//
//  ========================================================================
//  Copyright (c) 1995-2020 Mort Bay Consulting Pty Ltd and others.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public 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 org.eclipse.jetty.server;

import java.io.IOException;
import java.util.List;
import java.util.Set;
import java.util.concurrent.CopyOnWriteArrayList;

import org.eclipse.jetty.http.CookieCompliance;
import org.eclipse.jetty.http.HttpMethod;
import org.eclipse.jetty.http.HttpScheme;
import org.eclipse.jetty.util.Jetty;
import org.eclipse.jetty.util.TreeTrie;
import org.eclipse.jetty.util.Trie;
import org.eclipse.jetty.util.annotation.ManagedAttribute;
import org.eclipse.jetty.util.annotation.ManagedObject;
import org.eclipse.jetty.util.component.Dumpable;
import org.eclipse.jetty.util.component.DumpableCollection;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;

/**
 * HTTP Configuration.
 * <p>This class is a holder of HTTP configuration for use by the
 * {@link HttpChannel} class.  Typically an HTTPConfiguration instance
 * is instantiated and passed to a {@link ConnectionFactory} that can
 * create HTTP channels (e.g. HTTP, AJP or FCGI).</p>
 * <p>The configuration held by this class is not for the wire protocol,
 * but for the interpretation and handling of HTTP requests that could
 * be transported by a variety of protocols.
 * </p>
 */
@ManagedObject("HTTP Configuration")
public class HttpConfiguration implements Dumpable
{
    private static final Logger LOG = Log.getLogger(HttpConfiguration.class);

    public static final String SERVER_VERSION = "Jetty(" + Jetty.VERSION + ")";
    private final List<Customizer> _customizers = new CopyOnWriteArrayList<>();
    private final Trie<Boolean> _formEncodedMethods = new TreeTrie<>();
    private int _outputBufferSize = 32 * 1024;
    private int _outputAggregationSize = _outputBufferSize / 4;
    private int _requestHeaderSize = 8 * 1024;
    private int _responseHeaderSize = 8 * 1024;
    private int _headerCacheSize = 1024;
    private int _securePort;
    private long _idleTimeout = -1;
    private long _blockingTimeout = -1;
    private String _secureScheme = HttpScheme.HTTPS.asString();
    private boolean _sendServerVersion = true;
    private boolean _sendXPoweredBy = false;
    private boolean _sendDateHeader = true;
    private boolean _delayDispatchUntilContent = true;
    private boolean _persistentConnectionsEnabled = true;
    private int _maxErrorDispatches = 10;
    private long _minRequestDataRate;
    private long _minResponseDataRate;
    private CookieCompliance _requestCookieCompliance = CookieCompliance.RFC6265;
    private CookieCompliance _responseCookieCompliance = CookieCompliance.RFC6265;
    private MultiPartFormDataCompliance _multiPartCompliance = MultiPartFormDataCompliance.LEGACY; // TODO change default in jetty-10
    private boolean _notifyRemoteAsyncErrors = true;

    /**
     * <p>An interface that allows a request object to be customized
     * for a particular HTTP connector configuration.  Unlike Filters, customizer are
     * applied before the request is submitted for processing and can be specific to the
     * connector on which the request was received.</p>
     *
     * <p>Typically Customizers perform tasks such as:</p>
     * <ul>
     * <li>process header fields that may be injected by a proxy or load balancer.
     * <li>setup attributes that may come from the connection/connector such as SSL Session IDs
     * <li>Allow a request to be marked as secure or authenticated if those have been offloaded
     * and communicated by header, cookie or other out-of-band mechanism
     * <li>Set request attributes/fields that are determined by the connector on which the
     * request was received
     * </ul>
     */
    public interface Customizer
    {
        void customize(Connector connector, HttpConfiguration channelConfig, Request request);
    }

    public interface ConnectionFactory
    {
        HttpConfiguration getHttpConfiguration();
    }

    public HttpConfiguration()
    {
        _formEncodedMethods.put(HttpMethod.POST.asString(), Boolean.TRUE);
        _formEncodedMethods.put(HttpMethod.PUT.asString(), Boolean.TRUE);
    }

