package com.google.sps.data;

import com.google.appengine.api.datastore.DatastoreService;
import com.google.appengine.api.datastore.DatastoreServiceFactory;
import com.google.appengine.api.datastore.Entity;
import com.google.appengine.api.datastore.PreparedQuery;
import com.google.appengine.api.datastore.Query;
import com.google.appengine.api.datastore.Query.Filter;
import com.google.appengine.api.datastore.Query.FilterOperator;
import com.google.appengine.api.datastore.Query.FilterPredicate;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.ImmutableSet.Builder;
import com.google.sps.data.Book;
import com.google.sps.data.Review;
import com.google.sps.data.User;
import java.util.Set;

public class ReviewDaoDatastore implements ReviewDao {
  private DatastoreService datastore;

  public ReviewDaoDatastore() {
    datastore = DatastoreServiceFactory.getDatastoreService();
  }

  /**
   * Takes in a book and uploads all associated reviews
   * to Datastore with user set to default values
   *
   * @param book: Book object whose reviews are to be uploaded
   */
  @Override
  public void loadAll(Book book) {
    User defaultUser = User.create("unknown email", "GoodReads User");
    // loop through all the reviews of a book
    for (String review : book.reviews()) {
      Entity reviewEntity = new Entity("Review");
      reviewEntity.setProperty("Book", book);
      reviewEntity.setProperty("Content", review);
      reviewEntity.setProperty("User", defaultUser);
      datastore.put(reviewEntity);
    }
  }

  /**
   * Takes in a review and uploads to Datastore
   *
   * @param review: Review object to be uploaded
   */
  @Override
  public void loadNew(Review review) {
    Entity reviewEntity = new Entity("Review");
    reviewEntity.setProperty("Book", review.book());
    reviewEntity.setProperty("Content", review.fullText());
    reviewEntity.setProperty("User", review.user());
    datastore.put(reviewEntity);
  }

  /**
   * Takes in a book and returns a set of all Reviews associated
   * with that book in Datastore
   *
   * @param book: Book object whose reviews are to be returned
   * @return ImmutableSet of reviews associated with the book
   */
  @Override
  public ImmutableSet<Review> getAll(Book book) {
    ImmutableSet.Builder<Review> reviews = new ImmutableSet.Builder<Review>();
    Entity bookEntity = new Entity("Review");

    Filter bookFilter = new FilterPredicate("Book", FilterOperator.EQUAL, book);
    Query query = new Query("Review").setFilter(bookFilter);
    PreparedQuery results = datastore.prepare(query);
    if (results == null) {
      return reviews.build();
    }
    for (Entity entity : results.asIterable()) {
      Review review = entityToReview(entity);
      reviews.add(review);
    }
    return reviews.build();
  }

  private static Review entityToReview(Entity reviewEntity) {
    return Review.builder()
        .fullText((String) reviewEntity.getProperty("Content"))
        .book((Book) reviewEntity.getProperty("Book"))
        .user((User) reviewEntity.getProperty("User"))
        .build();
  }
}

@@ -2351,54 +2351,8 @@
 %3E();
-%0A    Entity bookEntity = new Entity(%22Review%22);
 %0A%0A  

remove unused code