/*
 * Firetweet - Twitter client for Android
 *
 *  Copyright (C) 2012-2015 Mariotaku Lee <mariotaku.lee@gmail.com>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package twitter4j;

import twitter4j.auth.AccessToken;
import twitter4j.auth.Authorization;
import twitter4j.auth.AuthorizationFactory;
import twitter4j.auth.OAuthAuthorization;
import twitter4j.conf.Configuration;
import twitter4j.conf.ConfigurationContext;

/**
 * A factory class for Twitter. <br>
 * An instance of this class is completely thread safe and can be re-used and
 * used concurrently.
 * 
 * @author Yusuke Yamamoto - yusuke at mac.com
 * @since Twitter4J 2.1.0
 */
public final class TwitterFactory {
	/* AsyncTwitterFactory and TWitterStream will access this field */
	static final Authorization DEFAULT_AUTHORIZATION = AuthorizationFactory.getInstance(ConfigurationContext
			.getInstance());
	private static final Twitter SINGLETON;

	private final Configuration conf;

	static {
		SINGLETON = new TwitterImpl(ConfigurationContext.getInstance(), DEFAULT_AUTHORIZATION);
	}

	/**
	 * Creates a TwitterFactory with the root configuration.
	 */
	public TwitterFactory() {
		this(ConfigurationContext.getInstance());
	}

	/**
	 * Creates a TwitterFactory with the given configuration.
	 * 
	 * @param conf the configuration to use
	 * @since Twitter4J 2.1.1
	 */
	public TwitterFactory(final Configuration conf) {
		if (conf == null) throw new NullPointerException("configuration cannot be null");
		this.conf = conf;
	}

	/**
	 * Returns a instance associated with the configuration bound to this
	 * factory.
	 * 
	 * @return default singleton instance
	 */
	public Twitter getInstance() {
		return getInstance(AuthorizationFactory.getInstance(conf));
	}

	/**
	 * Returns a OAuth Authenticated instance.<br>
	 * consumer key and consumer Secret must be provided by
	 * twitter4j.properties, or system properties.<br>
	 * Unlike {@link twitter4j.Twitter#setOAuthAccessToken(twitter4j.auth.AccessToken)} ,
	 * this factory method potentially returns a cached instance.
	 * 
	 * @param accessToken access token
	 * @return an instance
	 * @since Twitter4J 2.1.9
	 */
	public Twitter getInstance(final AccessToken accessToken) {
		final String consumerKey = conf.getOAuthConsumerKey();
		final String consumerSecret = conf.getOAuthConsumerSecret();
		if (null == consumerKey && null == consumerSecret)
			throw new IllegalStateException("Consumer key and Consumer secret not supplied.");
		final OAuthAuthorization oauth = new OAuthAuthorization(conf);
		oauth.setOAuthAccessToken(accessToken);
		return getInstance(oauth);
	}

	public Twitter getInstance(final Authorization auth) {
		return new TwitterImpl(conf, auth);
	}

	/**
	 * Returns default singleton Twitter instance.
	 * 
	 * @return default singleton Twitter instance
	 * @since Twitter4J 2.2.4
	 */
	public static Twitter getSingleton() {
		return SINGLETON;
	}
}