/*
 * Copyright 2014 Red Hat, Inc.
 *
 *  All rights reserved. This program and the accompanying materials
 *  are made available under the terms of the Eclipse License v1.0
 *  and Apache License v2.0 which accompanies this distribution.
 *
 *  The Eclipse 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 io.vertx.ext.web;

import io.vertx.codegen.annotations.*;
import io.vertx.core.*;
import io.vertx.core.buffer.Buffer;
import io.vertx.core.http.*;
import io.vertx.core.http.impl.MimeMapping;
import io.vertx.core.json.EncodeException;
import io.vertx.core.json.Json;
import io.vertx.core.json.JsonArray;
import io.vertx.core.json.JsonObject;
import io.vertx.ext.auth.User;
import io.vertx.ext.web.impl.ParsableMIMEValue;
import io.vertx.ext.web.impl.Utils;

import java.nio.charset.Charset;
import java.time.Instant;
import java.util.List;
import java.util.Map;
import java.util.Set;

import static io.vertx.codegen.annotations.GenIgnore.PERMITTED_TYPE;

Represents the context for the handling of a request in Vert.x-Web.
 A new instance is created for each HTTP request that is received in the Handler<HttpServerRequest>.handle(HttpServerRequest) of the router. 

The same instance is passed to any matching request or failure handlers during the routing of the request or
failure.
 The context provides access to the HttpServerRequest and HttpServerResponse and allows you to maintain arbitrary data that lives for the lifetime of the context. Contexts are discarded once they have been routed to the handler for the request. 
 The context also provides access to the Session, cookies and body for the request, given the correct handlers in the application. 

If you use the internal error handler
Author:
Tim Fox/**
 * Represents the context for the handling of a request in Vert.x-Web.
 * <p>
 * A new instance is created for each HTTP request that is received in the
 * {@link Router#handle(Object)} of the router.
 * <p>
 * The same instance is passed to any matching request or failure handlers during the routing of the request or
 * failure.
 * <p>
 * The context provides access to the {@link HttpServerRequest} and {@link HttpServerResponse}
 * and allows you to maintain arbitrary data that lives for the lifetime of the context. Contexts are discarded once they
 * have been routed to the handler for the request.
 * <p>
 * The context also provides access to the {@link Session}, cookies and body for the request, given the correct handlers
 * in the application.
 * <p>
 * If you use the internal error handler
 *
 * @author <a href="http://tfox.org">Tim Fox</a>
 */
@VertxGen
public interface RoutingContext {

  
Returns:
the HTTP request object/**
   * @return the HTTP request object
   */
  @CacheReturn
  HttpServerRequest request();

  
Returns:
the HTTP response object/**
   * @return the HTTP response object
   */
  @CacheReturn
  HttpServerResponse response();

  
Tell the router to route this context to the next matching route (if any).
This method, if called, does not need to be called during the execution of the handler, it can be called
some arbitrary time later, if required.

If next is not called for a handler then the handler should make sure it ends the response or no response
will be sent.
/**
   * Tell the router to route this context to the next matching route (if any).
   * This method, if called, does not need to be called during the execution of the handler, it can be called
   * some arbitrary time later, if required.
   * <p>
   * If next is not called for a handler then the handler should make sure it ends the response or no response
   * will be sent.
   */
  void next();

  
Fail the context with the specified status code.
 This will cause the router to route the context to any matching failure handlers for the request. If no failure handlers match It will trigger the error handler matching the status code. You can define such error handler with Router.errorHandler(int, Handler<RoutingContext>). If no error handler is not defined, It will send a default failure response with provided status code. 
Params:
statusCode –  the HTTP status code/**
   * Fail the context with the specified status code.
   * <p>
   * This will cause the router to route the context to any matching failure handlers for the request. If no failure handlers
   * match It will trigger the error handler matching the status code. You can define such error handler with
   * {@link Router#errorHandler(int, Handler)}. If no error handler is not defined, It will send a default failure response with provided status code.
   *
   * @param statusCode  the HTTP status code
   */
  void fail(int statusCode);

  
Fail the context with the specified throwable and 500 status code.
 This will cause the router to route the context to any matching failure handlers for the request. If no failure handlers match It will trigger the error handler matching the status code. You can define such error handler with Router.errorHandler(int, Handler<RoutingContext>). If no error handler is not defined, It will send a default failure response with 500 status code. 
Params:
throwable –  a throwable representing the failure/**
   * Fail the context with the specified throwable and 500 status code.
   * <p>
   * This will cause the router to route the context to any matching failure handlers for the request. If no failure handlers
   * match It will trigger the error handler matching the status code. You can define such error handler with
   * {@link Router#errorHandler(int, Handler)}. If no error handler is not defined, It will send a default failure response with 500 status code.
   *
   * @param throwable  a throwable representing the failure
   */
  void fail(Throwable throwable);

