/*******************************************************************************
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package at.gv.egiz.eaaf.core.impl.idp.controller;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;

import javax.naming.ConfigurationException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.text.StringEscapeUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.web.bind.annotation.ExceptionHandler;

import at.gv.egiz.components.eventlog.api.EventConstants;
import at.gv.egiz.eaaf.core.api.IRequest;
import at.gv.egiz.eaaf.core.api.IRequestStorage;
import at.gv.egiz.eaaf.core.api.IStatusMessager;
import at.gv.egiz.eaaf.core.api.data.EAAFConstants;
import at.gv.egiz.eaaf.core.api.data.ExceptionContainer;
import at.gv.egiz.eaaf.core.api.gui.IGUIBuilderConfiguration;
import at.gv.egiz.eaaf.core.api.gui.IGUIBuilderConfigurationFactory;
import at.gv.egiz.eaaf.core.api.gui.IGUIFormBuilder;
import at.gv.egiz.eaaf.core.api.gui.ModifyableGuiBuilderConfiguration;
import at.gv.egiz.eaaf.core.api.idp.IConfiguration;
import at.gv.egiz.eaaf.core.api.logging.IRevisionLogger;
import at.gv.egiz.eaaf.core.api.logging.IStatisticLogger;
import at.gv.egiz.eaaf.core.api.storage.ITransactionStorage;
import at.gv.egiz.eaaf.core.exceptions.AuthnRequestValidatorException;
import at.gv.egiz.eaaf.core.exceptions.EAAFException;
import at.gv.egiz.eaaf.core.exceptions.GUIBuildException;
import at.gv.egiz.eaaf.core.exceptions.InvalidProtocolRequestException;
import at.gv.egiz.eaaf.core.exceptions.ProcessExecutionException;
import at.gv.egiz.eaaf.core.exceptions.ProtocolNotActiveException;
import at.gv.egiz.eaaf.core.exceptions.TaskExecutionException;
import at.gv.egiz.eaaf.core.impl.utils.HTTPUtils;
import at.gv.egiz.eaaf.core.impl.utils.Random;
import at.gv.egiz.eaaf.core.impl.utils.ServletUtils;


/**
 * @author tlenz
 *
 */
public abstract class AbstractController {

	private static final Logger log = LoggerFactory.getLogger(AbstractController.class);

	@Autowired(required=true) protected ApplicationContext applicationContext;	
	@Autowired(required=true) protected IConfiguration authConfig;
	@Autowired(required=true) protected ITransactionStorage transactionStorage;
	@Autowired(required=true) protected IRequestStorage requestStorage;
	@Autowired(required=true) protected IGUIFormBuilder guiBuilder;
	@Autowired(required=true) protected IGUIBuilderConfigurationFactory guiConfigFactory;
	@Autowired(required=true) protected IStatusMessager statusMessager;
	
	@Autowired protected IStatisticLogger statisticLogger;
	@Autowired protected IRevisionLogger revisionsLogger;
	
	
	
	
	
	@ExceptionHandler({EAAFException.class})
	public void MOAIDExceptionHandler(HttpServletRequest req, HttpServletResponse resp, Exception e) throws IOException {				
		log.error(e.getMessage() , e);
		internalMOAIDExceptionHandler(req, resp, e, true);
		
	}
	
	@ExceptionHandler({Exception.class})
	public void GenericExceptionHandler(HttpServletResponse resp, Exception exception) throws IOException {
		log.error("Internel Server Error." , exception);
		resp.setContentType(EAAFConstants.CONTENTTYPE_HTML_UTF8);		
		resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Internal Server Error!" +
				"(Errorcode=9199"
				+" | Description=" 
				+ StringEscapeUtils.escapeHtml4(StringEscapeUtils.escapeEcmaScript(exception.getMessage())) 
				+ ")");
		return;
		
	}
	
	@ExceptionHandler({IOException.class})
	public void IOExceptionHandler(HttpServletResponse resp, Throwable exception) {
		log.error("Internel Server Error." , exception);
		resp.setContentType(EAAFConstants.CONTENTTYPE_HTML_UTF8);
		resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
		return;
		
	}
	
	protected void handleError(String errorMessage, Throwable exceptionThrown,
			HttpServletRequest req, HttpServletResponse resp, IRequest pendingReq) throws IOException {

		String pendingRequestID = null;
		if (pendingReq != null)
			pendingRequestID = pendingReq.getPendingRequestId();
		
		Throwable loggedException = null;
		Throwable extractedException = extractOriginalExceptionFromProcessException(exceptionThrown);
		
