/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.camel.component.undertow;

import java.net.URI;
import java.net.URISyntaxException;
import java.util.Locale;
import java.util.Map;
import javax.net.ssl.SSLContext;

import io.undertow.server.HttpServerExchange;
import org.apache.camel.AsyncEndpoint;
import org.apache.camel.Consumer;
import org.apache.camel.Exchange;
import org.apache.camel.Message;
import org.apache.camel.PollingConsumer;
import org.apache.camel.Processor;
import org.apache.camel.Producer;
import org.apache.camel.http.common.cookie.CookieHandler;
import org.apache.camel.impl.DefaultEndpoint;
import org.apache.camel.spi.HeaderFilterStrategy;
import org.apache.camel.spi.HeaderFilterStrategyAware;
import org.apache.camel.spi.Metadata;
import org.apache.camel.spi.UriEndpoint;
import org.apache.camel.spi.UriParam;
import org.apache.camel.spi.UriPath;
import org.apache.camel.util.ObjectHelper;
import org.apache.camel.util.jsse.SSLContextParameters;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.xnio.Option;
import org.xnio.OptionMap;
import org.xnio.Options;

/**
 * The undertow component provides HTTP-based endpoints for consuming and producing HTTP requests.
 */
@UriEndpoint(firstVersion = "2.16.0", scheme = "undertow", title = "Undertow", syntax = "undertow:httpURI",
        consumerClass = UndertowConsumer.class, label = "http", lenientProperties = true)
public class UndertowEndpoint extends DefaultEndpoint implements AsyncEndpoint, HeaderFilterStrategyAware {

    private static final Logger LOG = LoggerFactory.getLogger(UndertowEndpoint.class);
    private UndertowComponent component;
    private SSLContext sslContext;
    private OptionMap optionMap;

    @UriPath @Metadata(required = "true")
    private URI httpURI;
    @UriParam(label = "advanced")
    private UndertowHttpBinding undertowHttpBinding;
    @UriParam(label = "advanced")
    private HeaderFilterStrategy headerFilterStrategy = new UndertowHeaderFilterStrategy();
    @UriParam(label = "security")
    private SSLContextParameters sslContextParameters;
    @UriParam(label = "consumer")
    private String httpMethodRestrict;
    @UriParam(label = "consumer", defaultValue = "true")
    private Boolean matchOnUriPrefix = true;
    @UriParam(label = "producer", defaultValue = "true")
    private Boolean throwExceptionOnFailure = Boolean.TRUE;
    @UriParam(label = "producer", defaultValue = "false")
    private Boolean transferException = Boolean.FALSE;
    @UriParam(label = "producer", defaultValue = "true")
    private Boolean keepAlive = Boolean.TRUE;
    @UriParam(label = "producer", defaultValue = "true")
    private Boolean tcpNoDelay = Boolean.TRUE;
    @UriParam(label = "producer", defaultValue = "true")
    private Boolean reuseAddresses = Boolean.TRUE;
    @UriParam(label = "producer", prefix = "option.", multiValue = true)
    private Map<String, Object> options;
    @UriParam(label = "consumer",
            description = "Specifies whether to enable HTTP OPTIONS for this Servlet consumer. By default OPTIONS is turned off.")
    private boolean optionsEnabled;
    @UriParam(label = "producer")
    private CookieHandler cookieHandler;

    public UndertowEndpoint(String uri, UndertowComponent component) throws URISyntaxException {
        super(uri, component);
        this.component = component;
    }

    @Override
    public UndertowComponent getComponent() {
        return component;
    }

    @Override
    public Producer createProducer() throws Exception {
        return new UndertowProducer(this, optionMap);
    }

    @Override
    public Consumer createConsumer(Processor processor) throws Exception {
        return new UndertowConsumer(this, processor);
    }

    @Override
    public PollingConsumer createPollingConsumer() throws Exception {
        //throw exception as polling consumer is not supported
        throw new UnsupportedOperationException("This component does not support polling consumer");
    }

