/*
 * Copyright (c) 1997-2018 Oracle and/or its affiliates. All rights reserved.
 * Copyright 2004 The Apache Software Foundation
 *
 * Licensed 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.catalina.core;

import static jakarta.servlet.DispatcherType.ERROR;
import static jakarta.servlet.RequestDispatcher.ERROR_MESSAGE;
import static jakarta.servlet.RequestDispatcher.ERROR_REQUEST_URI;
import static jakarta.servlet.RequestDispatcher.ERROR_SERVLET_NAME;
import static jakarta.servlet.RequestDispatcher.ERROR_STATUS_CODE;
import static jakarta.servlet.http.HttpServletResponse.SC_INTERNAL_SERVER_ERROR;
import static java.util.Locale.ENGLISH;
import static java.util.logging.Level.FINE;
import static java.util.logging.Level.INFO;
import static java.util.logging.Level.WARNING;
import static org.apache.catalina.Globals.DISPATCHER_REQUEST_PATH_ATTR;
import static org.apache.catalina.LogFacade.NO_CONTEXT_TO_PROCESS;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ResourceBundle;
import java.util.logging.Logger;

import org.apache.catalina.Context;
import org.apache.catalina.HttpRequest;
import org.apache.catalina.HttpResponse;
import org.apache.catalina.LogFacade;
import org.apache.catalina.Request;
import org.apache.catalina.Response;
import org.apache.catalina.Wrapper;
import org.apache.catalina.connector.ClientAbortException;
import org.apache.catalina.deploy.ErrorPage;
import org.apache.catalina.util.ResponseUtil;
import org.apache.catalina.valves.ValveBase;
import org.glassfish.web.valve.GlassFishValve;

import jakarta.servlet.RequestDispatcher;
import jakarta.servlet.ServletContext;
import jakarta.servlet.ServletException;
import jakarta.servlet.ServletOutputStream;
import jakarta.servlet.ServletRequest;
import jakarta.servlet.ServletResponse;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

/**
 * Valve that implements the default basic behavior for the <code>StandardHost</code> container implementation.
 * <p>
 * <b>USAGE CONSTRAINT</b>: This implementation is likely to be useful only when processing HTTP requests.
 *
 * @author Craig R. McClanahan
 * @author Remy Maucherat
 * @version $Revision: 1.21 $ $Date: 2007/04/10 17:12:22 $
 */

final class StandardHostValve extends ValveBase {

    private static final Logger log = LogFacade.getLogger();
    private static final ResourceBundle rb = log.getResourceBundle();

    private static final ClassLoader standardHostValveClassLoader = StandardHostValve.class.getClassLoader();

    // ----------------------------------------------------- Instance Variables

    /**
     * The descriptive information related to this implementation.
     */
    private static final String info = "org.apache.catalina.core.StandardHostValve/1.0";

    private GlassFishValve errorReportValve;

    // ------------------------------------------------------------- Properties

    /**
     * Return descriptive information about this Valve implementation.
     */
    @Override
    public String getInfo() {
        return info;
    }

    // --------------------------------------------------------- Public Methods

    /**
     * Select the appropriate child Context to process this request, based on the specified request URI. If no matching
     * Context can be found, return an appropriate HTTP error.
     *
     * @param request Request to be processed
     * @param response Response to be produced
     *
     * @exception IOException if an input/output error occurred
     * @exception ServletException if a servlet error occurred
     */
    @Override
    public int invoke(Request request, Response response) throws IOException, ServletException {
        Context context = preInvoke(request, response);
        if (context == null) {
            return END_PIPELINE;
        }

        // Ask this Context to process this request
        if (context.getPipeline().hasNonBasicValves() || context.hasCustomPipeline()) {
            context.getPipeline().invoke(request, response);
        } else {
            context.getPipeline().getBasic().invoke(request, response);
        }

        return END_PIPELINE;
    }

    /**
     * Tomcat style invocation.
     */
    @Override
    public void invoke(org.apache.catalina.connector.Request request, org.apache.catalina.connector.Response response) throws IOException, ServletException {
        Context context = preInvoke(request, response);
        if (context == null) {
            return;
        }

        // Ask this Context to process this request
        if (context.getPipeline().hasNonBasicValves() || context.hasCustomPipeline()) {
            context.getPipeline().invoke(request, response);
        } else {
            context.getPipeline().getBasic().invoke(request, response);
        }

        postInvoke(request, response);
    }

    @Override
    public void postInvoke(Request request, Response response) throws IOException, ServletException {
        try {

