/**
    * Copyright 2012 The Kuali Foundation Licensed under the
    * Educational Community License, Version 2.0 (the "License"); you may
    * not use this file except in compliance with the License. You may
    * obtain a copy of the License at
    *
    * http://www.osedu.org/licenses/ECL-2.0
    *
    * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an "AS IS"
   * BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
   * or implied. See the License for the specific language governing
   * permissions and limitations under the License.
   *
   * Created by Charles on 11/15/12
   */
  package org.kuali.student.enrollment.class2.courseoffering.refdata;
  
  import org.apache.log4j.Logger;
  import org.kuali.student.r2.common.exceptions.InvalidParameterException;
  
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.TreeMap;
  
  /**
   * Stores the content of a spreadsheet with fieldNames and values
   * The map is a list of a header to a list of values (basically, column data)
   *
   * @author Kuali Student Team
   */
  public class SpreadsheetData implements Iterable<SpreadsheetRowData> {
      private static Logger LOGGER = Logger.getLogger(SpreadsheetData.class);
      List<String> fieldNames;
      Map<String, List<String>> headerToValueList;
      boolean isValid = false;
  
      public SpreadsheetData() {
  
      }
  
      public void addHeaders(List<String> fieldNames) {
          if (!isValid && fieldNames != null) {
              this.fieldNames = new ArrayList<String>();
              this.fieldNames.addAll(fieldNames); // Copy the fieldNames
              headerToValueList = new TreeMap<String, List<String>>();
              // TODO: Make sure fieldNames have unique names
              for (String field: fieldNames) {
                  // Stub out the map
                  headerToValueList.put(field, new ArrayList<String>());
              }
              isValid = true;
          } else {
              LOGGER.warn("Field names already set");
          }
      }
  
      /**
       *
       * @param row A list of strings in the order of the fieldNames
       * @throws InvalidParameterException due to a variety of errors that could occur in row
       */
      public void addRow(List<String> row) throws InvalidParameterException {
          if (row == null) {
              throw new InvalidParameterException("Row is null");
          } else if (!isValid) {
              throw new InvalidParameterException("Headers are not set");
          } else if (row.size() != fieldNames.size()) {
              throw new InvalidParameterException();
          } else {
              int index = 0;
              for (String val: row) {
                  if (val == null || val.isEmpty()) {
                      // Put null for empty strings
                      val = null;
                  }
                  // add the values at the end of appropriate list
                  headerToValueList.get(fieldNames.get(index)).add(val);
                  index++;
              }
          }
      }
  
      public int numRows() {
          // All columns should have the same length
          int firstFieldName = 0;
          return headerToValueList.get(fieldNames.get(firstFieldName)).size();
      }
  
      public SpreadsheetRowData getRowAt(int index) {
          if (index >= numRows() || index < 0) {
              return null;
          } else {
              SpreadsheetRowData rowData = new SpreadsheetRowData();
              for (String field: fieldNames) {
                  String value = headerToValueList.get(field).get(index);
                  // Added in same order as fieldNames
                 rowData.addData(field, value);
             }
             return rowData;
         }
     }
 
     public void showContents() {
         for (String str: fieldNames) {
             System.err.print(str + "\t");
         }
         System.err.println();
         System.err.println("------------------------------------------------------");
         int rows = numRows();
         for (int i = 0; i < rows; i++) {
             for (String data: getRowAt(i)) {
                 if (data == null) {
                     data = "null";
                 }
                 System.err.print(data + "\t");
             }
             System.err.println();
         }
     }
 
 
     @Override
     public Iterator<SpreadsheetRowData> iterator() {
         return new Iterator<SpreadsheetRowData>() {
             int index = 0;
             @Override
             public boolean hasNext() {
                 return index < numRows();
             }
 
             @Override
             public SpreadsheetRowData next() {
                 if (!hasNext()) {
                     throw new IndexOutOfBoundsException("No more rows left");
                 }
                 SpreadsheetRowData rowData = getRowAt(index);
                 index++;
                 return rowData;
             }
 
             @Override
             public void remove() {
                 throw new RuntimeException("Operation not supported");
             }
         };
     }
 }