/*
 * 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 feed;

import java.io.IOException;
import java.io.Reader;
import java.net.Socket;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.List;

import junit.framework.Assert;

import org.apache.abdera.Abdera;
import org.apache.abdera.model.Base;
import org.apache.abdera.model.Collection;
import org.apache.abdera.model.Document;
import org.apache.abdera.model.Entry;
import org.apache.abdera.model.Feed;
import org.apache.abdera.parser.Parser;
import org.apache.abdera.protocol.Response.ResponseType;
import org.apache.abdera.protocol.client.AbderaClient;
import org.apache.abdera.protocol.client.ClientResponse;
import org.apache.abdera.protocol.client.RequestOptions;
import org.apache.abdera.writer.Writer;
import org.apache.abdera.writer.WriterFactory;
import org.apache.tuscany.sca.host.embedded.SCADomain;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

/**
 * Tests use of server provided feed entity tags for Atom binding in Tuscany.
 * Tests conditional gets (e.g. get if-none-match) or conditional posts (post
 * if-match) using entity tags and last modified entries in headers. Uses the
 * SCA provided Provider composite to act as a server. Uses the Abdera provided
 * Client to act as a client.
 */
public class FeedAggregatorTestCase {
    public final static String providerURI = "http://localhost:8083/atomAggregator";
    protected static SCADomain scaProviderDomain;
    protected static Abdera abdera;
    protected static AbderaClient client;
    protected static Parser abderaParser;
    protected static String eTag;
    protected static Date lastModified;
    protected static long contentLength;
    protected static int numberEntries;
    protected static final SimpleDateFormat dateFormat = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss Z"); // RFC822 date time

    @BeforeClass
    public static void init() throws Exception {
        if (!internetConnected()) {
            // no internet connection
            return;
        }
        try {
            System.out.println(">>>FeedAggregatorTest.init");
            scaProviderDomain = SCADomain.newInstance("FeedAggregator.composite");
            abdera = new Abdera();
            client = new AbderaClient(abdera);
            abderaParser = Abdera.getNewParser();
        } catch (Throwable e) {
            System.out.println(e);
            e.printStackTrace();
        }
    }

    @AfterClass
    public static void destroy() throws Exception {
        System.out.println(">>>FeedAggregatorTest.destroy");
        if (scaProviderDomain != null) {
            scaProviderDomain.close();
        }
    }

    @Test
    public void testPrelim() throws Exception {
        if (scaProviderDomain == null) {
            // no internet connection
            return;
        }
        Assert.assertNotNull(scaProviderDomain);
        Assert.assertNotNull(client);
    }

    @Test
    public void testFeedBasics() throws Exception {
        if (scaProviderDomain == null) {
            // no internet connection
            return;
        }
        System.out.println(">>>FeedAggregatorTest.testFeedBasics");
        RequestOptions opts = new RequestOptions();
        // Normal feed request
        ClientResponse res = client.get(providerURI, opts);
        Assert.assertNotNull(res);
        try {
            // Assert feed provided since no predicates
            Assert.assertEquals(200, res.getStatus());
            Assert.assertEquals(ResponseType.SUCCESS, res.getType());
            // AtomTestCaseUtils.printResponseHeaders( "Feed response headers:",
            // "   ", res );

            // Perform other tests on feed.
            contentLength = getContentLength(res);
            System.out.println("FeedAggregatorTest.testFeedBasics full contentLength=" + contentLength);

            Document<Feed> doc = res.getDocument();
            Assert.assertNotNull(doc);
            Feed feed = doc.getRoot();
            Assert.assertNotNull(feed);

            // printFeed( "Feed values", "   ", feed );
            // RFC 4287 requires non-null id, title, updated elements
            Assert.assertNotNull(feed.getId());
            Assert.assertNotNull(feed.getTitle());
            Assert.assertNotNull(feed.getUpdated());

            eTag = res.getHeader("ETag");
            Assert.assertNotNull(eTag);
            lastModified = res.getLastModified();
            Assert.assertNotNull(lastModified);

            numberEntries = getEntryCount(feed);
            System.out.println("FeedAggregatorTest.testFeedBasics number entries=" + numberEntries);