  
Fail the context with the specified throwable and the specified the status code.
 This will cause the router to route the context to any matching failure handlers for the request. If no failure handlers match It will trigger the error handler matching the status code. You can define such error handler with Router.errorHandler(int, Handler<RoutingContext>). If no error handler is not defined, It will send a default failure response with provided status code. 
Params:
statusCode – the HTTP status code
throwable – a throwable representing the failure/**
   * Fail the context with the specified throwable and the specified the status code.
   * <p>
   * This will cause the router to route the context to any matching failure handlers for the request. If no failure handlers
   * match It will trigger the error handler matching the status code. You can define such error handler with
   * {@link Router#errorHandler(int, Handler)}. If no error handler is not defined, It will send a default failure response with provided status code.
   *
   * @param statusCode the HTTP status code
   * @param throwable a throwable representing the failure
   */
  void fail(int statusCode, Throwable throwable);

  
Put some arbitrary data in the context. This will be available in any handlers that receive the context.
Params:
key –  the key for the data
obj –  the data
Returns:
a reference to this, so the API can be used fluently/**
   * Put some arbitrary data in the context. This will be available in any handlers that receive the context.
   *
   * @param key  the key for the data
   * @param obj  the data
   * @return a reference to this, so the API can be used fluently
   */
  @Fluent
  RoutingContext put(String key, Object obj);

  
Get some data from the context. The data is available in any handlers that receive the context.
Params:
key –  the key for the data
Type parameters:
<T> –  the type of the data
Throws:
ClassCastException – if the data is not of the expected type
Returns:
 the data/**
   * Get some data from the context. The data is available in any handlers that receive the context.
   *
   * @param key  the key for the data
   * @param <T>  the type of the data
   * @return  the data
   * @throws ClassCastException if the data is not of the expected type
   */
  <T> T get(String key);

  
Remove some data from the context. The data is available in any handlers that receive the context.
Params:
key –  the key for the data
Type parameters:
<T> –  the type of the data
Throws:
ClassCastException – if the data is not of the expected type
Returns:
 the previous data associated with the key/**
   * Remove some data from the context. The data is available in any handlers that receive the context.
   *
   * @param key  the key for the data
   * @param <T>  the type of the data
   * @return  the previous data associated with the key
   * @throws ClassCastException if the data is not of the expected type
   */
  <T> T remove(String key);

  
Returns:
all the context data as a map/**
   * @return all the context data as a map
   */
  @GenIgnore(PERMITTED_TYPE)
  Map<String, Object> data();

  
Returns:
the Vert.x instance associated to the initiating Router for this context/**
   * @return the Vert.x instance associated to the initiating {@link Router} for this context
   */
  @CacheReturn
  Vertx vertx();

  
Returns:
the mount point for this router. It will be null for a top level router. For a sub-router it will be the path
at which the subrouter was mounted./**
   * @return the mount point for this router. It will be null for a top level router. For a sub-router it will be the path
   * at which the subrouter was mounted.
   */
  @Nullable String mountPoint();

  
Returns:
the current route this context is being routed through./**
   * @return the current route this context is being routed through.
   */
  Route currentRoute();

  
Use normalizedPath instead /**
   * Use {@link #normalizedPath} instead
   */
  @Deprecated()
  default String normalisedPath() {
    return this.normalizedPath();
  }

  
Return the normalized path for the request.

The normalized path is where the URI path has been decoded, i.e. any unicode or other illegal URL characters that
were encoded in the original URL with `%` will be returned to their original form. E.g. `%20` will revert to a space.
Also `+` reverts to a space in a query.

The normalized path will also not contain any `..` character sequences to prevent resources being accessed outside
of the permitted area.
 It's recommended to always use the normalized path as opposed to HttpServerRequest.path() if accessing server resources requested by a client. 
Returns:
the normalized path/**
   * Return the normalized path for the request.
   * <p>
   * The normalized path is where the URI path has been decoded, i.e. any unicode or other illegal URL characters that
   * were encoded in the original URL with `%` will be returned to their original form. E.g. `%20` will revert to a space.
   * Also `+` reverts to a space in a query.
   * <p>
   * The normalized path will also not contain any `..` character sequences to prevent resources being accessed outside
   * of the permitted area.
   * <p>
   * It's recommended to always use the normalized path as opposed to {@link HttpServerRequest#path()}
   * if accessing server resources requested by a client.
   *
   * @return the normalized path
   */
  String normalizedPath();

  
Get the cookie with the specified name.
Params:
name –  the cookie name
Returns:
the cookie/**
   * Get the cookie with the specified name.
   *
   * @param name  the cookie name
   * @return the cookie
   */
  @Nullable Cookie getCookie(String name);

  
Add a cookie. This will be sent back to the client in the response.
Params:
cookie –  the cookie
Returns:
a reference to this, so the API can be used fluently/**
   * Add a cookie. This will be sent back to the client in the response.
   *
   * @param cookie  the cookie
   * @return a reference to this, so the API can be used fluently
   */
  @Fluent
  RoutingContext addCookie(io.vertx.core.http.Cookie cookie);

