import { map } from 'rxjs/operators';

import { AngularFireObject, DatabaseQuery } from '../interfaces';

import { createObjectSnapshotChanges } from './snapshot-changes';

import { AngularFireDatabase } from '../database';

export function createObjectReference<T= any>(query: DatabaseQuery, afDatabase: AngularFireDatabase): AngularFireObject<T> {

return {

query,

snapshotChanges<T>() {

return createObjectSnapshotChanges<T>(query, afDatabase.schedulers.outsideAngular)().pipe(

afDatabase.keepUnstableUntilFirst

);

},

update(data: Partial<T>) { return query.ref.update(data as any) as Promise<void>; },

set(data: T) { return query.ref.set(data) as Promise<void>; },

remove() { return query.ref.remove() as Promise<void>; },

valueChanges<T>() {

const snapshotChanges$ = createObjectSnapshotChanges(query, afDatabase.schedulers.outsideAngular)();

return snapshotChanges$.pipe(

afDatabase.keepUnstableUntilFirst,

map(action => action.payload.exists() ? action.payload.val() as T : null)

);

},

};

}