/**
  * Converts HF broadcast station data file HF_BCD.txt to required data files
  * @author Robert J Morton
  * @version 22 November 2001 */

// This program uses the Java 1.1.8 API.

import java.io.*;


class hfbdp {

  public static void main(String args[]) throws IOException {

    BufferedReader  // create reader for the station data file.
      r = new BufferedReader(
            new InputStreamReader(
              new FileInputStream("hfbsn.txt")
            )
          );

    /* Create writers for the separate stations and frequencies files.
    Also create a file in which to write duplicate entries. */
    Writer
      stations = new FileWriter("stations.txt"),
      frequencies  = new FileWriter("freqs000.txt"),
      dups  = new FileWriter("duplicates.txt");

    String
      old_frequency = "",  // for capturing duplicates
      old_station = "",    // for capturing duplicates
      STATION = "",        // name of station currently being dealt with
      s;                   // to hold the current input line

    int sn = 0;  // number of station within the list

    /* While there are still more lines of text in the file, read
    in the next line and find the position of the tab character
    that separates the frequency from from station name. */

    while((s = r.readLine()) != null) {
      int x = s.indexOf('\t');

      /* Get the new frequency, then get the corresponding station
      name and strip off possible rogue space charaters from it.*/
      String
        frequency = (s.substring(0,x)),
        station = (s.substring(x + 1,s.length())).trim();

      /* If it is a duplicate entry, write this frequency
      and station name to the duplicates file. */

      if(frequency.equals(old_frequency) && station.equals(old_station))
        dups.write(frequency + '\t' + station + "\n");

      old_frequency = frequency;
      old_station = station;

      /* if we are still dealing with the same station,
      then write the next frequency for this station. */

      if(STATION.compareTo(station) == 0)
        frequencies.write(frequency + "\n");

      /* Else, it must be a new station; so, make this station's name
      the current station name and wite it to the stations file. */
      else {
        STATION = station;
        stations.write(station + "\n");

        /* Provided the previous station actually had at
        least one frequency, close its frequencies file*/

        if(sn > 0) frequencies.close();

        String SN = "" + sn;  // form string version of station number
        if(sn < 10)           // if it is less than 10
          SN = "00" + SN;     // pad it out with 2 leading zeros
        else if(sn < 100)     // else if it is less than 100
          SN = "0" + SN;      // pad it with just 1 leading zero

        /* Create a new frequencies file for this station
        and write first frequency for this station. */

        frequencies = new FileWriter("freqs" + SN + ".txt");
        frequencies.write(frequency + "\n");

        sn++;  // increment the station number for the next pass
      }
    }
    dups.close();
    stations.close();
    frequencies.close();
    r.close();
  }
}