/*
 * Copyright 2006 - 2013
 *     Stefan Balev     <stefan.balev@graphstream-project.org>
 *     Julien Baudry    <julien.baudry@graphstream-project.org>
 *     Antoine Dutot    <antoine.dutot@graphstream-project.org>
 *     Yoann Pigné      <yoann.pigne@graphstream-project.org>
 *     Guilhelm Savin   <guilhelm.savin@graphstream-project.org>
 * 
 * This file is part of GraphStream <http://graphstream-project.org>.
 * 
 * GraphStream is a library whose purpose is to handle static or dynamic
 * graph, create them from scratch, file or any source and display them.
 * 
 * This program is free software distributed under the terms of two licenses, the
 * CeCILL-C license that fits European law, and the GNU Lesser General Public
 * License. You can  use, modify and/ or redistribute the software under the terms
 * of the CeCILL-C license as circulated by CEA, CNRS and INRIA at the following
 * URL <http://www.cecill.info> or under the terms of the GNU LGPL as published by
 * the Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * The fact that you are presently reading this means that you have had
 * knowledge of the CeCILL-C and LGPL licenses and that you accept their terms.
 */
package org.graphstream.stream.file;

import java.io.IOException;
import java.io.PrintWriter;

/**
 * Graph writer for the GraphViz DOT format.
 */
public class FileSinkDOT extends FileSinkBase {
        // Attribute

        /**
         * The output.
         */
        protected PrintWriter out;

        /**
         * The graph name (set as soon as known).
         */
        protected String graphName = "";

        /**
         * Is the graph directed ?
         */
        protected boolean digraph;

        /**
         * What element ?.
         */
        protected enum What {
                NODE, EDGE, OTHER
        };

        /**
         * Build a new DOT sink to export undirected graph.
         */
        public FileSinkDOT() {
                this(false);
        }

        /**
         * Build a new DOT sink specifying if the graph is directed or not.
         * 
         * @param digraph
         *            true if the graph is directed
         */
        public FileSinkDOT(boolean digraph) {
                this.digraph = digraph;
        }

        // Command

        /**
         * Set flag indicating if exported graph is directed or not.
         * 
         * @param digraph
         *            true is exported graph is directed
         */
        public void setDirected(boolean digraph) {
                this.digraph = digraph;
        }

        /**
         * Get the flag indicating if exported graph is directed or not.
         * 
         * @return true if exported graph is directed
         */
        public boolean isDirected() {
                return digraph;
        }

        @Override
        protected void outputHeader() throws IOException {
                out = (PrintWriter) output;
                out.printf("%s {%n", digraph ? "digraph" : "graph");

                if (graphName.length() > 0)
                        out.printf("\tgraph [label=%s];%n", graphName);
        }

        @Override
        protected void outputEndOfFile() throws IOException {
                out.printf("}%n");
        }

        public void edgeAttributeAdded(String graphId, long timeId, String edgeId,
                        String attribute, Object value) {
                // NOP
        }

        public void edgeAttributeChanged(String graphId, long timeId,
                        String edgeId, String attribute, Object oldValue, Object newValue) {
                // NOP
        }

        public void edgeAttributeRemoved(String graphId, long timeId,
                        String edgeId, String attribute) {
                // NOP
        }

        public void graphAttributeAdded(String graphId, long timeId,
                        String attribute, Object value) {
                out
                                .printf("\tgraph [ %s ];%n", outputAttribute(attribute, value,
                                                true));
        }

        public void graphAttributeChanged(String graphId, long timeId,
                        String attribute, Object oldValue, Object newValue) {
                out.printf("\tgraph [ %s ];%n", outputAttribute(attribute, newValue,
                                true));
        }

        public void graphAttributeRemoved(String graphId, long timeId,
                        String attribute) {
                // NOP
        }

        public void nodeAttributeAdded(String graphId, long timeId, String nodeId,
                        String attribute, Object value) {
                out.printf("\t\"%s\" [ %s ];%n", nodeId, outputAttribute(attribute,
                                value, true));
        }

        public void nodeAttributeChanged(String graphId, long timeId,
                        String nodeId, String attribute, Object oldValue, Object newValue) {
                out.printf("\t\"%s\" [ %s ];%n", nodeId, outputAttribute(attribute,
                                newValue, true));
        }

        public void nodeAttributeRemoved(String graphId, long timeId,
                        String nodeId, String attribute) {
                // NOP
        }

        public void edgeAdded(String graphId, long timeId, String edgeId,
                        String fromNodeId, String toNodeId, boolean directed) {
                if (digraph) {
                        out.printf("\t\"%s\" -> \"%s\"", fromNodeId, toNodeId);

                        if (!directed)
                                out.printf(" -> \"%s\"", fromNodeId);

                        out.printf("\n;");
                } else
                        out.printf("\t\"%s\" -- \"%s\";%n", fromNodeId, toNodeId);
        }

        public void edgeRemoved(String graphId, long timeId, String edgeId) {
                // NOP
        }

        public void graphCleared(String graphId, long timeId) {
                // NOP
        }

        public void nodeAdded(String graphId, long timeId, String nodeId) {
                out.printf("\t\"%s\";%n", nodeId);
        }

        public void nodeRemoved(String graphId, long timeId, String nodeId) {
                // NOP
        }

        public void stepBegins(String graphId, long timeId, double step) {
                // NOP
        }

        // Utility
        /*
         * protected void outputAttributes(Map<String, Object> attributes, What
         * what) throws IOException { out.printf(" [");
         * 
         * boolean first = true;
         * 
         * for (String key : attributes.keySet()) { Object value =
         * attributes.get(key);
         * 
         * if (what == What.NODE) { // if( ! nodeForbiddenAttrs.contains( key ) ) {
         * first = outputAttribute(key, value, first); } } else if (what ==
         * What.EDGE) { // if( ! edgeForbiddenAttrs.contains( key ) ) { first =
         * outputAttribute(key, value, first); } } else { first =
         * outputAttribute(key, value, first); }
         * 
         * }
         * 
         * out.printf("]"); }
         */
        protected String outputAttribute(String key, Object value, boolean first) {
                boolean quote = true;

                if (value instanceof Number)
                        quote = false;

                return String.format("%s\"%s\"=%s%s%s", first ? "" : ",", key,
                                quote ? "\"" : "", value, quote ? "\"" : "");
        }
}