  
Expire a cookie, notifying a User Agent to remove it from its cookie jar.
Params:
name –  the name of the cookie
Returns:
the cookie, if it existed, or null/**
   * Expire a cookie, notifying a User Agent to remove it from its cookie jar.
   *
   * @param name  the name of the cookie
   * @return the cookie, if it existed, or null
   */
  default @Nullable Cookie removeCookie(String name) {
    return removeCookie(name, true);
  }

  
Remove a cookie from the cookie set. If invalidate is true then it will expire a cookie, notifying a User Agent to
remove it from its cookie jar.
Params:
name –  the name of the cookie
Returns:
the cookie, if it existed, or null/**
   * Remove a cookie from the cookie set. If invalidate is true then it will expire a cookie, notifying a User Agent to
   * remove it from its cookie jar.
   *
   * @param name  the name of the cookie
   * @return the cookie, if it existed, or null
   */
  @Nullable Cookie removeCookie(String name, boolean invalidate);

  
Returns:
the number of cookies./**
   * @return the number of cookies.
   */
  int cookieCount();

  
Returns:
a map of all the cookies./**
   * @return a map of all the cookies.
   */
  Map<String, io.vertx.core.http.Cookie> cookieMap();

  
Returns:
 the entire HTTP request body as a string, assuming UTF-8 encoding if the request does not provide the content type charset attribute. If a charset is provided in the request that it shall be respected. The context must have first been routed to a BodyHandler for this to be populated./**
   * @return  the entire HTTP request body as a string, assuming UTF-8 encoding if the request does not provide the
   * content type charset attribute. If a charset is provided in the request that it shall be respected. The context
   * must have first been routed to a {@link io.vertx.ext.web.handler.BodyHandler} for this to be populated.
   */
  @Nullable String getBodyAsString();

  
Get the entire HTTP request body as a string, assuming the specified encoding. The context must have first been routed to a BodyHandler for this to be populated. 
Params:
encoding –  the encoding, e.g. "UTF-16"
Returns:
the body/**
   * Get the entire HTTP request body as a string, assuming the specified encoding. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.BodyHandler} for this to be populated.
   *
   * @param encoding  the encoding, e.g. "UTF-16"
   * @return the body
   */
  @Nullable String getBodyAsString(String encoding);

  
Gets the current body buffer as a JsonObject. If a positive limit is provided the parsing will only happen if the buffer length is smaller or equal to the limit. Otherwise an IllegalStateException is thrown. When the application is only handling uploads in JSON format, it is recommended to set a limit on BodyHandler.setBodyLimit(long) as this will avoid the upload to be parsed and loaded into the application memory. 
Params:
maxAllowedLength – if the current buffer length is greater than the limit an IllegalStateException is thrown. This can be used to avoid DDoS attacks on very long JSON payloads that could take over the CPU while attempting to parse the data.
Returns:
Get the entire HTTP request body as a JsonObject. The context must have first been routed to a BodyHandler for this to be populated. 
 When the body is null or the "null" JSON literal then null is returned./**
   * Gets the current body buffer as a {@link JsonObject}. If a positive limit is provided the parsing will only happen
   * if the buffer length is smaller or equal to the limit. Otherwise an {@link IllegalStateException} is thrown.
   *
   * When the application is only handling uploads in JSON format, it is recommended to set a limit on
   * {@link io.vertx.ext.web.handler.BodyHandler#setBodyLimit(long)} as this will avoid the upload to be parsed and
   * loaded into the application memory.
   *
   * @param maxAllowedLength if the current buffer length is greater than the limit an {@link IllegalStateException} is
   *                         thrown. This can be used to avoid DDoS attacks on very long JSON payloads that could take
   *                         over the CPU while attempting to parse the data.
   *
   * @return Get the entire HTTP request body as a {@link JsonObject}. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.BodyHandler} for this to be populated.
   * <br/>
   * When the body is {@code null} or the {@code "null"} JSON literal then {@code null} is returned.
   */
  @Nullable JsonObject getBodyAsJson(int maxAllowedLength);

  
Gets the current body buffer as a JsonArray. If a positive limit is provided the parsing will only happen if the buffer length is smaller or equal to the limit. Otherwise an IllegalStateException is thrown. When the application is only handling uploads in JSON format, it is recommended to set a limit on BodyHandler.setBodyLimit(long) as this will avoid the upload to be parsed and loaded into the application memory. 
Params:
maxAllowedLength – if the current buffer length is greater than the limit an IllegalStateException is thrown. This can be used to avoid DDoS attacks on very long JSON payloads that could take over the CPU while attempting to parse the data.
Returns:
Get the entire HTTP request body as a JsonArray. The context must have first been routed to a BodyHandler for this to be populated. 
 When the body is null or the "null" JSON literal then null is returned./**
   * Gets the current body buffer as a {@link JsonArray}. If a positive limit is provided the parsing will only happen
   * if the buffer length is smaller or equal to the limit. Otherwise an {@link IllegalStateException} is thrown.
   *
   * When the application is only handling uploads in JSON format, it is recommended to set a limit on
   * {@link io.vertx.ext.web.handler.BodyHandler#setBodyLimit(long)} as this will avoid the upload to be parsed and
   * loaded into the application memory.
   *
   * @param maxAllowedLength if the current buffer length is greater than the limit an {@link IllegalStateException} is
   *                         thrown. This can be used to avoid DDoS attacks on very long JSON payloads that could take
   *                         over the CPU while attempting to parse the data.
   *
   * @return Get the entire HTTP request body as a {@link JsonArray}. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.BodyHandler} for this to be populated.
   * <br/>
   * When the body is {@code null} or the {@code "null"} JSON literal then {@code null} is returned.
   */
  @Nullable JsonArray getBodyAsJsonArray(int maxAllowedLength);

