/*
 *  $URL: svn://svn.webarts.bc.ca/open/trunk/projects/WebARTS/ca/bc/webarts/tools/KmlToGeoJSON.java $
 *  $Author: tgutwin $
 *  $Revision: 1052 $
 *  $Date: 2016-03-16 17:05:08 -0700 (Wed, 16 Mar 2016) $
*/
/*
 *
 *  Written by Tom Gutwin - WebARTS Design.
 *  Copyright (C) 2016 WebARTS Design, North Vancouver Canada
 *  http://www.webarts.ca
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

package ca.bc.webarts.tools;

import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;

import org.geotools.data.DataUtilities;
import org.geotools.data.simple.SimpleFeatureCollection;
import org.geotools.geojson.feature.FeatureJSON;
import org.geotools.kml.v22.KMLConfiguration;
import org.geotools.xml.PullParser;

import org.opengis.feature.simple.SimpleFeature;


/** Wraps and automates conversion of kml files to GeoJSON format.
  * It uses <a href="http://www.geotools.org">GeoTools</a>.<br /><b>NOTE:</b>geoJson does not have a <i>standard</i>
  * way of including styling, so none of the KML stsyles are transfered with this class.
  * <ul><li>You could use <a href="http://wiki.openstreetmap.org/wiki/Geojson_CSS">Geojson CSS</a> /
  * SVG styling into the geojson, but its use in the implementation varies.
  * <br />see:<ul><li><a href="http://geojson.org/geojson-spec.html">http://geojson.org/geojson-spec.html</a></li>
  * and
  * <li><a href="http://www.w3.org/TR/SVG/styling.html">http://www.w3.org/TR/SVG/styling.html</a></li></ul>
  * </li>
  * <li>another option, is using MapBox styling.</li>
  * </ul>
  **/
public class KmlToGeoJSON extends Object
{
  /** the full classname as a String for convenience. **/
  protected static String CLASSNAME = "ca.bc.webarts.tools.KmlToGeoJSON";  // ca.bc.webarts.widgets.Util.getCurrentClassName();

  /**  A holder for this clients System File Separator.  */
  public final static String SYSTEM_FILE_SEPERATOR = File.separator;

  /**  A holder for this clients System line termination separator.  */
  public final static String SYSTEM_LINE_SEPERATOR =
                                           System.getProperty("line.separator");

  /** Empty constructor. **/
  public KmlToGeoJSON()
  { }


  /** This Outputs a SimpleFeatureCollection to a GeoJSON String (for easier saving and output).
    *
    * @param fc is the feature collection to serialize into a String
    * @return the GeoJSON string of the SimpleFeatureCollection
    * @throws IOException when
  **/
  public static String featuresToString(SimpleFeatureCollection fc ) throws IOException
  {
    ByteArrayOutputStream baOs = new ByteArrayOutputStream();
    FeatureJSON fjson = new FeatureJSON();
    fjson.writeFeatureCollection(fc, baOs);
    return baOs.toString();
  }


  /**
   *  A simple String token replacement routine. Replaces all occurences of the
   *  token parameter with the replacement value in the passed in sentence
   *  parameter.
   *
   * @param  sentence     The String to perform the token replacement on
   * @param  token        the token String to seartch for and replace
   * @param  replacement  the tokens replacement value
   * @return              The new token replaced string
   */
  public static String tokenReplace(String sentence,
                                    String token,
                                    String replacement)
  {
    String retVal = "";
    /*
    int a = 0;
    while ((a = sentence.indexOf(token)) > -1)
    {
      retVal += sentence.substring(0, a) + replacement;
      sentence = sentence.substring(a + token.length());

    }

    retVal += sentence;
    */
    retVal = sentence.replace(token,replacement);
    return retVal;
  }


