
import java.util.logging.Logger;
import java.util.logging.Level;
import java.util.List;
import java.util.ArrayList;
import java.util.Arrays;

import java.time.Instant;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileNotFoundException;
import java.nio.file.StandardOpenOption;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

import java.time.*;// Timestamp in cut-filename
import java.io.ByteArrayOutputStream; // for SODA direct streaming doSubimgStream

// tar.gz compress
import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
import org.apache.commons.compress.archivers.tar.TarArchiveOutputStream;
import org.apache.commons.compress.compressors.gzip.GzipCompressorOutputStream;
import java.io.BufferedOutputStream;
import java.util.Date;
import java.text.SimpleDateFormat;
import org.json.simple.JSONArray;

import vo.parameter.*;

class VlkbCli implements Vlkb
{
   static final Logger LOGGER = Logger.getLogger(VlkbCli.class.getName());

   private Settings    settings   = null;
   private Subsurvey[] subsurveys = null;
   private Resolver    resolver   = null;
   private Soda        soda       = null;


   public VlkbCli()
   {
      LOGGER.fine("trace VlkbCli()");
      this.settings = Settings.getInstance();
      this.soda = new SodaImpl(settings.fitsPaths);
      this.resolver = (settings.dbConn.isDbUriEmpty() ? new ResolverFromId(subsurveys)
            : new ResolverByObsCore(settings.dbConn, subsurveys));
   }


   public VlkbCli(Settings settings)
   {
      LOGGER.fine("trace VlkbCli(settings)");
      this.settings = settings;
      this.soda = new SodaImpl(settings.fitsPaths);
      this.resolver = (settings.dbConn.isDbUriEmpty() ? new ResolverFromId(subsurveys)
            : new ResolverByObsCore(settings.dbConn, subsurveys));
   }


   public VlkbCli(Settings settings, Subsurvey[] subsurveys)
   {
      LOGGER.fine("trace VlkbCli(settings, subsurveys)");
      this.settings = settings;
      this.subsurveys = subsurveys;
      this.soda = new SodaImpl(settings.fitsPaths);
      this.resolver = (settings.dbConn.isDbUriEmpty() ? new ResolverFromId(subsurveys)
            : new ResolverByObsCore(settings.dbConn, subsurveys));
   }



   public CutResult doMerge(String[] idArr, Coord coord, boolean countNullValues)
      throws FileNotFoundException, IOException
   {
      LOGGER.fine("trace doMerge by CLI is NOT IMPLEMENTED (only by AMQP)");

      return new CutResult();
   }



   public CutResult doFile(String relPathname, int hdunum,
         Pos pos, Band band, Time time, Pol pol, String pixels,
         boolean countNullValues, FitsCard[] extraCards)
         throws IOException, InterruptedException
      {
         LOGGER.fine("trace: " + pos.toString() );

         CutResult cutResult = new CutResult();

         LOGGER.finer("Using doStream() to local file");

         String absSubimgPathname = settings.fitsPaths.cutouts()
            + "/" + generateSubimgPathname(relPathname, hdunum);

         LOGGER.finer("Uses local filename : " + absSubimgPathname);

         OutputStream fileOutputStream = new FileOutputStream( new File(absSubimgPathname) );

         soda.doStream(relPathname, hdunum, pos, band, time, pol, pixels, fileOutputStream);

         // engine returns absPathname see common/cutout.cpp::do_cutout_file()
         cutResult.fileName = absSubimgPathname;
         cutResult.fileSize = Files.size(Paths.get(absSubimgPathname));

         if(countNullValues)
         {
            cutResult.nullValueCount = doCountNullValues(absSubimgPathname, 1);
         }

         if(extraCards == null || (extraCards.length < 1))
         {
            LOGGER.finer("Adding extraCards to cut-file implemented only in VlkbAmql");
         }

         cutResult.pixels = null;
         return cutResult;
      }



   private NullValueCount doCountNullValues(String absPathname, int hdunum)
         throws IOException, InterruptedException
      {
         ByteArrayOutputStream bos = new ByteArrayOutputStream();
         if(bos == null)
            throw new AssertionError("byte output stream for bounds was not created, is null");

         String[] cmdBounds = new String[3];
         cmdBounds[0] = "/usr/local/bin/vlkb";
         cmdBounds[1] = "nullvals";
         cmdBounds[2] = absPathname;

