/*
 * ====================================================================
 * 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.hc.core5.testing.reactive;

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.nio.ByteBuffer;

import org.apache.hc.core5.function.Callback;
import org.apache.hc.core5.http.ContentType;
import org.apache.hc.core5.http.EntityDetails;
import org.apache.hc.core5.http.HeaderElements;
import org.apache.hc.core5.http.HttpException;
import org.apache.hc.core5.http.HttpHeaders;
import org.apache.hc.core5.http.HttpRequest;
import org.apache.hc.core5.http.HttpResponse;
import org.apache.hc.core5.http.HttpStatus;
import org.apache.hc.core5.http.MethodNotSupportedException;
import org.apache.hc.core5.http.ProtocolException;
import org.apache.hc.core5.http.impl.BasicEntityDetails;
import org.apache.hc.core5.http.message.BasicHeader;
import org.apache.hc.core5.http.message.BasicHttpResponse;
import org.apache.hc.core5.http.nio.ResponseChannel;
import org.apache.hc.core5.http.protocol.HttpContext;
import org.apache.hc.core5.reactive.ReactiveRequestProcessor;
import org.reactivestreams.Publisher;

import io.reactivex.Flowable;

public class ReactiveRandomProcessor implements ReactiveRequestProcessor {
    public ReactiveRandomProcessor() {
    }

    @Override
    public void processRequest(
            final HttpRequest request,
            final EntityDetails entityDetails,
            final ResponseChannel responseChannel,
            final HttpContext context,
            final Publisher<ByteBuffer> requestBody,
            final Callback<Publisher<ByteBuffer>> responseBodyCallback
    ) throws HttpException, IOException {
        final String method = request.getMethod();
        if (!"GET".equalsIgnoreCase(method) &&
                !"HEAD".equalsIgnoreCase(method) &&
                !"POST".equalsIgnoreCase(method) &&
                !"PUT".equalsIgnoreCase(method)) {
            throw new MethodNotSupportedException(method + " not supported by " + getClass().getName());
        }
        final URI uri;
        try {
            uri = request.getUri();
        } catch (final URISyntaxException ex) {
            throw new ProtocolException(ex.getMessage(), ex);
        }
        final String path = uri.getPath();
        final int slash = path.lastIndexOf('/');
        if (slash != -1) {
            final String payload = path.substring(slash + 1);
            final long n;
            if (!payload.isEmpty()) {
                try {
                    n = Long.parseLong(payload);
                } catch (final NumberFormatException ex) {
                    throw new ProtocolException("Invalid request path: " + path);
                }
            } else {
                // random length, but make sure at least something is sent
                n = 1 + (int) (Math.random() * 79.0);
            }

            if (new BasicHeader(HttpHeaders.EXPECT, HeaderElements.CONTINUE).equals(request.getHeader(HttpHeaders.EXPECT))) {
                responseChannel.sendInformation(new BasicHttpResponse(100), context);
            }

            final HttpResponse response = new BasicHttpResponse(HttpStatus.SC_OK);
            final Flowable<ByteBuffer> stream = ReactiveTestUtils.produceStream(n);
            final String hash = ReactiveTestUtils.getStreamHash(n);
            response.addHeader("response-hash-code", hash);
            final BasicEntityDetails basicEntityDetails = new BasicEntityDetails(n, ContentType.APPLICATION_OCTET_STREAM);
            responseChannel.sendResponse(response, basicEntityDetails, context);
            responseBodyCallback.execute(stream);
        } else {
            throw new ProtocolException("Invalid request path: " + path);
        }
    }
}