    /**
     * Creates a configuration from another.
     *
     * @param config The configuration to copy.
     */
    public HttpConfiguration(HttpConfiguration config)
    {
        _customizers.addAll(config._customizers);
        for (String s : config._formEncodedMethods.keySet())
        {
            _formEncodedMethods.put(s, Boolean.TRUE);
        }
        _outputBufferSize = config._outputBufferSize;
        _outputAggregationSize = config._outputAggregationSize;
        _requestHeaderSize = config._requestHeaderSize;
        _responseHeaderSize = config._responseHeaderSize;
        _headerCacheSize = config._headerCacheSize;
        _secureScheme = config._secureScheme;
        _securePort = config._securePort;
        _idleTimeout = config._idleTimeout;
        _blockingTimeout = config._blockingTimeout;
        _sendDateHeader = config._sendDateHeader;
        _sendServerVersion = config._sendServerVersion;
        _sendXPoweredBy = config._sendXPoweredBy;
        _delayDispatchUntilContent = config._delayDispatchUntilContent;
        _persistentConnectionsEnabled = config._persistentConnectionsEnabled;
        _maxErrorDispatches = config._maxErrorDispatches;
        _minRequestDataRate = config._minRequestDataRate;
        _minResponseDataRate = config._minResponseDataRate;
        _requestCookieCompliance = config._requestCookieCompliance;
        _responseCookieCompliance = config._responseCookieCompliance;
        _multiPartCompliance = config._multiPartCompliance;
        _notifyRemoteAsyncErrors = config._notifyRemoteAsyncErrors;
    }

    /**
     * <p>Adds a {@link Customizer} that is invoked for every
     * request received.</p>
     * <p>Customizers are often used to interpret optional headers (eg {@link ForwardedRequestCustomizer}) or
     * optional protocol semantics (eg {@link SecureRequestCustomizer}).
     *
     * @param customizer A request customizer
     */
    public void addCustomizer(Customizer customizer)
    {
        _customizers.add(customizer);
    }

    public List<Customizer> getCustomizers()
    {
        return _customizers;
    }

    public <T> T getCustomizer(Class<T> type)
    {
        for (Customizer c : _customizers)
        {
            if (type.isAssignableFrom(c.getClass()))
                return (T)c;
        }
        return null;
    }

    @ManagedAttribute("The size in bytes of the output buffer used to aggregate HTTP output")
    public int getOutputBufferSize()
    {
        return _outputBufferSize;
    }

    @ManagedAttribute("The maximum size in bytes for HTTP output to be aggregated")
    public int getOutputAggregationSize()
    {
        return _outputAggregationSize;
    }

    @ManagedAttribute("The maximum allowed size in bytes for an HTTP request header")
    public int getRequestHeaderSize()
    {
        return _requestHeaderSize;
    }

    @ManagedAttribute("The maximum allowed size in bytes for an HTTP response header")
    public int getResponseHeaderSize()
    {
        return _responseHeaderSize;
    }

    @ManagedAttribute("The maximum allowed size in bytes for an HTTP header field cache")
    public int getHeaderCacheSize()
    {
        return _headerCacheSize;
    }

    @ManagedAttribute("The port to which Integral or Confidential security constraints are redirected")
    public int getSecurePort()
    {
        return _securePort;
    }

    @ManagedAttribute("The scheme with which Integral or Confidential security constraints are redirected")
    public String getSecureScheme()
    {
        return _secureScheme;
    }

    @ManagedAttribute("Whether persistent connections are enabled")
    public boolean isPersistentConnectionsEnabled()
    {
        return _persistentConnectionsEnabled;
    }

