package org.autoplot.pds;

import gov.nasa.pds.label.Label;
import gov.nasa.pds.label.object.ArrayObject;
import gov.nasa.pds.label.object.FieldDescription;
import gov.nasa.pds.label.object.FieldType;
import gov.nasa.pds.label.object.TableObject;
import gov.nasa.pds.label.object.TableRecord;
import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.net.URL;
import java.text.ParseException;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.autoplot.datasource.AbstractDataSource;
import org.autoplot.datasource.DataSetURI;
import org.autoplot.datasource.URISplit;
import org.das2.datum.TimeParser;
import org.das2.datum.Units;
import org.das2.qds.ArrayDataSet;
import org.das2.qds.DDataSet;
import org.das2.qds.QDataSet;
import org.das2.qds.ops.Ops;
import org.das2.qds.util.DataSetBuilder;
import org.das2.util.monitor.NullProgressMonitor;
import org.das2.util.monitor.ProgressMonitor;

/**
 *
 * @author jbf
 */
public class PdsDataSource extends AbstractDataSource {

    public PdsDataSource(URI uri) {
        super(uri);
    }

    /**
     * bootstrap routine for getting data from fields of a TableObject.  TODO: rewrite so that
     * multiple fields are read at once.
     * @param t
     * @param columnName
     * @return
     * @throws IOException 
     */
    private QDataSet getFromTable( TableObject t, String[] columnNames ) throws IOException {
        
        int ncols= columnNames.length;
        int[] icols= new int[ncols];
        
        DataSetBuilder dsb= new DataSetBuilder(2,100,ncols);
        
        for ( int i=0; i<ncols; i++ ) {
            int icol= -1;
            FieldDescription[] fields= t.getFields();
            for ( int j=0; j<fields.length; j++ ) {
                if ( fields[j].getName().equals(columnNames[i]) ) {
                    icol= j;
                    break;
                }
            }
            //TODO: what is returned when column isn't found?
            icols[i]= icol;
            FieldDescription fieldDescription= t.getFields()[icol];
            dsb.setName( i, fieldDescription.getName() );
            dsb.setLabel( i, fieldDescription.getName() );
            //TODO: Larry has nice descriptions.  How to get at those? https://space.physics.uiowa.edu/pds/cassini-rpws-electron_density/data/2006/rpws_fpe_2006-141_v1.xml
            switch (fieldDescription.getType()) {
                case ASCII_DATE:
                case ASCII_DATE_DOY:
                case ASCII_DATE_TIME_DOY_UTC:
                case ASCII_DATE_TIME_UTC:
                case ASCII_DATE_TIME_DOY:
                case ASCII_DATE_TIME_YMD:
                case ASCII_DATE_TIME_YMD_UTC:
                    dsb.setUnits(i, Units.us2000);
                    break;
                    //TODO: create timeparser 
                default:
                    dsb.setUnits(i, Units.dimensionless ); // TODO: how to get "unit" from label
            }
        }
        
        TableRecord r;
        while ( ( r= t.readNext())!=null ) {
            for ( int i=0; i<ncols; i++ ) {
                try {
                    dsb.putValue( -1, i, r.getString(icols[i]+1) );
                } catch (ParseException ex) {
                    dsb.putValue( -1, i, dsb.getUnits(i).getFillDatum() );
                }
            }
            dsb.nextRecord();
        }
        
        return dsb.getDataSet();
    }
    
    private double[] flatten( double[][] dd ) {
        double[] rank1= new double[dd.length*dd[0].length];
        int nj= dd[0].length;
        int kk= 0;
        for ( int i=0; i<dd.length; i++ ) {
            double[] d= dd[i];
            for ( int j=0; j<nj; j++ ) {
                rank1[kk++]= d[j];
            }
        }
        return rank1;
    }
    
    @Override
    public org.das2.qds.QDataSet getDataSet(ProgressMonitor mon) throws Exception {
        String name= getParam("arg_0","");
        
        URISplit split= URISplit.parse( getURI() );
            
        URL fileUrl= PdsDataSourceFactory.getFileResource( split.resourceUri.toURL(), mon );
        File xmlfile = DataSetURI.getFile( split.resourceUri.toURL() ,new NullProgressMonitor());
        DataSetURI.getFile(fileUrl,mon );
                    
        Label label = Label.open( xmlfile.toURI().toURL() ); 
        
        for ( TableObject t : label.getObjects( TableObject.class) ) {
            
            for ( FieldDescription fd: t.getFields() ) {
                if ( name.equals( fd.getName() ) ) { 
                    QDataSet result= getFromTable( t, new String[] { fd.getName() } );
                    return Ops.unbundle(result, 0);
                }
            }
        }
        
        for ( ArrayObject a: label.getObjects(ArrayObject.class) ) {
            if ( a.getName().equals(name) ) {
                if ( a.getAxes()==2 ) {
                    double[][] dd= a.getElements2D();
                    double[] rank1= flatten(dd);
                    int[] qube= new int[] { dd.length, dd[0].length };
                    return DDataSet.wrap( rank1, qube );
                } else if ( a.getAxes()==1 ) {
                    double[] dd= a.getElements1D();
                    int[] qube= new int[] { dd.length };
                    DDataSet ddresult= DDataSet.wrap( dd, qube );
                    if ( name.equals("Epoch") ) {
                        logger.info("Epoch kludge results in CDF_TT2000 units");
                        ddresult.putProperty( QDataSet.UNITS, Units.cdfTT2000 );
                    }
                    return ddresult;
                }
            }
        }
        return null;
    }
    
}