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


public class EditorDriver implements Process {

    public final static String CLOSE_WINDOW_PROMPT =
        "The editing is done.  Please close this window when you are ready.";

    public final static String IN_FILE_PROMPT =
        "In the Input line, please enter the path for the input file.";

    public final static String OUT_FILE_PROMPT =
        "In the Input line, please enter the path for the output file.";

    protected GUI gui;

    protected Editor editor;

    protected BufferedReader fileReader;

    protected PrintWriter fileWriter;

    protected boolean readingInputPath,
                      inputFileFound;


    // Postcondition: this driver has been initialized.
    public EditorDriver() {

        gui = new GUI (this);
        readingInputPath = true;
        inputFileFound = false;
        editor = new Editor( );
        gui.println (IN_FILE_PROMPT);

    } //constructor


    // Postcondition: s, representing an input file path or an output file
    //                path, has been used to set up a file reader or writer.
    //                If a file writer, then the input file has been processed.
    public void processInput (String s) {

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

        final String IO_EXCEPTION_MESSAGE =
          "There was an IO exception.";

        try {

            gui.println (s);
            if (readingInputPath) {

                if (!inputFileFound) {

                    fileReader = new BufferedReader (new FileReader (s));
                    inputFileFound = true;
                    readingInputPath = false;
                    gui.println (OUT_FILE_PROMPT);

                } // input file not yet found

            } // input-path line
            else {

                fileWriter = new PrintWriter (new FileWriter (s));
                readAndProcessInFile();
                gui.println (CLOSE_WINDOW_PROMPT);
                gui.freeze();

            } // output-path line

        } // try
        catch (FileNotFoundException e) {

            gui.println (FILE_NOT_FOUND_MESSAGE + IN_FILE_PROMPT);

        } // catch FileNotFoundException
        catch (IOException e) {

            gui.println (IO_EXCEPTION_MESSAGE + e);

        } // catch I/O exception

    } // method processInput


    // Postcondition: All of the commands in the input file have been read in
    //                and processed.
    protected void readAndProcessInFile() throws IOException {

        final String LINE_PROMPT =
            "\nPlease enter a line; a command must start with a " +
            Editor.COMMAND_START + ".";

        String result = new String();

        fileWriter.println (LINE_PROMPT);
        String line = fileReader.readLine();
        while (line != null) {

            try {

                fileWriter.println (line);
                result = editor.interpret (line);

            } // try
            catch (RuntimeException e) {

                fileWriter.println (e);

            } // catch
            if (line.equals (Editor.DONE_COMMAND))
                fileWriter.println (result);
            else
                fileWriter.println (LINE_PROMPT);
            line = fileReader.readLine();
        } // while
        fileWriter.close();

    } // method readAndProcessInFile


} // class EditorDriver


/*
public class EditorDriver implements Process {

    public final static String CLOSE_WINDOW_PROMPT =
        "The editing is done.  Please close this window when you are ready.";

    public final static String LINE_PROMPT =
            "\nPlease enter a line; a command must start with a " +
            Editor.COMMAND_START + ".";

    protected GUI gui;

    protected Editor editor;


    // Postcondition: this driver has been initialized.
    public EditorDriver() {

        gui = new GUI (this);
        editor = new Editor( );
        gui.println (LINE_PROMPT);

    } //constructor


    // Postcondition: s, representing a line of text or an input command,
    //                has been processed.
    public void processInput (String s) {

        gui.println (s);
        try {

            String result = editor.interpret (s);
            if (s.equals (Editor.DONE_COMMAND)) {

                gui.println (result + CLOSE_WINDOW_PROMPT);
                gui.freeze();

            } // if
            else
                gui.println (LINE_PROMPT);

        } // try
        catch (RuntimeException e) {

            gui.println (e + LINE_PROMPT);

        } // catch

    } // method processInput


} // class EditorDriver

*/