    @Override
    public boolean isSingleton() {
        return true;
    }

    @Override
    public boolean isLenientProperties() {
        // true to allow dynamic URI options to be configured and passed to external system for eg. the UndertowProducer
        return true;
    }

    public Exchange createExchange(HttpServerExchange httpExchange) throws Exception {
        Exchange exchange = createExchange();

        Message in = getUndertowHttpBinding().toCamelMessage(httpExchange, exchange);

        exchange.setProperty(Exchange.CHARSET_NAME, httpExchange.getRequestCharset());
        in.setHeader(Exchange.HTTP_CHARACTER_ENCODING, httpExchange.getRequestCharset());

        exchange.setIn(in);
        return exchange;
    }

    public SSLContext getSslContext() {
        return sslContext;
    }

    public URI getHttpURI() {
        return httpURI;
    }

    /**
     * The url of the HTTP endpoint to use.
     */
    public void setHttpURI(URI httpURI) {
        if (ObjectHelper.isEmpty(httpURI.getPath())) {
            try {
                this.httpURI = new URI(httpURI.getScheme(), httpURI.getUserInfo(), httpURI.getHost(), httpURI.getPort(),
                    "/", httpURI.getQuery(), httpURI.getFragment());
            } catch (URISyntaxException e) {
                throw new IllegalArgumentException(e);
            }
        } else {
            this.httpURI = httpURI;
        }
    }

    public String getHttpMethodRestrict() {
        return httpMethodRestrict;
    }

    /**
     * Used to only allow consuming if the HttpMethod matches, such as GET/POST/PUT etc. Multiple methods can be specified separated by comma.
     */
    public void setHttpMethodRestrict(String httpMethodRestrict) {
        this.httpMethodRestrict = httpMethodRestrict;
    }

    public Boolean getMatchOnUriPrefix() {
        return matchOnUriPrefix;
    }

    /**
     * Whether or not the consumer should try to find a target consumer by matching the URI prefix if no exact match is found.
     */
    public void setMatchOnUriPrefix(Boolean matchOnUriPrefix) {
        this.matchOnUriPrefix = matchOnUriPrefix;
    }

    public HeaderFilterStrategy getHeaderFilterStrategy() {
        return headerFilterStrategy;
    }

    /**
     * To use a custom HeaderFilterStrategy to filter header to and from Camel message.
     */
    public void setHeaderFilterStrategy(HeaderFilterStrategy headerFilterStrategy) {
        this.headerFilterStrategy = headerFilterStrategy;
    }

    public SSLContextParameters getSslContextParameters() {
        return sslContextParameters;
    }

    /**
     * To configure security using SSLContextParameters
     */
    public void setSslContextParameters(SSLContextParameters sslContextParameters) {
        this.sslContextParameters = sslContextParameters;
    }

    public Boolean getThrowExceptionOnFailure() {
        return throwExceptionOnFailure;
    }

    /**
     * Option to disable throwing the HttpOperationFailedException in case of failed responses from the remote server.
     * This allows you to get all responses regardless of the HTTP status code.
     */
    public void setThrowExceptionOnFailure(Boolean throwExceptionOnFailure) {
        this.throwExceptionOnFailure = throwExceptionOnFailure;
    }

    public Boolean getTransferException() {
        return transferException;
    }

    /**
     * Option to disable throwing the HttpOperationFailedException in case of failed responses from the remote server.
     * This allows you to get all responses regardless of the HTTP status code.
     */
    public void setTransferException(Boolean transferException) {
        this.transferException = transferException;
    }

    public UndertowHttpBinding getUndertowHttpBinding() {
        if (undertowHttpBinding == null) {
            // create a new binding and use the options from this endpoint
            undertowHttpBinding = new DefaultUndertowHttpBinding();
            undertowHttpBinding.setHeaderFilterStrategy(getHeaderFilterStrategy());
            undertowHttpBinding.setTransferException(getTransferException());
        }
        return undertowHttpBinding;
    }

