/*
 * Copyright (c) 2011-2017 Contributors to the Eclipse Foundation
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 * which is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 */

package io.vertx.core.http;

import io.netty.handler.codec.http2.Http2CodecUtil;
import io.vertx.codegen.annotations.*;
import io.vertx.core.Handler;
import io.vertx.core.MultiMap;
import io.vertx.core.buffer.Buffer;
import io.vertx.core.net.NetSocket;
import io.vertx.core.net.SocketAddress;
import io.vertx.core.streams.ReadStream;

import javax.net.ssl.SSLPeerUnverifiedException;
import javax.net.ssl.SSLSession;
import javax.security.cert.X509Certificate;

Represents a server-side HTTP request.

Instances are created for each request and passed to the user via a handler.
 Each instance of this class is associated with a corresponding HttpServerResponse instance via response.
 It implements ReadStream so it can be used with Pump to pump data with flow control. 

Author:
Tim Fox/**
 * Represents a server-side HTTP request.
 * <p>
 * Instances are created for each request and passed to the user via a handler.
 * <p>
 * Each instance of this class is associated with a corresponding {@link HttpServerResponse} instance via
 * {@link #response}.<p>
 * It implements {@link io.vertx.core.streams.ReadStream} so it can be used with
 * {@link io.vertx.core.streams.Pump} to pump data with flow control.
 * <p>
 *
 * @author <a href="http://tfox.org">Tim Fox</a>
 */
@VertxGen
public interface HttpServerRequest extends ReadStream<Buffer> {

  @Override
  HttpServerRequest exceptionHandler(Handler<Throwable> handler);

  @Override
  HttpServerRequest handler(Handler<Buffer> handler);

  @Override
  HttpServerRequest pause();

  @Override
  HttpServerRequest resume();

  @Override
  HttpServerRequest fetch(long amount);

  @Override
  HttpServerRequest endHandler(Handler<Void> endHandler);

  
Returns:
the HTTP version of the request/**
   * @return the HTTP version of the request
   */
  HttpVersion version();

  
Returns:
the HTTP method for the request./**
   * @return the HTTP method for the request.
   */
  HttpMethod method();

  
Returns:
the HTTP method as sent by the client/**
   * @return the HTTP method as sent by the client
   */
  String rawMethod();

  
Returns:
true if this NetSocket is encrypted via SSL/TLS/**
   * @return true if this {@link io.vertx.core.net.NetSocket} is encrypted via SSL/TLS
   */
  boolean isSSL();

  
Returns:
the scheme of the request/**
   * @return the scheme of the request
   */
  @Nullable
  String scheme();

  
Returns:
the URI of the request. This is usually a relative URI/**
   * @return the URI of the request. This is usually a relative URI
   */
  String uri();

  
Returns:
The path part of the uri. For example /somepath/somemorepath/someresource.foo/**
   * @return The path part of the uri. For example /somepath/somemorepath/someresource.foo
   */
  @Nullable
  String path();

  
Returns:
the query part of the uri. For example someparam=32&someotherparam=x/**
   * @return the query part of the uri. For example someparam=32&amp;someotherparam=x
   */
  @Nullable
  String query();

  
Returns:
the request host. For HTTP2 it returns the :authority pseudo header otherwise it returns the Host header/**
   * @return the request host. For HTTP2 it returns the {@literal :authority} pseudo header otherwise it returns the {@literal Host} header
   */
  @Nullable
  String host();

  
Returns:
the total number of bytes read for the body of the request./**
   * @return the total number of bytes read for the body of the request.
   */
  long bytesRead();

  
Returns:
the response. Each instance of this class has an HttpServerResponse instance attached to it. This is used to send the response back to the client./**
   * @return the response. Each instance of this class has an {@link HttpServerResponse} instance attached to it. This is used
   * to send the response back to the client.
   */
  @CacheReturn
  HttpServerResponse response();

  
Returns:
the headers in the request./**
   * @return the headers in the request.
   */
  @CacheReturn
  MultiMap headers();

  
Return the first header value with the specified name
Params:
headerName –  the header name
Returns:
the header value/**
   * Return the first header value with the specified name
   *
   * @param headerName  the header name
   * @return the header value
   */
  @Nullable
  String getHeader(String headerName);

  
Return the first header value with the specified name
Params:
headerName –  the header name
Returns:
the header value/**
   * Return the first header value with the specified name
   *
   * @param headerName  the header name
   * @return the header value
   */
  @GenIgnore(GenIgnore.PERMITTED_TYPE)
  String getHeader(CharSequence headerName);

  
Returns:
the query parameters in the request/**
   * @return the query parameters in the request
   */
  @CacheReturn
  MultiMap params();

  
Return the first param value with the specified name
Params:
paramName –  the param name
Returns:
the param value/**
   * Return the first param value with the specified name
   *
   * @param paramName  the param name
   * @return the param value
   */
  @Nullable
  String getParam(String paramName);