         ExecCmd exec = new ExecCmd();
         exec.doRun(bos, cmdBounds);
         LOGGER.finest("exec NullVals exitValue: " + exec.exitValue);

         bos.close();

         boolean hasResult = (exec.exitValue == 0);
         if(hasResult)
         {
            String nullValsString = new String(bos.toByteArray());
            LOGGER.finest("vlkb nullvals: " + nullValsString);

            if((nullValsString != null) && nullValsString.trim().isEmpty())
            {
               throw new AssertionError("'vlkb nullvals' returned empty string");
            }

            // parse result: '<fill-ratio> <nullvals-count> <tot-count>'

            String[] splitStr = nullValsString.trim().split("\\s+");
            if(splitStr.length != 3)
               throw new AssertionError("'vlkb nullvals' did not return 3 numbers but: " + nullValsString);

            NullValueCount nvc = new NullValueCount();
            nvc.percent = Double.parseDouble(splitStr[0]);
            nvc.nullCount = Long.parseLong(splitStr[1]);
            nvc.totalCount = Long.parseLong(splitStr[2]);
            return nvc;
         }
         else
         {
            throw new AssertionError("'vlkb nullvals' exited without results for: " + absPathname);
         }
      }




   private CutResult doFileById(String id, Pos pos, Band band, Time time, Pol pol, String pixels,
         boolean countNullValues/*, Subsurvey[] subsurveys*/)
         throws IOException, InterruptedException
      {
         LOGGER.fine("trace");

         FitsCard[] extraCards = null;

         this.resolver.resolve(id);
         String relPathname = this.resolver.relPathname();
         int hdunum         = this.resolver.hdunum();
         String subsurveyId = this.resolver.obsCollection();

         if(subsurveyId != null)
         {
            extraCards = Subsurvey.subsurveysFindCards(this.subsurveys, subsurveyId);
         }
         else
         {
            LOGGER.finer("Resolver returns subsurveyId null: no extraCards loaded.");
         }

         final String DEFAULT_TIME_SYSTEM = "MJD_UTC"; // FIXME take from confif file

         CutResult cutResult = doFile(relPathname, hdunum, pos, band, time, pol, pixels,
               countNullValues, extraCards);

         return cutResult;
      }


   private  String generateSubimgPathname(String relPathname, int hdunum)
   {
      String cutfitsname = "vlkb-cutout";

      Instant instant = Instant.now() ;
      String timestamp = instant.toString().replace(":","-").replace(".","_");

      String tempPathname1 = relPathname.replaceAll("/","-");
      String tempPathname2 = tempPathname1.replaceAll(" ","_");

      if(hdunum == 1)
      {
         return cutfitsname + "_" + timestamp + "_" + tempPathname2;
      }
      else
      {
         String extnum = "EXT" + String.valueOf(hdunum-1);
         return cutfitsname + "_" + timestamp + "_" + extnum + "_" + tempPathname2;
      }
   }




   public MCutResult doMCutout(String jdlJson)
         throws IOException, InterruptedException
      {
         LOGGER.fine("trace");

         MCutResult mCutResult;

         CutArgs[] cutArgsArr = CutArgs.parseCutArgsArr(jdlJson);
         MCutResult.Cut[] cutResultArr = doCutouts( cutArgsArr );
         String respJsonString = genResponseJson( cutResultArr );
         mCutResult = doCompressCutFiles( cutResultArr, respJsonString );

         return mCutResult;
      }



   private MCutResult.Cut[] doCutouts(CutArgs[] cutArgsArr)
   {
      LOGGER.fine("trace, count of cuts : " + String.valueOf( cutArgsArr.length ) );

      List<MCutResult.Cut> cutResList = new ArrayList<MCutResult.Cut>();

      int ix = 0;
      for(CutArgs cutArgs: cutArgsArr)
      {
         MCutResult.Cut cut = doFileByIdWithErr(cutArgs.id,
               cutArgs.pos, cutArgs.band, cutArgs.time,  cutArgs.pol,  cutArgs.pixels,
               cutArgs.countNullValues);//,  null);//cutArgs.extraCards);

         cut.index = ix++;

         LOGGER.finest("cut" + String.valueOf(cut.index) + " : " + cut.content);

         cutResList.add(cut);
      }

      return cutResList.toArray(new MCutResult.Cut[0]);
   }


   // FIXME implement similar for Merge: MCutResult = call-Montage-demosaic-sequence(cutResultArr)
   private MCutResult doCompressCutFiles(MCutResult.Cut[] cutArr, String respJsonString)
         throws IOException, InterruptedException
      {
         Instant instant = Instant.now();
         String timestamp = new SimpleDateFormat("yyyyMMddHHmmss").format(new Date()) + "_" + instant.getNano();

         final String tgzFileName = settings.fitsPaths.cutouts() + "/mcutout_" + timestamp + ".tar.gz";

