/*
 * Copyright 2017 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.firestore.snippets;

import com.example.firestore.snippets.model.City;
import com.google.api.core.ApiFuture;
import com.google.api.core.ApiFutures;
import com.google.cloud.firestore.CollectionReference;
import com.google.cloud.firestore.DocumentSnapshot;
import com.google.cloud.firestore.Firestore;
import com.google.cloud.firestore.Query;
import com.google.cloud.firestore.Query.Direction;
import com.google.cloud.firestore.QueryDocumentSnapshot;
import com.google.cloud.firestore.QuerySnapshot;
import com.google.cloud.firestore.WriteResult;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/** Snippets to support firestore querying data documentation. */
class QueryDataSnippets {

  private final Firestore db;

  QueryDataSnippets(Firestore db) {
    this.db = db;
  }

  /**
   * Creates cities collection and add sample documents to test queries.
   *
   * @return collection reference
   */
  void prepareExamples() throws Exception {

    // [START firestore_query_filter_dataset]
    CollectionReference cities = db.collection("cities");
    List<ApiFuture<WriteResult>> futures = new ArrayList<>();
    futures.add(
        cities
            .document("SF")
            .set(
                new City(
                    "San Francisco",
                    "CA",
                    "USA",
                    false,
                    860000L,
                    Arrays.asList("west_coast", "norcal"))));
    futures.add(
        cities
            .document("LA")
            .set(
                new City(
                    "Los Angeles",
                    "CA",
                    "USA",
                    false,
                    3900000L,
                    Arrays.asList("west_coast", "socal"))));
    futures.add(
        cities
            .document("DC")
            .set(
                new City(
                    "Washington D.C.", null, "USA", true, 680000L, Arrays.asList("east_coast"))));
    futures.add(
        cities
            .document("TOK")
            .set(
                new City(
                    "Tokyo", null, "Japan", true, 9000000L, Arrays.asList("kanto", "honshu"))));
    futures.add(
        cities
            .document("BJ")
            .set(
                new City(
                    "Beijing",
                    null,
                    "China",
                    true,
                    21500000L,
                    Arrays.asList("jingjinji", "hebei"))));
    // (optional) block on documents successfully added
    ApiFutures.allAsList(futures).get();
    // [END firestore_query_filter_dataset]
  }

  /**
   * Creates a sample query.
   *
   * @return query
   */
  Query createQuery() throws Exception {
    // [START firestore_query_filter_eq_boolean]
    // Create a reference to the cities collection
    CollectionReference cities = db.collection("cities");
    // Create a query against the collection.
    Query query = cities.whereEqualTo("capital", true);
    // retrieve  query results asynchronously using query.get()
    ApiFuture<QuerySnapshot> querySnapshot = query.get();

    for (DocumentSnapshot document : querySnapshot.get().getDocuments()) {
      System.out.println(document.getId());
    }
    // [END firestore_query_filter_eq_boolean]
    return query;
  }

  /**
   * Creates a sample query.
   *
   * @return query
   */
  Query createQueryAlternate() throws Exception {
    // [START firestore_query_filter_eq_string]
    // Create a reference to the cities collection
    CollectionReference cities = db.collection("cities");
    // Create a query against the collection.
    Query query = cities.whereEqualTo("state", "CA");
    // retrieve  query results asynchronously using query.get()
    ApiFuture<QuerySnapshot> querySnapshot = query.get();

    for (DocumentSnapshot document : querySnapshot.get().getDocuments()) {
      System.out.println(document.getId());
    }
    // [END firestore_query_filter_eq_string]
    return query;
  }

  /**
   * Creates queries with simple where clauses.
   *
   * @return queries
   */
  List<Query> createSimpleQueries() {
    List<Query> querys = new ArrayList<>();
    CollectionReference cities = db.collection("cities");

    // [START firestore_query_filter_single_examples]
    Query stateQuery = cities.whereEqualTo("state", "CA");
    Query populationQuery = cities.whereLessThan("population", 1000000L);
    Query nameQuery = cities.whereGreaterThanOrEqualTo("name", "San Francisco");
    // [END firestore_query_filter_single_examples]

    querys.add(stateQuery);
    querys.add(populationQuery);
    querys.add(nameQuery);
    return querys;
  }

