/*
 * Copyright (c) 2016-present Invertase Limited & Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this library 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.
 *
 */
import {
  QueryKey,
  UseQueryOptions,
  UseQueryResult,
} from "@tanstack/react-query";
import {
  DocumentData,
  DocumentReference,
  DocumentSnapshot,
  onSnapshot,
  FirestoreError,
} from "firebase/firestore";
import { getSnapshot, UseFirestoreHookOptions } from "./index";
import { useSubscription } from "../../utils/src/useSubscription";
import { useCallback } from "react";

type NextOrObserver<T> = (data: DocumentSnapshot<T> | null) => Promise<void>;

export function useFirestoreDocument<T = DocumentData, R = DocumentSnapshot<T>>(
  queryKey: QueryKey,
  ref: DocumentReference<T>,
  options?: UseFirestoreHookOptions,
  useQueryOptions?: Omit<
    UseQueryOptions<DocumentSnapshot<T>, FirestoreError, R>,
    "queryFn"
  >
): UseQueryResult<R, FirestoreError> {
  const isSubscription = !!options?.subscribe;

  const subscribeFn = useCallback(
    (callback: NextOrObserver<T>) => {
      return onSnapshot(
        ref,
        {
          includeMetadataChanges: options?.includeMetadataChanges,
        },
        (snapshot: DocumentSnapshot<T>) => {
          // Set the data each time state changes.
          return callback(snapshot);
        }
      );
    },
    [ref]
  );

  return useSubscription<DocumentSnapshot<T>, FirestoreError, R>(
    queryKey,
    ["useFirestoreDocument", queryKey],
    subscribeFn,
    {
      ...useQueryOptions,
      onlyOnce: !isSubscription,
      fetchFn: async () => getSnapshot(ref, options?.source),
    }
  );
}