/*
 *   Lab 11
 *
 *  This code will read in a "flat" file containing data items for use in instantiating Bill objects.
 *    A variety of Bill objects will be instantiated based on the input values.
 *    Those objects will be added to a (globally declared) generic collection for holding/serialization
 *    Once all objects have been instantiated, the (globally declared) collection will be output
 *      as an XML-serialized document.
 *
 * (c) 2019, Terri Davis
 */
// ----------------------   IMPORTS for File Handling/Management    ------------------------------


// --------------------   IMPORTS for Collection Handling/Management    ---------------------------
import java.util.List;                              // Interface provides methods for manipulating objects by index
import java.util.ArrayList;                         // Class implements interfaces List & Collection

// ---------------------------   IMPORT for XML Serialization    ---------------------------------
import java.io.BufferedWriter;
import java.io.IOException;
import java.nio.file.Files;
import java.io.File;
import java.nio.file.Paths;
import java.util.NoSuchElementException;
import java.util.Scanner;
import javax.xml.bind.JAXB;



public class CreateBillObjects_Batch
{
  /*
   * Declared globally, as it will be needed in both sub-methods. This avoids having to pass the reference
   *   among methods.
   */
  private static List<Bill> billsCollection = new ArrayList<Bill>( );

  public static void main( String[] args )
  {
    readInput_BuildBills( );
    serializeBills( );
  } // end main

  private static void readInput_BuildBills( )
  {
    /*
     *  1. Set up "holding spaces" for various objects and variables we will use in the loop
     *  2. Declare and instantiate an object for input of the data "flat file" inputBills.txt
     *  3. Read each line from the input file, and using the data provided, instantiate a Bill object
     *  4. Add the new Bill object to the billsCollection (for later serialization)
     *  5. When all input has been read, remember to close the input file!!
     */

    Bill      newBill;                                 // This is a "holding space" for the Bill objects we instantiate

    try                                                // Because "stuff" can happen during I/O...
    {
      /*
       * Declare and instantiate a Scanner object to read the input file.
       */
      Scanner inputFile = new Scanner(new File("inputBills.txt"));

      // Modify Scanner object to use a comma (,) as the delimiter between inputs
      inputFile.useDelimiter( "," );

      while( inputFile.hasNext( ) )
      {
        /*
         *  Read input items from the file, and use that data to instantiate a new Bill object
         */
        newBill = new Bill( inputFile.next( ),
                            inputFile.next( ),
                            inputFile.nextDouble( ),
                            inputFile.next( ),
                            inputFile.next( ),
                            inputFile.next( ) );

        // Now that the new Bill object has been instantiated, add it to the (global) collection
        billsCollection.add( newBill );

      }  // end while loop

      /*
       *  ALWAYS CLOSE your file!
       */
      inputFile.close();

    }  // end try block
    catch( Exception xcptn )
    {
      System.err.printf( "There was an error involving the INPUT file. Refer to exception type & message for info.%n%s%n%s%n",
                          xcptn.getClass( ).getName( ),
                          xcptn.getMessage( ) );
      xcptn.printStackTrace( );
    }  // end catch IOException

  }  // end readInput_BuildBills

  private static void serializeBills( )
  {
    /*
     *  Complete the XML Serialization process using the billsCollection
     *
     *  1. Instantiate a local copy of the "helper" code - this is necessary for the XML serialization
     *       to complete properly.
     *  2. Declare and instantiate an output file
     *  3. Serialize the collection
     */

    /*
     *  Declare and instantiate a local copy of the "helper" code here
     */
    Bills bills = new Bills();


    try                                                // Because "stuff" can happen during I/O...
    {
      /*
       *  Declare and instantiate a BufferedWriter object for output. Use file name "outputBills.xml"
       */
      BufferedWriter output = Files.newBufferedWriter(Paths.get("outputBills.xml"));

      /*
       * Copy the Bill object references from the (globally declared) collection to the collection in the
       *   "helper" code. NOTE: This does not duplicate Bill objects, but simply duplicates references to
       *    those objects.
       */

      bills.getBills( ).addAll( billsCollection );

      /*
       *  Execute the actual serialization process using local copy of the "helper" code instantiated above
       *     and the the BufferedWriter object declare/instantiated above
       */

      JAXB.marshal(bills, output);

    }  // end try
    catch( IOException xcptn )
    {
      System.err.printf( "There was an error involving the OUTPUT file. Refer to exception type & message for info.%n%s%n%s%n",
                          xcptn.getClass( ).getName( ),
                          xcptn.getMessage( ) );
      xcptn.printStackTrace( );
    }  // end catch IOException

  }  // end serializeBills
}  // end CreateBillObjects_Batch