/*
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:  
 *       "This product includes software developed by the 
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written 
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * [Additional notices, if required by prior licensing conditions]
 *
 */


package org.apache.tomcat.context;

import org.apache.tomcat.core.*;
import org.apache.tomcat.core.Constants;
import org.apache.tomcat.request.*;
import org.apache.tomcat.util.*;
import java.io.*;
import java.net.*;
import java.util.*;
import java.security.*;

import org.apache.tomcat.logging.*;
import javax.servlet.*;
import javax.servlet.http.*;

/**
 * Check ContextManager and set defaults for non-set properties
 *
 * @author costin@dnt.ro
 */
public class DefaultCMSetter extends BaseInterceptor {

    public DefaultCMSetter() {
    }

    public void contextInit( Context ctx)
	throws TomcatException
    {
	setEngineHeader( ctx );


	ctx.addServlet( new ExceptionHandler());
	ctx.addServlet( new StatusHandler());

	// Default status handlers. If already set ( error-page in web.xml )
	// do nothing
	if( null==ctx.getErrorPage( "302" )) {
	    ctx.addServlet( new RedirectHandler());
	    ctx.addErrorPage( "302", "tomcat.redirectHandler");
	}
	if( null==ctx.getErrorPage( "404" )) {
	    ctx.addServlet( new NotFoundHandler());
	    ctx.addErrorPage( "404", "tomcat.notFoundHandler");
	}
    }

    // -------------------- implementation
    private void setEngineHeader(Context ctx) {
        String engineHeader=ctx.getEngineHeader();

	if( engineHeader==null) {
	    /*
	     * Whoever modifies this needs to check this modification is
	     * ok with the code in com.jsp.runtime.ServletEngine or talk
	     * to akv before you check it in. 
	     */
	    // Default value for engine header
	    // no longer use core.properties - the configuration comes from
	    // server.xml or web.xml - no more properties.
	    StringBuffer sb=new StringBuffer();
	    sb.append(Constants.TOMCAT_NAME).append("/");
	    sb.append(Constants.TOMCAT_VERSION);
	    sb.append(" (").append(Constants.JSP_NAME).append(" ");
	    sb.append(Constants.JSP_VERSION);
	    sb.append("; ").append(Constants.SERVLET_NAME).append(" ");
	    sb.append(Constants.SERVLET_MAJOR).append(".");
	    sb.append(Constants.SERVLET_MINOR);
	    sb.append( "; Java " );
	    sb.append(System.getProperty("java.version")).append("; ");
	    sb.append(System.getProperty("os.name") + " ");
	    sb.append(System.getProperty("os.version") + " ");
	    sb.append(System.getProperty("os.arch") + "; java.vendor=");
	    sb.append(System.getProperty("java.vendor")).append(")");
	    engineHeader=sb.toString();
	}
	ctx.setEngineHeader( engineHeader );
    }

}

class NotFoundHandler extends ServletWrapper {
    static StringManager sm=StringManager.
	getManager("org.apache.tomcat.resources");

    NotFoundHandler() {
	initialized=true;
	internal=true;
	name="tomcat.notFoundHandler";
    }

    public void doService(Request req, Response res)
	throws Exception
    {
	res.setContentType("text/html");	// ISO-8859-1 default

	String requestURI = (String)req.
	    getAttribute("javax.servlet.include.request_uri");

	if (requestURI == null || res.isIncluded()) {
	    requestURI = req.getRequestURI();
	}

	StringBuffer buf = new StringBuffer();
	buf.append("<head><title>")
	    .append(sm.getString("defaulterrorpage.notfound404"))
	    .append("</title></head>\r\n");
	buf.append("<body><h1>")
	    .append(sm.getString("defaulterrorpage.notfound404"))
	    .append("</h1>\r\n<b>");
	buf.append(sm.getString("defaulterrorpage.originalrequest"))
	    .append("</b> ")
	    .append( requestURI );

	if (contextM.getShowDebugInfo()) {
	    if (res.isIncluded()) {
		requestURI = (String)req.
		    getAttribute("javax.servlet.include.request_uri");
	    }
	    if (requestURI != null) {
		buf.append("<br><br>\r\n<b>")
		    .append(sm.getString("defaulterrorpage.notfoundrequest"))
		    .append("</b> ")
		    .append( requestURI );
	    }
	}

	buf.append("</body>\r\n");

