import java.util.Scanner;
import java.io.*;
/**
 * CS151 Fall 2007 Lab 11 Solution. <BR>
 * Class for practicing file reading and writing.  Uses United Nations data on cinema attendance by
 * country to demonstrate some potential issues when reading data files.
 * 
 * @author Scott Russell 
 * @version created 11/13/2007, last modified 11/14/2007
 */
public class UNDataReader
{
    /**
     * Conversion factor for computing data expressed in millions to the corresponding integer.
     */
    public static final double MILLION = 1000000;
    
    // since FileNotFoundException is a subclass of IOException we need only specify the superclass
    public static void main(String[] args) throws IOException
    {
        // Link a Scanner to the terminal window to get file name input from the user
        Scanner console = new Scanner(System.in);
        
        // Solicit a filename from the user
        System.out.print("Please enter the name of the file to read from: ");
        String inputFileName = console.next();
        
        // create a reader for that file and then a Scanner using that reader
        FileReader reader = new FileReader(inputFileName);
        Scanner input = new Scanner(reader);
        
        // Solicit a filename from the user using same console Scanner
        System.out.print("Please enter the name of the file to write to: ");
        String outputFileName = console.next();

        // Open a file for writing
        PrintWriter writer = new PrintWriter(outputFileName);
        
        // display some header information in the terminal window but not in the output file
        System.out.println("Country, Attendance (millions)");
        
        /* start reading the file
         * keep reading and discarding lines until the first line that starts with an integer 
         * that hopefully represents a Country Code is found
         */
        while (input.hasNextLine() && !input.hasNextInt())
        {
            // read and discard the entire line
            input.nextLine();
        }

        // continue to read records as long as there's another line that starts with an integer
        while (input.hasNextLine() && input.hasNextInt())
        {
            // read and discard the country code
            input.nextInt();
            
            // For each record, start with an empty String for the countryName and keep appending to it
            // the next word found until that is a double
            String countryName = new String();
            while (!input.hasNextDouble())
                countryName += input.next() + " ";
            
            // remove the trailing space
            countryName = countryName.trim();

            // read the attendance and multiply by a million to convert to actual integer
            double attendance = input.nextDouble() * MILLION;

            // discard the remainder of the line if any
            input.nextLine();

            // print out to the screen and file the information
            System.out.println(countryName + "," + (int) attendance);
            writer.println(countryName + "," + (int) attendance);
        }        

        // close both the reader and the writer
        reader.close();
        writer.close();
    }
}