//
//  ========================================================================
//  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.FileOutputStream;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.util.ArrayList;
import java.util.EventListener;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;

import org.eclipse.jetty.plus.webapp.EnvConfiguration;
import org.eclipse.jetty.quickstart.PreconfigureDescriptorProcessor;
import org.eclipse.jetty.quickstart.QuickStartDescriptorGenerator;
import org.eclipse.jetty.servlet.FilterHolder;
import org.eclipse.jetty.servlet.FilterMapping;
import org.eclipse.jetty.servlet.ServletHolder;
import org.eclipse.jetty.servlet.ServletMapping;
import org.eclipse.jetty.util.StringUtil;
import org.eclipse.jetty.util.URIUtil;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
import org.eclipse.jetty.util.resource.Resource;
import org.eclipse.jetty.util.resource.ResourceCollection;
import org.eclipse.jetty.webapp.Configuration;
import org.eclipse.jetty.webapp.WebAppContext;
import org.eclipse.jetty.webapp.WebInfConfiguration;

/**
 * JettyWebAppContext
 *
 * Extends the WebAppContext to specialize for the maven environment.
 * We pass in the list of files that should form the classpath for
 * the webapp when executing in the plugin, and any jetty-env.xml file
 * that may have been configured.
 */
public class JettyWebAppContext extends WebAppContext
{
    private static final Logger LOG = Log.getLogger(JettyWebAppContext.class);

    private static final String DEFAULT_CONTAINER_INCLUDE_JAR_PATTERN = ".*/javax.servlet-[^/]*\\.jar$|.*/servlet-api-[^/]*\\.jar$|.*javax.servlet.jsp.jstl-[^/]*\\.jar|.*taglibs-standard-impl-.*\\.jar";
    private static final String WEB_INF_CLASSES_PREFIX = "/WEB-INF/classes";
    private static final String WEB_INF_LIB_PREFIX = "/WEB-INF/lib";

    public static final String[] MINIMUM_CONFIGURATION_CLASSES = {
        "org.eclipse.jetty.maven.plugin.MavenWebInfConfiguration",
        "org.eclipse.jetty.webapp.WebXmlConfiguration",
        "org.eclipse.jetty.webapp.MetaInfConfiguration",
        "org.eclipse.jetty.webapp.FragmentConfiguration",
        "org.eclipse.jetty.webapp.JettyWebXmlConfiguration"
    };
    public static final String[] DEFAULT_CONFIGURATION_CLASSES = {
        "org.eclipse.jetty.maven.plugin.MavenWebInfConfiguration",
        "org.eclipse.jetty.webapp.WebXmlConfiguration",
        "org.eclipse.jetty.webapp.MetaInfConfiguration",
        "org.eclipse.jetty.webapp.FragmentConfiguration",
        "org.eclipse.jetty.plus.webapp.EnvConfiguration",
        "org.eclipse.jetty.plus.webapp.PlusConfiguration",
        "org.eclipse.jetty.annotations.AnnotationConfiguration",
        "org.eclipse.jetty.webapp.JettyWebXmlConfiguration"
    };

    public static final String[] QUICKSTART_CONFIGURATION_CLASSES = {
        "org.eclipse.jetty.maven.plugin.MavenQuickStartConfiguration",
        "org.eclipse.jetty.plus.webapp.EnvConfiguration",
        "org.eclipse.jetty.plus.webapp.PlusConfiguration",
        "org.eclipse.jetty.webapp.JettyWebXmlConfiguration"
    };

    private File _classes = null;
    private File _testClasses = null;
    private final List<File> _webInfClasses = new ArrayList<>();
    private final List<File> _webInfJars = new ArrayList<>();
    private final Map<String, File> _webInfJarMap = new HashMap<String, File>();
    private List<File> _classpathFiles; //webInfClasses+testClasses+webInfJars
    private String _jettyEnvXml;
    private List<Overlay> _overlays;
    private Resource _quickStartWebXml;
    private String _originAttribute;
    private boolean _generateOrigin;

    /**
     * Set the "org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern" with a pattern for matching jars on
     * container classpath to scan. This is analogous to the WebAppContext.setAttribute() call.
     */
    private String _containerIncludeJarPattern = null;

    /**
     * Set the "org.eclipse.jetty.server.webapp.WebInfIncludeJarPattern" with a pattern for matching jars on
     * webapp's classpath to scan. This is analogous to the WebAppContext.setAttribute() call.
     */
    private String _webInfIncludeJarPattern = null;