            // printFeed( "Aggregated Feed Contents:", "   ", feed );
            // System.out.println( "FeedAggregatorTest.testFeedBasics feed=" +
            // feed );
            // printResponseHeaders( "Aggregated Feed response headers:", "   ",
            // res );
            // System.out.println("Aggregated Feed response body:");
            // prettyPrint(abdera, res.getDocument());
            // printEntryUpdates( "Aggregated Feed feed updates", "   ", feed );
        } finally {
            res.release();
        }
    }

    @Test
    public void testUnmodifiedGetIfModified() throws Exception {
        if (scaProviderDomain == null) {
            // no internet connection
            return;
        }
        System.out.println(">>>FeedAggregatorTest.testFeedUnmodifiedGetIfModified");
        // Feed request with predicates
        RequestOptions opts = new RequestOptions();
        final String contentType = "application/atom+xml";
        opts.setContentType(contentType);
        opts.setHeader("If-Modified-Since", dateFormat.format(new Date(0)));

        ClientResponse res = client.get(providerURI, opts);
        Assert.assertNotNull(res);
        try {
            // Should return 200 - Feed provided since feed is changed.
            Assert.assertEquals(200, res.getStatus());
            Assert.assertEquals(ResponseType.SUCCESS, res.getType());

            String thisETag = res.getHeader("ETag");
            Assert.assertNotNull(thisETag);
            Date thisLastModified = res.getLastModified();
            Assert.assertNotNull(thisLastModified);

            // Entry count and body size should be equal to basic request
            long thisContentLength = getContentLength(res);

            Document<Feed> doc = res.getDocument();
            Assert.assertNotNull(doc);
            Feed feed = doc.getRoot();
            Assert.assertNotNull(feed);
            int thisNumberEntries = getEntryCount(feed);
            // System.out.println(
            // "FeedAggregatorTest.UnmodifiedGetIfModified number entries=" +
            // numberEntries + ", this number entries=" + thisNumberEntries ) ;
        } finally {
            res.release();
        }
    }

    @Test
    public void testUnmodifiedGetIfUnModified() throws Exception {
        if (scaProviderDomain == null) {
            // no internet connection
            return;
        }
        System.out.println(">>>FeedAggregatorTest.testFeedUnmodifiedGetIfUnModified");
        // Feed request with predicates
        RequestOptions opts = new RequestOptions();
        final String contentType = "application/atom+xml";
        opts.setContentType(contentType);
        opts.setHeader("If-Unmodified-Since", dateFormat.format(new Date(0)));

        ClientResponse res = client.get(providerURI, opts);
        Assert.assertNotNull(res);
        try {
            // Should return 412 - Feed not provided since feed is modified
            // since.
            Assert.assertEquals(412, res.getStatus());

            // Entry count and body size should be equal to basic request
            long thisContentLength = getContentLength(res);
            System.out
                .println("FeedAggregatorTest.UnModifiedGetIfUnModified saved " + (contentLength - thisContentLength)
                    + " bytes of network traffic due to caching.");
        } finally {
            res.release();
        }
    }

    /** Print feed vital fields. */
    public static void printFeed(String title, String indent, Feed feed) {
        if (feed == null) {
            System.out.println(title + " feed is null");
            return;
        }

        System.out.println(title);
        System.out.println(indent + "id=" + feed.getId());
        System.out.println(indent + "title=" + feed.getTitle());
        System.out.println(indent + "updated=" + feed.getUpdated());
        System.out.println(indent + "author=" + feed.getAuthor());
        System.out.println(indent + "self link=" + feed.getSelfLink());
        Collection collection = feed.getCollection();
        if (collection == null) {
            System.out.println(indent + "collection=null");
        } else {
            System.out.println(indent + "collection=" + collection);
        }
    }