  
Returns:
the remote (client side) address of the request/**
   * @return the remote (client side) address of the request
   */
  @CacheReturn
  SocketAddress remoteAddress();

  
Returns:
the local (server side) address of the server that handles the request/**
   * @return the local (server side) address of the server that handles the request
   */
  @CacheReturn
  SocketAddress localAddress();

  
See Also:
SSLSession
Returns:
SSLSession associated with the underlying socket. Returns null if connection is
        not SSL./**
   * @return SSLSession associated with the underlying socket. Returns null if connection is
   *         not SSL.
   * @see javax.net.ssl.SSLSession
   */
  @GenIgnore(GenIgnore.PERMITTED_TYPE)
  SSLSession sslSession();

  
Note: Java SE 5+ recommends to use javax.net.ssl.SSLSession#getPeerCertificates() instead of of javax.net.ssl.SSLSession#getPeerCertificateChain() which this method is based on. Use sslSession() to access that method. 
Throws:
SSLPeerUnverifiedException – SSL peer's identity has not been verified.
See Also:
SSLSession.getPeerCertificateChain()
sslSession()
Returns:
an ordered array of the peer certificates. Returns null if connection is
        not SSL./**
   * Note: Java SE 5+ recommends to use javax.net.ssl.SSLSession#getPeerCertificates() instead of
   * of javax.net.ssl.SSLSession#getPeerCertificateChain() which this method is based on. Use {@link #sslSession()} to
   * access that method.
   *
   * @return an ordered array of the peer certificates. Returns null if connection is
   *         not SSL.
   * @throws javax.net.ssl.SSLPeerUnverifiedException SSL peer's identity has not been verified.
   * @see javax.net.ssl.SSLSession#getPeerCertificateChain()
   * @see #sslSession()
   */
  @GenIgnore
  X509Certificate[] peerCertificateChain() throws SSLPeerUnverifiedException;

  
Returns:
the absolute URI corresponding to the the HTTP request/**
   * @return the absolute URI corresponding to the the HTTP request
   */
  String absoluteURI();

  
Convenience method for receiving the entire request body in one piece.

This saves the user having to manually setting a data and end handler and append the chunks of the body until
the whole body received. Don't use this if your request body is large - you could potentially run out of RAM.
Params:
bodyHandler – This handler will be called after all the body has been received/**
   * Convenience method for receiving the entire request body in one piece.
   * <p>
   * This saves the user having to manually setting a data and end handler and append the chunks of the body until
   * the whole body received. Don't use this if your request body is large - you could potentially run out of RAM.
   *
   * @param bodyHandler This handler will be called after all the body has been received
   */
  @Fluent
  default HttpServerRequest bodyHandler(@Nullable Handler<Buffer> bodyHandler) {
    if (bodyHandler != null) {
      Buffer body = Buffer.buffer();
      handler(body::appendBuffer);
      endHandler(v -> bodyHandler.handle(body));
    }
    return this;
  }

  
Get a net socket for the underlying connection of this request.

This method must be called before the server response is ended.
 With CONNECT requests, a 200 response is sent with no content-length header set before returning the socket. 

server.requestHandler(req -> {
  if (req.method() == HttpMethod.CONNECT) {
    // Send a 200 response to accept the connect
    NetSocket socket = req.netSocket();
    socket.handler(buff -> {
      socket.write(buff);
    });
  }
  ...
});


For other HTTP/1 requests once you have called this method, you must handle writing to the connection yourself using
the net socket, the server request instance will no longer be usable as normal. USE THIS WITH CAUTION! Writing to the socket directly if you don't know what you're
doing can easily break the HTTP protocol.
 With HTTP/2, a 200 response is always sent with no content-length header set before returning the socket like in the CONNECT case above. 

Throws:
IllegalStateException – when the socket can't be created
Returns:
the net socket/**
   * Get a net socket for the underlying connection of this request.
   * <p/>
   * This method must be called before the server response is ended.
   * <p/>
   * With {@code CONNECT} requests, a {@code 200} response is sent with no {@code content-length} header set
   * before returning the socket.
   * <p/>
   * <pre>
   * server.requestHandler(req -> {
   *   if (req.method() == HttpMethod.CONNECT) {
   *     // Send a 200 response to accept the connect
   *     NetSocket socket = req.netSocket();
   *     socket.handler(buff -> {
   *       socket.write(buff);
   *     });
   *   }
   *   ...
   * });
   * </pre>
   * <p/>
   * For other HTTP/1 requests once you have called this method, you must handle writing to the connection yourself using
   * the net socket, the server request instance will no longer be usable as normal. USE THIS WITH CAUTION! Writing to the socket directly if you don't know what you're
   * doing can easily break the HTTP protocol.
   * <p/>
   * With HTTP/2, a {@code 200} response is always sent with no {@code content-length} header set before returning the socket
   * like in the {@code CONNECT} case above.
   * <p/>
   *
   * @return the net socket
   * @throws IllegalStateException when the socket can't be created
   */
  @CacheReturn
  NetSocket netSocket();

