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package com.camillepradel.movierecommender.controller;

import com.camillepradel.movierecommender.model.Genre;
import com.camillepradel.movierecommender.model.Movie;
import com.camillepradel.movierecommender.model.Rating;
import com.mongodb.AggregationOutput;
import com.mongodb.BasicDBList;
import com.mongodb.BasicDBObject;
import com.mongodb.client.AggregateIterable;
import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;
import static com.mongodb.client.model.Filters.eq;
import com.mongodb.client.model.UpdateOptions;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import org.bson.Document;

/**
 *
 * @author sidya
 */
public class MongoDBController implements DBControllerInterface {
    public List<Movie>getMoviesByUser(Integer user_id){
            ArrayList<Movie> listMovies= new  ArrayList<Movie>();
            MongoCursor<Document> cursor;
            
            MongoDatabase db = MongoDBConnector.getInstance().getConnexion();
            MongoCollection<Document> movies = db.getCollection("movies");
            if(user_id != null)
            {
                MongoCollection<Document> users = db.getCollection("users");
                BasicDBObject whereQuery = new BasicDBObject();
                whereQuery.put("_id", user_id);
                
                cursor = users.find(whereQuery).iterator();
                Document user;
                try {
                    user = cursor.next();
                } catch(Exception e)
                {
                    return new ArrayList<Movie>();
                }
                ArrayList<Document> user_movies;
                user_movies = (ArrayList) user.get("movies");
                BasicDBObject inQuery = new BasicDBObject();
                List<Integer> list = new ArrayList<Integer>();
                for(Document movie : user_movies)
                    list.add(movie.getInteger("movieid"));

                inQuery.put("_id", new BasicDBObject("$in", list));
                cursor = movies.find(inQuery).iterator();
            }
            else
            {
                cursor = movies.find().iterator();
            }
            
            while (cursor.hasNext()) {
                Document movie = cursor.next();
                String[] genres;
                genres = movie.getString("genres").split("\\|");
                ArrayList<Genre> listGenres = new ArrayList<Genre>();
                for(String genre : genres){
                    listGenres.add(new Genre(1,genre));
                }
                
                listMovies.add(new Movie(movie.getInteger("_id"), movie.getString("title"), listGenres));
            }
            return listMovies;
        }
        
    public List<Rating>getRatinByUser(Integer user_id){
            ArrayList<Rating> listRating= new  ArrayList<Rating>();
            MongoCursor<Document> cursor;
            
            MongoDatabase db = MongoDBConnector.getInstance().getConnexion();
            MongoCollection<Document> users = db.getCollection("users");
            MongoCollection<Document> movies = db.getCollection("movies");
            
            BasicDBObject whereQuery = new BasicDBObject();
            whereQuery.put("_id", user_id);

            cursor = users.find(whereQuery).iterator();
            Document user;
            try {
                user = cursor.next();
            } catch(Exception e)
            {
                return new ArrayList<Rating>();
            }
            
            ArrayList<Document> user_movies = (ArrayList) user.get("movies");
            BasicDBObject inQuery = new BasicDBObject();
            HashMap<Integer,Integer> list = new HashMap<Integer,Integer>();
            for(Document movie : user_movies)
                list.put(movie.getInteger("movieid"),movie.getInteger("rating"));

            inQuery.put("_id", new BasicDBObject("$in", list.keySet()));
            cursor = movies.find(inQuery).iterator();
          
            while (cursor.hasNext()) {
                Document movie = cursor.next();
                String[] genres;
                genres = movie.getString("genres").split("\\|");
                ArrayList<Genre> listGenres = new ArrayList<Genre>();
                for(String genre : genres){
                    listGenres.add(new Genre(1,genre));
                }
                
                listRating.add(new Rating(new Movie(movie.getInteger("_id"), movie.getString("title"), 
                        listGenres),user_id, list.get(movie.getInteger("_id"))));
            }
            return listRating;
        }

    public void updateMovieRating(Rating rating) {
        ArrayList<Rating> listRating= new  ArrayList<Rating>();
        MongoCursor<Document> cursor;

        MongoDatabase db = MongoDBConnector.getInstance().getConnexion();
        MongoCollection<Document> users = db.getCollection("users");