    /* Print headers of request. */
    public static void printRequestHeaders(String title, String indent, RequestOptions request) {
        System.out.println(title);
        if (request == null) {
            System.out.println(indent + " request is null");
            return;
        }
        String[] headerNames = request.getHeaderNames();
        for (String headerName : headerNames) {
            String header = request.getHeader(headerName);
            System.out.println(indent + " header name,value=" + headerName + "," + header);
        }
    }

    /* Print headers of response. */
    public static void printResponseHeaders(String title, String indent, ClientResponse response) {
        System.out.println(title);
        if (response == null) {
            System.out.println(indent + " response is null");
            return;
        }
        String[] headerNames = response.getHeaderNames();
        for (String headerName : headerNames) {
            String header = response.getHeader(headerName);
            System.out.println(indent + " header name,value=" + headerName + "," + header);
        }

    }

    /** Pretty print the document body. */
    public static void prettyPrint(Abdera abdera, Base doc) throws IOException {
        WriterFactory factory = abdera.getWriterFactory();
        Writer writer = factory.getWriter("prettyxml");
        writer.writeTo(doc, System.out);
        System.out.println();
    }

    /** Print the updated elements of the feed entries. */
    public static void printEntryUpdates(String title, String indent, Feed feed) {
        if (feed == null) {
            System.out.println(title + " feed is null");
            return;
        }

        System.out.println(title);
        List<Entry> entries = feed.getEntries();
        if (entries == null) {
            System.out.println(indent + " null entries");
        }
        System.out.println(indent + "entries size=" + entries.size());

        int i = 0;
        for (Entry entry : entries) {
            String entryTitle = entry.getTitle();
            if ((entryTitle != null) && (entryTitle.length() > 20))
                entryTitle = entryTitle.substring(0, 20);
            // System.out.println( indent + i++ + ": title=\"" + entryTitle +
            // "\", updated=" + entry.getUpdated() + ", published=" +
            // entry.getPublished() );
            System.out.println(indent + i++ + ": title=\"" + entryTitle + "\", updated=" + entry.getUpdated());
        }
    }

    /** Get the length of the response body content. */
    public static long getContentLength(ClientResponse response) {
        // getContentLenght returns -1
        // contentLength = response.getContentLength();
        try {
            Reader reader = response.getReader();
            long actualSkip = reader.skip(Long.MAX_VALUE);
            return actualSkip;
        } catch (IOException e) {
        }
        return -1L;
    }

    /** Get a count of entries in the feed. */
    public static int getEntryCount(Feed feed) {
        if (feed == null) {
            return 0;
        }

        List<Entry> entries = feed.getEntries();
        if (entries == null) {
            return 0;
        }
        return entries.size();
    }

    /**
     * Given a feed, determine the median point of the entries. Use the updated
     * field of the entries to determine median.
     * 
     * @param feed
     * @return
     */
    public static Date getUpdatedMedian(Feed feed) {
        Date sentinal = null;
        if (feed == null) {
            return sentinal;
        }

        List<Entry> entries = feed.getEntries();
        if (entries == null) {
            return sentinal;
        }
        int size = entries.size();
        if (size == 0) {
            return sentinal;
        }
        // System.out.println( "getUpdatedMedian entries size=" +
        // entries.size());
        ArrayList<Date> updates = new ArrayList<Date>(size);

        for (Entry entry : entries) {
            Date entryUpdated = entry.getUpdated();
            if (entryUpdated == null) {
                entryUpdated = new Date(0);
            }
            updates.add(entryUpdated);
        }
        Collections.sort(updates);
        // System.out.println( "getUpdatedMedian entry min update=" +
        // updates.get( 0 ));
        // System.out.println( "getUpdatedMedian entry max update=" +
        // updates.get( size - 1 ));
        Date median = updates.get(size / 2);
        // System.out.println( "getUpdatedMedian entry max median=" + median );
        return median;
    }

    private static boolean internetConnected() {
        try {
            // see whether an internet connection is available 
            Socket testInternet = new Socket("tuscany.apache.org", 80);
            testInternet.close();

            // internet connection available
            return true;

        } catch (Exception e) {
            // no internet connection
            System.out.println("Unable to run test because no internet connection available");
            return false;
        }
    }
}