/*
 * This file is part of McIDAS-V
 *
 * Copyright 2007-2016
 * Space Science and Engineering Center (SSEC)
 * University of Wisconsin - Madison
 * 1225 W. Dayton Street, Madison, WI 53706, USA
 * https://www.ssec.wisc.edu/mcidas
 * 
 * All Rights Reserved
 * 
 * McIDAS-V is built on Unidata's IDV and SSEC's VisAD libraries, and
 * some McIDAS-V source code is based on IDV and VisAD source code.  
 * 
 * McIDAS-V is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 * 
 * McIDAS-V 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 Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser Public License
 * along with this program.  If not, see http://www.gnu.org/licenses.
 */

package edu.wisc.ssec.mcidasv.data.hydra;

import visad.FlatField;
import visad.VisADException;
import visad.RealType;
import visad.SetType;
import visad.FunctionType;
import visad.Set;
import java.rmi.RemoteException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

public abstract class MultiDimensionAdapter {

   MultiDimensionReader reader = null;
   Map<String, Object> metadata = null;
   String arrayName = null;
   String[] array_dim_names = null;
   int[] array_dim_lengths  = null;
   int array_rank;
   Class arrayType;

   Map<String, String> dimNameMap = new HashMap<>();

   RealType rangeType;

   RangeProcessor rangeProcessor = null;

   public MultiDimensionAdapter() {
   }

   public MultiDimensionAdapter(MultiDimensionReader reader, Map<String, Object> metadata) {
     this.reader = reader;
     this.metadata = metadata;
     this.init();
   }

   public abstract Map<String, double[]> getDefaultSubset();

   public abstract Set makeDomain(Map<String, double[]> subset) throws Exception;

   private void init() {
     this.arrayName = (String) metadata.get("array_name");

     String[] suppliedDimNames = (String[]) metadata.get("array_dimension_names");
     if (suppliedDimNames != null) {
       array_dim_names = suppliedDimNames;
     }
     else {
       array_dim_names = reader.getDimensionNames(arrayName);
     }

     array_dim_lengths = reader.getDimensionLengths(arrayName);
     array_rank = array_dim_lengths.length;
     arrayType = reader.getArrayType(arrayName);

     for (int i=0; i<array_rank; i++) {
       dimNameMap.put(array_dim_names[i], array_dim_names[i]);
     }

     Iterator<String> iter = metadata.keySet().iterator();
     while (iter.hasNext()) {
       String key = iter.next();
       Object val = metadata.get(key);
       if (!(val instanceof String)) continue;
       String name = (String) val; 
       for (int kk=0; kk<array_rank; kk++) {
         if (array_dim_names[kk].equals(name)) {
           dimNameMap.put(array_dim_names[kk], key);
         }
       }
     }

   }

   public Subset getIndexes(Map<String, double[]> select) {
     Subset subset = new Subset(array_rank);
     int[] start = subset.getStart();
     int[] count = subset.getCount();
     int[] stride = subset.getStride();

     Iterator<String> iter = select.keySet().iterator();
     while (iter.hasNext()) {
       String key = iter.next();
       String name = (String) metadata.get(key);

       if (name == null) name = key;

       for (int kk=0; kk<array_rank; kk++) {
         if (array_dim_names[kk].equals(name)) {
           double[] coords = select.get(key);

           if (array_dim_lengths[kk] == 1) {
             start[kk] = 0;
             count[kk] = 1;
             stride[kk] = 1;
           }
           else {
             start[kk] = (int) coords[0];
             count[kk] = (int) ((coords[1] - coords[0])/coords[2] + 1f);
             stride[kk] = (int) coords[2];
           }