            HttpServletRequest hreq = (HttpServletRequest) request.getRequest();

            // Error page processing
            response.setSuspended(false);

            Throwable t = (Throwable) hreq.getAttribute(RequestDispatcher.ERROR_EXCEPTION);

            if (t != null) {
                throwable(request, response, t);
            } else {
                status(request, response);
            }

            boolean isDefaultErrorPageEnabled = true;
            Wrapper wrapper = request.getWrapper();
            if (wrapper != null) {
                String initParam = wrapper.findInitParameter(Constants.IS_DEFAULT_ERROR_PAGE_ENABLED_INIT_PARAM);
                if (initParam != null) {
                    isDefaultErrorPageEnabled = Boolean.parseBoolean(initParam);
                }
            }

            if (errorReportValve != null && response.isError() && isDefaultErrorPageEnabled) {
                errorReportValve.postInvoke(request, response);
            }

            Context context = request.getContext();
            if (context != null) {
                context.fireRequestDestroyedEvent(hreq);
            }
        } finally {
            Thread.currentThread().setContextClassLoader(standardHostValveClassLoader);
        }
    }

    // ------------------------------------------------------ Protected Methods

    /**
     * Handle the specified Throwable encountered while processing the specified Request to produce the specified Response.
     * Any exceptions that occur during generation of the exception report are logged and swallowed.
     *
     * @param request The request being processed
     * @param response The response being generated
     * @param throwable The throwable that occurred (which possibly wraps a root cause exception
     */
    protected void throwable(Request request, Response response, Throwable throwable) {
        Context context = request.getContext();
        if (context == null) {
            return;
        }

        Throwable realError = throwable;
        if (realError instanceof ServletException) {
            realError = ((ServletException) realError).getRootCause();
            if (realError == null) {
                realError = throwable;
            }
        }

        // If this is an aborted request from a client just log it and return
        if (realError instanceof ClientAbortException) {
            if (log.isLoggable(FINE)) {
                log.log(FINE, LogFacade.REMOTE_CLIENT_ABORTED_EXCEPTION, realError.getCause().getMessage());
            }
            return;
        }

        ErrorPage errorPage = findErrorPage(context, throwable);
        if ((errorPage == null) && (realError != throwable)) {
            errorPage = findErrorPage(context, realError);
        }

        if (errorPage != null) {
            dispatchToErrorPage(request, response, errorPage, throwable, realError, 0);
        } else if (context.getDefaultErrorPage() != null) {
            dispatchToErrorPage(request, response, context.getDefaultErrorPage(), throwable, realError, 0);
        } else {
            // A custom error-page has not been defined for the exception
            // that was thrown during request processing. Check if an
            // error-page for error code 500 was specified and if so,
            // send that page back as the response.
            ServletResponse servletResponse = (ServletResponse) response;

            ((HttpServletResponse) servletResponse).setStatus(SC_INTERNAL_SERVER_ERROR);

            // The response is an error
            response.setError();

            status(request, response);
        }

    }

    /**
     * Handle the HTTP status code (and corresponding message) generated while processing the specified Request to produce
     * the specified Response. Any exceptions that occur during generation of the error report are logged and swallowed.
     *
     * @param request The request being processed
     * @param response The response being generated
     */
    protected void status(Request request, Response response) {
        // Handle a custom error page for this status code
        Context context = request.getContext();
        if (context == null) {
            return;
        }

        /*
         * Only look for error pages when isError() is set. isError() is set when response.sendError() is invoked.
         */
        if (!response.isError()) {
            return;
        }

        int statusCode = ((HttpResponse) response).getStatus();
        ErrorPage errorPage = context.findErrorPage(statusCode);
        if (errorPage != null) {
            if (errorPage.getLocation() != null) {
                File file = new File(context.getDocBase(), errorPage.getLocation());
                if (!file.exists()) {
                    File file2 = new File(errorPage.getLocation());
                    if (!file2.exists()) {
                        log.log(WARNING, LogFacade.ERROR_PAGE_NOT_EXIST,
                                new Object[] { file.getAbsolutePath(), file2.getAbsolutePath() });
                    }
                }
            }
            setErrorPageContentType(response, errorPage.getLocation(), context);
            dispatchToErrorPage(request, response, errorPage, null, null, statusCode);
        } else if (statusCode >= 400 && statusCode < 600 && context.getDefaultErrorPage() != null) {
            dispatchToErrorPage(request, response, context.getDefaultErrorPage(), null, null, statusCode);
        }
        // START SJSAS 6324911
        else {
            errorPage = ((StandardHost) getContainer()).findErrorPage(statusCode);
            if (errorPage != null) {
                if (errorPage.getLocation() != null) {
                    File file = new File(context.getDocBase(), errorPage.getLocation());
                    if (!file.exists()) {
                        File file2 = new File(errorPage.getLocation());
                        if (!file2.exists()) {
                            log.log(WARNING, LogFacade.ERROR_PAGE_NOT_EXIST,
                                    new Object[] { file.getAbsolutePath(), file2.getAbsolutePath() });
                        }
                    }
                }
                try {
                    setErrorPageContentType(response, errorPage.getLocation(), context);
                    handleHostErrorPage(response, errorPage, statusCode);
                } catch (Exception e) {
                    log("Exception processing " + errorPage, e);
                }
            }
        }
        // END SJSAS 6324911
    }