        BasicDBObject updateQuery = new BasicDBObject();
        BasicDBObject newDocument = new BasicDBObject();
        BasicDBObject deleteDocument = new BasicDBObject();
        
        deleteDocument.append("$pull", new BasicDBObject()
            .append("movies", new BasicDBObject()
                .append("movieid", rating.getMovieId())
            )
        );
        
        newDocument.append("$push", new BasicDBObject()
            .append("movies", new BasicDBObject()
                .append("movieid", rating.getMovieId())
                .append("rating", rating.getScore())
                .append("timestamp", (int) (new Date().getTime()/1000))
            )
        );
        
        BasicDBObject searchQuery = new BasicDBObject()
            .append("_id", rating.getUserId());
        
        FindIterable<Document> movie = users.find(searchQuery);
        

        users.updateOne(searchQuery,deleteDocument);
        users.updateOne(searchQuery, newDocument);
        
    }

    public List<Rating> ProcessRecommendationV1(Integer userId) {
        MongoDatabase db = MongoDBConnector.getInstance().getConnexion();
        MongoCollection<Document> users = db.getCollection("users");
        
        BasicDBObject project;
        BasicDBObject match;
        BasicDBObject sort;
        BasicDBObject limit;
        BasicDBObject unwind;
        BasicDBObject group;
        
        project = new BasicDBObject("$project", 
                new BasicDBObject("moviesid", "$movies.movieid")
        );
        
        match = new BasicDBObject("$match", 
                new BasicDBObject("_id", new BasicDBObject("$eq", userId))
        );
        
        AggregateIterable<Document> output = users.aggregate(Arrays.asList(project, match));
        
        final Document moviesid = output.first();
        
        BasicDBList intersectionList = new BasicDBList();
        intersectionList.add("$movies.movieid" );
        intersectionList.add( moviesid.get("moviesid") );
        
        project = new BasicDBObject("$project", 
            new BasicDBObject("nbMoviesIntersect", 
                new BasicDBObject("$size", 
                    new BasicDBObject("$setIntersection",
                        intersectionList
                    )
                )
            )
        );
        
        match = new BasicDBObject("$match", 
                new BasicDBObject("_id", new BasicDBObject("$ne", userId))
        );
        
        sort = new BasicDBObject("$sort", 
                new BasicDBObject("nbMoviesIntersect", -1)
        );
        
        limit = new BasicDBObject("$limit", 5);
        
        output = users.aggregate(Arrays.asList(project, match, sort, limit));
        
        Document simUser = output.first();
        
        unwind = new BasicDBObject("$unwind", "$movies");
        
        match = new BasicDBObject("$match", 
                new BasicDBObject()
                .append("_id", simUser.getInteger("_id"))
                .append("movies.movieid", new BasicDBObject("$nin", moviesid.get("moviesid")))
        );
        
        group = new BasicDBObject("$group",  new BasicDBObject()
                .append("movies", new BasicDBObject("$push", "$movies"))
        );
        
        sort = new BasicDBObject("$sort", new BasicDBObject("movies.rating",  -1));
                  
        output = users.aggregate(Arrays.asList(unwind, match, sort, group));
        
        Document listMoviesDiff = output.first();
        
        
        ArrayList<Rating> listRating= new  ArrayList<Rating>();
        MongoCollection<Document> movies = db.getCollection("movies");
        MongoCursor<Document> cursor;

        ArrayList<Document> user_movies = (ArrayList) listMoviesDiff.get("movies");
        BasicDBObject inQuery = new BasicDBObject();
        HashMap<Integer,Integer> list = new HashMap<Integer,Integer>();
        for(Document movie : user_movies )
            list.put(movie.getInteger("movieid"), movie.getInteger("rating"));

        inQuery.put("_id", new BasicDBObject("$in", list.keySet()));
        cursor = movies.find(inQuery).iterator();

        HashMap<Integer,Rating> hashMoviesRating = new HashMap<Integer,Rating>();
        while (cursor.hasNext()) {
            Document movie = cursor.next();
            String[] genres;
            genres = movie.getString("genres").split("\\|");
            ArrayList<Genre> listGenres = new ArrayList<Genre>();
            for(String genre : genres){
                listGenres.add(new Genre(1,genre));
            }
             hashMoviesRating.put(movie.getInteger("_id"),
                new Rating(new Movie(movie.getInteger("_id"), movie.getString("title"), listGenres), 
                             userId, list.get(movie.getInteger("_id"))));
            
       }
       
        for(Document movie : user_movies )
            listRating.add(hashMoviesRating.get(movie.getInteger("movieid")));
        
        return listRating;
     }

    public List<Rating> ProcessRecommendationV2(Integer userId) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

    public List<Rating> ProcessRecommendationV3(Integer userId) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }
}