/*
 * 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.device;

import org.osgi.framework.*;
import org.osgi.service.device.*;

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

public class MatchImpl implements Match {
  static final int UNKNOWN = -1;

  private Activator act;
  private ServiceReference dev;
  private String id;
  private DriverRef ref;
  private int match;
  private Vector /*DriverLocator*/ dls;
  private Bundle b;

  MatchImpl(Activator act, ServiceReference dev, String id) {
    this.act=act;
    this.dev=dev;
    this.id=id;
    match=act.getCachedMatch(id,dev);
  }

  MatchImpl(Activator act, ServiceReference dev, DriverRef dr) {
    this.act=act;
    this.dev=dev;
    id=dr.id;
    ref=dr;
    match=act.getCachedMatch(id,dev);
  }

  boolean equals(String id) {
    return this.id.equals(id);
  }

  boolean connect(DriverRef dr) {
    if(id.equals(dr.id) && (ref==dr || ref==null)) {
      ref=dr;
      return true;
    }
    return false;
  }

  int compare(MatchImpl m) {
    int cmp=getMatchValue()-m.getMatchValue();
    if(cmp==0) cmp=ref.ranking-m.ref.ranking;
    if(cmp==0) cmp=ref.servid<m.ref.servid ? 1 : -1;
    return cmp;
  }

  void addDriverLocator(DriverLocator dl) {
    if(dls==null) dls=new Vector();
    dls.addElement(dl);
  }

  Bundle getBundle() {
    return b;
  }

  private boolean load() {
    String name=Activator.DYNAMIC_DRIVER_TAG+id;
    Bundle[] ba=act.bc.getBundles();
    if(ba!=null) {
      for(int i=0;i<ba.length;i++) {
	if(name.equals(ba[i].getLocation())) {
	  return false;
	}
      }
    }
    if(dls!=null) {
      for(int i=0;i<dls.size();i++) {
	if(load1(name,(DriverLocator)dls.elementAt(i))) return true;
      }
    } else {
      DriverLocator[] locs=act.locators;
      for(int i=0;i<locs.length;i++) {
	if(load1(name,locs[i])) return true;
      }
    }
    return false;
  }

  private boolean load1(String name, DriverLocator dl) {
    InputStream is=null;
    try {
      is=dl.loadDriver(id);
      b=act.installBundle(name,is);
      if(b!=null) return true;
    } catch(Exception e) {
    } finally {
      try { is.close(); } catch(Exception e1) {}
    }
    return false;
  }

  String attach() throws Exception {
    if(match>Device.MATCH_NONE && ref==null && b==null && load()) {
      return null;
    } else {
      match=Device.MATCH_NONE;
      return ref.drv.attach(dev);
    }
  }

  public ServiceReference getDriver() {
    return ref.sr;
  }

  public int getMatchValue() {
    if(match==UNKNOWN) {
      if(ref!=null || b!=null) {
	try {
	  match=ref.drv.match(dev);
	  act.putCachedMatch(id,dev,match);
	} catch(Exception e) {
	  match=Device.MATCH_NONE;
	}
      } else if( !load() ) {
	match=Device.MATCH_NONE;
      }
    }
    return match;
  }
}