package org.simantics.document.linking.report.templates;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Map;

import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.common.utils.NameUtils;
import org.simantics.db.exception.DatabaseException;
import org.simantics.document.DocumentResource;
import org.simantics.document.linking.report.Document;
import org.simantics.document.linking.report.DocumentTitlePage;
import org.simantics.document.linking.report.RowContentProvider;
import org.simantics.document.linking.report.Table;
import org.simantics.document.linking.report.TextItem;
import org.simantics.layer0.Layer0;
import org.simantics.structural.stubs.StructuralResource2;



/**
 * Writes report with Model's internal documents.
 * 
 * Model information
    □ Document folder 1
        • Document 1-1
        • Document 1-2 rev1
        • Document 1-2 rev2
        • Document 1-2 rev3
        • Document 1-3
    □ Document folder 2
        • Document folder 3
            o Document 3-1
            o Document 3-2
        • Document folder 4
            o Document 4-1
            o Document 4-2
 * 
 * @author Marko Luukkainen <marko.luukkainen@vtt.fi>
 *
 */
public class ModelDocumentWriter extends  DocumentWriter<List<Resource>> {
	
	ReadGraph graph;
	Layer0 l0;
	Resource model;
	Map<Object, Object> context;
	Comparator<Resource> comparator;

	
	@Override
	public String getName() {
		return "Model Internal Documents"; //$NON-NLS-1$
	}
	
	@Override
	public void start(ReadGraph graph, Resource model, Document lineWriter, Map<Object, Object> context) throws Exception{
		super.start(graph, model, lineWriter, context);
		this.context = context;
		this.model = model;
		DocumentTitlePage titlePage = lineWriter.newElement(DocumentTitlePage.class);
		titlePage.writeTitle(graph, context);
		Table table = lineWriter.newElement(Table.class);
		table.addColumn("Folder", 0.4); //$NON-NLS-1$
		table.addColumn("Document", 0.6); //$NON-NLS-1$
		
		//lineWriter.nextPage();
		this.graph = graph;
		this.l0 = Layer0.getInstance(graph);
		clearProviders();
		addCellProvider(new HierarchyContentProvider());
		addCellProvider(new DocumentContentProvider());
		
	}
	
	@Override
	public List<List<Resource>> getReportItems(ReadGraph graph)	throws DatabaseException {
		
		comparator = new ResourceNameComparator(graph, model);
		List<List<Resource>> result = new ArrayList<List<Resource>>();
		List<Resource> root = Collections.singletonList(model);
		collect(graph, root, result);
		return result;
	}
	
	private void collect(ReadGraph graph, List<Resource> location, List<List<Resource>> result) throws DatabaseException{
		// TODO : at the moment document structure in the model is customizable, so this method may not be able to collect the documents.
		// Current logic is:
		// 1. browse L0.ConsistsOf
		// 2a. If found resource is Document, add it into results
		// 2b. Otherwise, if resource is not structural component, go to step 1. 
		// 
		// Note: Filtering structural components prevents browsing the whole model structure for locating the documents.
		
		Layer0 l0 = Layer0.getInstance(graph);
		DocumentResource doc = DocumentResource.getInstance(graph);
		StructuralResource2 sr = StructuralResource2.getInstance(graph);
		Resource lastInPath = location.get(location.size() -1);
		List<Resource> set = new ArrayList<Resource>();
		set.addAll(graph.getObjects(lastInPath, l0.ConsistsOf));
		Collections.sort(set, comparator);
		for (Resource r : set) {
			List<Resource> path = new ArrayList<Resource>(location.size()+1);
			path.addAll(location);
			path.add(r);
			if (graph.isInstanceOf(r, doc.Document)) {
				result.add(path);
				collect(graph, path, result);
			} else if (!graph.isInstanceOf(r, sr.Component)){
				collect(graph, path, result);
			}
		}
	}
	
	
	
	
	private String getText(List<Resource> current, boolean indent) throws DatabaseException {
		String text = ""; //$NON-NLS-1$
		if (indent)
			for (int i = 0; i < current.size()-1; i++) {
				text += "  "; //$NON-NLS-1$
			}
		
		text += NameUtils.getSafeLabel(graph, current.get(current.size()-1));
		return text;
	}
	
	private class HierarchyContentProvider implements RowContentProvider<List<Resource>> {
		@Override
		public void setText(Document writer, List<Resource> previous,
				List<Resource> current, List<Resource> next, TextItem[] text)
				throws Exception {
			int writeFolder = 0;
			int fic = folderIndex(current);
			if (previous == null) {
				writeFolder =  fic+1;
			} else {
				int fip = folderIndex(previous);
				
				if (fip < fic) {
					writeFolder = fic-fip;
				} else if (fip == fic) {
					for (int i = 0; i <= fic; i++) {
						if (!previous.get(i).equals(current.get(i))) {
							writeFolder = previous.size()-i;
							break;
						}
					}
				}
			}
			
			if (writeFolder > 0) {
				text[0] = writer.newItem(TextItem.class);
				if (writeFolder > 1) {
					Table table = writer.getCurrentElement(Table.class);
					for (int i = current.size()-writeFolder+1; i < current.size()-1; i++) {
						text[0].setText(getText(current.subList(0, i),true));
						text[1] = null;
						table.writeRowItem(text);
					}
				}
				text[0].setText(getText(current.subList(0, fic+1),true));
			} else {
				text[0] = null;
			}
			
		}
	}
	
	private int folderIndex(List<Resource> path) throws DatabaseException{
		for (int i = path.size()-1; i >= 0; i--) {
			if (graph.isInstanceOf(path.get(i), doc.Document))
				continue;
			return i;
		}
		return -1;
	}
	
	private int revisionIndex(Resource document) throws DatabaseException{
		Resource r = document;
		int i = -1;
		while (r != null) {
			Resource r2 = graph.getPossibleObject(r, l0.PartOf);
			r = graph.getPossibleObject(r, doc.HasNewerVersion);
			i++;
			if (r2 != null && !r2.equals(r)) // prevent indent if document revisions are not in tree form.
				break;
		}
		return i;
	}
	
	private class DocumentContentProvider implements RowContentProvider<List<Resource>> {
		public void setText(Document writer, java.util.List<Resource> previous, java.util.List<Resource> current, java.util.List<Resource> next, TextItem[] row) throws Exception {
			String s = ""; //$NON-NLS-1$
			
			Resource document = current.get(current.size()-1);
			int rev = revisionIndex(document);
			for (int i = 0; i < rev; i++)
				s += "  "; //$NON-NLS-1$
			row[1] = getDocumentItem(document);
			row[1].setText(s + row[1].getText());
		};
	}

}