    /**
     * If there is no maven-war-plugin config for ordering of the current project in the
     * sequence of overlays, use this to control whether the current project is added
     * first or last in list of overlaid resources
     */
    private boolean _baseAppFirst = true;

    private boolean _isGenerateQuickStart;
    private PreconfigureDescriptorProcessor _preconfigProcessor;

    public JettyWebAppContext()
        throws Exception
    {
        super();
        // Turn off copyWebInf option as it is not applicable for plugin.
        super.setCopyWebInf(false);
    }

    public void setContainerIncludeJarPattern(String pattern)
    {
        _containerIncludeJarPattern = pattern;
    }

    public String getContainerIncludeJarPattern()
    {
        return _containerIncludeJarPattern;
    }

    public String getWebInfIncludeJarPattern()
    {
        return _webInfIncludeJarPattern;
    }

    public void setWebInfIncludeJarPattern(String pattern)
    {
        _webInfIncludeJarPattern = pattern;
    }

    public List<File> getClassPathFiles()
    {
        return this._classpathFiles;
    }

    public void setJettyEnvXml(String jettyEnvXml)
    {
        this._jettyEnvXml = jettyEnvXml;
    }

    public String getJettyEnvXml()
    {
        return this._jettyEnvXml;
    }

    public void setClasses(File dir)
    {
        _classes = dir;
    }

    public File getClasses()
    {
        return _classes;
    }

    public void setWebInfLib(List<File> jars)
    {
        _webInfJars.addAll(jars);
    }

    public void setTestClasses(File dir)
    {
        _testClasses = dir;
    }

    public File getTestClasses()
    {
        return _testClasses;
    }

    /**
     * Ordered list of wars to overlay on top of the current project. The list
     * may contain an overlay that represents the current project.
     *
     * @param overlays the list of overlays
     */
    public void setOverlays(List<Overlay> overlays)
    {
        _overlays = overlays;
    }

    /**
     * @return the originAttribute
     */
    public String getOriginAttribute()
    {
        return _originAttribute;
    }

    /**
     * @param originAttribute the originAttribute to set
     */
    public void setOriginAttribute(String originAttribute)
    {
        _originAttribute = originAttribute;
    }

    /**
     * @return the generateOrigin
     */
    public boolean isGenerateOrigin()
    {
        return _generateOrigin;
    }

    /**
     * @param generateOrigin the generateOrigin to set
     */
    public void setGenerateOrigin(boolean generateOrigin)
    {
        _generateOrigin = generateOrigin;
    }

    public List<Overlay> getOverlays()
    {
        return _overlays;
    }

    public void setBaseAppFirst(boolean value)
    {
        _baseAppFirst = value;
    }

    public boolean getBaseAppFirst()
    {
        return _baseAppFirst;
    }

    public void setQuickStartWebDescriptor(String quickStartWebXml) throws Exception
    {
        setQuickStartWebDescriptor(Resource.newResource(quickStartWebXml));
    }

    protected void setQuickStartWebDescriptor(Resource quickStartWebXml)
    {
        _quickStartWebXml = quickStartWebXml;
    }

    public Resource getQuickStartWebDescriptor()
    {
        return _quickStartWebXml;
    }

    /**
     * This method is provided as a convenience for jetty maven plugin configuration
     *
     * @param resourceBases Array of resources strings to set as a {@link ResourceCollection}. Each resource string may be a comma separated list of resources
     * @see Resource
     */
    public void setResourceBases(String[] resourceBases)
    {
        List<String> resources = new ArrayList<String>();
        for (String rl : resourceBases)
        {
            String[] rs = StringUtil.csvSplit(rl);
            for (String r : rs)
            {
                resources.add(r);
            }
        }

        setBaseResource(new ResourceCollection(resources.toArray(new String[resources.size()])));
    }

    public List<File> getWebInfLib()
    {
        return _webInfJars;
    }

    public List<File> getWebInfClasses()
    {
        return _webInfClasses;
    }

    public void setGenerateQuickStart(boolean quickStart)
    {
        _isGenerateQuickStart = quickStart;
    }

    public boolean isGenerateQuickStart()
    {
        return _isGenerateQuickStart;
    }

    @Override
    protected void startWebapp() throws Exception
    {
        if (isGenerateQuickStart())
        {
            if (getQuickStartWebDescriptor() == null)
                throw new IllegalStateException("No location to generate quickstart descriptor");

