Refactor sources (#40)

* major refactor to exclude multiple sources

Co-authored-by: Matt Hill <matthewonthemoon@gmail.com>

client/lib/patch-db.ts

@@ -1,44 +1,18 @@
-import { EMPTY, merge, Observable, ReplaySubject, Subject } from 'rxjs'
-import { catchError, switchMap } from 'rxjs/operators'
+import { map, Observable, shareReplay } from 'rxjs'
+import { tap } from 'rxjs/operators'
 import { Store } from './store'
-import { DBCache, Http } from './types'
-import { RPCError } from './source/ws-source'
-import { Source } from './source/source'
+import { DBCache, Update } from './types'
 
 export class PatchDB<T> {
-  public store: Store<T> = new Store(this.http, this.initialCache)
-  public connectionError$ = new Subject<Error>()
-  public rpcError$ = new Subject<RPCError>()
-  public cache$ = new ReplaySubject<DBCache<T>>(1)
-
-  private sub = this.sources$
-    .pipe(
-      switchMap(sources =>
-        merge(...sources.map(s => s.watch$(this.store))).pipe(
-          catchError(e => {
-            this.connectionError$.next(e)
-
-            return EMPTY
-          }),
-        ),
-      ),
-    )
-    .subscribe(res => {
-      if ('result' in res) {
-        this.store.update(res.result)
-        this.cache$.next(this.store.cache)
-      } else {
-        this.rpcError$.next(res)
-      }
-    })
+  public store: Store<T> = new Store(this.initialCache)
+  public cache$ = this.source$.pipe(
+    tap(res => this.store.update(res)),
+    map(_ => this.store.cache),
+    shareReplay(1),
+  )
 
   constructor(
-    private readonly sources$: Observable<Source<T>[]>,
-    private readonly http: Http<T>,
+    private readonly source$: Observable<Update<T>>,
     private readonly initialCache: DBCache<T>,
   ) {}
-
-  clean() {
-    this.sub.unsubscribe()
-  }
 }