    /**
     * Find and return the ErrorPage instance for the specified exception's class, or an ErrorPage instance for the closest
     * superclass for which there is such a definition. If no associated ErrorPage instance is found, return
     * <code>null</code>.
     *
     * @param context The Context in which to search
     * @param exception The exception for which to find an ErrorPage
     */
    protected static ErrorPage findErrorPage(Context context, Throwable exception) {
        if (exception == null) {
            return null;
        }

        Class<?> clazz = exception.getClass();
        String name = clazz.getName();
        while (!Object.class.equals(clazz)) {
            ErrorPage errorPage = context.findErrorPage(name);
            if (errorPage != null) {
                return errorPage;
            }

            clazz = clazz.getSuperclass();
            if (clazz == null) {
                break;
            }
            name = clazz.getName();
        }

        return null;
    }

    /**
     * Handle an HTTP status code or Java exception by forwarding control to the location included in the specified
     * errorPage object. It is assumed that the caller has already recorded any request attributes that are to be forwarded
     * to this page. Return <code>true</code> if we successfully utilized the specified error page location, or
     * <code>false</code> if the default error report should be rendered.
     *
     * @param request The request being processed
     * @param response The response being generated
     * @param errorPage The errorPage directive we are obeying
     */
    protected boolean custom(Request request, Response response, ErrorPage errorPage) {
        if (debug >= 1) {
            log("Processing " + errorPage);
        }

        HttpResponse httpResponse = (HttpResponse) response;
        HttpRequest httpRequest = (HttpRequest) request;

        HttpServletRequest httpServletRequest = (HttpServletRequest) request.getRequest();
        HttpServletResponse httpServletResponse = (HttpServletResponse) response.getResponse();

        httpRequest.setPathInfo(errorPage.getLocation());

        try {
            httpResponse.setError(
                (Integer) httpServletRequest.getAttribute(ERROR_STATUS_CODE),
                (String) httpServletRequest.getAttribute(ERROR_MESSAGE));

            // Forward control to the specified location
            ServletContext servletContext = request.getContext().getServletContext();
            ApplicationDispatcher dispatcher = (ApplicationDispatcher) servletContext.getRequestDispatcher(errorPage.getLocation());

            if (httpServletResponse.isCommitted()) {
                // Response is committed - including the error page is the best we can do
                dispatcher.include(httpServletRequest, httpServletResponse);
            } else {
                // Reset the response (keeping the real error code and message)
                response.resetBuffer(true);

                dispatcher.dispatch(httpServletRequest, httpServletResponse, ERROR);

                // If we forward, the response is suspended again
                response.setSuspended(false);
            }

            // Indicate that we have successfully processed this custom page
            return true;

        } catch (Throwable t) {
            // Report our failure to process this custom page
            log("Exception Processing " + errorPage, t);
            return false;
        }

    }

    /**
     * Log a message on the Logger associated with our Container (if any).
     *
     * @param message Message to be logged
     */
    protected void log(String message) {
        org.apache.catalina.Logger logger = container.getLogger();
        if (logger != null) {
            logger.log(this.toString() + ": " + message);
        } else {
            if (log.isLoggable(INFO)) {
                log.log(INFO, this.toString() + ": " + message);
            }
        }
    }

    /**
     * Log a message on the Logger associated with our Container (if any).
     *
     * @param message Message to be logged
     * @param t Associated exception
     */
    protected void log(String message, Throwable t) {
        org.apache.catalina.Logger logger = container.getLogger();
        if (logger != null) {
            logger.log(this.toString() + ": " + message, t, org.apache.catalina.Logger.WARNING);
        } else {
            log.log(WARNING, this.toString() + ": " + message, t);
        }
    }