            QuickStartDescriptorGenerator generator = new QuickStartDescriptorGenerator(this, _preconfigProcessor.getXML(), _originAttribute, _generateOrigin);
            try (FileOutputStream fos = new FileOutputStream(getQuickStartWebDescriptor().getFile()))
            {
                generator.generateQuickStartWebXml(fos);
            }
        }
        else
        {
            if (LOG.isDebugEnabled())
            {
                LOG.debug("Calling full start on webapp");
            }
            super.startWebapp();
        }
    }

    @Override
    protected void stopWebapp() throws Exception
    {
        if (isGenerateQuickStart())
            return;

        if (LOG.isDebugEnabled())
        {
            LOG.debug("Calling stop of fully started webapp");
        }
        super.stopWebapp();
    }

    @Override
    public void doStart() throws Exception
    {

        if (isGenerateQuickStart())
        {
            _preconfigProcessor = new PreconfigureDescriptorProcessor();
            getMetaData().addDescriptorProcessor(_preconfigProcessor);
        }

        //Set up the pattern that tells us where the jars are that need scanning

        //Allow user to set up pattern for names of jars from the container classpath
        //that will be scanned - note that by default NO jars are scanned
        String tmp = _containerIncludeJarPattern;
        if (tmp == null || "".equals(tmp))
            tmp = (String)getAttribute(WebInfConfiguration.CONTAINER_JAR_PATTERN);

        tmp = addPattern(tmp, DEFAULT_CONTAINER_INCLUDE_JAR_PATTERN);
        setAttribute(WebInfConfiguration.CONTAINER_JAR_PATTERN, tmp);

        //Allow user to set up pattern of jar names from WEB-INF that will be scanned.
        //Note that by default ALL jars considered to be in WEB-INF will be scanned - setting
        //a pattern restricts scanning
        if (_webInfIncludeJarPattern != null)
            setAttribute(WebInfConfiguration.WEBINF_JAR_PATTERN, _webInfIncludeJarPattern);

        //Set up the classes dirs that comprises the equivalent of WEB-INF/classes
        if (_testClasses != null)
            _webInfClasses.add(_testClasses);
        if (_classes != null)
            _webInfClasses.add(_classes);

        // Set up the classpath
        _classpathFiles = new ArrayList<>();
        _classpathFiles.addAll(_webInfClasses);
        _classpathFiles.addAll(_webInfJars);

        // Initialize map containing all jars in /WEB-INF/lib
        _webInfJarMap.clear();
        for (File file : _webInfJars)
        {
            // Return all jar files from class path
            String fileName = file.getName();
            if (fileName.endsWith(".jar"))
                _webInfJarMap.put(fileName, file);
        }

        //check for CDI
        initCDI();

        // CHECK setShutdown(false);
        super.doStart();
    }

    @Override
    protected void loadConfigurations() throws Exception
    {
        super.loadConfigurations();

        //inject configurations with config from maven plugin    
        for (Configuration c : getConfigurations())
        {
            if (c instanceof EnvConfiguration && getJettyEnvXml() != null)
                ((EnvConfiguration)c).setJettyEnvXml(Resource.toURL(new File(getJettyEnvXml())));
        }
    }

    @Override
    public void doStop() throws Exception
    {
        if (_classpathFiles != null)
            _classpathFiles.clear();
        _classpathFiles = null;

        _classes = null;
        _testClasses = null;

        if (_webInfJarMap != null)
            _webInfJarMap.clear();

        _webInfClasses.clear();
        _webInfJars.clear();

        // CHECK setShutdown(true);
        //just wait a little while to ensure no requests are still being processed
        Thread.sleep(500L);

        super.doStop();

        //remove all listeners, servlets and filters. This is because we will re-apply
        //any context xml file, which means they would potentially be added multiple times.
        setEventListeners(new EventListener[0]);
        getServletHandler().setFilters(new FilterHolder[0]);
        getServletHandler().setFilterMappings(new FilterMapping[0]);
        getServletHandler().setServlets(new ServletHolder[0]);
        getServletHandler().setServletMappings(new ServletMapping[0]);
    }

    @Override
    public Resource getResource(String uriInContext) throws MalformedURLException
    {
        Resource resource = null;
        // Try to get regular resource
        resource = super.getResource(uriInContext);