  
Returns:
Get the entire HTTP request body as a JsonObject. The context must have first been routed to a BodyHandler for this to be populated. 
 When the body is null or the "null" JSON literal then null is returned./**
   * @return Get the entire HTTP request body as a {@link JsonObject}. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.BodyHandler} for this to be populated.
   * <br/>
   * When the body is {@code null} or the {@code "null"} JSON literal then {@code null} is returned.
   */
  default @Nullable JsonObject getBodyAsJson() {
    return getBodyAsJson(-1);
  }

  
Returns:
Get the entire HTTP request body as a JsonArray. The context must have first been routed to a BodyHandler for this to be populated. 
 When the body is null or the "null" JSON literal then null is returned./**
   * @return Get the entire HTTP request body as a {@link JsonArray}. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.BodyHandler} for this to be populated.
   * <br/>
   * When the body is {@code null} or the {@code "null"} JSON literal then {@code null} is returned.
   */
  default @Nullable JsonArray getBodyAsJsonArray() {
    return getBodyAsJsonArray(-1);
  }

  
Returns:
Get the entire HTTP request body as a Buffer. The context must have first been routed to a BodyHandler for this to be populated./**
   * @return Get the entire HTTP request body as a {@link Buffer}. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.BodyHandler} for this to be populated.
   */
  @Nullable Buffer getBody();

  
Returns:
a set of fileuploads (if any) for the request. The context must have first been routed to a BodyHandler for this to work./**
   * @return a set of fileuploads (if any) for the request. The context must have first been routed to a
   * {@link io.vertx.ext.web.handler.BodyHandler} for this to work.
   */
  Set<FileUpload> fileUploads();

  
Get the session. The context must have first been routed to a SessionHandler for this to be populated. Sessions live for a browser session, and are maintained by session cookies. 
Returns:
 the session./**
   * Get the session. The context must have first been routed to a {@link io.vertx.ext.web.handler.SessionHandler}
   * for this to be populated.
   * Sessions live for a browser session, and are maintained by session cookies.
   * @return  the session.
   */
  @Nullable Session session();

  
Whether the session() has been already called or not. This is usually used by the SessionHandler. 
Returns:
true if the session has been accessed./**
   * Whether the {@link RoutingContext#session()} has been already called or not. This is usually used by the
   * {@link io.vertx.ext.web.handler.SessionHandler}.
   *
   * @return true if the session has been accessed.
   */
  boolean isSessionAccessed();

  
Get the authenticated user (if any). This will usually be injected by an auth handler if authentication if successful.
Returns:
 the user, or null if the current user is not authenticated./**
   * Get the authenticated user (if any). This will usually be injected by an auth handler if authentication if successful.
   * @return  the user, or null if the current user is not authenticated.
   */
  @Nullable User user();

  
If the context is being routed to failure handlers after a failure has been triggered by calling fail(Throwable) then this will return that throwable. It can be used by failure handlers to render a response, e.g. create a failure response page. 
Returns:
 the throwable used when signalling failure/**
   * If the context is being routed to failure handlers after a failure has been triggered by calling
   * {@link #fail(Throwable)} then this will return that throwable. It can be used by failure handlers to render a response,
   * e.g. create a failure response page.
   *
   * @return  the throwable used when signalling failure
   */
  @CacheReturn
  @Nullable
  Throwable failure();

  
If the context is being routed to failure handlers after a failure has been triggered by calling fail(int) then this will return that status code. It can be used by failure handlers to render a response, e.g. create a failure response page. When the status code has not been set yet (it is undefined) its value will be -1. 
Returns:
 the status code used when signalling failure/**
   * If the context is being routed to failure handlers after a failure has been triggered by calling
   * {@link #fail(int)}  then this will return that status code.  It can be used by failure handlers to render a response,
   * e.g. create a failure response page.
   *
   * When the status code has not been set yet (it is undefined) its value will be -1.
   *
   * @return  the status code used when signalling failure
   */
  @CacheReturn
  int statusCode();

  
If the route specifies produces matches, e.g. produces `text/html` and `text/plain`, and the `accept` header
matches one or more of these then this returns the most acceptable match.
Returns:
 the most acceptable content type./**
   * If the route specifies produces matches, e.g. produces `text/html` and `text/plain`, and the `accept` header
   * matches one or more of these then this returns the most acceptable match.
   *
   * @return  the most acceptable content type.
   */
  @Nullable String getAcceptableContentType();