    /**
     * Copies the contents of the given error page to the response, and updates the status message with the reason string of
     * the error page.
     *
     * @param response The response object
     * @param errorPage The error page whose contents are to be copied
     * @param statusCode The status code
     */
    private void handleHostErrorPage(Response response, ErrorPage errorPage, int statusCode) throws Exception {
        ServletOutputStream outputStream = null;
        PrintWriter writer = null;
        FileReader reader = null;
        BufferedInputStream istream = null;
        IOException ioException = null;

        if (!response.getResponse().isCommitted()) {
            response.resetBuffer(true);
        }

        String message = errorPage.getReason();
        if (message != null) {
            ((HttpResponse) response).reset(statusCode, message);
        }

        try {
            outputStream = response.getResponse().getOutputStream();
        } catch (IllegalStateException e) {
            // If it fails, we try to get a Writer instead if we're
            // trying to serve a text file
            writer = response.getResponse().getWriter();
        }

        if (writer != null) {
            reader = new FileReader(errorPage.getLocation());
            ioException = ResponseUtil.copy(reader, writer);
            try {
                reader.close();
            } catch (Throwable t) {

            }
        } else {
            istream = new BufferedInputStream(new FileInputStream(errorPage.getLocation()));
            ioException = ResponseUtil.copy(istream, outputStream);
            try {
                istream.close();
            } catch (Throwable t) {

            }
        }

        // Rethrow any exception that may have occurred
        if (ioException != null) {
            throw ioException;
        }
    }

    void setErrorReportValve(GlassFishValve errorReportValve) {
        this.errorReportValve = errorReportValve;
    }

    private Context preInvoke(Request request, Response response) throws IOException, ServletException {
        // Select the Context to be used for this Request
        Context context = request.getContext();
        if (context == null) {
            ((HttpServletResponse) response.getResponse()).sendError(SC_INTERNAL_SERVER_ERROR);
            response.setDetailMessage(rb.getString(NO_CONTEXT_TO_PROCESS));
            return null;
        }

        // Bind the context CL to the current thread
        if (context.getLoader() != null) {
            // Not started - it should check for availability first
            // This should eventually move to Engine, it's generic.
            Thread.currentThread().setContextClassLoader(context.getLoader().getClassLoader());
        }

        // Update the session last access time for our session (if any)
        HttpServletRequest httpServletRequest = (HttpServletRequest) request.getRequest();
        httpServletRequest.getSession(false);

        context.fireRequestInitializedEvent(httpServletRequest);

        return context;
    }

    private void dispatchToErrorPage(Request request, Response response, ErrorPage errorPage, Throwable throwable, Throwable realError, int statusCode) {
        response.setAppCommitted(false);

        ServletRequest servletRequest = request.getRequest();
        ServletResponse servletResponse = response.getResponse();

        servletRequest.setAttribute(DISPATCHER_REQUEST_PATH_ATTR, errorPage.getLocation());
        servletRequest.setAttribute(ERROR_REQUEST_URI, ((HttpServletRequest) servletRequest).getRequestURI());
        Wrapper wrapper = request.getWrapper();
        if (wrapper != null) {
            servletRequest.setAttribute(ERROR_SERVLET_NAME, wrapper.getName());
        }

        if (throwable != null) {
            servletRequest.setAttribute(ERROR_STATUS_CODE, Integer.valueOf(SC_INTERNAL_SERVER_ERROR));
            servletRequest.setAttribute(ERROR_MESSAGE, throwable.getMessage());
            servletRequest.setAttribute(RequestDispatcher.ERROR_EXCEPTION, realError);
            servletRequest.setAttribute(RequestDispatcher.ERROR_EXCEPTION_TYPE, realError.getClass());
        } else {
            servletRequest.setAttribute(ERROR_STATUS_CODE, Integer.valueOf(statusCode));
            String message = ((HttpResponse) response).getMessage();
            if (message == null) {
                message = "";
            }
            servletRequest.setAttribute(ERROR_MESSAGE, message);
        }

        if (custom(request, response, errorPage)) {
            try {
                servletResponse.flushBuffer();
            } catch (IOException e) {
                log("Exception processing " + errorPage, e);
            }
        }
    }

    private void setErrorPageContentType(Response response, String location, Context context) {
        if (response.getContentType() == null && location != null) {
            String contentType = location.substring(location.lastIndexOf('.') + 1);
            contentType = context.findMimeMapping(contentType.toLowerCase(ENGLISH));
            if (contentType != null) {
                ((ServletResponse) response).setContentType(contentType);
            }
        }
    }

}