	String body = buf.toString();

	res.setContentLength(body.length());

	if( res.isUsingStream() ) {
	    ServletOutputStream out = res.getOutputStream();
	    out.print(body);
	    out.flush();
	} else {
	    PrintWriter out = res.getWriter();
	    out.print(body);
	    out.flush();
	}
    }
}

class ExceptionHandler extends ServletWrapper {
    static StringManager sm=StringManager.
	getManager("org.apache.tomcat.resources");

    ExceptionHandler() {
	initialized=true;
	internal=true;
	name="tomcat.exceptionHandler";
    }

    public void doService(Request req, Response res)
	throws Exception
    {
	String msg=(String)req.getAttribute("javax.servlet.error.message");
	String errorURI = res.getErrorURI();
	
	Throwable e= (Throwable)req.
	    getAttribute("tomcat.servlet.error.throwable");
	if( e==null ) {
	    System.out.println("ASSERT: Exception handler without exception");
	    /*DEBUG*/ try {throw new Exception(); } catch(Exception ex) {ex.printStackTrace();}
	    return;
	}

	res.setContentType("text/html");
	res.setStatus( 500 );
	
	StringBuffer buf = new StringBuffer();
	buf.append("<h1>");
	if( errorURI != null ) {
	    buf.append(sm.getString("defaulterrorpage.includedservlet") ).
		append(" ");
	}  else {
	    buf.append("Error: ");
	}
	
	buf.append( 500 );
	buf.append("</h1>\r\n");

	// More info - where it happended"
	buf.append("<h2>")
	    .append(sm.getString("defaulterrorpage.location"))
	    .append(" ")
	    .append(req.getRequestURI())
	    .append("</h2>");

	if ( errorURI != null && contextM.getShowDebugInfo()) {
	    buf.append("\r\n<h2>")
		.append(sm.getString("defaulterrorpage.errorlocation"))
		.append(" ")
		.append(errorURI)
		.append("</h2>");
	}

	buf.append("<b>")
	    .append(sm.getString("defaulterrorpage.internalservleterror"));

	if (contextM.getShowDebugInfo()) {
	    buf.append("</b><br>");

	    buf.append("<pre>");

	    StringWriter sw = new StringWriter();
	    PrintWriter pw = new PrintWriter(sw);
	    e.printStackTrace(pw);

	    buf.append(sw.toString());

	    buf.append("</pre>\r\n");
	} else {
	    buf.append("</b> ")
    	        .append(e.getMessage())
		.append("<br><br>\r\n");
	}

        if (e instanceof ServletException) {
	    Throwable cause = ((ServletException)e).getRootCause();
	    if (cause != null) {
		buf.append("<b>")
		    .append(sm.getString("defaulterrorpage.rootcause"));

		if (contextM.getShowDebugInfo()) {
		    buf.append("</b>\r\n");

		    buf.append("<pre>");

		    StringWriter sw = new StringWriter();
		    PrintWriter pw = new PrintWriter(sw);
		    cause.printStackTrace( pw );
		    buf.append( sw.toString());

		    buf.append("</pre>\r\n");
		} else {
		    buf.append("</b> ")
			.append(cause.getMessage());
		}
	    }
	}
	
	buf.append("\r\n");
	
	if( res.isUsingStream() ) {
	    ServletOutputStream out = res.getOutputStream();
	    out.print(buf.toString());
	} else {
	    PrintWriter out = res.getWriter();
	    out.print(buf.toString());
	}
    }
}

class StatusHandler extends ServletWrapper {
    static StringManager sm=StringManager.
	getManager("org.apache.tomcat.resources");

    StatusHandler() {
	initialized=true;
	internal=true;
	name="tomcat.statusHandler";
    }
    
    // We don't want interceptors called for redirect
    // handler
    public void doService(Request req, Response res)
	throws Exception
    {
	String msg=(String)req.getAttribute("javax.servlet.error.message");
	String errorURI = res.getErrorURI();
	
	res.setContentType("text/html");
	// res is reset !!!
	// status is already set
	int sc=res.getStatus();
	
