source: gli/trunk/src/org/greenstone/gatherer/greenstone/LocalLibraryServer.java@ 19004

/**
 *############################################################################
 * A component of the Greenstone Librarian Interface, part of the Greenstone
 * digital library suite from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * Author: Michael Dewsnip, NZDL Project, University of Waikato, NZ
 *
 * Copyright (C) 2004 New Zealand Digital Library Project
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *############################################################################
 */

package org.greenstone.gatherer.greenstone;


import java.io.*;
import java.lang.*;
import java.net.*;
import java.util.*;
import javax.swing.*;
import org.greenstone.gatherer.Configuration;
import org.greenstone.gatherer.DebugStream;
import org.greenstone.gatherer.Dictionary;
import org.greenstone.gatherer.Gatherer;
import org.greenstone.gatherer.util.PortFinder;
import org.greenstone.gatherer.util.Utility;


public class LocalLibraryServer
{
    static final private String ADD_COMMAND = "?a=config&cmd=add-collection&c=";
    static final private String RELEASE_COMMAND = "?a=config&cmd=release-collection&c=";
    static final private String QUIT_COMMAND = "?a=config&cmd=kill";

    static private LLSSiteConfig llssite_cfg_file = null;
    static private File local_library_server_file = null;

    static private boolean running = false;
    static private String ID = "greenstone-server"; // a sort of process ID

    // Need to use sockets to tell the server program to terminate when on Linux
    // The socket port number that we will use to communicate the termination
    static private int port;

    // The server is persistent if it does not have to reload all the values
    // over and over again each time. Tomcat is persistent and fastcgi is too,
    // but the Apache webserver is not persistent by default.
    // Change the initialisation of this value depending on whether fastcgi is 
    // on. At the moment, this does not apply to the Linux' local library server.
    static private boolean isPersistentServer = Utility.isWindows();

    static public void addCollection(String collection_name)
    {
    if (isPersistentServer) {
        config(ADD_COMMAND + collection_name);
    }
    }


    // Used to send messages to the local library
    static private void config(String command)
    {
    if (!isPersistentServer) {
        return;
    }
    if (Configuration.library_url == null) {
        System.err.println("Error: Trying to configure local library with null Configuration.library_url!");
        return;
    }

    try {
        URL url = new URL(Configuration.library_url.toString() + command);
        HttpURLConnection library_connection = (HttpURLConnection) url.openConnection();

        // It's very important that we read the output of the command
        // This ensures that the command has actually finished
        // (The response code is returned immediately)
        InputStream library_is = library_connection.getInputStream();
        BufferedReader library_in = new BufferedReader(new InputStreamReader(library_is, "UTF-8"));
        String library_output_line = library_in.readLine();
        while (library_output_line != null) {
        DebugStream.println("Local library server output: " + library_output_line);
        library_output_line = library_in.readLine();
        }
        library_in.close();

        int response_code = library_connection.getResponseCode();
        if (response_code >= HttpURLConnection.HTTP_OK && response_code < HttpURLConnection.HTTP_MULT_CHOICE) {
        DebugStream.println("200 - Complete.");
        }
        else {
        DebugStream.println("404 - Failed.");
        }
    }
    catch (Exception exception) {
        DebugStream.printStackTrace(exception);
    }
    }

    // Used to send messages to the local server on Linux
    static private boolean sendMessageToServer(String message) {
    if(Utility.isWindows()) {
        return false;
    }
    
    if(port == -1) {
        return false;
    }
        
    try {
        Socket clientSocket = new Socket("localhost", port);
        Writer writer = new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream()));
        writer.write(message);
        writer.close();
        writer = null;
    } catch (Exception e) {
        System.err.println("An exception occurred when trying to send the message: " + message 
                   + "\nto the LocalLibraryServer.\n" + e);
        return false;
    } 
    return true;
    }

    static public boolean isRunning()
    {
    if (!running) return false;
    llssite_cfg_file.load(true);
    if (llssite_cfg_file.getURL() == null)  return false;
    return true;
    }


    static public void releaseCollection(String collection_name)
    {
    if (isPersistentServer) {
        config(RELEASE_COMMAND + collection_name);
    }
    }

    static public void start(String gsdl_path, String local_library_server_file_path)
    {
    // Check the local library server file (server.exe or gs2-server.sh) exists
    local_library_server_file = new File(local_library_server_file_path);
    
    if (!local_library_server_file.exists()) {
        DebugStream.println("No local library at given file path.");
    
