/*
 *  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.jk.config;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;

import org.apache.catalina.Context;


/**
    Generates automatic IIS isapi_redirect configurations based on
    the Tomcat server.xml settings and the war contexts
    initialized during startup.
    <p>
    This config interceptor is enabled by inserting an IISConfig
    element in the <b>&lt;ContextManager&gt;</b> tag body inside
    the server.xml file like so:
    <pre>
    * < ContextManager ... >
    *   ...
    *   <<b>IISConfig</b> <i>options</i> />
    *   ...
    * < /ContextManager >
    </pre>
    where <i>options</i> can include any of the following attributes:
    <ul>
     <li><b>configHome</b> - default parent directory for the following paths.
                            If not set, this defaults to TOMCAT_HOME. Ignored
                            whenever any of the following paths is absolute.
                             </li>
     <li><b>regConfig</b> - path to use for writing IIS isapi_redirect registry
                            file. If not set, defaults to
                            "conf/auto/iis_redirect.reg".</li>
     <li><b>workersConfig</b> - path to workers.properties file used by 
                                isapi_redirect. If not set, defaults to
                                "conf/jk/workers.properties".</li>
     <li><b>uriConfig</b> - path to use for writing IIS isapi_redirect uriworkermap
                            file. If not set, defaults to
                            "conf/auto/uriworkermap.properties".</li>
     <li><b>jkLog</b> - path to log file to be used by isapi_redirect.</li>
     <li><b>jkDebug</b> - Loglevel setting.  May be debug, info, error, or emerg.
                          If not set, defaults to emerg.</li>
     <li><b>jkWorker</b> The desired worker.  Must be set to one of the workers
                         defined in the workers.properties file. "ajp12", "ajp13"
                         or "inprocess" are the workers found in the default
                         workers.properties file. If not specified, defaults
                         to "ajp13" if an Ajp13Interceptor is in use, otherwise
                         it defaults to "ajp12".</li>
     <li><b>forwardAll</b> - If true, forward all requests to Tomcat. This helps
                             insure that all the behavior configured in the web.xml
                             file functions correctly.  If false, let IIS serve
                             static resources assuming it has been configured
                             to do so. The default is true.
                             Warning: When false, some configuration in
                             the web.xml may not be duplicated in IIS.
                             Review the uriworkermap file to see what
                             configuration is actually being set in IIS.</li>
     <li><b>noRoot</b> - If true, the root context is not mapped to
                         Tomcat.  If false and forwardAll is true, all requests
                         to the root context are mapped to Tomcat. If false and
                         forwardAll is false, only JSP and servlets requests to
                         the root context are mapped to Tomcat. When false,
                         to correctly serve Tomcat's root context you must also
                         modify the Home Directory setting in IIS
                         to point to Tomcat's root context directory.
                         Otherwise some content, such as the root index.html,
                         will be served by IIS before isapi_redirect gets a chance
                         to claim the request and pass it to Tomcat.
                         The default is true.</li>
    </ul>
  <p>
    @author Costin Manolache
    @author Larry Isaacs
    @author Gal Shachor
    @author Bill Barker
 */
public class IISConfig extends BaseJkConfig  { 
    private static org.apache.juli.logging.Log log =
        org.apache.juli.logging.LogFactory.getLog(IISConfig.class);

    public static final String WORKERS_CONFIG = "/conf/jk/workers.properties";
    public static final String URI_WORKERS_MAP_CONFIG = "/conf/auto/uriworkermap.properties";
    public static final String ISAPI_LOG_LOCATION = "/logs/iis_redirect.log";
    public static final String ISAPI_REG_FILE = "/conf/auto/iis_redirect.reg";    

    private File regConfig = null;
    private File uriConfig = null;

    public IISConfig() 
    {
    }

    //-------------------- Properties --------------------
    
    /**
        set the path to the output file for the auto-generated
        isapi_redirect registry file.  If this path is relative
        then getRegConfig() will resolve it absolutely against
        the getConfigHome() path.
        <p>
        @param path String path to a file
    */
    public void setRegConfig(String path){
	regConfig= (path==null)?null:new File(path);
    }

    /**
        set a path to the uriworkermap.properties file.
        @param path String path to uriworkermap.properties file
    */
    public void setUriConfig(String path){
        uriConfig= (path==null?null:new File(path));
    }

    // -------------------- Initialize/guess defaults --------------------

    /** Initialize defaults for properties that are not set
	explicitely
    */
    protected void initProperties() {
        super.initProperties();

	regConfig=getConfigFile( regConfig, configHome, ISAPI_REG_FILE);
	workersConfig=getConfigFile( workersConfig, configHome, WORKERS_CONFIG);
	uriConfig=getConfigFile( uriConfig, configHome, URI_WORKERS_MAP_CONFIG);
	jkLog=getConfigFile( jkLog, configHome, ISAPI_LOG_LOCATION);
    }

    // -------------------- Generate config --------------------

    protected PrintWriter getWriter() throws IOException {
	String abUriConfig = uriConfig.getAbsolutePath();
	return new PrintWriter(new FileWriter(abUriConfig,append));        
    }
    protected boolean generateJkHead(PrintWriter mod_jk) {
	try {
	    PrintWriter regfile = new PrintWriter(new FileWriter(regConfig));
	    log.info("Generating IIS registry file = "+regConfig );
	    generateRegistrySettings(regfile);
	    regfile.close();
	} catch(IOException iex) {
	    log.warn("Unable to generate registry file " +regConfig);
	    return false;
	}
	log.info("Generating IIS URI worker map file = "+uriConfig );
	generateUriWorkerHeader(mod_jk);            
	return true;
    }

