/*
 * FileArgumentScheme.java 
 *
 * Copyright (C) 2003 Miika Nurminen
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */
import java.io.*;

/**
 * Searches arguments -i and -o for input/output filenames. If filename
 * is not found, standard i/o stream is used instead.
 *
 * To do: correct path handling with absolute names
 *
 * @author  Miika Nurminen
 */
public class FileArgumentScheme {
  InputStream in = System.in;
  PrintStream out = System.out;
  String[] args;
  String[] helpStrings = new String[]{"-h","-?"};
  
  public boolean helpWanted() {
     int i = StringLib.arrayIndexOf(args,helpStrings,true);
     return (i!=-1);
  }
  
  /**
   * If no dir is given, userdir is used. File separator is appended to end
   * of string.
   */
  public String determineDir(String argname) {
    String ret = determineFilename(argname);
    if (ret==null) ret = System.getProperty("user.dir");
    ret = StringLib.catOnce(ret,File.separator);
    return ret;
  }
  
  public String determineFilename(String argname) {
    int i =  StringLib.arrayIndexOf(args,argname,true);
    if ((i==-1) || (i==args.length-1)) return null;
    return args[i+1];
  }
  
  /** Creates a new instance of FileArgumentScheme */
  public FileArgumentScheme(String[] args) {
    this.args=args;
  }
  
  public File getAbsoluteFile(String s) throws FileNotFoundException, IOException {
    File f = new File(s);
//    System.out.println(f.getAbsolutePath());
//    System.out.println(f.getCanonicalPath());
//    if (!f.isAbsolute()) f = new File(System.getProperty("user.dir")+java.io.File.separator+s);
    return f.getCanonicalFile();
  }
  
  public void openStreams() throws FileNotFoundException, IOException {
    String s;
    s = determineFilename("-i");
    if (s!=null) in = new FileInputStream(getAbsoluteFile(s));
    s = determineFilename("-o");    
    if (s!=null) out = new PrintStream(new FileOutputStream(getAbsoluteFile(s)));
  }
  
  public InputStream getInput() {
    return in;
  }
  
  public PrintStream getOutput() {
    return out;
  }
}