    /**
     * <p>The max idle time is applied to an HTTP request for IO operations and
     * delayed dispatch.</p>
     *
     * @return the max idle time in ms or if == 0 implies an infinite timeout, &lt;0
     * implies no HTTP channel timeout and the connection timeout is used instead.
     */
    @ManagedAttribute("The idle timeout in ms for I/O operations during the handling of an HTTP request")
    public long getIdleTimeout()
    {
        return _idleTimeout;
    }

    /**
     * <p>The max idle time is applied to an HTTP request for IO operations and
     * delayed dispatch.</p>
     *
     * @param timeoutMs the max idle time in ms or if == 0 implies an infinite timeout, &lt;0
     * implies no HTTP channel timeout and the connection timeout is used instead.
     */
    public void setIdleTimeout(long timeoutMs)
    {
        _idleTimeout = timeoutMs;
    }

    /**
     * <p>This timeout is in addition to the {@link Connector#getIdleTimeout()}, and applies
     * to the total operation (as opposed to the idle timeout that applies to the time no
     * data is being sent). This applies only to blocking operations and does not affect
     * asynchronous read and write.</p>
     *
     * @return -1, for no blocking timeout (default), 0 for a blocking timeout equal to the
     * idle timeout; &gt;0 for a timeout in ms applied to the total blocking operation.
     * @deprecated Replaced by {@link #getMinResponseDataRate()} and {@link #getMinRequestDataRate()}
     */
    @ManagedAttribute(value = "Total timeout in ms for blocking I/O operations. DEPRECATED!", readonly = true)
    @Deprecated
    public long getBlockingTimeout()
    {
        return _blockingTimeout;
    }

    /**
     * <p>This timeout is in addition to the {@link Connector#getIdleTimeout()}, and applies
     * to the total operation (as opposed to the idle timeout that applies to the time no
     * data is being sent).This applies only to blocking operations and does not affect
     * asynchronous read and write.</p>
     *
     * @param blockingTimeout -1, for no blocking timeout (default), 0 for a blocking timeout equal to the
     * idle timeout; &gt;0 for a timeout in ms applied to the total blocking operation.
     * @deprecated Replaced by {@link #setMinResponseDataRate(long)} and {@link #setMinRequestDataRate(long)}
     */
    @Deprecated
    public void setBlockingTimeout(long blockingTimeout)
    {
        if (blockingTimeout > 0)
            LOG.warn("HttpConfiguration.setBlockingTimeout is deprecated!");
        _blockingTimeout = blockingTimeout;
    }

    public void setPersistentConnectionsEnabled(boolean persistentConnectionsEnabled)
    {
        _persistentConnectionsEnabled = persistentConnectionsEnabled;
    }

    public void setSendServerVersion(boolean sendServerVersion)
    {
        _sendServerVersion = sendServerVersion;
    }

    @ManagedAttribute("Whether to send the Server header in responses")
    public boolean getSendServerVersion()
    {
        return _sendServerVersion;
    }

    public void writePoweredBy(Appendable out, String preamble, String postamble) throws IOException
    {
        if (getSendServerVersion())
        {
            if (preamble != null)
                out.append(preamble);
            out.append(Jetty.POWERED_BY);
            if (postamble != null)
                out.append(postamble);
        }
    }

    public void setSendXPoweredBy(boolean sendXPoweredBy)
    {
        _sendXPoweredBy = sendXPoweredBy;
    }

    @ManagedAttribute("Whether to send the X-Powered-By header in responses")
    public boolean getSendXPoweredBy()
    {
        return _sendXPoweredBy;
    }

    /**
     * Indicates if the {@code Date} header should be sent in responses.
     *
     * @param sendDateHeader true if the {@code Date} header should be sent in responses
     * @see <a href="https://tools.ietf.org/html/rfc7231#section-7.1.1.2">HTTP/1.1 Standard Header: Date</a>
     * @see #getSendDateHeader()
     */
    public void setSendDateHeader(boolean sendDateHeader)
    {
        _sendDateHeader = sendDateHeader;
    }