    // -------------------- Config sections  --------------------

    /** Writes the registry settings required by the IIS connector
     */
    private void generateRegistrySettings(PrintWriter regfile)
    {
        regfile.println("REGEDIT4");
        regfile.println();
        regfile.println("[HKEY_LOCAL_MACHINE\\SOFTWARE\\Apache Software Foundation\\Jakarta Isapi Redirector\\1.0]");
        regfile.println("\"extension_uri\"=\"/jakarta/isapi_redirect.dll\"");
        regfile.println("\"log_file\"=\"" + dubleSlash(jkLog.toString()) +"\"");
        regfile.println("\"log_level\"=\"" + jkDebug + "\"");
        regfile.println("\"worker_file\"=\"" + dubleSlash(workersConfig.toString()) +"\"");
        regfile.println("\"worker_mount_file\"=\"" + dubleSlash(uriConfig.toString()) +"\"");
    }

    /** Writes the header information to the uriworkermap file
     */
    private void generateUriWorkerHeader(PrintWriter uri_worker)
    {
        uri_worker.println("###################################################################");		    
        uri_worker.println("# Auto generated configuration. Dated: " +  new Date());
        uri_worker.println("###################################################################");		    
        uri_worker.println();

        uri_worker.println("#");        
        uri_worker.println("# Default worker to be used through our mappings");
        uri_worker.println("#");        
        uri_worker.println("default.worker=" + jkWorker);        
        uri_worker.println();
    }

    /** Forward all requests for a context to tomcat.
	The default.
     */
    protected void generateStupidMappings(Context context, PrintWriter uri_worker )
    {
        String ctxPath  = context.getPath();
	String nPath=("".equals(ctxPath)) ? "/" : ctxPath;

        if( noRoot &&  "".equals(ctxPath) ) {
            log.debug("Ignoring root context in forward-all mode  ");
            return;
        } 

        // map all requests for this context to Tomcat
        uri_worker.println(nPath +"=$(default.worker)");
        if( "".equals(ctxPath) ) {
            uri_worker.println(nPath +"*=$(default.worker)");
            uri_worker.println(
                    "# Note: To correctly serve the Tomcat's root context, IIS's Home Directory must");
            uri_worker.println(
                    "# must be set to: \"" + getAbsoluteDocBase(context) + "\"");
        }
        else
            uri_worker.println(nPath +"/*=$(default.worker)");
    }

    protected void generateContextMappings(Context context, PrintWriter uri_worker )
    {
        String ctxPath  = context.getPath();
	String nPath=("".equals(ctxPath)) ? "/" : ctxPath;

        if( noRoot &&  "".equals(ctxPath) ) {
            log.debug("Ignoring root context in forward-all mode  ");
            return;
        } 

        // Static files will be served by IIS
        uri_worker.println();
        uri_worker.println("#########################################################");		    
        uri_worker.println("# Auto configuration for the " + nPath + " context.");
        uri_worker.println("#########################################################");		    
        uri_worker.println();

        // Static mappings are not set in uriworkermap, but must be set with IIS admin.

	// InvokerInterceptor - it doesn't have a container,
	// but it's implemented using a special module.

	// XXX we need to better collect all mappings

	if(context.getLoginConfig() != null) {
	    String loginPage = context.getLoginConfig().getLoginPage();
	    if(loginPage != null) {
		int lpos = loginPage.lastIndexOf("/");
		String jscurl = loginPage.substring(0,lpos+1) + "j_security_check";
		addMapping( ctxPath, jscurl, uri_worker);
	    }
	}
		String [] servletMaps=context.findServletMappings();
	for( int ii=0; ii < servletMaps.length ; ii++) {
	    addMapping( ctxPath , servletMaps[ii] , uri_worker );
	}
    }

    /** Add an IIS extension mapping.
     */
    protected boolean addMapping( String ctxPath, String ext,
					 PrintWriter uri_worker )
    {
        if( log.isDebugEnabled() )
            log.debug( "Adding extension map for " + ctxPath + "/*." + ext );
	if(! ext.startsWith("/") )
	    ext = "/" + ext;
	if(ext.length() > 1)
	    uri_worker.println(ctxPath + "/*." + ext + "=$(default.worker)");
        return true;
    }

    /** Add a fulling specified IIS mapping.
     */
    protected boolean addMapping( String fullPath, PrintWriter uri_worker ) {
        if( log.isDebugEnabled() )
            log.debug( "Adding map for " + fullPath );
        uri_worker.println(fullPath + "=$(default.worker)" );
        return true;
    }

    // -------------------- Utils --------------------

    private String dubleSlash(String in) 
    {
        StringBuffer sb = new StringBuffer();
        
        for(int i = 0 ; i < in.length() ; i++) {
            char ch = in.charAt(i);
            if('\\' == ch) {
                sb.append("\\\\");
            } else {
                sb.append(ch);
            }
        }
        
        return sb.toString();
    }

}