         }
       }
     }
     return subset;
   }

   public FlatField getData(Map<String, double[]> subset) throws Exception {
     Set domainSet = makeDomain(subset);
     return makeFlatField(domainSet, subset);
   }

   private FlatField makeFlatField(Set domainSet, float[][] range) throws VisADException, RemoteException {
     FlatField f_field = makeFlatField(domainSet);
     f_field.setSamples(range, false);
     return f_field;
   }

   private FlatField makeFlatField(Set domainSet, double[][] range) throws VisADException, RemoteException {
     FlatField f_field = makeFlatField(domainSet);
     f_field.setSamples(range, false);
     return f_field;
   }

   private FlatField makeFlatField(Set domainSet) throws VisADException, RemoteException {
     FlatField f_field = new FlatField(new FunctionType(((SetType)domainSet.getType()).getDomain(), rangeType), domainSet);
     return f_field;
   }

   public FlatField makeFlatField(Set domainSet, Map<String, double[]> subset) throws Exception {
     FlatField f_field = null;

     Object range = readArray(subset);

     if (range instanceof float[]) {
       float[] new_range = processRange((float[]) range, subset);
       f_field = makeFlatField(domainSet, new float[][] {new_range});
     }
     else if (range instanceof double[]) {
       double[] new_range = processRange((double[]) range, subset);
       f_field = makeFlatField(domainSet, new double[][] {new_range});
     }
     else if (range instanceof short[]) {
       float[] float_range = processRange((short[])range, subset);
       f_field = makeFlatField(domainSet, new float[][] {float_range});
     }
     else if (range instanceof byte[]) {
       float[] float_range = processRange((byte[])range, subset);
       f_field = makeFlatField(domainSet, new float[][] {float_range});
     }

     return f_field;
   }

   public RangeProcessor getRangeProcessor() {
     return rangeProcessor;
   }

   public void setRangeProcessor(RangeProcessor rangeProcessor) {
     this.rangeProcessor = rangeProcessor;
   }

   public float[] processRange(short[] range, Map<String, double[]> subset) {
     if (rangeProcessor == null) {
       float[] f_range = new float[range.length];
       for (int i=0; i<range.length;i++) f_range[i] = (float) range[i]; 
       return f_range;
     }
     else { 
       return rangeProcessor.processRange(range, subset);
     }
   }

   public float[] processRange(byte[] range, Map<String, double[]> subset) {
     if (rangeProcessor == null) {
       float[] f_range = new float[range.length];
       for (int i=0; i<range.length;i++) f_range[i] = (float) range[i];
       return f_range;
     }
     else {
       return rangeProcessor.processRange(range, subset);
     }
   }

   public float[] processRange(float[] range, Map<String, double[]> subset) {
     if (rangeProcessor == null) {
       return range;
     }
     else {
       return rangeProcessor.processRange(range, subset);
     }
   }

   public double[] processRange(double[] range, Map<String, double[]> subset) {
     if (rangeProcessor == null) {
       return range;
     }
     else {
       return rangeProcessor.processRange(range, subset);
     }
   }


   public Object readArray(Map<String, double[]> subset) throws Exception {
     Subset select = getIndexes(subset);
     int[] start = select.getStart();
     int[] count = select.getCount();
     int[] stride = select.getStride();

     return reader.getArray(arrayName, start, count, stride);
   }

   public MultiDimensionReader getReader() {
     return reader;
   }

   public Map<String, Object> getMetadata() {
     return metadata;
   }

   String getArrayName() {
     return arrayName;
   }

   public RealType getRangeType() {
     return rangeType;
   }
   
   public Map<String, double[]> getSubsetFromLonLatRect(Map<String, double[]> subset, double minLat, double maxLat,
                                      double minLon, double maxLon) {
     return subset;
   }

   public Map<String, double[]> getSubsetFromLonLatRect(double minLat, double maxLat,
                                          double minLon, double maxLon) {
     return null;
   }

   public Map<String, double[]> getSubsetFromLonLatRect(double minLat, double maxLat,
                                          double minLon, double maxLon,
                                          int xStride, int yStride, int zStride) {
     return null;
   }

}