//
//  ========================================================================
//  Copyright (c) 1995-2019 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//

package org.eclipse.jetty.maven.plugin;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import java.util.Properties;
import java.util.Set;

import org.apache.maven.artifact.Artifact;
import org.apache.maven.plugin.AbstractMojo;
import org.apache.maven.plugin.MojoExecution;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.MojoFailureException;
import org.apache.maven.plugins.annotations.Parameter;
import org.apache.maven.project.MavenProject;
import org.codehaus.plexus.util.StringUtils;
import org.eclipse.jetty.security.LoginService;
import org.eclipse.jetty.server.RequestLog;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.ShutdownMonitor;
import org.eclipse.jetty.server.handler.ContextHandler;
import org.eclipse.jetty.server.handler.ContextHandlerCollection;
import org.eclipse.jetty.server.handler.HandlerCollection;
import org.eclipse.jetty.util.PathWatcher;
import org.eclipse.jetty.util.StringUtil;
import org.eclipse.jetty.util.resource.Resource;
import org.eclipse.jetty.xml.XmlConfiguration;

/**
 * Common base class for most jetty mojos.
 */
public abstract class AbstractJettyMojo extends AbstractMojo
{
    /**
     * Whether or not to include dependencies on the plugin's classpath with &lt;scope&gt;provided&lt;/scope&gt;
     * Use WITH CAUTION as you may wind up with duplicate jars/classes.
     * 
     * @since jetty-7.5.2
     */
    @Parameter(defaultValue = "false")
    protected boolean useProvidedScope;
    
    /**
     * List of goals that are NOT to be used
     * 
     * @since jetty-7.5.2
     */
    @Parameter
    protected String[] excludedGoals;
    
    /**
     * List of other contexts to set up. Consider using instead
     * the &lt;jettyXml&gt; element to specify external jetty xml config file. 
     * Optional.
     * 
     */
    @Parameter
    protected ContextHandler[] contextHandlers;
    
    /**
     * List of security realms to set up. Consider using instead
     * the &lt;jettyXml&gt; element to specify external jetty xml config file. 
     * Optional.
     * 
     */
    @Parameter
    protected LoginService[] loginServices;

    /**
     * A RequestLog implementation to use for the webapp at runtime.
     * Consider using instead the &lt;jettyXml&gt; element to specify external jetty xml config file. 
     * Optional.
     * 
     */
    @Parameter
    protected RequestLog requestLog;
    
    /**
     * An instance of org.eclipse.jetty.webapp.WebAppContext that represents the webapp.
     * Use any of its setters to configure the webapp. This is the preferred and most
     * flexible method of configuration, rather than using the (deprecated) individual
     * parameters like "tmpDirectory", "contextPath" etc.
     * 
     */
    @Parameter(alias = "webAppConfig")
    protected JettyWebAppContext webApp;

    /**
     * The interval in seconds to scan the webapp for changes 
     * and restart the context if necessary. Ignored if reload
     * is enabled. Disabled by default.
     * 
     */
    @Parameter(property = "jetty.scanIntervalSeconds", defaultValue = "0", required = true)
    protected int scanIntervalSeconds;
    
    /**
     * reload can be set to either 'automatic' or 'manual'
     *
     * if 'manual' then the context can be reloaded by a linefeed in the console
     * if 'automatic' then traditional reloading on changed files is enabled.
     *
     */
    @Parameter(property = "jetty.reload", defaultValue = "automatic")
    protected String reload;

    
    /**
     * File containing system properties to be set before execution
     * 
     * Note that these properties will NOT override System properties
     * that have been set on the command line, by the JVM, or directly 
     * in the POM via systemProperties. Optional.
     * 
     */
    @Parameter(property = "jetty.systemPropertiesFile")
    protected File systemPropertiesFile;

    
    /**
     * System properties to set before execution. 
     * Note that these properties will NOT override System properties 
     * that have been set on the command line or by the JVM. They WILL 
     * override System properties that have been set via systemPropertiesFile.
     * Optional.
     */
    @Parameter
    protected SystemProperties systemProperties;
    
