package mongodb;

import static com.mongodb.client.model.Filters.and;
import static com.mongodb.client.model.Filters.eq;
import static com.mongodb.client.model.Filters.gt;

import java.util.concurrent.ThreadLocalRandom;

import org.bson.Document;
import org.bson.conversions.Bson;

import com.mongodb.Block;
import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.model.Projections;

public class ExempleProjection {

	public static void main(String[] args) {
		MongoClient client = new MongoClient();
		MongoDatabase db = client.getDatabase("exemples");
		MongoCollection<Document> coll = db.getCollection("punts");
		
		coll.drop();
		
		for (int i=0; i<100; i++) {
			int x = ThreadLocalRandom.current().nextInt(100);
			int y = ThreadLocalRandom.current().nextInt(100);
			int z = ThreadLocalRandom.current().nextInt(10);
			Document document = new Document("x",x).append("y", y).append("z", z);
			coll.insertOne(document);
		}
		
		Bson filter = and(gt("x", 50), eq("z", 5));
		// Retorna tots els elements, excepte que els s'indiqui amb un 0.
		// db.punts.find({$and : [{"x" : {$gt:50}}, {"z" : {$eq:5}}]}, {"x":0,"_id":0})
		Bson projection = new Document("x", 0).append("_id", 0);
		coll.find(filter).projection(projection).forEach((Block<Document>) doc -> System.out.println(doc.toJson()));
		System.out.println();
		
		// Retorna només els elements indicats amb un 1, i l'_id.
		// db.punts.find({$and : [{"x" : {$gt:50}}, {"z" : {$eq:5}}]}, {"x":1})
		projection = new Document("x",1);
		coll.find(filter).projection(projection).forEach((Block<Document>) doc -> System.out.println(doc.toJson()));
		System.out.println();
		
		// Retorna només els elements indicats amb un 1.
		// db.punts.find({$and : [{"x" : {$gt:50}}, {"z" : {$eq:5}}]}, {"y":1,"_id":0})
		projection = new Document("y", 1).append("_id", 0);
		coll.find(filter).projection(projection).forEach((Block<Document>) doc -> System.out.println(doc.toJson()));
		System.out.println();
		
		// Equivalent al primer exemple
		projection = Projections.exclude("x","_id");
		coll.find(filter).projection(projection).forEach((Block<Document>) doc -> System.out.println(doc.toJson()));
		System.out.println();
		
		// Equivalent al segon exemple
		projection = Projections.include("x");
		coll.find(filter).projection(projection).forEach((Block<Document>) doc -> System.out.println(doc.toJson()));
		System.out.println();
		
		// Equivalent al tercer exemple
		projection = Projections.fields(Projections.include("y"), Projections.excludeId());
		coll.find(filter).projection(projection).forEach((Block<Document>) doc -> System.out.println(doc.toJson()));
		System.out.println();
		
		client.close();
	}

}