/*
 * 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.net.URL;
import java.util.*;

import org.osgi.framework.*;
import org.knopflerfish.service.console.*;
import org.osgi.service.log.LogService;

//  ********************     SessionCommandGroup    ********************
/**
 ** Interface for commands to be handled by the console.
 **
 ** @author  Gatespace AB
 ** @version $Revision: 1.1.1.1 $
 */


public class SessionCommandGroup implements CommandGroup {

  final static String NAME = "session";

  final static String help_alias   = "alias [<alias>] [<val>] ...  - Set or show aliases";
  final static String help_help    = "help [<command group> | all] - Help about specific command group or all command groups";
  final static String help_echo    = "echo [-n] ...                - Echo command arguments";
  final static String help_enter   = "enter <command group>        - Enter command group mode";
  final static String help_leave   = "leave                        - Leave command group mode";
  final static String help_prompt  = "prompt <command prompt>      - Set command prompt";
  final static String help_quit    = "quit                         - Exit this session";
  final static String help_save    = "save [<file>]                - Save current aliases as a property file";
  final static String help_restore = "restore [<file>]             - Restore aliases from a property file or from default aliases";
  final static String help_source  = "source <URL>                 - Source commands at URL";
  final static String help_unalias = "unalias <alias name>         - Remove an alias";

  private BundleContext bc;

  public SessionCommandGroup(BundleContext bc) {
    this.bc = bc;
  }

  /**
   * Utility method used for logging.
   *
   * @param level log level
   * @param msg log message
   * @param t throwable
   */
  void log(int level, String msg, Throwable t) {
    ServiceReference srLog =
      bc.getServiceReference("org.osgi.service.log.LogService");
    if (srLog != null) {
      LogService sLog = (LogService)bc.getService(srLog);
      if (sLog != null) {
        sLog.log(level, msg, t);
      }
      bc.ungetService(srLog);
    }
  }


  /**
   * Returns the command group name.
   *
   * @return command name.
   */
  public String getGroupName() {
    return NAME;
  }

  /**
   * Returns short command group help.
   *
   * @return short command group help.
   */
  public String getShortHelp() {
    return "Session commands built into the console";
  }

  /**
   * Returns long command group help.
   *
   * @return long command group help.
   */
  public String getLongHelp() {
    return "Available " + NAME + " commands:\n" +
      "  " + help_alias + "\n" +
      "  " + help_echo + "\n" +
      "  " + help_enter + "\n" +
      "  " + help_help + "\n" +
      "  " + help_leave + "\n" +
      "  " + help_prompt + "\n" +
      "  " + help_quit + "\n" +
      "  " + help_save + "\n" +
      "  " + help_restore + "\n" +
      "  " + help_source + "\n" +
      "  " + help_unalias + "\n";
  }