    
    /**
     * Comma separated list of a jetty xml configuration files whose contents 
     * will be applied before any plugin configuration. Optional.
     *
     */
    @Parameter(alias="jettyConfig")
    protected String jettyXml;
    
    
    /**
     * Port to listen to stop jetty on executing -DSTOP.PORT=&lt;stopPort&gt; 
     * -DSTOP.KEY=&lt;stopKey&gt; -jar start.jar --stop
     *
     */
    @Parameter
    protected int stopPort;
    
    
    /**
     * Key to provide when stopping jetty on executing java -DSTOP.KEY=&lt;stopKey&gt; 
     * -DSTOP.PORT=&lt;stopPort&gt; -jar start.jar --stop
     *
     */
    @Parameter
    protected String stopKey;

    /**
     * Use the dump() facility of jetty to print out the server configuration to logging
     *
     */
    @Parameter( property="dumponStart", defaultValue="false")
    protected boolean dumpOnStart;
    
    
    /**  
     * Skip this mojo execution.
     */
    @Parameter(property="jetty.skip", defaultValue="false")
    protected boolean skip;

    
    /**
     * Location of a context xml configuration file whose contents
     * will be applied to the webapp AFTER anything in &lt;webApp&gt;.Optional.
     *
     */
    @Parameter(alias="webAppXml")
    protected String contextXml;


    /**
     * The maven project.
     *
     */
    @Parameter(defaultValue="${project}", readonly = true)
    protected MavenProject project;

    
    /**
     * The artifacts for the project.
     *
     */
    @Parameter(defaultValue="${project.artifacts}", readonly = true)
    protected Set<Artifact> projectArtifacts;
    
    
    @Parameter(defaultValue="${mojoExecution}", readonly = true)
    protected MojoExecution execution;

    /**
     * The artifacts for the plugin itself.
     *
     */
    @Parameter(defaultValue="${plugin.artifacts}", readonly = true)
    protected List<Artifact> pluginArtifacts;

    /**
     * A ServerConnector to use.
     *
     */
    @Parameter
    protected MavenServerConnector httpConnector;
    
    
    /**
     * A wrapper for the Server object
     */
    @Parameter
    protected Server server;
    
    
    /**
     * A scanner to check for changes to the webapp
     */
    protected PathWatcher scanner;
    

    /**
     * A scanner to check ENTER hits on the console
     */
    protected Thread consoleScanner;
    
    protected ServerSupport serverSupport;

    /**
     * <p>
     * Determines whether or not the server blocks when started. The default
     * behavior (false) will cause the server to pause other processes
     * while it continues to handle web requests. This is useful when starting the
     * server with the intent to work with it interactively. This is the 
     * behaviour of the jetty:run, jetty:run-war, jetty:run-war-exploded goals. 
     * </p><p>
     * If true, the server will not block the execution of subsequent code. This
     * is the behaviour of the jetty:start and default behaviour of the jetty:deploy goals.
     * </p>
     */
    @Parameter(defaultValue = "false")
    protected boolean nonBlocking = false;

    /**
     * Per default this goal support only <code>war</code> packaging.
     * If your project use an other type please configure it here.
     *
     */
    @Parameter
    protected List<String> supportedPackagings = Collections.singletonList( "war");
      
    
    public abstract void restartWebApp(boolean reconfigureScanner) throws Exception;

    
    public boolean checkPomConfiguration() throws MojoExecutionException
    {
        return true;
    }

    public abstract void configureScanner () throws MojoExecutionException;

    protected String getSkipMessage(String reason)
    {
        String projectName = project.getName();
        if (StringUtils.isBlank(projectName))
        {
            projectName = project.getGroupId() + ":" + project.getArtifactId();
        }
        return "Skipping " + projectName + " : " + reason;
    }

    public boolean checkPackagingConfiguration()
    {
        if (!supportedPackagings.contains( project.getPackaging() ))
        {
            getLog().info(getSkipMessage("packaging type [" + project.getPackaging() + "] is unsupported"));
            return false;
        }
        return true;
    }