  
The headers:

Accept
Accept-Charset
Accept-Encoding
Accept-Language
Content-Type
 Parsed into ParsedHeaderValue 
Returns:
A container with the parsed headers./**
   * The headers:
   * <ol>
   * <li>Accept</li>
   * <li>Accept-Charset</li>
   * <li>Accept-Encoding</li>
   * <li>Accept-Language</li>
   * <li>Content-Type</li>
   * </ol>
   * Parsed into {@link ParsedHeaderValue}
   * @return A container with the parsed headers.
   */
  @CacheReturn
  ParsedHeaderValues parsedHeaders();

  
Add a handler that will be called just before headers are written to the response. This gives you a hook where
you can write any extra headers before the response has been written when it will be too late.
Params:
handler –  the handler
Returns:
 the id of the handler. This can be used if you later want to remove the handler./**
   * Add a handler that will be called just before headers are written to the response. This gives you a hook where
   * you can write any extra headers before the response has been written when it will be too late.
   *
   * @param handler  the handler
   * @return  the id of the handler. This can be used if you later want to remove the handler.
   */
  int addHeadersEndHandler(Handler<Void> handler);

  
Remove a headers end handler
Params:
handlerID –  the id as returned from addHeadersEndHandler(Handler<Void>).
Returns:
true if the handler existed and was removed, false otherwise/**
   * Remove a headers end handler
   *
   * @param handlerID  the id as returned from {@link io.vertx.ext.web.RoutingContext#addHeadersEndHandler(Handler)}.
   * @return true if the handler existed and was removed, false otherwise
   */
  boolean removeHeadersEndHandler(int handlerID);

  
Provides a handler that will be called after the last part of the body is written to the wire.
The handler is called asynchronously of when the response has been received by the client.
This provides a hook allowing you to do more operations once the request has been sent over the wire.
Do not use this for resource cleanup as this handler might never get called (e.g. if the connection is reset).
Params:
handler –  the handler
Returns:
 the id of the handler. This can be used if you later want to remove the handler./**
   * Provides a handler that will be called after the last part of the body is written to the wire.
   * The handler is called asynchronously of when the response has been received by the client.
   * This provides a hook allowing you to do more operations once the request has been sent over the wire.
   * Do not use this for resource cleanup as this handler might never get called (e.g. if the connection is reset).
   *
   * @param handler  the handler
   * @return  the id of the handler. This can be used if you later want to remove the handler.
   */
  int addBodyEndHandler(Handler<Void> handler);

  
Remove a body end handler
Params:
handlerID –  the id as returned from addBodyEndHandler(Handler<Void>).
Returns:
true if the handler existed and was removed, false otherwise/**
   * Remove a body end handler
   *
   * @param handlerID  the id as returned from {@link io.vertx.ext.web.RoutingContext#addBodyEndHandler(Handler)}.
   * @return true if the handler existed and was removed, false otherwise
   */
  boolean removeBodyEndHandler(int handlerID);

  
Add an end handler for the request/response context. This will be called when the response is disposed or an
exception has been encountered to allow consistent cleanup. The handler is called asynchronously of when the
response has been received by the client.
Params:
handler – the handler that will be called with either a success or failure result.
Returns:
 the id of the handler. This can be used if you later want to remove the handler./**
   * Add an end handler for the request/response context. This will be called when the response is disposed or an
   * exception has been encountered to allow consistent cleanup. The handler is called asynchronously of when the
   * response has been received by the client.
   *
   * @param handler the handler that will be called with either a success or failure result.
   * @return  the id of the handler. This can be used if you later want to remove the handler.
   */
  int addEndHandler(Handler<AsyncResult<Void>> handler);

  
Add an end handler for the request/response context. This will be called when the response is disposed or an
exception has been encountered to allow consistent cleanup. The handler is called asynchronously of when the
response has been received by the client.
See Also:
addEndHandler(Handler)
Returns:
future that will be called with either a success or failure result./**
   * Add an end handler for the request/response context. This will be called when the response is disposed or an
   * exception has been encountered to allow consistent cleanup. The handler is called asynchronously of when the
   * response has been received by the client.
   *
   * @see #addEndHandler(Handler)
   *
   * @return future that will be called with either a success or failure result.
   */
  default Future<Void> addEndHandler() {
    Promise<Void> promise = Promise.promise();
    addEndHandler(promise);
    return promise.future();
  }

  
Remove an end handler
Params:
handlerID –  the id as returned from addEndHandler(Handler<AsyncResult<Void>>).
Returns:
true if the handler existed and was removed, false otherwise/**
   * Remove an end handler
   *
   * @param handlerID  the id as returned from {@link io.vertx.ext.web.RoutingContext#addEndHandler(Handler)}.
   * @return true if the handler existed and was removed, false otherwise
   */
  boolean removeEndHandler(int handlerID);

