/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2014 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * 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 io.undertow.websockets.spi;

import io.undertow.server.HttpUpgradeListener;
import io.undertow.util.AttachmentKey;
import io.undertow.websockets.core.WebSocketChannel;
import org.xnio.IoFuture;
import org.xnio.OptionMap;
import io.undertow.connector.ByteBufferPool;

import java.io.Closeable;
import java.nio.ByteBuffer;
import java.security.Principal;
import java.util.List;
import java.util.Map;
import java.util.Set;


/**
 * An abstraction for a Http exchange. Undertow uses 3 different types of exchanges:
 * <p>
 * - async
 * - blocking
 * - servlet
 * <p>
 * This class provides a way to operate on the underling exchange while providing the
 * correct semantics regardless of the underlying exchange type.
 * <p>
 * The main use case for this is web sockets. Web sockets should be able to perform
 * a handshake regardless of the nature of the underlying request, while still respecting
 * servlet filters, security etc.
 *
 * @author Stuart Douglas
 */
public interface WebSocketHttpExchange extends Closeable {

    <T> void putAttachment(AttachmentKey<T> key, T value);

    <T> T getAttachment(AttachmentKey<T> key);

    /**
     * gets the first request header with the specified name
     *
     * @param headerName The header name
     * @return The header value, or null
     */
    String getRequestHeader(String headerName);

    /**
     * @return An unmodifiable map of request headers
     */
    Map<String, List<String>> getRequestHeaders();

    /**
     * get a response header
     *
     * @param headerName The header name
     * @return The header value, or null
     */
    String getResponseHeader(String headerName);

    /**
     * @return An unmodifiable map of response headers
     */
    Map<String, List<String>> getResponseHeaders();


    /**
     * Sets the response headers
     */
    void setResponseHeaders(Map<String, List<String>> headers);

    /**
     * Set a response header
     *
     * @param headerName  The header name
     * @param headerValue The header value
     */
    void setResponseHeader(String headerName, String headerValue);

    /**
     * Upgrade the underlying channel
     *
     * @param upgradeCallback
     */
    void upgradeChannel(HttpUpgradeListener upgradeCallback);

    /**
     * Send some data
     *
     * @param data The data
     */
    IoFuture<Void> sendData(ByteBuffer data);

    /**
     * Gets the body of the request.
     */
    IoFuture<byte[]> readRequestData();

    /**
     * End the exchange normally. If this is a blocking exchange this may be a noop, and the exchange
     * will actually end when the call stack returns
     */
    void endExchange();

    /**
     * Forcibly close the exchange.
     */
    void close();

    /**
     * Get the request scheme, usually http or https
     *
     * @return The request scheme
     */
    String getRequestScheme();

    /**
     * @return The request URI, including the query string
     */
    String getRequestURI();

    /**
     * @return The buffer pool
     */
    ByteBufferPool getBufferPool();

    /**
     * @return The query string
     */
    String getQueryString();

    /**
     * Gets the session, if any
     *
     * @return The session object, or null
     */
    Object getSession();

    Map<String,List<String>> getRequestParameters();

    Principal getUserPrincipal();

    boolean isUserInRole(String role);

    Set<WebSocketChannel> getPeerConnections();

    OptionMap getOptions();
}
