/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

package com.nokia.carbide.cpp.internal.news.reader.gen.FeedInfo;

import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.URISyntaxException;

import java.net.URL;

import java.net.URLConnection;

import org.eclipse.core.runtime.IPath;

import org.eclipse.core.runtime.Path;

import com.nokia.carbide.cpp.internal.news.reader.CarbideNewsReaderPlugin;

import com.nokia.cpp.internal.api.utils.core.FileUtils;

/**

 * A class for managing feed information.

 *

 */

public class FeedInfoManager {

	// private data

	private static final String FEED_INFO_FILE_KEY = "com.nokia.carbide.cpp.news.reader.feed.listing.file";

	private static final String FEED_INFO_FILE_NAME = "feedListing.xml";

	private File feedInfoFile;

	private FeedInfoType feedInfo;

	/**

	 * Check whether a feed is news feed.

	 * @param feed - feed to be checked

	 * @return true if it is a news feed

	 */

	public static boolean isNewsFeed(FeedType feed) {

		return feed.getType().toLowerCase().equals(FeedInfoConstants.FEED_TYPE_NEWS);

	}

	/**

	 * Check whether a feed is resource feed.

	 * @param feed - feed to be checked

	 * @return true if it is a resource feed

	 */

	public static boolean isResourceFeed(FeedType feed) {

		return feed.getType().toLowerCase().equals(FeedInfoConstants.FEED_TYPE_RESOURCE);

	}

	public static boolean isSubscribed(FeedType feed) {

		String subscribed = feed.getType().toLowerCase();

		if (subscribed.equals(FeedInfoConstants.SUBSCRIBED_ALWAYS) || subscribed.equals(FeedInfoConstants.SUBSCRIBED_TRUE)) {

			return true;

		}

		else {

			return false;

		}

	}

	/**

	 * Load feed information from a file.

	 * @param url - URL to the file

	 * @return true on success

	 */

	public boolean loadFeedInfo(URL url) {

		if (url == null) {

			return false;

		}

		boolean success = true;

		try {

			feedInfo = FeedInfoLoader.loadFeedInfo(url);

			success = (feedInfo != null);

		} catch (URISyntaxException eURI){

			CarbideNewsReaderPlugin.log(eURI);

			success = false;

		} catch (IOException eIO){

			CarbideNewsReaderPlugin.log(eIO);

			success = false;

		}

		return success;

	}

	/**

	 * Return the stored feed information.

	 * @return stored feed information

	 */

	public FeedInfoType getFeedInfo() {

		return feedInfo;

	}

	/**

	 * Retrieve the feed info file from remote server, make a local copy of this file

	 * and returns the URL to the local copy.

	 * @param useLocal - use local copy of feed listing file? 

	 * @return URL of local copy of feed info file

	 * @throws Exception

	 */

	public URL getFeedInfoFileURL(boolean useLocalCopy) throws Exception {

		if (feedInfoFile == null) {

			feedInfoFile = createFeedInfoFile();

		}

		if (useLocalCopy) {

			// try to use local copy of the fee info file if it exists.

			if (feedInfoFile != null && feedInfoFile.exists()) {

				return feedInfoFile.toURL();

			}

			else {

				return null;

			}

		}

		// retrieve the feed info file from remote server and make a local copy of this file

		String pathStr = CarbideNewsReaderPlugin.getFeedManager().getProperty(FEED_INFO_FILE_KEY);

		if (pathStr != null) {

			URL fileUrl = new URL(pathStr);

			if (fileUrl != null) {

				HttpURLConnection connection = null;

				InputStream inputStream = null;

				try {

					setRequestHeaders(connection);

					connection.setUseCaches(false);

					connection.connect();

					int responseCode = connection.getResponseCode();

					handlesHttpErrorCode(responseCode);

					inputStream = connection.getInputStream();

					if (inputStream != null) {

						if (feedInfoFile != null) {

							if (feedInfoFile.exists()) {

								feedInfoFile.delete();

							}

							FileUtils.copyFile(inputStream, feedInfoFile);

							return feedInfoFile.toURL();

						}

					}

				} catch (Exception e) {

					CarbideNewsReaderPlugin.log(e);

				} finally {

					if (connection != null) {

					    connection.disconnect();

					}

					if (inputStream != null) {

						inputStream.close();

					}

				}

			}

		}

		return null;

	}

	/**

	 * Save feed information to a file.

	 * @param url - URL to the file

	 * @return true on success

	 */

	public boolean saveFeedInfo(URL url) {

		if (url == null) {

			return false;

		}

		boolean success = true;

		try {

			if (feedInfo != null) {

				success = FeedInfoLoader.saveFeedInfo(feedInfo, url);

			}

		} catch (URISyntaxException eURI){

			CarbideNewsReaderPlugin.log(eURI);

			success = false;

		} catch (IOException eIO){

			CarbideNewsReaderPlugin.log(eIO);

			success = false;

		}

		return success;

	}

	/**

	 * Set the stored feed information

	 * @param feedInfo - incoming feed information

	 */

	public void setFeedInfo(FeedInfoType feedInfo) {

		this.feedInfo = feedInfo;

	}

	/**

	 * Create a feed info file in the local temp directory.

	 * @return feed info file in the local temp directory

	 */

	private File createFeedInfoFile() {

		File tempDir = FileUtils.getTemporaryDirectory();

		IPath path = new Path(tempDir.getAbsolutePath());

		path = path.append(FEED_INFO_FILE_NAME);

		File file = path.toFile();

		return file;

	}

	/**

	 * Handles HTTP error codes.

	 * @param responseCode - HTTP response code

	 */

	private void handlesHttpErrorCode(int responseCode) throws Exception {

		if (responseCode == 403) {

			throw new Exception("Authentication required for that resource. HTTP Response code was:" + responseCode);

		} else if (responseCode >= 400 && responseCode < 500) {

			throw new Exception("The requested resource could not be found. HTTP Response code was:" + responseCode);

		} else if (responseCode >= 500 && responseCode < 600) {

			throw new Exception("The server encountered an error. HTTP Response code was:" + responseCode);

		}

	}

	/**

	 * Sets appropriate HTTP headers.

	 * @param connection - URL connection

	 */

	private void setRequestHeaders(URLConnection connection) {

		// specify acceptable content types

		connection.setRequestProperty("Accept", "*/xml");

	}

}