  
Returns:
true if the context is being routed to failure handlers./**
   * @return true if the context is being routed to failure handlers.
   */
  boolean failed();

  
Set the body. Used by the BodyHandler. You will not normally call this method. 
Params:
body –  the body/**
   * Set the body. Used by the {@link io.vertx.ext.web.handler.BodyHandler}. You will not normally call this method.
   *
   * @param body  the body
   */
  void setBody(Buffer body);

  
Set the session. Used by the SessionHandler. You will not normally call this method. 
Params:
session –  the session/**
   * Set the session. Used by the {@link io.vertx.ext.web.handler.SessionHandler}. You will not normally call this method.
   *
   * @param session  the session
   */
  void setSession(Session session);

  
Set the user. Usually used by auth handlers to inject a User. You will not normally call this method.
Params:
user –  the user/**
   * Set the user. Usually used by auth handlers to inject a User. You will not normally call this method.
   *
   * @param user  the user
   */
  void setUser(User user);

  
Clear the current user object in the context. This usually is used for implementing a log out feature, since the
current user is unbounded from the routing context.
/**
   * Clear the current user object in the context. This usually is used for implementing a log out feature, since the
   * current user is unbounded from the routing context.
   */
  void clearUser();

  
Set the acceptable content type. Used by
Params:
contentType –  the content type/**
   * Set the acceptable content type. Used by
   * @param contentType  the content type
   */
  void setAcceptableContentType(@Nullable String contentType);

  
Restarts the current router with a new path and reusing the original method. All path parameters are then parsed
and available on the params list. Query params will also be allowed and available.
Params:
path – the new http path./**
   * Restarts the current router with a new path and reusing the original method. All path parameters are then parsed
   * and available on the params list. Query params will also be allowed and available.
   *
   * @param path the new http path.
   */
  default void reroute(String path) {
    reroute(request().method(), path);
  }

  
Restarts the current router with a new method and path. All path parameters are then parsed and available on the
params list. Query params will also be allowed and available.
Params:
method – the new http request
path – the new http path./**
   * Restarts the current router with a new method and path. All path parameters are then parsed and available on the
   * params list. Query params will also be allowed and available.
   *
   * @param method the new http request
   * @param path the new http path.
   */
  void reroute(HttpMethod method, String path);

  
Returns the languages for the current request. The languages are determined from the Accept-Language
header and sorted on quality.
When 2 or more entries have the same quality then the order used to return the best match is based on the lowest
index on the original list. For example if a user has en-US and en-GB with same quality and this order the best
match will be en-US because it was declared as first entry by the client.
Returns:
The best matched language for the request/**
   * Returns the languages for the current request. The languages are determined from the <code>Accept-Language</code>
   * header and sorted on quality.
   *
   * When 2 or more entries have the same quality then the order used to return the best match is based on the lowest
   * index on the original list. For example if a user has en-US and en-GB with same quality and this order the best
   * match will be en-US because it was declared as first entry by the client.
   *
   * @return The best matched language for the request
   */
  @CacheReturn
  default List<LanguageHeader> acceptableLanguages(){
    return parsedHeaders().acceptLanguage();
  }

  
Helper to return the user preferred language.
It is the same action as returning the first element of the acceptable languages.
Returns:
the users preferred locale./**
   * Helper to return the user preferred language.
   * It is the same action as returning the first element of the acceptable languages.
   *
   * @return the users preferred locale.
   */
  @CacheReturn
  default LanguageHeader preferredLanguage() {
    List<? extends LanguageHeader> acceptableLanguages = acceptableLanguages();
    return acceptableLanguages.size() > 0 ? acceptableLanguages.get(0) : null;
  }

  
Returns a map of named parameters as defined in path declaration with their actual values
Returns:
the map of named parameters/**
   * Returns a map of named parameters as defined in path declaration with their actual values
   *
   * @return the map of named parameters
   */
  Map<String, String> pathParams();

  
Gets the value of a single path parameter
Params:
name – the name of parameter as defined in path declaration
Returns:
the actual value of the parameter or null if it doesn't exist/**
   * Gets the value of a single path parameter
   *
   * @param name the name of parameter as defined in path declaration
   * @return the actual value of the parameter or null if it doesn't exist
   */
  @Nullable
  String pathParam(String name);

  
Returns a map of all query parameters inside the query string

The query parameters are lazily decoded: the decoding happens on the first time this method is called. If the query string is invalid
it fails the context
Returns:
the multimap of query parameters/**
   * Returns a map of all query parameters inside the <a href="https://en.wikipedia.org/wiki/Query_string">query string</a><br/>
   * The query parameters are lazily decoded: the decoding happens on the first time this method is called. If the query string is invalid
   * it fails the context
   *
   * @return the multimap of query parameters
   */
  MultiMap queryParams();