  /**
   * Creates a query based on array containment.
   *
   * @return query
   */
  Query createArrayQuery() {
    // [START firestore_query_filter_array_contains]
    CollectionReference citiesRef = db.collection("cities");
    Query westCoastQuery = citiesRef.whereArrayContains("regions", "west_coast");
    // [END firestore_query_filter_array_contains]

    return westCoastQuery;
  }

  /**
   * Creates chained where clauses.
   *
   * <p>Note : equality and inequality clauses over multiple fields cannot be chained.
   *
   * @return query
   */
  Query createChainedQuery() {
    CollectionReference cities = db.collection("cities");
    // [START firestore_query_filter_compound_multi_eq]
    Query chainedQuery1 = cities.whereEqualTo("state", "CO").whereEqualTo("name", "Denver");
    // [END firestore_query_filter_compound_multi_eq]
    return chainedQuery1;
  }

  /**
   * An instance of a currently unsupported chained query: equality with inequality. NOTE : Requires
   * support for creation of composite indices.
   *
   * @return query
   */
  Query createCompositeIndexChainedQuery() {
    CollectionReference cities = db.collection("cities");
    // [START firestore_query_filter_compound_multi_eq_lt]
    Query chainedQuery2 = cities.whereEqualTo("state", "CA").whereLessThan("population", 1000000L);
    // [END firestore_query_filter_compound_multi_eq_lt]
    return chainedQuery2;
  }

  /**
   * An instance of a valid range/inequality query : range operators are limited to a single field.
   *
   * @return query
   */
  Query createRangeQuery() {
    CollectionReference cities = db.collection("cities");
    // [START firestore_query_filter_range_valid]
    Query validQuery1 =
        cities.whereGreaterThanOrEqualTo("state", "CA").whereLessThanOrEqualTo("state", "IN");
    Query validQuery2 = cities.whereEqualTo("state", "CA").whereGreaterThan("population", 1000000);
    // [END firestore_query_filter_range_valid]
    return validQuery1;
  }

  /**
   * An instance of an invalid range query : range operators are limited to a single field.
   *
   * @return query
   */
  Query createInvalidRangeQuery() {
    CollectionReference cities = db.collection("cities");
    // Violates constraint : range operators are limited to a single field
    // [START firestore_query_filter_range_invalid]
    Query invalidRangeQuery =
        cities.whereGreaterThanOrEqualTo("state", "CA").whereGreaterThan("population", 100000);
    // [END firestore_query_filter_range_invalid]
    return invalidRangeQuery;
  }

  /**
   * Creates a query that combines order by with limit.
   *
   * @return query
   */
  Query createOrderByNameWithLimitQuery() {
    CollectionReference cities = db.collection("cities");
    // [START firestore_query_order_limit]
    Query query = cities.orderBy("name").limit(3);
    // [END firestore_query_order_limit]
    return query;
  }

  /**
   * Creates a query that combines order by with limitToLast.
   *
   * @return query
   */
  Query createOrderByNameWithLimitToLastQuery() {
    CollectionReference cities = db.collection("cities");
    // [START firestore_query_order_limit]
    Query query = cities.orderBy("name").limitToLast(3);
    // [END firestore_query_order_limit]
    return query;
  }

  /**
   * Creates a query that orders by country and population(descending).
   *
   * @return query
   */
  Query createOrderByCountryAndPopulation() {
    CollectionReference cities = db.collection("cities");
    // [START firestore_query_order_multi]
    Query query = cities.orderBy("state").orderBy("population", Direction.DESCENDING);
    // [END firestore_query_order_multi]
    return query;
  }

  /**
   * Creates a query that combines order by in descending order with the limit operator.
   *
   * @return query
   */
  Query createOrderByNameDescWithLimitQuery() {
    CollectionReference cities = db.collection("cities");
    // [START firestore_query_order_desc_limit]
    Query query = cities.orderBy("name", Direction.DESCENDING).limit(3);
    // [END firestore_query_order_desc_limit]
    return query;
  }

  /**
   * Creates a query that combines where clause with order by and limit operator.
   *
   * @return query
   */
  Query createWhereWithOrderByAndLimitQuery() {
    CollectionReference cities = db.collection("cities");
    // [START firestore_query_order_limit_field_valid]
    Query query = cities.whereGreaterThan("population", 2500000L).orderBy("population").limit(2);
    // [END firestore_query_order_limit_field_valid]
    return query;
  }