		//extract pendingRequestID and originalException if it was a TaskExecutionException
		if (extractedException instanceof TaskExecutionException) {
			//set original exception
			loggedException = ((TaskExecutionException) extractedException).getOriginalException();
			
			//use TaskExecutionException directly, if no Original Exeception is included
			if (loggedException == null)
				loggedException = exceptionThrown;
			
			//set pending-request ID if it is set
			String reqID = ((TaskExecutionException) extractedException).getPendingRequestID();
			if (StringUtils.isNotEmpty(reqID))
				pendingRequestID = reqID; 
						
		} else
			loggedException = exceptionThrown;
					
		try {			
			//switch to protocol-finalize method to generate a protocol-specific error message

			//log error directly in debug mode
			if (log.isDebugEnabled())
				log.warn(loggedException.getMessage(), loggedException);
				
			
			//put exception into transaction store for redirect
			String key = Random.nextLongRandom();
			if (pendingReq != null) {
				revisionsLogger.logEvent(pendingReq, EventConstants.TRANSACTION_ERROR);
				transactionStorage.put(key, 
						new ExceptionContainer(pendingReq, loggedException), -1);
			
			} else {
				transactionStorage.put(key, 
						new ExceptionContainer(null, loggedException), -1);
				
			}
			
			//build up redirect URL
			String redirectURL = null;
			redirectURL = ServletUtils.getBaseUrl(req);	
			redirectURL += "/"+AbstractAuthProtocolModulController.ENDPOINT_ERRORHANDLING 
					+ "?" + EAAFConstants.PARAM_HTTP_ERROR_CODE + "=" + key;
									
//			//only add pending-request Id if it exists 
//			if (StringUtils.isNotEmpty(pendingRequestID))							
//				redirectURL += "&" + EAAFConstants.PARAM_HTTP_TARGET_PENDINGREQUESTID + "=" + pendingRequestID;

			resp.setContentType("text/html");
			resp.setStatus(302);

			resp.addHeader("Location", redirectURL);		
			log.debug("REDIRECT TO: " + redirectURL);	

			return;
					
		} catch (Exception e) {
			log.warn("Default error-handling FAILED. Exception can not be stored ....", e);
			log.info("Switch to generic generic backup error-handling ... ");
			handleErrorNoRedirect(loggedException, req, resp, true);
			
		}

	}
		
	/**
	 * Handles all exceptions with no pending request.
	 * Therefore, the error is written to the users browser
	 * 
	 * @param throwable
	 * @param req
	 * @param resp
	 * @throws IOException 
	 */
	protected void handleErrorNoRedirect(Throwable throwable, HttpServletRequest req, 
			HttpServletResponse resp, boolean writeExceptionToStatisticLog) throws IOException {
		
		//log Exception into statistic database
		if (writeExceptionToStatisticLog)
			statisticLogger.logErrorOperation(throwable);
		
		//write errror to console
		logExceptionToTechnicalLog(throwable);
		
		//return error to Web browser
		if (throwable instanceof EAAFException || throwable instanceof ProcessExecutionException)
			internalMOAIDExceptionHandler(req, resp, (Exception)throwable, false);
		
		else {
			//write generic message for general exceptions
			String msg = statusMessager.getMessage(IStatusMessager.CODES_INTERNAL_ERROR_GENERIC, null);			
			writeHTMLErrorResponse(req, resp, msg, "9199", (Exception) throwable);
			
		}
			
	}
	
	/**
	 * Write a Exception to the MOA-ID-Auth internal technical log
	 * 
	 * @param loggedException Exception to log
	 */	
	protected void logExceptionToTechnicalLog(Throwable loggedException) {
		if (!( loggedException instanceof EAAFException 
				 || loggedException instanceof ProcessExecutionException )) {
			log.error("Receive an internal error: Message=" + loggedException.getMessage(), loggedException);
	
		} else {
			if (log.isDebugEnabled() || log.isTraceEnabled()) {
				log.warn(loggedException.getMessage(), loggedException);
	
			} else {
				log.warn(loggedException.getMessage());
	
			}			
		}		
	}
		
	private void writeBadRequestErrorResponse(HttpServletRequest req, HttpServletResponse resp, EAAFException e) throws IOException {
		String code = statusMessager.mapInternalErrorToExternalError(((InvalidProtocolRequestException)e).getErrorId());
		String descr = StringEscapeUtils.escapeHtml4(StringEscapeUtils.escapeEcmaScript(e.getMessage()));
		resp.setContentType(EAAFConstants.CONTENTTYPE_HTML_UTF8);
		resp.sendError(HttpServletResponse.SC_BAD_REQUEST, "Protocol validation FAILED!" +
				"(Errorcode=" + code +
				" | Description=" + descr + ")");
		