  
Call this with true if you are expecting a multi-part body to be submitted in the request.
This must be called before the body of the request has been received
Params:
expect –  true - if you are expecting a multi-part body
Returns:
a reference to this, so the API can be used fluently/**
   * Call this with true if you are expecting a multi-part body to be submitted in the request.
   * This must be called before the body of the request has been received
   *
   * @param expect  true - if you are expecting a multi-part body
   * @return a reference to this, so the API can be used fluently
   */
  @Fluent
  HttpServerRequest setExpectMultipart(boolean expect);

  
Returns:
 true if we are expecting a multi-part body for this request. See setExpectMultipart./**
   * @return  true if we are expecting a multi-part body for this request. See {@link #setExpectMultipart}.
   */
  boolean isExpectMultipart();

  
Set an upload handler. The handler will get notified once a new file upload was received to allow you to deal
with the file upload.
Returns:
a reference to this, so the API can be used fluently/**
   * Set an upload handler. The handler will get notified once a new file upload was received to allow you to deal
   * with the file upload.
   *
   * @return a reference to this, so the API can be used fluently
   */
  @Fluent
  HttpServerRequest uploadHandler(@Nullable Handler<HttpServerFileUpload> uploadHandler);

  
Returns a map of all form attributes in the request.

Be aware that the attributes will only be available after the whole body has been received, i.e. after
the request end handler has been called.
 setExpectMultipart(boolean) must be called first before trying to get the form attributes. 
Returns:
the form attributes/**
   * Returns a map of all form attributes in the request.
   * <p>
   * Be aware that the attributes will only be available after the whole body has been received, i.e. after
   * the request end handler has been called.
   * <p>
   * {@link #setExpectMultipart(boolean)} must be called first before trying to get the form attributes.
   *
   * @return the form attributes
   */
  @CacheReturn
  MultiMap formAttributes();

  
Return the first form attribute value with the specified name
Params:
attributeName –  the attribute name
Returns:
the attribute value/**
   * Return the first form attribute value with the specified name
   *
   * @param attributeName  the attribute name
   * @return the attribute value
   */
  @Nullable
  String getFormAttribute(String attributeName);

  
Upgrade the connection to a WebSocket connection.
 This is an alternative way of handling WebSockets and can only be used if no WebSocket handler is set on the HttpServer, and can only be used during the upgrade request during the WebSocket handshake. 
Throws:
IllegalStateException – if the current request cannot be upgraded, when it happens an appropriate response
                              is sent
Returns:
the WebSocket/**
   * Upgrade the connection to a WebSocket connection.
   * <p>
   * This is an alternative way of handling WebSockets and can only be used if no WebSocket handler is set on the
   * {@code HttpServer}, and can only be used during the upgrade request during the WebSocket handshake.
   *
   * @return the WebSocket
   * @throws IllegalStateException if the current request cannot be upgraded, when it happens an appropriate response
   *                               is sent
   */
  ServerWebSocket upgrade();

  
Has the request ended? I.e. has the entire request, including the body been read?
Returns:
true if ended/**
   * Has the request ended? I.e. has the entire request, including the body been read?
   *
   * @return true if ended
   */
  boolean isEnded();

  
Set a custom frame handler. The handler will get notified when the http stream receives an custom HTTP/2
frame. HTTP/2 permits extension of the protocol.
Returns:
a reference to this, so the API can be used fluently/**
   * Set a custom frame handler. The handler will get notified when the http stream receives an custom HTTP/2
   * frame. HTTP/2 permits extension of the protocol.
   *
   * @return a reference to this, so the API can be used fluently
   */
  @Fluent
  HttpServerRequest customFrameHandler(Handler<HttpFrame> handler);

  
Returns:
the HttpConnection associated with this request/**
   * @return the {@link HttpConnection} associated with this request
   */
  @CacheReturn
  HttpConnection connection();

  
Returns:
the priority of the associated HTTP/2 stream for HTTP/2 otherwise null/**
   * @return the priority of the associated HTTP/2 stream for HTTP/2 otherwise {@code null}
   */
  default StreamPriority streamPriority() {
      return null;
  }

  
Set an handler for stream priority changes

This is not implemented for HTTP/1.x.
Params:
handler – the handler to be called when stream priority changes/**
   * Set an handler for stream priority changes
   * <p>
   * This is not implemented for HTTP/1.x.
   * 
   * @param handler the handler to be called when stream priority changes
   */
  @Fluent
  HttpServerRequest streamPriorityHandler(Handler<StreamPriority> handler);
}