  /** Very basic formatter to make a JSON string more readable.
  **/
  public static String formatJsonString(String inStr)
  {
    String retVal = "\n"+inStr;
    System.out.println("\n\nPretty Formatting the JSONString");
    retVal=tokenReplace(retVal,"{","{"+SYSTEM_LINE_SEPERATOR+"  ");
    retVal=tokenReplace(retVal,",",","+SYSTEM_LINE_SEPERATOR);
    retVal=tokenReplace(retVal,"}",SYSTEM_LINE_SEPERATOR+"}");
    System.out.println(retVal);

    return retVal;
  }


    /** Indents/spaces out an JSON result. **/
  public static StringBuilder jsonIndenter(String s)
  {
    StringBuilder retVal = new StringBuilder("");
    if (s!=null)
    {
      int indent = 0;
      boolean opening = false;
      boolean closing = false;
      boolean lf = false;
      char [] sbChar = s.toCharArray();

      for (int i=0; i< sbChar.length;i++)
      {
        opening = false;
        closing = false;
        lf = false;
        if (sbChar[i]=='}' ) // closing
        {
          retVal.append("\n");
          for (int j=0;j<indent-1;j++) retVal.append("  ");
          retVal.append(sbChar[i]);
          indent--; //indent--;
          if(i+1<sbChar.length && sbChar[i+1]!=',')
          {
            if(sbChar[i+1]!=']') indent--;
            retVal.append("\n");
            for (int j=0;j<((sbChar[i+1]!=']')?indent:indent-1);j++) retVal.append("  ");
          }
        }
        else if(sbChar[i]=='[')  // opening
        {
          indent++;
          retVal.append("\n");
          for (int j=0;j<indent-1;j++) retVal.append("  ");
          retVal.append(sbChar[i]);
        }
        else if(sbChar[i]==']')  // closing
        {
          indent--;
          retVal.append(sbChar[i]);
        }
        else if(sbChar[i]=='{')  // opening
        {
          indent++;
          retVal.append("\n");
          for (int j=0;j<indent-1;j++) retVal.append("  ");
          retVal.append(sbChar[i]);
          retVal.append("\n");
          for (int j=0;j<indent;j++) retVal.append("  ");
        }
        else if(sbChar[i]==','&&!Character.isDigit(sbChar[i-1]))  // continue  attributes
        {
          //indent++;
          retVal.append(sbChar[i]);
          retVal.append("\n");
          for (int j=0;j<indent;j++) retVal.append("  ");
        }
        else if (sbChar[i]!='\n')
        {
          retVal.append(sbChar[i]);
        }
      }
    }
    return retVal;
  }


    /** Indents/spaces out an XML result. **/
  public static StringBuilder responseXMLIndenter(StringBuilder sb)
  {
    StringBuilder retVal = new StringBuilder("");
    if (sb!=null)
    {
      int indent = -1;
      boolean opening = false;
      boolean closing = false;
      boolean lf = false;
      char [] sbChar = sb.toString().toCharArray();

      for (int i=0; i< sbChar.length;i++)
      {
        opening = false;
        closing = false;
        lf = false;
        if ((sbChar[i]=='<'&&sbChar[i+1]=='/') )
        {
          retVal.append("\n");
          for (int j=0;j<indent;j++) retVal.append("  ");
          retVal.append(sbChar[i]);
          indent--; //indent--;
        }
        else if(sbChar[i]=='<')
        {
          indent++;
          retVal.append("\n");
          for (int j=0;j<indent;j++) retVal.append("  ");
          retVal.append(sbChar[i]);
        }
        else if ((sbChar[i]=='/'&&sbChar[i+1]=='>') )
        {
          indent--; //indent--;
          retVal.append(sbChar[i]);
        }
        else if (sbChar[i]=='>')
        {
          retVal.append(sbChar[i]);
          //for (int j=0;j<indent;j++) retVal.append("  ");
        }
        else if (sbChar[i]!='\n')
        {
          retVal.append(sbChar[i]);
        }
      }
    }
    return retVal;
  }


  /** Takes a kml file and converts its geo features to a GeoTools SimpleFeatureCollection. Use the
    * {@link #featuresToString(SimpleFeatureCollection) featuresToString}
    * method to get a String version of it.
    *
    * @param kmlFile is a File to process
    * @return a SimpleFeatureCollection holding all the geo features
  **/
  public static SimpleFeatureCollection convertKmlFile(File kmlFile) throws Exception
  {
    FileInputStream reader = new FileInputStream(kmlFile);
    PullParser parser = new PullParser(new KMLConfiguration(), reader, SimpleFeature.class);

    ArrayList<SimpleFeature> features = new ArrayList<>();
    SimpleFeature simpleFeature = (SimpleFeature) parser.parse();
    while (simpleFeature != null)
    {
      System.out.println(simpleFeature);
      features.add(simpleFeature);
      simpleFeature = (SimpleFeature) parser.parse();
    }
    SimpleFeatureCollection fc = DataUtilities.collection(features);
    return fc;
  }