        String defaultServerFilename = Utility.isWindows() ? "server.exe" : "gs2-server.sh";
        local_library_server_file = new File(gsdl_path + defaultServerFilename);
        if (!local_library_server_file.exists()) {
        DebugStream.println("No local library at all.");
        return;
        }
    }
    llssite_cfg_file = new LLSSiteConfig(local_library_server_file);
    
    // Spawn local library server process
    String local_library_server_command = local_library_server_file.getAbsolutePath() + getExtraLaunchArguments(llssite_cfg_file);

    // Check if the server is already running
    String url = llssite_cfg_file.getURL();
    if (url != null) {
        // If it is already running then set the Greenstone web server address and we're done
        // E.g. if previously GLI was not properly shut down, the URL property (signifying 
        // the server is still running) would still be in the glisite_cfg file.
        try {
        Configuration.library_url = new URL(url);
        running = true;

        // Run the server interface
        Gatherer.spawnApplication(local_library_server_command, ID);
        return;
        }
        catch (MalformedURLException exception) {
        DebugStream.printStackTrace(exception);
        }
    }   

    // Configure the server for immediate entry
    //llssite_cfg_file.set();

    // Spawn local library server process
    Gatherer.spawnApplication(local_library_server_command, ID);
    
    // Wait until program has started
    try {
        testServerRunning(); // will set running = true when the server is up and running successfully
    } catch (IOException bad_url_connection) {
        try {
        // If this fails then we try changing the url to be localhost
        Configuration.library_url = new URL(llssite_cfg_file.getLocalHostURL());
        DebugStream.println("Try connecting to server on local host: '" + Configuration.library_url + "'");
        URLConnection connection = Configuration.library_url.openConnection();
        connection.getContent();
        running = true;
        
        } catch (IOException worse_url_connection) {
        DebugStream.println("Can't connect to server on either address.");
        Configuration.library_url = null;
        running = false;
        }
    }
    }


    static public void stop()
    {
    if (running == false) {
        return;
    }

    // Send the command for it to exit.
    if (isPersistentServer) {
        config(QUIT_COMMAND);
    } else {
        if(sendMessageToServer("QUIT")) {
        Gatherer.terminateApplication(ID);
        } else {
        System.err.println("Unable to stop the server, since there's no communication port to send the quit msg over."
                   + "\nPlease stop the local Greenstone server manually.");        
        }
    }

    // Wait until program has stopped, by reloading and checking the URL field
    llssite_cfg_file.load(false);
    int attempt_count = 0;
    while (llssite_cfg_file.getURL() != null) {
        new OneSecondWait();  // Wait one second (give or take)
        llssite_cfg_file.load(false);
        attempt_count++;

        // After waiting a minute ask the user whether they want to wait another minute
        if (attempt_count == 60) {
        int try_again = JOptionPane.showConfirmDialog(Gatherer.g_man, Dictionary.get("Server.QuitTimeOut"), Dictionary.get("General.Warning"), JOptionPane.YES_NO_OPTION);
        if (try_again == JOptionPane.NO_OPTION) {
            return;
        }
        attempt_count = 0;
        }
    }

    // Restore the llssite_cfg.
    llssite_cfg_file.restore();

    // If the local server is still running then our changed values will get overwritten.
    if (llssite_cfg_file.getURL() != null) {
        JOptionPane.showMessageDialog(Gatherer.g_man, Dictionary.get("Server.QuitManual"), Dictionary.get("General.Error"), JOptionPane.ERROR_MESSAGE);
    }

    running = false;
    }
    
    static private String getExtraLaunchArguments(LLSSiteConfig site_cfg_file) {
    String args = " " + site_cfg_file.getSiteConfigFilename();

    if(Utility.isWindows()) {
        return args;
    }
    
    // Else, when running the Local Library Server on Linux, need to provide a port argument
    try {
        PortFinder portFinder = new PortFinder(50100, 100);
        port = portFinder.findPortInRange();
    } catch(Exception e) {
        System.err.println("Exception when trying to find an available port: " + e);
        port = -1;
    }
    
    return args + " --quitport=" + port;
    }


    // This method first tests whether there is a URL in the llssite_cfg_file 
    // and after that appears, it tests whether the URL is functional.
    static private void testServerRunning() throws IOException {
    // Wait until program has started, by reloading and checking the URL field
    llssite_cfg_file.load(false);
    int attempt_count = 0;
    while (llssite_cfg_file.getURL() == null) {
        new OneSecondWait();  // Wait one second (give or take)
        llssite_cfg_file.load(false);
        attempt_count++;