    /** 
     * @see org.apache.maven.plugin.Mojo#execute()
     */
    @Override
    public void execute() throws MojoExecutionException, MojoFailureException
    {
        if (isConfigurationSupported())
        {
            if (skip)
            {
                getLog().info(getSkipMessage("jetty.skip==true"));
                return;
            }

            getLog().info("Configuring Jetty for project: " + this.project.getName());

            if (isExcluded(execution.getMojoDescriptor().getGoal()))
            {
                getLog().info("The goal \""+execution.getMojoDescriptor().getFullGoalName()+
                              "\" has been made unavailable for this web application by an <excludedGoal> configuration.");
                return;
            }

            configurePluginClasspath();
            PluginLog.setLog(getLog());
            startJetty();
        }
    }
    
    public boolean isConfigurationSupported() throws MojoExecutionException
    {
        return (checkPackagingConfiguration() && checkPomConfiguration());
    }
    
    
    public void configurePluginClasspath() throws MojoExecutionException
    {  
        //if we are configured to include the provided dependencies on the plugin's classpath
        //(which mimics being on jetty's classpath vs being on the webapp's classpath), we first
        //try and filter out ones that will clash with jars that are plugin dependencies, then
        //create a new classloader that we setup in the parent chain.
        if (useProvidedScope)
        {
            try
            {
                List<URL> provided = new ArrayList<>();

                for ( Artifact artifact : projectArtifacts)
                {                   
                    if (Artifact.SCOPE_PROVIDED.equals(artifact.getScope()) && !isPluginArtifact(artifact))
                    {
                        provided.add(artifact.getFile().toURI().toURL());
                        if (getLog().isDebugEnabled()) { getLog().debug("Adding provided artifact: "+artifact);}
                    }
                }

                if (!provided.isEmpty())
                {
                    URL[] urls = provided.stream().toArray(URL[]::new);
                    URLClassLoader loader  = new URLClassLoader(urls, getClass().getClassLoader());
                    Thread.currentThread().setContextClassLoader(loader);
                    getLog().info("Plugin classpath augmented with <scope>provided</scope> dependencies: "+Arrays.toString(urls));
                }
            }
            catch (MalformedURLException e)
            {
                throw new MojoExecutionException("Invalid url", e);
            }
        }
    }
    
    public boolean isPluginArtifact(Artifact artifact)
    {
        if (pluginArtifacts == null || pluginArtifacts.isEmpty())
            return false;
        
        for (Artifact pluginArtifact : pluginArtifacts )
        {
            if (getLog().isDebugEnabled()) { getLog().debug("Checking "+pluginArtifact);}
            if (pluginArtifact.getGroupId().equals(artifact.getGroupId()) //
                && pluginArtifact.getArtifactId().equals(artifact.getArtifactId()))
                return true;
        }
        
        return false;
    }

    public void finishConfigurationBeforeStart() throws Exception
    {
        HandlerCollection contexts = server.getChildHandlerByClass(ContextHandlerCollection.class);
        if (contexts==null)
            contexts = server.getChildHandlerByClass(HandlerCollection.class);
        
        for (int i=0; (this.contextHandlers != null) && (i < this.contextHandlers.length); i++)
        {
            contexts.addHandler(this.contextHandlers[i]);
        }
    }

    public void applyJettyXml() throws Exception
    {        
        Server tmp = ServerSupport.applyXmlConfigurations(server, getJettyXmlFiles());
        if (server == null)
            server = tmp;
        
        if (server == null)
            server = new Server();
    }

    public void startJetty () throws MojoExecutionException
    {
        try
        {
            getLog().debug("Starting Jetty Server ...");
            
            //make sure Jetty does not use URLConnection caches with the plugin
            Resource.setDefaultUseCaches(false);
         
            configureMonitor();
            
            printSystemProperties();
            
            //apply any config from a jetty.xml file first which is able to
            //be overwritten by config in the pom.xml
            applyJettyXml ();      
            
            // if a <httpConnector> was specified in the pom, use it
            if (httpConnector != null)
            {