  /**
   * Creates a query using a range where clause with order by. Order by must be based on the same
   * field as the range clause.
   *
   * @return query
   */
  Query createRangeWithOrderByQuery() {
    CollectionReference cities = db.collection("cities");
    // [START firestore_query_order_with_filter]
    Query query = cities.whereGreaterThan("population", 2500000L).orderBy("population");
    // [END firestore_query_order_with_filter]
    return query;
  }

  /**
   * Creates an instance of an invalid range combined with order. Violates the constraint that range
   * and order by are required to be on the same field.
   *
   * @return query
   */
  Query createInvalidRangeWithOrderByQuery() {
    CollectionReference cities = db.collection("cities");
    // Violates the constraint that range and order by are required to be on the same field
    // [START firestore_query_order_field_invalid]
    Query query = cities.whereGreaterThan("population", 2500000L).orderBy("country");
    // [END firestore_query_order_field_invalid]
    return query;
  }

  /**
   * Create a query defining the start point of a query.
   *
   * @return query
   */
  Query createStartAtFieldQueryCursor() {
    CollectionReference cities = db.collection("cities");
    // [START firestore_query_cursor_start_at_field_value_single]
    Query query = cities.orderBy("population").startAt(4921000L);
    // [END firestore_query_cursor_start_at_field_value_single]
    return query;
  }

  /**
   * Create a query defining the start point of a query.
   *
   * @return query
   */
  Query createEndAtFieldQueryCursor() {
    CollectionReference cities = db.collection("cities");
    // [START firestore_query_cursor_end_at_field_value_single]
    Query query = cities.orderBy("population").endAt(4921000L);
    // [END firestore_query_cursor_end_at_field_value_single]
    return query;
  }

  /* Create queries with multiple cursor conditions. */
  void createMultipleCursorConditionsQuery() {
    // [START firestore_query_cursor_start_at_field_value_multi]
    // Will return all Springfields
    Query query1 = db.collection("cities").orderBy("name").orderBy("state").startAt("Springfield");

    // Will return "Springfield, Missouri" and "Springfield, Wisconsin"
    Query query2 =
        db.collection("cities").orderBy("name").orderBy("state").startAt("Springfield", "Missouri");
    // [END firestore_query_cursor_start_at_field_value_multi]
  }

  /**
   * Create a query using a snapshot as a start point.
   *
   * @return query
   */
  Query createStartAtSnapshotQueryCursor()
      throws InterruptedException, ExecutionException, TimeoutException {
    // [START firestore_query_cursor_start_at_document]
    // Fetch the snapshot with an API call, waiting for a maximum of 30 seconds for a result.
    ApiFuture<DocumentSnapshot> future = db.collection("cities").document("SF").get();
    DocumentSnapshot snapshot = future.get(30, TimeUnit.SECONDS);

    // Construct the query
    Query query = db.collection("cities").orderBy("population").startAt(snapshot);
    // [END firestore_query_cursor_start_at_document]
    return query;
  }

  /** Example of a paginated query. */
  List<Query> paginateCursor() throws InterruptedException, ExecutionException, TimeoutException {
    // [START firestore_query_cursor_pagination]
    // Construct query for first 25 cities, ordered by population.
    CollectionReference cities = db.collection("cities");
    Query firstPage = cities.orderBy("population").limit(25);

    // Wait for the results of the API call, waiting for a maximum of 30 seconds for a result.
    ApiFuture<QuerySnapshot> future = firstPage.get();
    List<QueryDocumentSnapshot> docs = future.get(30, TimeUnit.SECONDS).getDocuments();

    // Construct query for the next 25 cities.
    QueryDocumentSnapshot lastDoc = docs.get(docs.size() - 1);
    Query secondPage = cities.orderBy("population").startAfter(lastDoc).limit(25);

    future = secondPage.get();
    docs = future.get(30, TimeUnit.SECONDS).getDocuments();
    // [END firestore_query_cursor_pagination]
    return Arrays.asList(firstPage, secondPage);
  }

  void collectionGroupQuery() throws ExecutionException, InterruptedException {
    // CHECKSTYLE OFF: Indentation
    // CHECKSTYLE OFF: RightCurlyAlone
    // [START firestore_query_collection_group_dataset]
    CollectionReference cities = db.collection("cities");

