)
    				return "<a class=\"small\" href=\"resource:"+ parent.getResource() +"\"" + (parent.getUri() == null ? "" : " title=\""+parent.getUri()+"\">")+StringUtil.escape(parent.getName())+"</a>"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$ //$NON-NLS-6$
    			return ""; //$NON-NLS-1$
    		default:
    			return ""; //$NON-NLS-1$
    		}
    	}
    }
	
}