                // check that its port was set
                if (httpConnector.getPort() <= 0)
                {
                    //use any jetty.http.port settings provided
                    String tmp = System.getProperty(MavenServerConnector.PORT_SYSPROPERTY, //
                                                    System.getProperty("jetty.port", MavenServerConnector.DEFAULT_PORT_STR));
                    httpConnector.setPort(Integer.parseInt(tmp.trim()));
                }  
                httpConnector.setServer(server);
            }

            ServerSupport.configureConnectors(server, httpConnector);

            //set up a RequestLog if one is provided and the handle structure
            ServerSupport.configureHandlers(server, this.requestLog);
            
            //Set up list of default Configurations to apply to a webapp
            ServerSupport.configureDefaultConfigurationClasses(server);
            configureWebApplication();
            ServerSupport.addWebApplication(server, webApp);

            // set up security realms
            ServerSupport.configureLoginServices(server, loginServices);

            //do any other configuration required by the
            //particular Jetty version
            finishConfigurationBeforeStart();

            // start Jetty
            this.server.start();

            getLog().info( "Started Jetty Server" );

            if ( dumpOnStart )
            {
                getLog().info(this.server.dump());
            }

            // start the scanner thread (if necessary) on the main webapp
            if (isScanningEnabled())
            {
                scanner = new PathWatcher();
                configureScanner ();
                startScanner();
            }

            // start the new line scanner thread if necessary
            startConsoleScanner();

            // keep the thread going if not in daemon mode
            if (!nonBlocking )
            {
                server.join();
            }

        }
        catch (Exception e)
        {
            throw new MojoExecutionException("Failure", e);
        }
        finally
        {
            if (!nonBlocking )
            {
                getLog().info("Jetty server exiting.");
            }            
        }        
    }
    
    
    public void configureMonitor()
    { 
        if(stopPort>0 && stopKey!=null)
        {
            ShutdownMonitor monitor = ShutdownMonitor.getInstance();
            monitor.setPort(stopPort);
            monitor.setKey(stopKey);
            monitor.setExitVm(!nonBlocking );
        }
    }

    
    
    
    
    
    /**
     * Subclasses should invoke this to setup basic info
     * on the webapp
     * 
     * @throws Exception if unable to configure web application 
     */
    public void configureWebApplication () throws Exception
    {
        //As of jetty-7, you must use a <webApp> element
        if (webApp == null)
            webApp = new JettyWebAppContext();
        
        //Apply any context xml file to set up the webapp
        //CAUTION: if you've defined a <webApp> element then the
        //context xml file can OVERRIDE those settings
        if (contextXml != null)
        {
            Path path = Paths.get(contextXml);
            if (!path.isAbsolute())
            {
                Path workDir = Paths.get(System.getProperty("user.dir"));
                path = workDir.resolve(path);
                contextXml = path.toFile().getAbsolutePath();
            }
    
            XmlConfiguration xmlConfiguration = new XmlConfiguration(Resource.toURL(path.toFile()));
            getLog().info("Applying context xml file "+contextXml);
            xmlConfiguration.configure(webApp);   
        }
        
        //If no contextPath was specified, go with default of project artifactid
        String cp = webApp.getContextPath();
        if (cp == null || "".equals(cp))
        {
            cp = "/"+project.getArtifactId();
            webApp.setContextPath(cp);
        }        

        //If no tmp directory was specified, and we have one, use it
        if (webApp.getTempDirectory() == null)
        {
            File target = new File(project.getBuild().getDirectory());
            File tmp = new File(target,"tmp");
            if (!tmp.exists())
                tmp.mkdirs();            
            webApp.setTempDirectory(tmp);
        }
      
        getLog().info("Context path = " + webApp.getContextPath());
        getLog().info("Tmp directory = "+ (webApp.getTempDirectory()== null? " determined at runtime": webApp.getTempDirectory()));
        getLog().info("Web defaults = "+(webApp.getDefaultsDescriptor()==null?" jetty default":webApp.getDefaultsDescriptor()));
        getLog().info("Web overrides = "+(webApp.getOverrideDescriptor()==null?" none":webApp.getOverrideDescriptor()));
    }