    /**
     * Indicates if the {@code Date} header will be sent in responses.
     *
     * @return true by default
     */
    @ManagedAttribute("Whether to send the Date header in responses")
    public boolean getSendDateHeader()
    {
        return _sendDateHeader;
    }

    /**
     * @param delay if true, delays the application dispatch until content is available (defaults to true)
     */
    public void setDelayDispatchUntilContent(boolean delay)
    {
        _delayDispatchUntilContent = delay;
    }

    @ManagedAttribute("Whether to delay the application dispatch until content is available")
    public boolean isDelayDispatchUntilContent()
    {
        return _delayDispatchUntilContent;
    }

    /**
     * <p>Sets the {@link Customizer}s that are invoked for every
     * request received.</p>
     * <p>Customizers are often used to interpret optional headers (eg {@link ForwardedRequestCustomizer}) or
     * optional protocol semantics (eg {@link SecureRequestCustomizer}).</p>
     *
     * @param customizers the list of customizers
     */
    public void setCustomizers(List<Customizer> customizers)
    {
        _customizers.clear();
        _customizers.addAll(customizers);
    }

    /**
     * Set the size of the buffer into which response content is aggregated
     * before being sent to the client.  A larger buffer can improve performance by allowing
     * a content producer to run without blocking, however larger buffers consume more memory and
     * may induce some latency before a client starts processing the content.
     *
     * @param outputBufferSize buffer size in bytes.
     */
    public void setOutputBufferSize(int outputBufferSize)
    {
        _outputBufferSize = outputBufferSize;
        setOutputAggregationSize(outputBufferSize / 4);
    }

    /**
     * Set the max size of the response content write that is copied into the aggregate buffer.
     * Writes that are smaller of this size are copied into the aggregate buffer, while
     * writes that are larger of this size will cause the aggregate buffer to be flushed
     * and the write to be executed without being copied.
     *
     * @param outputAggregationSize the max write size that is aggregated
     */
    public void setOutputAggregationSize(int outputAggregationSize)
    {
        _outputAggregationSize = outputAggregationSize;
    }

    /**
     * <p>Larger headers will allow for more and/or larger cookies plus larger form content encoded
     * in a URL. However, larger headers consume more memory and can make a server more vulnerable to denial of service
     * attacks.</p>
     *
     * @param requestHeaderSize the maximum size in bytes of the request header
     */
    public void setRequestHeaderSize(int requestHeaderSize)
    {
        _requestHeaderSize = requestHeaderSize;
    }

    /**
     * <p>Larger headers will allow for more and/or larger cookies and longer HTTP headers (eg for redirection).
     * However, larger headers will also consume more memory.</p>
     *
     * @param responseHeaderSize the maximum size in bytes of the response header
     */
    public void setResponseHeaderSize(int responseHeaderSize)
    {
        _responseHeaderSize = responseHeaderSize;
    }

    /**
     * @param headerCacheSize The size in bytes of the header field cache.
     */
    public void setHeaderCacheSize(int headerCacheSize)
    {
        _headerCacheSize = headerCacheSize;
    }

    /**
     * <p>Sets the TCP/IP port used for CONFIDENTIAL and INTEGRAL redirections.</p>
     *
     * @param securePort the secure port to redirect to.
     */
    public void setSecurePort(int securePort)
    {
        _securePort = securePort;
    }

    /**
     * <p>Set the  URI scheme used for CONFIDENTIAL and INTEGRAL redirections.</p>
     *
     * @param secureScheme A scheme string like "https"
     */
    public void setSecureScheme(String secureScheme)
    {
        _secureScheme = secureScheme;
    }

    /**
     * Sets the form encoded HTTP methods.
     *
     * @param methods the HTTP methods of requests that can be decoded as
     * {@code x-www-form-urlencoded} content to be made available via the
     * {@link Request#getParameter(String)} and associated APIs
     */
    public void setFormEncodedMethods(String... methods)
    {
        _formEncodedMethods.clear();
        for (String method : methods)
        {
            addFormEncodedMethod(method);
        }
    }