        // If no regular resource exists check for access to /WEB-INF/lib or /WEB-INF/classes
        if ((resource == null || !resource.exists()) && uriInContext != null && _classes != null)
        {
            String uri = URIUtil.canonicalPath(uriInContext);
            if (uri == null)
                return null;

            try
            {
                // Replace /WEB-INF/classes with candidates for the classpath
                if (uri.startsWith(WEB_INF_CLASSES_PREFIX))
                {
                    if (uri.equalsIgnoreCase(WEB_INF_CLASSES_PREFIX) || uri.equalsIgnoreCase(WEB_INF_CLASSES_PREFIX + "/"))
                    {
                        //exact match for a WEB-INF/classes, so preferentially return the resource matching the web-inf classes
                        //rather than the test classes
                        if (_classes != null)
                            return Resource.newResource(_classes);
                        else if (_testClasses != null)
                            return Resource.newResource(_testClasses);
                    }
                    else
                    {
                        //try matching                       
                        Resource res = null;
                        int i = 0;
                        while (res == null && (i < _webInfClasses.size()))
                        {
                            String newPath = StringUtil.replace(uri, WEB_INF_CLASSES_PREFIX, _webInfClasses.get(i).getPath());
                            res = Resource.newResource(newPath);
                            if (!res.exists())
                            {
                                res = null;
                                i++;
                            }
                        }
                        return res;
                    }
                }
                else if (uri.startsWith(WEB_INF_LIB_PREFIX))
                {
                    // Return the real jar file for all accesses to
                    // /WEB-INF/lib/*.jar
                    String jarName = StringUtil.strip(uri, WEB_INF_LIB_PREFIX);
                    if (jarName.startsWith("/") || jarName.startsWith("\\"))
                        jarName = jarName.substring(1);
                    if (jarName.length() == 0)
                        return null;
                    File jarFile = _webInfJarMap.get(jarName);
                    if (jarFile != null)
                        return Resource.newResource(jarFile.getPath());

                    return null;
                }
            }
            catch (MalformedURLException e)
            {
                throw e;
            }
            catch (IOException e)
            {
                LOG.ignore(e);
            }
        }
        return resource;
    }

    @Override
    public Set<String> getResourcePaths(String path)
    {
        // Try to get regular resource paths - this will get appropriate paths from any overlaid wars etc
        Set<String> paths = super.getResourcePaths(path);

        if (path != null)
        {
            TreeSet<String> allPaths = new TreeSet<>();
            allPaths.addAll(paths);

            //add in the dependency jars as a virtual WEB-INF/lib entry
            if (path.startsWith(WEB_INF_LIB_PREFIX))
            {
                for (String fileName : _webInfJarMap.keySet())
                {
                    // Return all jar files from class path
                    allPaths.add(WEB_INF_LIB_PREFIX + "/" + fileName);
                }
            }
            else if (path.startsWith(WEB_INF_CLASSES_PREFIX))
            {
                int i = 0;

                while (i < _webInfClasses.size())
                {
                    String newPath = StringUtil.replace(path, WEB_INF_CLASSES_PREFIX, _webInfClasses.get(i).getPath());
                    allPaths.addAll(super.getResourcePaths(newPath));
                    i++;
                }
            }
            return allPaths;
        }
        return paths;
    }

    public String addPattern(String s, String pattern)
    {
        if (s == null)
            s = "";
        else
            s = s.trim();

        if (!s.contains(pattern))
        {
            if (s.length() != 0)
                s = s + "|";
            s = s + pattern;
        }

        return s;
    }

    public void initCDI()
    {
        Class cdiInitializer = null;
        try
        {
            cdiInitializer = Thread.currentThread().getContextClassLoader().loadClass("org.eclipse.jetty.cdi.servlet.JettyWeldInitializer");
            Method initWebAppMethod = cdiInitializer.getMethod("initWebApp", WebAppContext.class);
            initWebAppMethod.invoke(null, this);
        }
        catch (ClassNotFoundException e)
        {
            LOG.debug("o.e.j.cdi.servlet.JettyWeldInitializer not found, no cdi integration available");
        }
        catch (NoSuchMethodException e)
        {
            LOG.warn("o.e.j.cdi.servlet.JettyWeldInitializer.initWebApp() not found, no cdi integration available");
        }
        catch (Exception e)
        {
            LOG.warn("Problem initializing cdi", e);
        }
    }
}