	StringBuffer buf = new StringBuffer();
	buf.append("<head><title>");
	// if an included request originated
	if( errorURI != null ) {
	    // use error code from include
	    sc = ((Integer)req.getAttribute("javax.servlet.error.status_code")).intValue();
	    buf.append(sm.getString("defaulterrorpage.includedservlet") );
	}  else {
	    buf.append("Error: ");
	}

	buf.append( sc );
	buf.append("</title></head>\r\n");

	buf.append("<h1>");
	if( errorURI != null ) {
	    buf.append(sm.getString("defaulterrorpage.includedservlet") )
		.append(" ");
	}  else {
	    buf.append("Error: ");
	}
	
	buf.append( sc );
	buf.append("</h1>\r\n");

	// More info - where it happended"
	buf.append("<h2>")
	    .append(sm.getString("defaulterrorpage.location"))
	    .append(" ")
	    .append(req.getRequestURI())
	    .append("</h2>");

	if ( sc >= 400 && errorURI != null && contextM.getShowDebugInfo()) {
	    buf.append("\r\n<h2>")
		.append(sm.getString("defaulterrorpage.errorlocation"))
		.append(" ")
		.append(errorURI)
		.append("</h2>");
	}

	buf.append("<b>")
	    .append(msg)
	    .append("</b><br>");

	// add unavailable time if present
	if ( sc == 503) {
            Integer ut = (Integer)req.getAttribute("tomcat.servlet.error.unavailableTime");
            if ( ut != null) {
                // if permanent
                if (ut.intValue() < 0) {
		    buf.append("<br>")
                	.append(sm.getString("defaulterrorpage.service.permanently.unavailable"))
			.append("<br>");
                } else {
		    buf.append("<br>")
                	.append(sm.getString("defaulterrorpage.service.unavailable",ut))
			.append("<br>");
                }
	    }
	}

	buf.append("</body>\r\n");

	if( res.isUsingStream() ) {
	    ServletOutputStream out = res.getOutputStream();
	    out.print(buf.toString());
	} else {
	    PrintWriter out = res.getWriter();
	    out.print(buf.toString());
	}
    }
}
	
class RedirectHandler extends ServletWrapper {
    static StringManager sm=StringManager.
	getManager("org.apache.tomcat.resources");

    RedirectHandler() {
	initialized=true;
	internal=true;
	name="tomcat.redirectHandler";
    }

    // We don't want interceptors called for redirect
    // handler
    public void doService(Request req, Response res)
	throws Exception
    {
	String location	= (String)
	    req.getAttribute("javax.servlet.error.message");
	Context ctx=req.getContext();
	
	location = makeAbsolute(req, location);

	if( debug>0) ctx.log("Redirect " + location + " " + req );

	res.setContentType("text/html");	// ISO-8859-1 default
	res.setHeader("Location", location);

	StringBuffer buf = new StringBuffer();
	buf.append("<head><title>").
	    append(sm.getString("defaulterrorpage.documentmoved")).
	    append("</title></head>\r\n<body><h1>").
	    append(sm.getString("defaulterrorpage.documentmoved")).
	    append("</h1>\r\n").
	    append(sm.getString("defaulterrorpage.thisdocumenthasmoved")).
	    append(" <a href=\"").
	    append(location).
	    append("\">here</a>.<p>\r\n</body>\r\n");

	String body = buf.toString();

	res.setContentLength(body.length());

	if( res.isUsingStream() ) {
	    ServletOutputStream out = res.getOutputStream();
	    out.print(body);
	    out.flush();
	} else {
	    PrintWriter out = res.getWriter();
	    out.print(body);
	    out.flush();
	}
    }

    // XXX Move it to URLUtil !!!
    private String makeAbsolute(Request req, String location) {
        URL url = null;
        try {
	    // Try making a URL out of the location
	    // Throws an exception if the location is relative
            url = new URL(location);
	} catch (MalformedURLException e) {
	    String requrl = HttpUtils.getRequestURL(req.getFacade()).
		toString();
	    try {
	        url = new URL(new URL(requrl), location);
	    }
	    catch (MalformedURLException ignored) {
	        // Give up
	        return location;
	    }
	}
        return url.toString();
    }
}