    /**
     * To use a custom UndertowHttpBinding to control the mapping between Camel message and undertow.
     */
    public void setUndertowHttpBinding(UndertowHttpBinding undertowHttpBinding) {
        this.undertowHttpBinding = undertowHttpBinding;
    }

    public Boolean getKeepAlive() {
        return keepAlive;
    }

    /**
     * Setting to ensure socket is not closed due to inactivity
     */
    public void setKeepAlive(Boolean keepAlive) {
        this.keepAlive = keepAlive;
    }

    public Boolean getTcpNoDelay() {
        return tcpNoDelay;
    }

    /**
     * Setting to improve TCP protocol performance
     */
    public void setTcpNoDelay(Boolean tcpNoDelay) {
        this.tcpNoDelay = tcpNoDelay;
    }

    public Boolean getReuseAddresses() {
        return reuseAddresses;
    }

    /**
     * Setting to facilitate socket multiplexing
     */
    public void setReuseAddresses(Boolean reuseAddresses) {
        this.reuseAddresses = reuseAddresses;
    }

    public Map<String, Object> getOptions() {
        return options;
    }

    /**
     * Sets additional channel options. The options that can be used are defined in {@link org.xnio.Options}.
     * To configure from endpoint uri, then prefix each option with <tt>option.</tt>, such as <tt>option.close-abort=true&option.send-buffer=8192</tt>
     */
    public void setOptions(Map<String, Object> options) {
        this.options = options;
    }

    public boolean isOptionsEnabled() {
        return optionsEnabled;
    }

    /**
     * Specifies whether to enable HTTP OPTIONS for this Servlet consumer. By default OPTIONS is turned off.
     */
    public void setOptionsEnabled(boolean optionsEnabled) {
        this.optionsEnabled = optionsEnabled;
    }

    public CookieHandler getCookieHandler() {
        return cookieHandler;
    }

    /**
     * Configure a cookie handler to maintain a HTTP session
     */
    public void setCookieHandler(CookieHandler cookieHandler) {
        this.cookieHandler = cookieHandler;
    }

    @Override
    protected void doStart() throws Exception {
        super.doStart();

        if (sslContextParameters != null) {
            sslContext = sslContextParameters.createSSLContext(getCamelContext());
        }

        // create options map
        if (options != null && !options.isEmpty()) {

            // favor to use the classloader that loaded the user application
            ClassLoader cl = getComponent().getCamelContext().getApplicationContextClassLoader();
            if (cl == null) {
                cl = Options.class.getClassLoader();
            }

            OptionMap.Builder builder = OptionMap.builder();
            for (Map.Entry<String, Object> entry : options.entrySet()) {
                String key = entry.getKey();
                Object value = entry.getValue();
                if (key != null && value != null) {
                    // upper case and dash as underscore
                    key = key.toUpperCase(Locale.ENGLISH).replace('-', '_');
                    // must be field name
                    key = Options.class.getName() + "." + key;
                    Option option = Option.fromString(key, cl);
                    value = option.parseValue(value.toString(), cl);
                    LOG.trace("Parsed option {}={}", option.getName(), value);
                    builder.set(option, value);
                }
            }
            optionMap = builder.getMap();
        } else {
            // use an empty map
            optionMap = OptionMap.EMPTY;
        }

        // and then configure these default options if they have not been explicit configured
        if (keepAlive != null && !optionMap.contains(Options.KEEP_ALIVE)) {
            // rebuild map
            OptionMap.Builder builder = OptionMap.builder();
            builder.addAll(optionMap).set(Options.KEEP_ALIVE, keepAlive);
            optionMap = builder.getMap();
        }
        if (tcpNoDelay != null && !optionMap.contains(Options.TCP_NODELAY)) {
            // rebuild map
            OptionMap.Builder builder = OptionMap.builder();
            builder.addAll(optionMap).set(Options.TCP_NODELAY, tcpNoDelay);
            optionMap = builder.getMap();
        }
        if (reuseAddresses != null && !optionMap.contains(Options.REUSE_ADDRESSES)) {
            // rebuild map
            OptionMap.Builder builder = OptionMap.builder();
            builder.addAll(optionMap).set(Options.REUSE_ADDRESSES, reuseAddresses);
            optionMap = builder.getMap();
        }
    }

}