  
Always decode the current query string with the given encoding. The decode result is never cached. Callers to this method are expected to cache the result if needed. Usually users should use queryParams(). This method is only useful when the requests without content type (GET requests as an example) expect that query params are in the ASCII format ISO-5559-1. 
Params:
encoding – a non null character set.
Returns:
the multimap of query parameters/**
   * Always decode the current query string with the given {@code encoding}. The decode result is never cached. Callers
   * to this method are expected to cache the result if needed. Usually users should use {@link #queryParams()}.
   *
   * This method is only useful when the requests without content type ({@code GET} requests as an example) expect that
   * query params are in the ASCII format {@code ISO-5559-1}.
   *
   * @param encoding a non null character set.
   * @return the multimap of query parameters
   */
  @GenIgnore(PERMITTED_TYPE)
  MultiMap queryParams(Charset encoding);

  
Gets the value of a single query parameter. For more info queryParams() 
Params:
name – The name of query parameter
Returns:
The list of all parameters matching the parameter name. It returns an empty list if no query parameter with name was found/**
   * Gets the value of a single query parameter. For more info {@link RoutingContext#queryParams()}
   *
   * @param name The name of query parameter
   * @return The list of all parameters matching the parameter name. It returns an empty list if no query parameter with {@code name} was found
   */
  List<String> queryParam(String name);

  
Set Content-Disposition get to "attachment" with optional filename mime type. 
Params:
filename – the filename for the attachment/**
   * Set Content-Disposition get to "attachment" with optional {@code filename} mime type.
   *
   * @param filename the filename for the attachment
   */
  @Fluent
  default RoutingContext attachment(String filename) {
    if (filename != null) {
      String contentType = MimeMapping.getMimeTypeForFilename(filename);

      if (contentType != null) {
        response()
          .putHeader(HttpHeaders.CONTENT_TYPE, contentType);
      }

    }

    response()
      .putHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=" + filename);

    return this;
  }

  
Perform a 302 redirect to url. If a custom 3xx code is already defined, then that one will be preferred. 

The string "back" is special-cased
to provide Referrer support, when Referrer
is not present "/" is used.

Examples:

redirect('back');
redirect('/login');
redirect('http://google.com');
Params:
url – the target url/**
   * Perform a 302 redirect to {@code url}. If a custom 3xx code is already defined, then that
   * one will be preferred.
   * <p/>
   * The string "back" is special-cased
   * to provide Referrer support, when Referrer
   * is not present "/" is used.
   * <p/>
   * Examples:
   * <p/>
   * redirect('back');
   * redirect('/login');
   * redirect('http://google.com');
   *
   * @param url the target url
   */
  default Future<Void> redirect(String url) {
    // location
    if ("back".equals(url)) {
      url = request().getHeader(HttpHeaders.REFERER);
      if (url == null) {
        url = "/";
      }
    }

    response()
      .putHeader(HttpHeaders.LOCATION, url);

    // status
    int status = response().getStatusCode();

    if (status < 300 || status >= 400) {
      // if a custom code is in use that will be
      // respected
      response().setStatusCode(302);
    }

    return response()
      .putHeader(HttpHeaders.CONTENT_TYPE, "text/plain; charset=utf-8")
      .end("Redirecting to " + url + ".");
  }

  
See redirect(String). /**
   * See {@link #redirect(String)}.
   */
  @Fluent
  default RoutingContext redirect(String url, Handler<AsyncResult<Void>> handler) {
    redirect(url).onComplete(handler);
    return this;
  }

  
Encode an Object to JSON and end the request.
The method will apply the correct content type to the response,
perform the encoding and end.
Params:
json – the json
Returns:
a future to handle the end of the request/**
   * Encode an Object to JSON and end the request.
   * The method will apply the correct content type to the response,
   * perform the encoding and end.
   *
   * @param json the json
   * @return a future to handle the end of the request
   */
  default Future<Void> json(Object json) {
    final HttpServerResponse res = response();

    if (json == null) {
      // apply the content type header
      res.putHeader(HttpHeaders.CONTENT_TYPE, "application/json; charset=utf-8");
      return res.end("null");
    } else {
      try {
        Buffer buffer = Json.encodeToBuffer(json);
        // apply the content type header only if the encoding succeeds
        res.putHeader(HttpHeaders.CONTENT_TYPE, "application/json; charset=utf-8");
        return res.end(buffer);
      } catch (EncodeException | UnsupportedOperationException e) {
        // handle the failure
        fail(e);
        // as the operation failed return a failed future
        // this is purely a notification
        return Future.failedFuture(e);
      }
    }
  }

  
See json(Object). /**
   * See {@link #json(Object)}.
   */
  @Fluent
  default RoutingContext json(Object json, Handler<AsyncResult<Void>> handler) {
    json(json).onComplete(handler);
    return this;
  }

  
Check if the incoming request contains the "Content-Type"
get field, and it contains the give mime `type`.
If there is no request body, `false` is returned.
If there is no content type, `false` is returned.
Otherwise, it returns true if the `type` that matches.