    /**
     * @return the set of HTTP methods of requests that can be decoded as
     * {@code x-www-form-urlencoded} content to be made available via the
     * {@link Request#getParameter(String)} and associated APIs
     */
    public Set<String> getFormEncodedMethods()
    {
        return _formEncodedMethods.keySet();
    }

    /**
     * Adds a form encoded HTTP Method
     *
     * @param method the HTTP method of requests that can be decoded as
     * {@code x-www-form-urlencoded} content to be made available via the
     * {@link Request#getParameter(String)} and associated APIs
     */
    public void addFormEncodedMethod(String method)
    {
        _formEncodedMethods.put(method, Boolean.TRUE);
    }

    /**
     * Tests whether the HTTP method supports {@code x-www-form-urlencoded} content
     *
     * @param method the HTTP method
     * @return true if requests with this method can be
     * decoded as {@code x-www-form-urlencoded} content to be made available via the
     * {@link Request#getParameter(String)} and associated APIs
     */
    public boolean isFormEncodedMethod(String method)
    {
        return Boolean.TRUE.equals(_formEncodedMethods.get(method));
    }

    /**
     * @return The maximum error dispatches for a request to prevent looping on an error
     */
    @ManagedAttribute("The maximum ERROR dispatches for a request for loop prevention (default 10)")
    public int getMaxErrorDispatches()
    {
        return _maxErrorDispatches;
    }

    /**
     * @param max The maximum error dispatches for a request to prevent looping on an error
     */
    public void setMaxErrorDispatches(int max)
    {
        _maxErrorDispatches = max;
    }

    /**
     * @return The minimum request data rate in bytes per second; or &lt;=0 for no limit
     */
    @ManagedAttribute("The minimum request content data rate in bytes per second")
    public long getMinRequestDataRate()
    {
        return _minRequestDataRate;
    }

    /**
     * @param bytesPerSecond The minimum request data rate in bytes per second; or &lt;=0 for no limit
     */
    public void setMinRequestDataRate(long bytesPerSecond)
    {
        _minRequestDataRate = bytesPerSecond;
    }

    /**
     * @return The minimum response data rate in bytes per second; or &lt;=0 for no limit
     */
    @ManagedAttribute("The minimum response content data rate in bytes per second")
    public long getMinResponseDataRate()
    {
        return _minResponseDataRate;
    }

    /**
     * <p>Sets an minimum response content data rate.</p>
     * <p>The value is enforced only approximately - not precisely - due to the fact that
     * for efficiency reasons buffer writes may be comprised of both response headers and
     * response content.</p>
     *
     * @param bytesPerSecond The minimum response data rate in bytes per second; or &lt;=0 for no limit
     */
    public void setMinResponseDataRate(long bytesPerSecond)
    {
        _minResponseDataRate = bytesPerSecond;
    }

    /**
     * @return The CookieCompliance used for parsing request <code>Cookie</code> headers.
     * @see #getResponseCookieCompliance()
     */
    public CookieCompliance getRequestCookieCompliance()
    {
        return _requestCookieCompliance;
    }

    /**
     * @return The CookieCompliance used for generating response <code>Set-Cookie</code> headers
     * @see #getRequestCookieCompliance()
     */
    public CookieCompliance getResponseCookieCompliance()
    {
        return _responseCookieCompliance;
    }

    /**
     * @param cookieCompliance The CookieCompliance to use for parsing request <code>Cookie</code> headers.
     * @see #setRequestCookieCompliance(CookieCompliance)
     */
    public void setRequestCookieCompliance(CookieCompliance cookieCompliance)
    {
        _requestCookieCompliance = cookieCompliance == null ? CookieCompliance.RFC6265 : cookieCompliance;
    }

