package db_operations import com mongodb import java net UnknownHostEx

package db_operations;

import com.mongodb.*;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.Map;

/**
 * Created by Kell on 31.03.14.
 */
public class StudentDataOperations {
    Mongo mongoClient;
    DB db;

    public void deleteMinScores() {
        DBCollection studsCollection = db.getCollection("students");
        DBCursor studsCursor = studsCollection.find();
        BasicDBObject minScore;
        try {
            for (int i = 0; studsCursor.hasNext(); i++) {
                DBObject cur = studsCursor.next();
                minScore = getMinScore((ArrayList) cur.get("scores"));
                studsCollection.update(new BasicDBObject("_id", i),
                        new BasicDBObject("$pull", new BasicDBObject("scores", minScore)));
            }
        } finally {
            studsCursor.close();
        }
    }

    public BasicDBObject getMinScore(ArrayList scores) {
        int scoresSize = scores.size();
        double curNumScore = 0;
        double minNumScore = 0;
        BasicDBObject minScore = new BasicDBObject((Map) scores.get(0));
        for (int i = 1; i < scoresSize; i++) {
            curNumScore = Double.parseDouble(((BasicDBObject) scores.get(i)).get("score").toString());
            minNumScore = Double.parseDouble(minScore.get("score").toString());
            if (curNumScore < minNumScore) {
                minScore = new BasicDBObject((Map) scores.get(i));
            }
        }
        return minScore;
    }

    public StudentDataOperations() throws UnknownHostException {
        try {
            this.mongoClient = new Mongo();
            this.db = mongoClient.getDB("school");
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }
    }
}