	}
	
	private void writeHTMLErrorResponse(HttpServletRequest req, HttpServletResponse httpResp, String msg, String errorCode, Exception error) throws IOException {

		try {
			IGUIBuilderConfiguration config 
				= guiConfigFactory.getDefaultErrorGUI(HTTPUtils.extractAuthURLFromRequest(req));

//				HTTPUtils.extractAuthURLFromRequest(req), 
//					DefaultGUIFormBuilderConfiguration.VIEW_ERRORMESSAGE, 
//					null);
				
			//add errorcode and errormessage
			if (config instanceof ModifyableGuiBuilderConfiguration) {
				((ModifyableGuiBuilderConfiguration)config).putCustomParameter("errorMsg", msg);
				((ModifyableGuiBuilderConfiguration)config).putCustomParameter("errorCode", errorCode);
				
				//add stacktrace if debug is enabled
				if (log.isTraceEnabled()) {
					((ModifyableGuiBuilderConfiguration)config).putCustomParameter("stacktrace", getStacktraceFromException(error));
				
				}
				
			} else 
				log.info("Can not ADD error message, because 'GUIBuilderConfiguration' is not modifieable ");
		
			
			
			guiBuilder.build(httpResp, config, "Error-Message");
			
		} catch (GUIBuildException e) {
			log.warn("Can not build error-message GUI.", e);
			GenericExceptionHandler(httpResp, e);
			
		}
		
	}
	
	private void writeHTMLErrorResponse(HttpServletRequest req, HttpServletResponse httpResp, Exception error) throws IOException {				
		writeHTMLErrorResponse(req, httpResp, 
				error.getMessage(), 
				statusMessager.getResponseErrorCode(error), 
				error);		
	}
	
	
	private String getStacktraceFromException(Exception ex) {
		StringWriter errors = new StringWriter();
	    ex.printStackTrace(new PrintWriter(errors));
	    return errors.toString();
	    
	}
		
	/**
	 * Extracts a TaskExecutionException of a ProcessExecutionExeception Stacktrace.
	 * 
	 * @param exception 
	 * @return Return the latest TaskExecutionExecption if exists, otherwise the latest ProcessExecutionException
	 */
	private Throwable extractOriginalExceptionFromProcessException(Throwable exception) {
		Throwable exholder = exception;
		TaskExecutionException taskExc = null;
		
		while(exholder != null 
				&& exholder instanceof ProcessExecutionException) {
			ProcessExecutionException procExc = (ProcessExecutionException) exholder;
			if (procExc.getCause() != null && 
					procExc.getCause() instanceof TaskExecutionException) {
				taskExc = (TaskExecutionException) procExc.getCause();
				exholder = taskExc.getOriginalException();
			
			} else
				break;
			
		}
				
		if (taskExc == null)
			return exholder;
		
		else
			return taskExc;
	}
	
	private void internalMOAIDExceptionHandler(HttpServletRequest req, HttpServletResponse resp, Exception e, boolean writeExceptionToStatisicLog) throws IOException {				
		if (e instanceof ProtocolNotActiveException) {
			resp.getWriter().write(e.getMessage());
			resp.setContentType(EAAFConstants.CONTENTTYPE_HTML_UTF8);
			resp.sendError(HttpServletResponse.SC_FORBIDDEN, 
					StringEscapeUtils.escapeHtml4(StringEscapeUtils.escapeEcmaScript(e.getMessage())));
		
		} else if (e instanceof AuthnRequestValidatorException) {
			AuthnRequestValidatorException ex = (AuthnRequestValidatorException)e;
			//log Error Message
			if (writeExceptionToStatisicLog)
				statisticLogger.logErrorOperation(ex, ex.getErrorRequest());
			
			//write error message
			writeBadRequestErrorResponse(req, resp, (EAAFException) e);			
		
		} else if (e instanceof InvalidProtocolRequestException) {		
			//send error response
			writeBadRequestErrorResponse(req, resp, (EAAFException) e);
			
		} else if (e instanceof ConfigurationException) {
			//send HTML formated error message
			writeHTMLErrorResponse(req, resp, (EAAFException) e);
		
		} else if (e instanceof EAAFException) {
			//send HTML formated error message
			writeHTMLErrorResponse(req, resp, e);
					
		} else if (e instanceof ProcessExecutionException) {
			//send HTML formated error message
			writeHTMLErrorResponse(req, resp, e);
					
		}
		
	}
	
}