package twitterdownloader;

import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import twitter4j.Query;
import twitter4j.QueryResult;
import twitter4j.RateLimitStatus;
import twitter4j.Status;
import twitter4j.Twitter;
import twitter4j.TwitterException;
import twitter4j.TwitterFactory;
import twitter4j.auth.AccessToken;

public class TwitterManag {

    private final String consumerKey = "XXXX"; //working credentials
    private final String consumerKeySecret = "XXXXX"; //working credentials
    private final String accessToken = "XXXX"; //working credentials
    private final String accessTokenSecret = "XXX"; //working credentials
    private final Twitter twitter; //Twitter4J Instance
    private final Set<Long> idSet; //set od tweet's ids in order to filter result ro receive only unique tweets
    private long maxID = -1; //holding maxId to filter tweets
    private int alreadyDownloaded = 0; //amount of already downloaded unique tweets
    private boolean isBlocked = false; //is API Rate Limit hit?
    private int waitTimeLeftSeconds = 0; //how much to wait till API is available again

    public TwitterManag() {
        twitter = TwitterFactory.getSingleton(); //create Twitter4J Instance
        twitter.setOAuthConsumer(consumerKey, consumerKeySecret);
        AccessToken accessTokenAPI = new AccessToken(accessToken, accessTokenSecret);
        twitter.setOAuthAccessToken(accessTokenAPI);
        idSet = new HashSet();
    }

    public void downloadTweets(String query, int ammount, String filePathToSave) throws FileNotFoundException, UnsupportedEncodingException, InterruptedException {
        PrintWriter writer = new PrintWriter(filePathToSave, "UTF-8"); //writting tweets to file
        Query twitterQuery = new Query(query);
        twitterQuery.setCount(100);
        twitterQuery.setLang("en");

        downloadData(writer, twitterQuery);

        while (alreadyDownloaded != ammount) {
            if (!isBlocked) { //if we are not blocked by API
                twitterQuery.setMaxId(maxID); //set maxID
                if (ammount - alreadyDownloaded < 100) { //set count to appopiate ammount
                    twitterQuery.setCount(ammount - alreadyDownloaded);
                } else {
                    twitterQuery.setCount(100);
                }
                downloadData(writer, twitterQuery);
            } else { //if we are blocked
                System.out.println("BLOCKED, WAITING FOR " + waitTimeLeftSeconds / 60 + " minutess.");
                if (waitTimeLeftSeconds <= 0)
                    waitTimeLeftSeconds = 1;
                Thread.sleep(waitTimeLeftSeconds * 1000);
                isBlocked = false;
            }

        }
        writer.close();
    }

    private void downloadData(PrintWriter writer, Query twitterQuery) {
        try {
            QueryResult result = twitter.search(twitterQuery);
            for (Status singleTweet : result.getTweets()) {
                if (!idSet.contains(singleTweet.getId()) && !singleTweet.isRetweet()) { //if tweet is not yet in our small database and it is not retweet
                    if (maxID == -1 || singleTweet.getId() < maxID) //get new maxId
                        maxID = singleTweet.getId() - 1;

                    idSet.add(singleTweet.getId()); //add tweet ID to "database"
                    writer.println(singleTweet.getText());
                    alreadyDownloaded++;
                }
            }
            System.out.println("Already downloaded: " + alreadyDownloaded);
        } catch (TwitterException ex) {
            if (ex.exceededRateLimitation()) {
                try {
                    Map<String, RateLimitStatus> rateLimitStatus = twitter.getRateLimitStatus("search");
                    RateLimitStatus searchTweetsRateLimit = rateLimitStatus.get("/search/tweets");
                    isBlocked = true;
                    waitTimeLeftSeconds = searchTweetsRateLimit.getSecondsUntilReset();
                } catch (TwitterException ex1) {
                    waitTimeLeftSeconds = 15 * 60;
                }
            }
        }
    }
}