import java.io.EOFException;		// For when we hit end of file
import java.io.FileNotFoundException;	// Dealing with files
import java.io.IOException;		// Misc. I/O errors
import rebelsky.util.IncomparableException;	// Required by quickSort
import rebelsky.util.ComparableString;	// Comparing strings
import rebelsky.util.EmptyListException;// Required for dealing with lists
import rebelsky.io.SimpleReader;	// Reading input
import rebelsky.io.SimpleOutput;	// Writing output
import NodeList;			// Does the work

/**
 * Sort the lines of a file specified on the command line.
 *
 * @author Samuel A. Rebelsky
 * @version 1.0 of March 1998a
 */
public class LineSorter 
{
  /**
   * Sort the lines of a file specified on the command line.
   */
  public static void main(String[] args)
  {
    // Input and output
    SimpleOutput out = new SimpleOutput();
    // The input will be changed to a file, but we initialize it
    // to something so that Java doesn't complain.
    SimpleReader in = new SimpleReader();
    // A list of the lines of the file
    NodeList lines = new NodeList();

    // Ensure that there is exactly one file specified on the
    // command line.
    if (args.length != 1) {
      out.println("You must specify a file to sort.");
      System.exit(1);
    }

    // Open the input file
    try {
      in = new SimpleReader(args[0]);
    }
    catch (FileNotFoundException fnfe) {
      out.println("Couldn't find file '" + args[0] + "'");
      System.exit(2);
    }

    // Read the lines
    try {
      try {
        while (true) {
          // Read a line, make it comparable, shove it in a node, and
          // add to the end of the list.
          lines.addToEnd(new Node(new ComparableString(in.readLine())));
        }
      }
      catch (EOFException ee) {
        // We're done with the input file.  Close it.
        in.close();
      }
    }
    catch (IOException ie) {
      out.println("Agh.  Some weird IO problem.");
      System.exit(3);
    }

    // Sort the lines
    try {
      lines = lines.quickSort();
    }
    catch (IncomparableException ie) {
      out.println("Failed to sort.");
      System.exit(4);
    }

    // And print them out
    try {
      while (!lines.empty()) {
        out.println(lines.first().toString());
        lines.deleteFirst();
      } // while
    }
    catch (EmptyListException ele) {
      // Do nothing, it's over
    }
  } // main(String[])

} // LineSorter