/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.felix.dependencymanager.shell;

import java.io.PrintStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.StringTokenizer;

import org.apache.felix.dependencymanager.ServiceComponent;
import org.apache.felix.dependencymanager.ServiceComponentDependency;
import org.apache.felix.shell.Command;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceReference;

/**
 * Shell command for showing all services and dependencies that are managed
 * by the dependency manager.
 * 
 * @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
 */
public class DMCommand implements Command {
    private static final BundleIdSorter SORTER = new BundleIdSorter();
    private final BundleContext m_context;

    public DMCommand(BundleContext context) {
        m_context = context;
    }

    public void execute(String line, PrintStream out, PrintStream err) {
        boolean nodeps = false;
        boolean notavail = false;
        boolean compact = false;
        ArrayList ids = new ArrayList();

        // parse the command line
        StringTokenizer st = new StringTokenizer(line);
        if (st.hasMoreTokens()) {
            st.nextToken();
            while (st.hasMoreTokens()) {
                String token = st.nextToken();
                if ("nodeps".equals(token)) {
                    nodeps = true;
                }
                else if ("notavail".equals(token)) {
                    notavail = true;
                }
                else if ("compact".equals(token)) {
                    compact = true;
                }
                else {
                    try {
                        ids.add(Long.valueOf(token));
                    }
                    catch (NumberFormatException e) {
                        // if it's not a number, we abort with an error
                        err.println("Argument " + token + " is not a valid number.");
                        return;
                    }
                }
            }
            // lookup all dependency manager service components
            try {
                ServiceReference[] references = m_context.getServiceReferences(ServiceComponent.class.getName(), null);
                // show their state
                if (references != null) {
                    Arrays.sort(references, SORTER);
                    long lastBundleId = -1;
                    for (int i = 0; i < references.length; i++) {
                        ServiceReference ref = references[i];
                        ServiceComponent sc = (ServiceComponent) m_context.getService(ref);
                        if (sc != null) {
                            String name = sc.getName();
                            int state = sc.getState();
                            Bundle bundle = ref.getBundle();
                            long bundleId = bundle.getBundleId();
                            if (ids.size() == 0 || ids.contains(Long.valueOf(bundleId))) {
                                if (!notavail || (notavail && sc.getState() == ServiceComponent.STATE_UNREGISTERED)) {
                                    if (lastBundleId != bundleId) {
                                        lastBundleId = bundleId;
                                        if (compact) {
                                            out.println("[" + bundleId + "] " + compactName(bundle.getSymbolicName()));
                                        }
                                        else {
                                            out.println("[" + bundleId + "] " + bundle.getSymbolicName());
                                        }
                                    }
                                    if (compact) {
                                        out.print(" " + compactName(name) + " " + compactState(ServiceComponent.STATE_NAMES[state]));
                                    }
                                    else {
                                        out.println("  " + name + " " + ServiceComponent.STATE_NAMES[state]);
                                    }
                                    if (!nodeps) {
                                        ServiceComponentDependency[] dependencies = sc.getComponentDependencies();
                                        if (dependencies != null && dependencies.length > 0) {
                                            if (compact) {
                                                out.print('(');
                                            }
                                            for (int j = 0; j < dependencies.length; j++) {
                                                ServiceComponentDependency dep = dependencies[j];
                                                String depName = dep.getName();
                                                String depType = dep.getType();
                                                int depState = dep.getState();
                                                if (compact) {
                                                    if (j > 0) {
                                                        out.print(' ');
                                                    }
                                                    out.print(compactName(depName) + " " + compactState(depType) + " " + compactState(ServiceComponentDependency.STATE_NAMES[depState]));
                                                }
                                                else {
                                                    out.println("    " + depName + " " + depType + " " + ServiceComponentDependency.STATE_NAMES[depState]);
                                                }
                                            }
                                            if (compact) {
                                                out.print(')');
                                            }
                                        }
                                    }
                                    if (compact) {
                                        out.println();
                                    }
                                }
                            }
                            m_context.ungetService(ref);
                        }
                    }
                }
            }
            catch (InvalidSyntaxException e) {
                // very weird since I'm not specifying a filter
                e.printStackTrace(err);
            }
        }
        else {
            err.println("Invalid command line: " + line);
        }
    }
    
    /**
     * Compact names that look like state strings. State strings consist of
     * one or more words. Each word will be shortened to the first letter,
     * all letters concatenated and uppercased.
     */
    private String compactState(String input) {
        StringBuffer output = new StringBuffer();
        StringTokenizer st = new StringTokenizer(input);
        while (st.hasMoreTokens()) {
            output.append(st.nextToken().toUpperCase().charAt(0));
        }
        return output.toString();
    }
    
    /**
     * Compacts names that look like fully qualified class names. All packages
     * will be shortened to the first letter, except for the last one. So
     * something like "org.apache.felix.MyClass" will become "o.a.f.MyClass".
     */
    private String compactName(String input) {
        StringBuffer output = new StringBuffer();
        int lastIndex = 0;
        for (int i = 0; i < input.length(); i++) {
            char c = input.charAt(i);
            switch (c) {
                case '.':
                    output.append(input.charAt(lastIndex));
                    output.append('.');
                    lastIndex = i + 1;
                    break;
                case ' ':
                case ',':
                    if (lastIndex < i) {
                        output.append(input.substring(lastIndex, i));
                    }
                    output.append(c);
                    lastIndex = i + 1;
                    break;
            }
        }
        if (lastIndex < input.length()) {
            output.append(input.substring(lastIndex));
        }
        return output.toString();
    }

    public String getName() {
        return "dm";
    }

    public String getShortDescription() {
        return "list dependency manager component diagnostics.";
    }

    public String getUsage() {
        return "dm [nodeps] [notavail] [compact] [<bundleid> ...]";
    }
}

final class BundleIdSorter implements Comparator {
    public int compare(Object o1, Object o2) {
        ServiceReference r1 = (ServiceReference) o1;
        ServiceReference r2 = (ServiceReference) o2;
        long id1 = r1.getBundle().getBundleId();
        long id2 = r2.getBundle().getBundleId();
        return id1 > id2 ? 1 : -1;
    }
}