import java.io.*;
import java.util.*;


public class EditorDriver
{
    protected Editor editor;

    protected BufferedReader fileReader;

    protected PrintWriter fileWriter;


    /**
     * Initializes this EditorDriver object.
     */
    public EditorDriver()
    {
        editor = new Editor();
    } //constructor


    /**
     * Reads in the file paths, declares and opens the input and output files
     * 
     * @return a reference to the file writer
     * 
     */
    public PrintWriter openFiles()
    {
        final String IN_FILE_PROMPT =
              "\n\nPlease enter the path for the input file: ";

        final String OUT_FILE_PROMPT =
              "\n\nPlease enter the path for the output file: ";

        final String IO_EXCEPTION_MESSAGE = "The file was not found.\n\n";

        BufferedReader keyboardReader = new BufferedReader
                                        (new InputStreamReader (System.in));

        String inFilePath,
               outFilePath;

        boolean pathsOK = false;

        while (!pathsOK)
        {
            try
            {
                System.out.print (IN_FILE_PROMPT);
                inFilePath = keyboardReader.readLine();
                fileReader = new BufferedReader (new FileReader (inFilePath));
                System.out.print (OUT_FILE_PROMPT);
                outFilePath = keyboardReader.readLine();
                fileWriter = new PrintWriter (new FileWriter (outFilePath));                
                pathsOK = true;
            } // try
            catch (IOException e)
            {
                System.out.println (IO_EXCEPTION_MESSAGE + e);
            } // catch I/O exception
        } // while
        return fileWriter;
    } // method openFiles


    /**
     * Creates the output file by performing the input-file commands.
     *     
     */
    public void editText()
    {
        String line = new String(),
               result = new String();

        while (true)
        {
            try
            {
                line = fileReader.readLine();
                if (line == null)
                    break;

                fileWriter.println (line);
                result = editor.interpret (line);
             } // try
             catch (RuntimeException e)
             {
                 fileWriter.println (e);
             } // catch RuntimeException
             catch (IOException e)
             {
                 System.out.println (e);
             } // catch IOException
             if (line.equals (Editor.DONE_COMMAND))
                 fileWriter.println (result);
          } // while          
    } // method editText

} // class EditorDriver