    
    /**
     * Run a scanner thread on the given list of files and directories, calling
     * stop/start on the given list of LifeCycle objects if any of the watched
     * files change.
     * @throws Exception if unable to start scanner 
     */
    public void startScanner() throws Exception
    {
        if (!isScanningEnabled())
            return;

        scanner.setNotifyExistingOnStart(false);
       
       
        scanner.start();
    }
    
    
    public boolean isScanningEnabled ()
    {
        if (scanIntervalSeconds <=0 || "manual".equalsIgnoreCase( reload ))
            return false;
        return true;
    }
    
    public void stopScanner() throws Exception
    {
        if (!isScanningEnabled())
            return;
        
        if (scanner != null)
            scanner.stop();
    }
    
    
    /**
     * Run a thread that monitors the console input to detect ENTER hits.
     * @throws Exception if unable to start the console
     */
    protected void startConsoleScanner() throws Exception
    {
        if ( "manual".equalsIgnoreCase( reload ) )
        {
            getLog().info("Console reloading is ENABLED. Hit ENTER on the console to restart the context.");
            consoleScanner = new ConsoleScanner(this);
            consoleScanner.start();
        }       
    }

    protected void printSystemProperties ()
    {
        // print out which system properties were set up
        if (getLog().isDebugEnabled())
        {
            if (systemProperties != null)
            {
                systemProperties.getSystemProperties().stream().forEach( prop -> {
                    getLog().debug("Property "+prop.getName()+"="+prop.getValue()+" was "+ (prop.isSet() ? "set" : "skipped"));
                } );
            }
        }
    }

    /**
     * Try and find a jetty-web.xml file, using some
     * historical naming conventions if necessary.
     * @param webInfDir the web inf directory
     * @return the jetty web xml file
     */
    public File findJettyWebXmlFile (File webInfDir)
    {
        if (webInfDir == null)
            return null;
        if (!webInfDir.exists())
            return null;

        File f = new File (webInfDir, "jetty-web.xml");
        if (f.exists())
            return f;

        //try some historical alternatives
        f = new File (webInfDir, "web-jetty.xml");
        if (f.exists())
            return f;
        
        return null;
    }

    public void setSystemPropertiesFile(File file) throws Exception
    {
        this.systemPropertiesFile = file;
        Properties properties = new Properties();
        try (InputStream propFile = new FileInputStream(systemPropertiesFile))
        {
            properties.load(propFile);
        }
        if (this.systemProperties == null )
            this.systemProperties = new SystemProperties();
        
        for (Enumeration<?> keys = properties.keys(); keys.hasMoreElements();  )
        {
            String key = (String)keys.nextElement();
            if ( ! systemProperties.containsSystemProperty(key) )
            {
                SystemProperty prop = new SystemProperty();
                prop.setKey(key);
                prop.setValue(properties.getProperty(key));
                
                this.systemProperties.setSystemProperty(prop);
            }
        } 
    }
    
    public void setSystemProperties(SystemProperties systemProperties)
    {
        if (this.systemProperties == null)
            this.systemProperties = systemProperties;
        else
        {
            for (SystemProperty prop: systemProperties.getSystemProperties())
            {
                this.systemProperties.setSystemProperty(prop);
            }   
        }
    }
    
    public List<File> getJettyXmlFiles()
    {
        if ( this.jettyXml == null )
        {
            return null;
        }
        
        List<File> jettyXmlFiles = new ArrayList<File>();
        
        if ( this.jettyXml.indexOf(',') == -1 )
        {
            jettyXmlFiles.add( new File( this.jettyXml ) );
        }
        else
        {
            String[] files = StringUtil.csvSplit(this.jettyXml);
            
            for ( String file : files )
            {
                jettyXmlFiles.add( new File(file) );
            }
        }
        
        return jettyXmlFiles;
    }

    public boolean isExcluded (String goal)
    {
        if (excludedGoals == null || goal == null)
            return false;
        
        goal = goal.trim();
        if ("".equals(goal))
            return false;
        
        boolean excluded = false;
        for (int i=0; i<excludedGoals.length && !excluded; i++)
        {
            if (excludedGoals[i].equalsIgnoreCase(goal))
                excluded = true;
        }
        
        return excluded;
    }
}
