package com.mapr.music.service;
import com.mapr.music.dao.*;
import com.mapr.music.dto.RateDto;
import com.mapr.music.exception.ResourceNotFoundException;
import com.mapr.music.model.*;
import org.apache.commons.beanutils.PropertyUtilsBean;
import javax.inject.Inject;
import javax.inject.Named;
import java.lang.reflect.InvocationTargetException;
import java.security.Principal;
import java.util.List;
import java.util.UUID;
public class RateService {
private final AlbumRateDao albumRateDao;
private final ArtistRateDao artistRateDao;
private final AlbumDao albumDao;
private final ArtistDao artistDao;
private final MaprDbDao<User> userDao;
@Inject
public RateService(AlbumRateDao albumRateDao,
ArtistRateDao artistRateDao,
@Named("albumDao") AlbumDao albumDao,
@Named("artistDao") ArtistDao artistDao,
@Named("userDao") MaprDbDao<User> userDao) {
this.albumRateDao = albumRateDao;
this.artistRateDao = artistRateDao;
this.albumDao = albumDao;
this.artistDao = artistDao;
this.userDao = userDao;
}
/**
* Returns User's rate for the specified Album.
*
* @param user user's principal.
* @param albumId album's identifier.
* @return User's rate for the specified Album. Empty rate will be returned in case when there is no such rate.
*/
public RateDto getAlbumRate(Principal user, String albumId) {
if (user == null || user.getName() == null || user.getName().isEmpty()) {
return new RateDto();
}
String userId = user.getName();
if (!userDao.exists(userId)) {
throw new ResourceNotFoundException("User with id '" + userId + "' not found");
}
if (!albumDao.exists(albumId)) {
throw new ResourceNotFoundException("Album with id '" + albumId + "' not found");
}
AlbumRate rate = albumRateDao.getRate(userId, albumId);
return (rate != null) ? albumRateToDto(rate) : new RateDto();
}
/**
* Allows to rate specified Album on behalf of specified User.
*
* @param userId user's identifier.
* @param albumId album's identifier.
* @param albumRate rate Data Transfer Object.
* @return created or updated Album's rate.
*/
public RateDto rateAlbum(String userId, String albumId, RateDto albumRate) {
if (albumRate == null) {
throw new IllegalArgumentException("Album rate can not be null");
}
return rateAlbum(userId, albumId, albumRate.getRating());
}
/**
* Allows to rate specified Album on behalf of specified User.
*
* @param userId user's identifier.
* @param albumId album's identifier.
* @param rate rate.
* @return created or updated Album's rate.
*/
public RateDto rateAlbum(String userId, String albumId, double rate) {
if (userId == null || userId.isEmpty()) {
throw new IllegalArgumentException("User id can not be empty");
}
if (albumId == null || albumId.isEmpty()) {
throw new IllegalArgumentException("Album id can not be empty");
}
if (!userDao.exists(userId)) {
throw new ResourceNotFoundException("User with id '" + userId + "' not found");
}
Album existingAlbum = albumDao.getById(albumId);
if (existingAlbum == null) {
throw new ResourceNotFoundException("Album with id '" + albumId + "' not found");
}
AlbumRate possibleExistingRate = albumRateDao.getRate(userId, albumId);
if (possibleExistingRate != null) {
possibleExistingRate.setRating(rate);
AlbumRate newAlbumRate = albumRateDao.update(possibleExistingRate.getId(), possibleExistingRate);
return recomputeAlbumRate(newAlbumRate, existingAlbum);
}
AlbumRate albumRate = new AlbumRate();
albumRate.setId(UUID.randomUUID().toString());
albumRate.setUserId(userId);
albumRate.setDocumentId(albumId);
albumRate.setRating(rate);
AlbumRate newAlbumRate = albumRateDao.create(albumRate);
return recomputeAlbumRate(newAlbumRate, existingAlbum);
}
private RateDto recomputeAlbumRate(AlbumRate newAlbumRate, Album existingAlbum) {
List<AlbumRate> albumRates = albumRateDao.getByAlbumId(newAlbumRate.getDocumentId());
double aggregatedRating = albumRates.stream().mapToDouble(AlbumRate::getRating).sum() / albumRates.size();
existingAlbum.setRating(aggregatedRating);
albumDao.update(existingAlbum.getId(), existingAlbum);
return new RateDto(aggregatedRating);
}
private RateDto recomputeArtistRate(ArtistRate newArtistRate, Artist existingArtist) {
List<ArtistRate> artistRates = artistRateDao.getByArtistId(newArtistRate.getDocumentId());
double aggregatedRating = artistRates.stream().mapToDouble(ArtistRate::getRating).sum() / artistRates.size();
existingArtist.setRating(aggregatedRating);
artistDao.update(existingArtist.getId(), existingArtist);
return new RateDto(aggregatedRating);
}
/**
* Allows to rate specified Album on behalf of specified User.