  /** Takes a kml file and converts it to a GeoJSON file holding all the Geo Features
    * using GeoTools SimpleFeatureCollection. <br /> It saves the geojson file in the same
    * dir with the same filename BUT with a ".geojson" extension.<br />
    * It uses {@link #convertKmlFile(File) convertKmlFile} to do the actual file processing.
    *
    * @param kmlDirFile is a directory File to recursivly process
    **/
  public static void convertKmlFilesInDir(File kmlDirFile) throws Exception
  {
    String fName = "";
    String kmlFilenameNOExtension = "";
    String geoJsonFilename = "";
    if (kmlDirFile!=null && kmlDirFile.isDirectory())
    {
      File[] fList = kmlDirFile.listFiles();
      for( int i=0; i< fList.length; i++)
      {
        if (fList[i].isDirectory())
        {
          convertKmlFilesInDir(fList[i]);
        }
        else
        {
          if (fList[i].isFile())
          {
            fName = fList[i].getAbsolutePath();
            if(fName.substring(fName.length()-3).equalsIgnoreCase("kml"))
            {
              kmlFilenameNOExtension = fName.substring(0,fName.length()-4);
              geoJsonFilename = kmlFilenameNOExtension + ".geojson";
              System.out.println("\n  --> "+ fName+" to "+geoJsonFilename);
              SimpleFeatureCollection fc = convertKmlFile(fList[i]);
              String geoJsonStr = featuresToString(fc);
              writeStringToFile(jsonIndenter(geoJsonStr).toString(), geoJsonFilename);
            }
          }
        }
      }
    }
  }


  /**
   * Abstracts the writing of string to a file.
   *
   * @param s is the String to writeout
   * @param fileName is the file name of the file to write the String into
   * @return if success.. the full pathed filename is returned else null
   **/
  public static String writeStringToFile(String s, String fileName)
  {return  writeStringToFile( s,  fileName, false);}


  /**
   * Abstracts the writing of string to a (zip) file (Zip NOT IMPLEMENTED YET).
   *
   * @param s is the String to writeout
   * @param fileName is the file name of the file to write the String into
   * @param zipCompress boolean fall to compress with zip compression
   * @return if success.. the full pathed filename is returned else null
   **/
  public static String writeStringToFile(String s, String fileName, boolean zipCompress)
  {
    String retVal = fileName;

    try
    {
      // FileWriter was not closing the stream
      /*
      FileWriter f = new FileWriter(fileName);
      f.write(s);
      f.flush();
      f.close();
      f = null;
      */
      FileOutputStream fos = new FileOutputStream(fileName);
      byte[] strBytes = s.getBytes();
      fos.write(strBytes);
      fos.flush();
      fos.close();
      fos = null;
      System.gc(); // this is required because a bug in Java won't realease
    }
    catch (IOException ioEx)
    {
      System.out.println("\nERROR Writing file: "+fileName);
      retVal = null;
    }

    return retVal;
  }


  /**
   * Class main commandLine entry method. <br />It takes <b>one</b> commandline parameter: a filename that points at EITHER a kml
   *  <b>file</b> OR a <b>directory</b> to recursivly process the kml files.
   **/
  public static void main(String[] args)
  {
    final String methodName = CLASSNAME + ": main()";
    KmlToGeoJSON instance = new KmlToGeoJSON();

    if (args.length>0)
    {
      try
      {
        String kmlFilenameNOExtension = args[0].substring(0,args[0].length()-4);
        String geoJsonFilename = kmlFilenameNOExtension + ".geojson";
        //System.out.println("\n  --> "+ args[0]+" to "+geoJsonFilename);

        File cmdFile = new File(args[0]);
        if (cmdFile.isFile())
        {
          SimpleFeatureCollection fc = convertKmlFile(cmdFile);
          String geoJsonStr = featuresToString(fc);
          writeStringToFile(jsonIndenter(geoJsonStr).toString(), geoJsonFilename);
        }
        else if (cmdFile.isDirectory())
        {
          convertKmlFilesInDir(cmdFile);
        }


      }
      catch (Exception ex)
      {
        System.out.println("Puked on the file");
        ex.printStackTrace();
      }
    }
    else
      System.out.println("Please enter a kml filename.");
  }

}