Examples:

// With Content-Type: text/html; charset=utf-8
is("html"); // => true
is("text/html"); // => true

// When Content-Type is application/json
is("application/json"); // => true
is("html"); // => false
Params:
type – content type
Returns:
The most close value/**
   * Check if the incoming request contains the "Content-Type"
   * get field, and it contains the give mime `type`.
   * If there is no request body, `false` is returned.
   * If there is no content type, `false` is returned.
   * Otherwise, it returns true if the `type` that matches.
   * <p/>
   * Examples:
   * <p/>
   * // With Content-Type: text/html; charset=utf-8
   * is("html"); // => true
   * is("text/html"); // => true
   * <p/>
   * // When Content-Type is application/json
   * is("application/json"); // => true
   * is("html"); // => false
   *
   * @param type content type
   * @return The most close value
   */
  @CacheReturn
  default boolean is(String type) {
    MIMEHeader contentType = parsedHeaders().contentType();

    if (contentType == null) {
      return false;
    }

    ParsedHeaderValue value;


    // if we received an incomplete CT
    if (type.indexOf('/') == -1) {
      // when the content is incomplete we assume */type, e.g.:
      // json -> */json
      value = new ParsableMIMEValue("*/" + type).forceParse();
    } else {
      value = new ParsableMIMEValue(type).forceParse();
    }

    return contentType.isMatchedBy(value);
  }

  
Check if the request is fresh, aka
Last-Modified and/or the ETag
still match.
Returns:
true if content is fresh according to the cache./**
   * Check if the request is fresh, aka
   * Last-Modified and/or the ETag
   * still match.
   *
   * @return true if content is fresh according to the cache.
   */
  default boolean isFresh() {
    final HttpMethod method = request().method();

    // GET or HEAD for weak freshness validation only
    if (method != HttpMethod.GET && method != HttpMethod.HEAD) {
      return false;
    }

    final int s = response().getStatusCode();
    // 2xx or 304 as per rfc2616 14.26
    if ((s >= 200 && s < 300) || 304 == s) {
      return Utils.fresh(this);
    }

    return false;
  }

  
Set the ETag of a response.
This will normalize the quotes if necessary.

etag('md5hashsum');
etag('"md5hashsum"');
('W/"123456789"');
Params:
etag – the etag value/**
   * Set the ETag of a response.
   * This will normalize the quotes if necessary.
   * <p/>
   * etag('md5hashsum');
   * etag('"md5hashsum"');
   * ('W/"123456789"');
   *
   * @param etag the etag value
   */
  @Fluent
  default RoutingContext etag(String etag) {
    boolean quoted =
      // at least 2 characters
      etag.length() > 2 &&
        // either starts with " or W/"
        (etag.charAt(0) == '\"' || etag.startsWith("W/\"")) &&
        // ends with "
        etag.charAt(etag.length() -1) == '\"';

    if (!quoted) {
      response().putHeader(HttpHeaders.ETAG, "\"" + etag + "\"");
    } else {
      response().putHeader(HttpHeaders.ETAG, etag);
    }

    return this;
  }

  
Set the Last-Modified date using a Instant.
Params:
instant – the last modified instant/**
   * Set the Last-Modified date using a Instant.
   *
   * @param instant the last modified instant
   */
  @Fluent
  @GenIgnore(PERMITTED_TYPE)
  default RoutingContext lastModified(Instant instant) {
    response().putHeader(HttpHeaders.LAST_MODIFIED, Utils.formatRFC1123DateTime(instant.toEpochMilli()));
    return this;
  }

  
Set the Last-Modified date using a String.
Params:
instant – the last modified instant/**
   * Set the Last-Modified date using a String.
   *
   * @param instant the last modified instant
   */
  @Fluent
  default RoutingContext lastModified(String instant) {
    response().putHeader(HttpHeaders.LAST_MODIFIED, instant);
    return this;
  }

  
Shortcut to the response end.
Params:
chunk – a chunk
Returns:
future/**
   * Shortcut to the response end.
   * @param chunk a chunk
   * @return future
   */
  default Future<Void> end(String chunk) {
    return response().end(chunk);
  }

  
See end(String) /**
   * See {@link #end(String)}
   */
  @Fluent
  default RoutingContext end(String chunk, Handler<AsyncResult<Void>> handler) {
    end(chunk).onComplete(handler);
    return this;
  }

  
Shortcut to the response end.
Params:
buffer – a chunk
Returns:
future/**
   * Shortcut to the response end.
   * @param buffer a chunk
   * @return future
   */
  default Future<Void> end(Buffer buffer) {
    return response().end(buffer);
  }

  
See end(Buffer) /**
   * See {@link #end(Buffer)}
   */
  @Fluent
  default RoutingContext end(Buffer buffer, Handler<AsyncResult<Void>> handler) {
    end(buffer).onComplete(handler);
    return this;
  }

  
Shortcut to the response end.
Returns:
future/**
   * Shortcut to the response end.
   * @return future
   */
  default Future<Void> end() {
    return response().end();
  }

  
See end() /**
   * See {@link #end()}
   */
  @Fluent
  default RoutingContext end(Handler<AsyncResult<Void>> handler) {
    end().onComplete(handler);
    return this;
  }
}