*
* @param user user's principal.
* @param albumId album's identifier.
* @param albumRate rate Data Transfer Object.
* @return created or updated Album's rate.
*/
public RateDto rateAlbum(Principal user, String albumId, RateDto albumRate) {
if (user == null) {
throw new IllegalArgumentException("User principal can not be null");
}
if (albumRate == null) {
throw new IllegalArgumentException("Album rate can not be null");
}
return rateAlbum(user.getName(), albumId, albumRate.getRating());
}
/**
* Returns User's rate for the specified Artist.
*
* @param user user's principal.
* @param artistId artists's identifier.
* @return User's rate for the specified Artist. Empty rate will be returned in case when there is no such rate.
*/
public RateDto getArtistRate(Principal user, String artistId) {
if (user == null || user.getName() == null || user.getName().isEmpty()) {
return new RateDto();
}
String userId = user.getName();
if (!userDao.exists(userId)) {
throw new ResourceNotFoundException("User with id '" + userId + "' not found");
}
if (!artistDao.exists(artistId)) {
throw new ResourceNotFoundException("Artist with id '" + artistId + "' not found");
}
ArtistRate rate = artistRateDao.getRate(userId, artistId);
return (rate != null) ? artistRateToDto(rate) : new RateDto();
}
/**
* Allows to rate specified Artist on behalf of specified User.
*
* @param userId user's identifier.
* @param artistId artist's identifier.
* @param artistRate rate Data Transfer Object.
* @return created or updated Artist's rate.
*/
public RateDto rateArtist(String userId, String artistId, RateDto artistRate) {
if (artistRate == null) {
throw new IllegalArgumentException("Artist rate can not be null");
}
return rateArtist(userId, artistId, artistRate.getRating());
}
/**
* Allows to rate specified Artist on behalf of specified User.
*
* @param userId user's identifier.
* @param artistId artist's identifier.
* @param rate rate.
* @return created or updated Artist's rate.
*/
public RateDto rateArtist(String userId, String artistId, double rate) {
if (userId == null || userId.isEmpty()) {
throw new IllegalArgumentException("User id can not be empty");
}
if (artistId == null || artistId.isEmpty()) {
throw new IllegalArgumentException("Artist id can not be empty");
}
if (!userDao.exists(userId)) {
throw new ResourceNotFoundException("User with id '" + userId + "' not found");
}
Artist existingArtist = artistDao.getById(artistId);
if (existingArtist == null) {
throw new ResourceNotFoundException("Artist with id '" + artistId + "' not found");
}
ArtistRate possibleExistingRate = artistRateDao.getRate(userId, artistId);
if (possibleExistingRate != null) {
possibleExistingRate.setRating(rate);
ArtistRate newArtistRate = artistRateDao.update(possibleExistingRate.getId(), possibleExistingRate);
return recomputeArtistRate(newArtistRate, existingArtist);
}
ArtistRate artistRate = new ArtistRate();
artistRate.setId(UUID.randomUUID().toString());
artistRate.setUserId(userId);
artistRate.setDocumentId(artistId);
artistRate.setRating(rate);
ArtistRate newArtistRate = artistRateDao.create(artistRate);
return recomputeArtistRate(newArtistRate, existingArtist);
}
/**
* Allows to rate specified Artist on behalf of specified User.
*
* @param user user's principal.
* @param artistId artist's identifier.
* @param artistRate rate Data Transfer Object.
* @return created or updated Artist's rate.
*/
public RateDto rateArtist(Principal user, String artistId, RateDto artistRate) {
if (user == null) {
throw new IllegalArgumentException("User principal can not be null");
}
if (artistRate == null) {
throw new IllegalArgumentException("Artist rate can not be null");
}
return rateArtist(user.getName(), artistId, artistRate.getRating());
}
private RateDto artistRateToDto(ArtistRate artistRate) {
RateDto rateDto = new RateDto();
PropertyUtilsBean propertyUtilsBean = new PropertyUtilsBean();
try {
propertyUtilsBean.copyProperties(rateDto, artistRate);
} catch (IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
throw new RuntimeException("Can not create artist rate Data Transfer Object", e);
}
return rateDto;
}
private RateDto albumRateToDto(AlbumRate albumRate) {
RateDto rateDto = new RateDto();
PropertyUtilsBean propertyUtilsBean = new PropertyUtilsBean();
try {
propertyUtilsBean.copyProperties(rateDto, albumRate);
} catch (IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
throw new RuntimeException("Can not create album rate Data Transfer Object", e);
}
return rateDto;
}
}
