/*
 * Copyright (c) 2003, KNOPFLERFISH project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 * - Neither the name of the KNOPFLERFISH project nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.knopflerfish.bundle.console;

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

import org.osgi.framework.*;
import org.knopflerfish.service.console.*;
import org.osgi.service.log.LogService;
/**
 * Class for command parseing and execution.
 *
 * @author  Jan Stein
 * @version $Revision: 1.1.1.1 $
 */
public class Command implements ServiceListener, Runnable {

  final static String COMMAND_GROUP = 
    org.knopflerfish.service.console.CommandGroup.class.getName();

  static SessionCommandGroup sessionCommandGroup;

  final BundleContext bc;
  String [] args;
  Reader in;
  Writer out;
  Alias aliases;
  String groupName;
  Session session;
  ServiceReference commandGroupRef;
  Thread thread = null;
  int status = -1;
  public boolean isPiped = false;
  public boolean isBackground = false;

  public Command(BundleContext bc, String group, Alias aliases, final StreamTokenizer cmd, Reader in, PrintWriter out, Session session) throws IOException {
    this.bc = bc;
    this.in = in;
    this.out = out;
    this.aliases = aliases;
    this.session = session;
    if (sessionCommandGroup == null) {
      sessionCommandGroup = new SessionCommandGroup(bc);
    }
    groupName = group;
    try {
      AccessController.doPrivileged(new PrivilegedExceptionAction() {
	  public Object run() throws IOException {
	    parseCommand(cmd);
	    return null;
	  }
	});
    } catch (PrivilegedActionException e) {
      throw (IOException)e.getException();
    }
  }

  void parseCommand(StreamTokenizer in) throws IOException {
    if (in.nextToken() != StreamTokenizer.TT_WORD) {
      throw new IOException("Unexpected token: " + in.ttype);
    }
    String word;
    String [] aliasBuf = null;
    int aliasPos;
    if (aliases != null && (aliasBuf = (String []) aliases.get(in.sval)) != null) {
      word = aliasBuf[0];
      aliasPos = 1;
    } else {
      word = in.sval;
      aliasPos = 0;
    }
    if ("".equals(groupName) || word.startsWith("/")) {
      if (word.startsWith("/"))
	word = word.substring(1);
      commandGroupRef = matchCommandGroup(bc, word);
      word = null;
    } else {
      if (SessionCommandGroup.NAME.equals(groupName)) {
	commandGroupRef = null;
      } else {
	ServiceReference [] refs = null;
	try {
	  refs = bc.getServiceReferences(COMMAND_GROUP, "(groupName=" + groupName + ")");
	} catch (InvalidSyntaxException ignore) { }
	if (refs == null) {
	  throw new IOException("No such command group: " + groupName);
	}
	commandGroupRef = refs[0];
      }
    }
    ArrayList vargs = new ArrayList();
    boolean done = false;
    while (!done) {
      if (word != null) {
	vargs.add(word);
	word = null;
      } else if (aliasPos > 0) {
	if (aliasPos < aliasBuf.length) {
	  word = aliasBuf[aliasPos++];
	} else {
	  aliasPos = 0;
	}
      } else {
	switch (in.nextToken()) {
	case '|':
	  out = new Pipe();
	  isPiped = true;
	  done = true;
	  break;
	case '&':
	  isBackground = true;
	case ';':
	  done = true;
	  break;
	case '<':
	  if (in.nextToken() != StreamTokenizer.TT_WORD) {
	    throw new IOException("Empty input redirect");
	  }
	  // Set input to file
	  break;
	case '>':
	  if (in.nextToken() != StreamTokenizer.TT_WORD) {
	    throw new IOException("Empty output redirect");
	  }
	  // Set output to file
	  break;
	case StreamTokenizer.TT_EOL:
	case StreamTokenizer.TT_EOF:
	  in.pushBack();
	  done = true;
	  break;
	case '"':
	case '\'':
	case StreamTokenizer.TT_WORD:
	  word = in.sval;
	  break;
	default:
	  throw new IOException("Unknown token: " + in.ttype);
	}
      }
    }
    args = (String []) vargs.toArray(new String [vargs.size()]);
  }

  public void runThreaded() {
    String gname = commandGroupRef != null ?
      (String)commandGroupRef.getProperty("groupName") :
      SessionCommandGroup.NAME;
    
    thread = new Thread(this, "Console cmd: " + gname + (args.length == 0 ? "" : "/" + args[0]));

    thread.start();

  }

  public synchronized void run() {
    bc.addServiceListener(this);
    AccessController.doPrivileged(new PrivilegedAction() {
	public Object run() {
	  CommandGroup cg;
	  if (commandGroupRef != null) {
	    cg = (CommandGroup) bc.getService(commandGroupRef);
	    if (cg == null) {
	      status = -2;
	      return null;
	    }
	  } else {
	    cg = sessionCommandGroup;
	  }
	  if (out instanceof PrintWriter) {
	    status = cg.execute(args, in, (PrintWriter)out, session);
	  } else {
	    status = cg.execute(args, in, new PrintWriter(out), session);
	  }
	  if (commandGroupRef != null) {
	    bc.ungetService(commandGroupRef);
	  }
	  if (out instanceof Pipe) {
	    try {
	      out.close();
	    } catch (IOException ignore) { }
	  }
	  return null;
	}
      });
    bc.removeServiceListener(this);
  }

  public void serviceChanged(ServiceEvent e) {
    if (e.getServiceReference() == commandGroupRef) {
      synchronized (this) {
	// Wait for run command
      }
    }
  }


  static ServiceReference matchCommandGroup(BundleContext bc, String word) 
    throws IOException
  {
    ServiceReference res = null;
    ServiceReference [] refs = null;
    try {
      refs = bc.getServiceReferences(COMMAND_GROUP, "(groupName=" + word + "*)");
    } catch (InvalidSyntaxException ignore) { }
    if (refs != null) {
      if (refs.length == 1) {
	res = refs[0];
      } else if (refs.length > 1) {
	for (int i = 0; i < refs.length; i++) {
	  if (word.equals(refs[i].getProperty("groupName"))) {
	    res = refs[i];
	    break;
	  }
	}
      }
    }
    if (SessionCommandGroup.NAME.startsWith(word)) {
      if (refs == null || SessionCommandGroup.NAME.equals(word)) {
	return null;
      }
    } else if (res != null) {
      return res;
    } else if (refs == null) {
      throw new IOException("No such command group: " + word);
    }
    throw new IOException("Several command groups starting with: " + word);
  }

}