    final List<ApiFuture<WriteResult>> futures =
        Arrays.asList(
            cities
                .document("SF")
                .collection("landmarks")
                .document()
                .set(
                    new HashMap<String, String>() {
                      {
                        put("name", "Golden Gate Bridge");
                        put("type", "bridge");
                      }
                    }),
            cities
                .document("SF")
                .collection("landmarks")
                .document()
                .set(
                    new HashMap<String, String>() {
                      {
                        put("name", "Legion of Honor");
                        put("type", "museum");
                      }
                    }),
            cities
                .document("LA")
                .collection("landmarks")
                .document()
                .set(
                    new HashMap<String, String>() {
                      {
                        put("name", "Griffith Park");
                        put("type", "park");
                      }
                    }),
            cities
                .document("LA")
                .collection("landmarks")
                .document()
                .set(
                    new HashMap<String, String>() {
                      {
                        put("name", "The Getty");
                        put("type", "museum");
                      }
                    }),
            cities
                .document("DC")
                .collection("landmarks")
                .document()
                .set(
                    new HashMap<String, String>() {
                      {
                        put("name", "Lincoln Memorial");
                        put("type", "memorial");
                      }
                    }),
            cities
                .document("DC")
                .collection("landmarks")
                .document()
                .set(
                    new HashMap<String, String>() {
                      {
                        put("name", "National Air and Space Museum");
                        put("type", "museum");
                      }
                    }),
            cities
                .document("TOK")
                .collection("landmarks")
                .document()
                .set(
                    new HashMap<String, String>() {
                      {
                        put("name", "Ueno Park");
                        put("type", "park");
                      }
                    }),
            cities
                .document("TOK")
                .collection("landmarks")
                .document()
                .set(
                    new HashMap<String, String>() {
                      {
                        put("name", "National Museum of Nature and Science");
                        put("type", "museum");
                      }
                    }),
            cities
                .document("BJ")
                .collection("landmarks")
                .document()
                .set(
                    new HashMap<String, String>() {
                      {
                        put("name", "Jingshan Park");
                        put("type", "park");
                      }
                    }),
            cities
                .document("BJ")
                .collection("landmarks")
                .document()
                .set(
                    new HashMap<String, String>() {
                      {
                        put("name", "Beijing Ancient Observatory");
                        put("type", "museum");
                      }
                    }));
    final List<WriteResult> landmarks = ApiFutures.allAsList(futures).get();
    // [END firestore_query_collection_group_dataset]

    // [START firestore_query_collection_group_filter_eq]
    final Query museums = db.collectionGroup("landmarks").whereEqualTo("type", "museum");
    final ApiFuture<QuerySnapshot> querySnapshot = museums.get();
    for (DocumentSnapshot document : querySnapshot.get().getDocuments()) {
      System.out.println(document.getId());
    }
    // [END firestore_query_collection_group_filter_eq]
    // CHECKSTYLE ON: RightCurlyAlone
    // CHECKSTYLE ON: Indentation
  }

  public Query arrayContainsAnyQueries() {
    // [START firestore_query_filter_array_contains_any]
    CollectionReference citiesRef = db.collection("cities");

    Query query =
        citiesRef.whereArrayContainsAny("regions", Arrays.asList("west_coast", "east_coast"));
    // [END firestore_query_filter_array_contains_any]
    return query;
  }

  public Query inQueryWithoutArray() {
    // [START firestore_query_filter_in]
    CollectionReference citiesRef = db.collection("cities");

    Query query = citiesRef.whereIn("country", Arrays.asList("USA", "Japan"));
    // [END firestore_query_filter_in]
    return query;
  }

  public Query inQueryWithArray() {
    // [START firestore_query_filter_in_with_array]
    CollectionReference citiesRef = db.collection("cities");

    Query query =
        citiesRef.whereIn(
            "regions", Arrays.asList(Arrays.asList("west_coast"), Arrays.asList("east_coast")));
    // [END firestore_query_filter_in_with_array]
    return query;
  }

  Query notEqualsQuery() {
    // [START firestore_query_filter_not_eq]
    CollectionReference citiesRef = db.collection("cities");

    Query query = citiesRef.whereNotEqualTo("capital", false);
    // [END firestore_query_filter_not_eq]
    return query;
  }

  Query filterNotIn() {
    // [START firestore_query_filter_not_in]
    CollectionReference citiesRef = db.collection("cities");

    Query query = citiesRef.whereNotIn("country", Arrays.asList("USA", "Japan"));
    // [END firestore_query_filter_not_in]
    return query;
  }

  /** Closes the gRPC channels associated with this instance and frees up their resources. */
  void close() throws Exception {
    db.close();
  }
}