         // generate response-*.json with timestamp
         String respJsonPathname = settings.fitsPaths.cutouts() + "/response_" + timestamp + ".json";
         try (PrintWriter out = new PrintWriter(respJsonPathname))
         {
            out.print(respJsonString);
         }

         List<Path> paths = new ArrayList<Path>();

         paths.add(Paths.get(respJsonPathname));

         for(MCutResult.Cut cut : cutArr)
         {
            LOGGER.finest("cut-id"+ String.valueOf(cut.index) + " -> " + cut.content);
            if(cut.contentType == MCutResult.Cut.ContentType.FILENAME)
            {
               Path p = Paths.get(cut.content);
               paths.add(p);
            }
         }

         Path output = Paths.get(tgzFileName);
         createTarGzipFiles(paths, output);

         MCutResult mCutResult = new MCutResult();
         mCutResult.cutResArr = cutArr;
         mCutResult.fileName = tgzFileName;
         mCutResult.fileSize = Files.size(output);

         return mCutResult;
      }


   private String genResponseJson(MCutResult.Cut[] cutArr)
   {
      List<Path> paths = new ArrayList<Path>();

      JSONArray jArr = new JSONArray();

      for(MCutResult.Cut cut : cutArr)
      {
         jArr.add(cut.toJsonObject());
      }

      return jArr.toString();
   }



   private MCutResult.Cut doFileByIdWithErr(String id, Pos pos, Band band, Time time, Pol pol, String pixels,
         boolean countNullValues/*, Subsurvey[] subsurveys*/)
   {
      LOGGER.fine("trace");

      MCutResult mCutResult = new MCutResult();
      MCutResult.Cut cut = mCutResult.new Cut(/* FIXME eventually add here new Inputs(id, pos,..) */);

      try
      {
         CutResult cutResult = doFileById(id,
               pos,  band, time,  pol, pixels,
               countNullValues/*,  subsurveys*/);

         cut.content     = cutResult.fileName;
         cut.contentType = MCutResult.Cut.ContentType.FILENAME;
      }
      catch(MultiValuedParamNotSupported ex) 
      {
         cut.content = "MultiValuedParamNotSupported: " + ex.getMessage();
         cut.contentType = MCutResult.Cut.ContentType.BAD_REQUEST;
         LOGGER.warning(cut.content);
      }
      catch(IllegalArgumentException ex) 
      {
         cut.content = "IllegalArgumentException: " + ex.getMessage();
         cut.contentType = MCutResult.Cut.ContentType.BAD_REQUEST;
         LOGGER.warning(cut.content);
      }
      catch(Exception ex) 
      {
         cut.content     = "Exception: " + ex.getMessage();
         cut.contentType = MCutResult.Cut.ContentType.SERVICE_ERROR;
         LOGGER.severe(cut.content);
         ex.printStackTrace();
      }

      return cut;
   }



  /*
      <dependency>
      <groupId>org.apache.commons</groupId>
      <artifactId>commons-compress</artifactId>
      <version>1.20</version>
      </dependency>

      import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
      import org.apache.commons.compress.archivers.tar.TarArchiveOutputStream;
      import org.apache.commons.compress.compressors.gzip.GzipCompressorOutputStream;
  */
   private static void createTarGzipFiles(List<Path> paths, Path output)
         throws IOException
      {
         try (OutputStream fOut = Files.newOutputStream(output);
               BufferedOutputStream buffOut = new BufferedOutputStream(fOut);
               GzipCompressorOutputStream gzOut = new GzipCompressorOutputStream(buffOut);
               TarArchiveOutputStream tOut = new TarArchiveOutputStream(gzOut))
         {
            for (Path path : paths)
            {
               if (!Files.isRegularFile(path))
               {
                  throw new IOException("Must be regular file, but was : " + path.toString());
               }

               TarArchiveEntry tarEntry = new TarArchiveEntry(
                     path.toFile(),
                     path.getFileName().toString());

               tOut.putArchiveEntry(tarEntry);

               // copy file to TarArchiveOutputStream
               Files.copy(path, tOut);

               tOut.closeArchiveEntry();
            }

            tOut.finish();
         }
      }

}