        // After waiting a minute ask the user whether they want to wait another minute
        if (attempt_count == 60) {
        int try_again = JOptionPane.showConfirmDialog(Gatherer.g_man, Dictionary.get("Server.QuitTimeOut"), Dictionary.get("General.Warning"), JOptionPane.YES_NO_OPTION);
        if (try_again == JOptionPane.NO_OPTION) {
            return;
        }
        attempt_count = 0;
        }
    }
    
    // Ta-da. Now the url should be available
    try {
        Configuration.library_url = new URL(llssite_cfg_file.getURL());
    }
    catch (MalformedURLException exception) {
        DebugStream.printStackTrace(exception);
    }

    // A quick test involves opening a connection to get the home page for this collection
    try {
        DebugStream.println("Try connecting to server on config url: '" + Configuration.library_url + "'");
        URLConnection connection = Configuration.library_url.openConnection();
        connection.getContent();
        running = true;
    }
    catch (IOException bad_url_connection) {
        throw bad_url_connection;
    }

    
    }

    static public void checkServerRunning() {
    if (!running) return; // don't worry about it if its not supposed to be running 
    llssite_cfg_file.load(true); // don't force reload, load only if modified

    String url = llssite_cfg_file.getURL();
    if(url != null) {
        try {
        Configuration.library_url = new URL(url);
        }
        catch (MalformedURLException exception) {
        DebugStream.printStackTrace(exception);
        }
    } else {
        // need to restart the server again
        llssite_cfg_file.set();

        // Spawn local library server process
        String local_library_server_command = local_library_server_file.getAbsolutePath() + getExtraLaunchArguments(llssite_cfg_file);
        running = false;
        Gatherer.spawnApplication(local_library_server_command, ID);
        try {
        testServerRunning(); // don't return until the webserver is up and running
        } catch (IOException bad_url_connection) {
        DebugStream.println("Can't connect to server on address " + Configuration.library_url);
        running = false;
        }
    }
    }

    static private class OneSecondWait
    {
    public OneSecondWait()
    {
        synchronized(this) {
        try {
            wait(1000);
        }
        catch (InterruptedException exception) {
        }
        }
    }
    }


    static public class LLSSiteConfig
    extends LinkedHashMap {
    private File llssite_cfg;
    private File glisite_cfg;
    private String autoenter_initial;
    private String start_browser_initial;

    private long lastModified = 0;
    
    static final private String AUTOENTER = "autoenter";
    static final private String COLON = ":";
    static final private String ENTERLIB = "enterlib";
    static final private String FALSE = "0";
    static final private String GLISITE_CFG = "glisite.cfg";
    static final private String GSDL = "greenstone"; // httpprefix is no longer /gsdl but /greenstone
    static final private String LLSSITE_CFG = "llssite.cfg";
    static final private String LOCAL_HOST = "http://localhost"; 
    static final private String PORTNUMBER = "portnumber";
    static final private String SEPARATOR = "/";
    static final private String SPECIFIC_CONFIG = "--config=";
    static final private String STARTBROWSER = "start_browser";
    static final private String TRUE = "1";
    static final private String URL = "url";

    public LLSSiteConfig(File server_exe) {
        debug("New LLSSiteConfig for: " + server_exe.getAbsolutePath());
        
        llssite_cfg = new File(server_exe.getParentFile(), LLSSITE_CFG);
        glisite_cfg = new File(server_exe.getParentFile(), GLISITE_CFG);

        File configFile = null;
        if(glisite_cfg.exists()) {
        configFile = glisite_cfg;
        } else if(llssite_cfg.exists()) {
        configFile = llssite_cfg;
        } else {
        debug("Neither the file glisite.cfg nor llssite.cfg can be found!");
        }
        
        autoenter_initial = null;
        start_browser_initial = null;
        if(configFile != null) {
        debug("Load: " + configFile.getAbsolutePath());
        clear();
        try {
            BufferedReader in = new BufferedReader(new FileReader(configFile));
            String line = null;
            while((line = in.readLine()) != null) {
            String key = null;
            String value = null;
            int index = -1;
            if((index = line.indexOf("=")) != -1 && line.length() >= index + 1) {
                key = line.substring(0, index);
                value = line.substring(index + 1);
            }
            else {
                key = line;
            }
            put(key, value);
            }
            in.close();
        }
        catch (Exception error) {
            error.printStackTrace();
        }
        }

        if(glisite_cfg.exists()) {
        lastModified = glisite_cfg.lastModified();
        }
    }
    