    /**
     * @param cookieCompliance The CookieCompliance to use for generating response <code>Set-Cookie</code> headers
     * @see #setResponseCookieCompliance(CookieCompliance)
     */
    public void setResponseCookieCompliance(CookieCompliance cookieCompliance)
    {
        _responseCookieCompliance = cookieCompliance == null ? CookieCompliance.RFC6265 : cookieCompliance;
    }

    @Deprecated
    public void setCookieCompliance(CookieCompliance compliance)
    {
        setRequestCookieCompliance(compliance);
    }

    @Deprecated
    public CookieCompliance getCookieCompliance()
    {
        return getRequestCookieCompliance();
    }

    @Deprecated
    public boolean isCookieCompliance(CookieCompliance compliance)
    {
        return _requestCookieCompliance.equals(compliance);
    }

    /**
     * Sets the compliance level for multipart/form-data handling.
     *
     * @param multiPartCompliance The multipart/form-data compliance level.
     */
    public void setMultiPartFormDataCompliance(MultiPartFormDataCompliance multiPartCompliance)
    {
        // TODO change default in jetty-10 
        _multiPartCompliance = multiPartCompliance == null ? MultiPartFormDataCompliance.LEGACY : multiPartCompliance;
    }

    public MultiPartFormDataCompliance getMultipartFormDataCompliance()
    {
        return _multiPartCompliance;
    }

    /**
     * @param notifyRemoteAsyncErrors whether remote errors, when detected, are notified to async applications
     */
    public void setNotifyRemoteAsyncErrors(boolean notifyRemoteAsyncErrors)
    {
        this._notifyRemoteAsyncErrors = notifyRemoteAsyncErrors;
    }

    /**
     * @return whether remote errors, when detected, are notified to async applications
     */
    @ManagedAttribute("Whether remote errors, when detected, are notified to async applications")
    public boolean isNotifyRemoteAsyncErrors()
    {
        return _notifyRemoteAsyncErrors;
    }

    @Override
    public String dump()
    {
        return Dumpable.dump(this);
    }

    @Override
    public void dump(Appendable out, String indent) throws IOException
    {
        Dumpable.dumpObjects(out, indent, this,
            new DumpableCollection("customizers", _customizers),
            new DumpableCollection("formEncodedMethods", _formEncodedMethods.keySet()),
            "outputBufferSize=" + _outputBufferSize,
            "outputAggregationSize=" + _outputAggregationSize,
            "requestHeaderSize=" + _requestHeaderSize,
            "responseHeaderSize=" + _responseHeaderSize,
            "headerCacheSize=" + _headerCacheSize,
            "secureScheme=" + _secureScheme,
            "securePort=" + _securePort,
            "idleTimeout=" + _idleTimeout,
            "blockingTimeout=" + _blockingTimeout,
            "sendDateHeader=" + _sendDateHeader,
            "sendServerVersion=" + _sendServerVersion,
            "sendXPoweredBy=" + _sendXPoweredBy,
            "delayDispatchUntilContent=" + _delayDispatchUntilContent,
            "persistentConnectionsEnabled=" + _persistentConnectionsEnabled,
            "maxErrorDispatches=" + _maxErrorDispatches,
            "minRequestDataRate=" + _minRequestDataRate,
            "minResponseDataRate=" + _minResponseDataRate,
            "cookieCompliance=" + _requestCookieCompliance,
            "setRequestCookieCompliance=" + _responseCookieCompliance,
            "notifyRemoteAsyncErrors=" + _notifyRemoteAsyncErrors
        );
    }

    @Override
    public String toString()
    {
        return String.format("%s@%x{%d/%d,%d/%d,%s://:%d,%s}",
            this.getClass().getSimpleName(),
            hashCode(),
            _outputBufferSize,
            _outputAggregationSize,
            _requestHeaderSize,
            _responseHeaderSize,
            _secureScheme,
            _securePort,
            _customizers);
    }
}