  /**
   * Executes the command.
   *
   * @param args   argument list passed to the command
   * @param out    output device to print result
   * @param in     input for command
   * @return params logical format parameters 
   */
  public int execute(String[] args, Reader in, PrintWriter out, Session session) {
    SessionImpl si = (SessionImpl) session;
    String usage = null;
    if (args.length > 0) {
      //
      // Help
      //
      if ("help".startsWith(args[0])) {
	if (args.length == 1) {
	  if ("".equals(si.currentGroup)) {
	    return help(out, si);
	  } else {
	    return helpAbout(si.currentGroup, out, si);
	  }
	} else if (args.length == 2) {
	  if (args[1].equals("all")) {
	    return help(out, si);
	  } else {
	    return helpAbout(args[1], out, si);
	  }
	}
	usage = help_help;
      //
      // Alias
      //
      } else if ("alias".startsWith(args[0])) {
	if (si == null) {
	  out.println("Alias not available from runCommand method");
	  return 1;
	}
	if (args.length == 1) {
	  for (Enumeration e = si.aliases.keys(); e.hasMoreElements();) {
	    String a = (String) e.nextElement();
	    out.println(a + " = " + si.aliases.getString(a));
	  }
	} else if (args.length == 2) {
	  String a = si.aliases.getString(args[1]);
	  if (a != null) {
	    out.println(args[1] + " = " + a);
	  } else {
	    out.println("No alias for: " + args[1]);
	  }
	} else {
	  String [] na = new String [args.length - 2];
	  System.arraycopy(args, 2, na, 0, na.length);
	  si.aliases.put(args[1], na);
	}
	return 0;
      //
      // Enter
      //
      } else if ("enter".startsWith(args[0])) {
	if (args.length == 2) {
	  try {
	    ServiceReference ref = Command.matchCommandGroup(bc, args[1]);
	    if (ref != null) {
	      si.currentGroup = (String) ref.getProperty("groupName");
	    } else {
	      si.currentGroup = NAME;
	    }
	    return 0;
	  } catch (IOException e) {
	    out.println(e.getMessage());
	    return 1;
	  }
	}
	usage = help_enter;
	return 1;
      //
      // Echo
      //
      } else if ("echo".startsWith(args[0])) {
	int pos = 1;
	boolean nl = true;
	if (args.length >= 2 && "-n".equals(args[1])) {
	  nl = false;
	  pos = 2;
	}
	while (pos < args.length) {
	  out.print(args[pos]);
	  if (++pos < args.length) {
	    out.print(" ");
	  }
	}
	if (nl) {
	  out.println();
	}
	return 0;
      //
      // Leave
      //
      } else if ("leave".startsWith(args[0])) {
	if (args.length == 1) {
	  si.currentGroup = "";
	  return 0;
	}
	usage = help_leave;
      //
      // Prompt
      //
      } else if ("prompt".startsWith(args[0])) {
	if (args.length == 2) {
	  si.prompt = args[1];
	  return 0;
	}
	usage = help_prompt;
      //
      // Quit
      //
      } else if ("quit".startsWith(args[0])) {
	if (args.length == 1) {
	  si.close();
	  return 0;
	}
	usage = help_quit;
      //
      // Save
      //
      } else if ("save".startsWith(args[0])) {
	File file = null;
	if (args.length == 1) {
	  file = bc.getDataFile(SessionImpl.ALIAS_SAVE);
	} else if(args.length == 2) {
	  file = new File(args[1]);
	}
	if(file != null) {
	  try {
	    OutputStream p = new FileOutputStream(file);
	    si.aliases.save(p);
	  } catch (IOException e) {
	    out.println("Failed to save aliases: " + e);
	    return 1;
	  }
	  return 0;
	}
	usage = help_save;
      //
      // Restore
      //
      } else if ("restore".startsWith(args[0])) {
	if (args.length == 1) {
	  si.aliases.setDefault();
	  return 0;
	} else if (args.length == 2) {
	  try {
	    InputStream r = new FileInputStream(new File(args[1]));
	    si.aliases.clear();
	    si.aliases.restore(r);
	  } catch (IOException e) {
	    out.println("Failed to restore aliases from " + args[1] + ": " + e);
	    return 1;
	  }
	  return 0;
	}
	usage = help_restore;
      //
      // Source
      //
      } else if ("source".startsWith(args[0])) {
	if (args.length == 2) {
	  InputStreamReader sin = null;
	  try {
	    URL surl = new URL(args[1]);
	    sin = new InputStreamReader(surl.openStream());
	    SessionImpl ss = new SessionImpl(bc, "source: " + args[1], sin, out, null);
	    ss.prompt = null;
	    ss.start();
	    try {
	      ss.join();
	    } catch (InterruptedException ignore) { }
	    ss.close();
	  } catch (IOException e) {
	    out.println("Failed to source URL: " + e.getMessage());
	    return 1;
	  } finally {
	    if (sin != null) {
	      try {
		sin.close();
	      } catch (IOException ignore) { }
	    }
	  }
	  return 0;
	}
	usage = help_source;
      //
      // Unalias
      //
      } else if ("unalias".startsWith(args[0])) {
	if (si == null) {
	  out.println("Unalias not available from runCommand method");
	  return 1;
	}
	if (args.length == 2) {
	  if (si.aliases.remove(args[1]) != null) {
	    return 0;
	  } else {
	    return 1;
	  }
	}
	usage = help_unalias;
      }
      
    }
    if (usage != null) {
      usage = "Usage: " + usage;
    } else {
      usage = getLongHelp();
    }
    out.println(usage);
    return -1;
  }

  /**
   * Help about available command groups.
   *
   * @param out output device to print result
   */
  int help(PrintWriter out, SessionImpl si) {
    ArrayList cg = new ArrayList();
    cg.add(this);
    ServiceReference [] refs = null;
    try {
      refs = bc.getServiceReferences(Command.COMMAND_GROUP, null);
    } catch (InvalidSyntaxException ignore) { }
    if (refs != null) {
      for (int i = 0; i < refs.length; i++) {
	CommandGroup c = (CommandGroup)bc.getService(refs[i]);
	if (c != null) {
	  String n = c.getGroupName();
	  int j;
	  for (j = 0; j < cg.size(); j++) {
	    if (n.compareTo(((CommandGroup)cg.get(j)).getGroupName()) > 0) {
	      break;
	    }
	  }
	  cg.add(j, c);
	}
      }
    }
    out.println("Available command groups (type 'enter' to enter a group):");
    for (Iterator e = cg.iterator(); e.hasNext();) {
      CommandGroup c = (CommandGroup)e.next();
      out.println(c.getGroupName() + " - " + c.getShortHelp());
    }
    if (refs != null) {
      for (int i = 0; i < refs.length; i++) {
	bc.ungetService(refs[i]);
      }
    }

    /*
    out.println("");
    out.println("Available aliases:");
    for (Enumeration e = si.aliases.keys(); e.hasMoreElements();) {
      String a = (String) e.nextElement();
      out.println(a + " = " + si.aliases.getString(a));
    }
    */
    return 0;
  }


  /**
   * Help about a command group.
   *
   * @param out output device to print result
   */
  int helpAbout(String group, PrintWriter out, SessionImpl si) {
    try {
      ServiceReference ref = Command.matchCommandGroup(bc, group);
      if (ref != null) {
	CommandGroup c = (CommandGroup)bc.getService(ref);
	if (c != null) {
	  out.print(c.getLongHelp());
	  bc.ungetService(ref);
	  return 0;
	}
      } else {
	// Null means session command group
	out.print(getLongHelp());
	return 0;
      }
    } catch (IOException e) {
      out.println(e.getMessage());
      return 1;
    }
    out.println("No such command group: " + group);
    return 1;
  }
}