    public boolean exists() {
        return llssite_cfg.exists();
    }

    public String getLocalHostURL() {
        StringBuffer url = new StringBuffer(LOCAL_HOST);
        url.append(COLON);
        url.append((String)get(PORTNUMBER));
        String enterlib = (String)get(ENTERLIB);
        if(enterlib == null || enterlib.length() == 0) {
        // Use the default /gsdl and hope for the best.
        url.append(SEPARATOR);
        url.append(GSDL);
        }
        else {
        if(!enterlib.startsWith(SEPARATOR)) {
            url.append(SEPARATOR);
        }
        url.append(enterlib);
        }
        enterlib = null;
        debug("Found Local Library Address: " + url.toString());
        return url.toString();
    }

    public String getSiteConfigFilename() {
        return SPECIFIC_CONFIG + glisite_cfg.getAbsolutePath();
    }

    public String getURL() {
        // URL is made from url and portnumber
        String url = (String) get(URL);

        if(!Utility.isWindows()) {
        return url;
        }

        if(url != null) {
        StringBuffer temp = new StringBuffer(url);
        temp.append(COLON);
        temp.append((String)get(PORTNUMBER));
        String enterlib = (String)get(ENTERLIB);
        if(enterlib == null || enterlib.length() == 0) {
            // Use the default /gsdl and hope for the best.
            temp.append(SEPARATOR);
            temp.append(GSDL);
        }
        else {
            if(!enterlib.startsWith(SEPARATOR)) {
            temp.append(SEPARATOR);
            }
            temp.append(enterlib);
        }
        enterlib = null;
        url = temp.toString();
        }
        debug("Found Local Library Address: " + url);
        return url;
    }

    public boolean isModified() {
        return (lastModified != glisite_cfg.lastModified());
    }

    public void load(boolean reloadOnlyIfModified) {        

        if(isModified()) {
        lastModified = glisite_cfg.lastModified();
        } else if(reloadOnlyIfModified) {
        return; // asked to reload only if modified. Don't reload since not modified
        }

        if(glisite_cfg.exists()) {
        debug("Load: " + glisite_cfg.getAbsolutePath());
        clear();
        try {
            BufferedReader in = new BufferedReader(new FileReader(glisite_cfg));
            String line = null;
            while((line = in.readLine()) != null) {
            String key = null;
            String value = null;
            int index = -1;
            if((index = line.indexOf("=")) != -1 && line.length() >= index + 1) {
                key = line.substring(0, index);
                value = line.substring(index + 1);
            }
            else {
                key = line;
            }
            put(key, value);
            }
            in.close();
        }
        catch (Exception error) {
            error.printStackTrace();
        }
        }
        else {
        debug("No glisite.cfg file can be found!");
        }
    }

    /** Restore the autoenter value to its initial value, and remove url if present. */
    public void restore() {
        if(glisite_cfg != null) {
        // Delete the file
        glisite_cfg.delete();
        }
        else {
        debug("Restore Initial Settings");
        put(AUTOENTER, autoenter_initial);
        put(STARTBROWSER, start_browser_initial);
        remove(URL);
        save();
        }
    }

    public void set() {
        debug("Set Session Settings");
        if(autoenter_initial == null) {
        autoenter_initial = (String) get(AUTOENTER);
        debug("Remember autoenter was: " + autoenter_initial);
        }
        put(AUTOENTER, TRUE);
        if(start_browser_initial == null) {
        start_browser_initial = (String) get(STARTBROWSER);
        debug("Remember start_browser was: " + start_browser_initial);
        }
        put(STARTBROWSER, FALSE);
        save();
    }

    private void debug(String message) {
        ///ystem.err.println(message);
    }

    private void save() {
        //debug("Save: " + llssite_cfg.getAbsolutePath());
        debug("Save: " + glisite_cfg.getAbsolutePath());
        try {
        //BufferedWriter out = new BufferedWriter(new FileWriter(llssite_cfg, false));
        BufferedWriter out = new BufferedWriter(new FileWriter(glisite_cfg, false));
        for(Iterator keys = keySet().iterator(); keys.hasNext(); ) {
            String key = (String) keys.next();
            String value = (String) get(key);
            out.write(key, 0, key.length());
            if(value != null) {
            out.write('=');
            out.write(value, 0, value.length());
            }
            out.newLine();
        }
        out.flush();
        out.close();
        }
        catch (Exception error) {
        error.printStackTrace();
        }
    }
    }
}