[PM-6147]Using reactive methods on SendAddEditComponent load (#8013)

* Using SendService get$ on SendAddEditComponent load

* Calling reactive method on loadSend

* Improved code quality on send add edit

* removed unnecessary patch value

* Improved error message on send add-edit.component

* Add comment regarding promise.reject completing the BehaviourSubject

* Corrected send null validation

libs/angular/src/tools/send/add-edit.component.ts

@@ -1,7 +1,7 @@
 import { DatePipe } from "@angular/common";
 import { Directive, EventEmitter, Input, OnDestroy, OnInit, Output } from "@angular/core";
 import { FormBuilder, Validators } from "@angular/forms";
-import { Subject, map, takeUntil } from "rxjs";
+import { BehaviorSubject, Subject, concatMap, firstValueFrom, map, takeUntil } from "rxjs";
 
 import { PolicyService } from "@bitwarden/common/admin-console/abstractions/policy/policy.service.abstraction";
 import { PolicyType } from "@bitwarden/common/admin-console/enums";
@@ -167,7 +167,7 @@ export class AddEditComponent implements OnInit, OnDestroy {
         }
       });
 
-    this.formGroup.controls.type.valueChanges.subscribe((val) => {
+    this.formGroup.controls.type.valueChanges.pipe(takeUntil(this.destroy$)).subscribe((val) => {
       this.type = val;
       this.typeChanged();
     });
@@ -210,28 +210,46 @@ export class AddEditComponent implements OnInit, OnDestroy {
 
     this.type = !this.canAccessPremium || !this.emailVerified ? SendType.Text : SendType.File;
     if (this.send == null) {
-      if (this.editMode) {
+      const send = new BehaviorSubject<SendView>(this.send);
-        const send = this.loadSend();
+      send.subscribe({
-        this.send = await send.decrypt();
+        next: (decryptedSend: SendView | undefined) => {
+          if (!(decryptedSend instanceof SendView)) {
+            return;
+          }
+
+          this.send = decryptedSend;
+          decryptedSend.type = decryptedSend.type ?? this.type;
           this.type = this.send.type;
           this.updateFormValues();
-      } else {
-        this.send = new SendView();
-        this.send.type = this.type;
-        this.send.file = new SendFileView();
-        this.send.text = new SendTextView();
-        this.send.deletionDate = new Date();
-        this.send.deletionDate.setDate(this.send.deletionDate.getDate() + 7);
-        this.formGroup.controls.type.patchValue(this.send.type);
-
-        this.formGroup.patchValue({
-          selectedDeletionDatePreset: DatePreset.SevenDays,
-          selectedExpirationDatePreset: DatePreset.Never,
-        });
-      }
-    }
-
           this.hasPassword = this.send.password != null && this.send.password.trim() !== "";
+        },
+        error: (error: unknown) => {
+          const errorMessage = (error as Error).message ?? "An unknown error occurred";
+          this.logService.error("Failed to decrypt send: " + errorMessage);
+        },
+      });
+
+      if (this.editMode) {
+        this.sendService
+          .get$(this.sendId)
+          .pipe(
+            //Promise.reject will complete the BehaviourSubject, if desktop starts relying only on BehaviourSubject, this should be changed.
+            concatMap((s) =>
+              s instanceof Send ? s.decrypt() : Promise.reject(new Error("Failed to load send.")),
+            ),
+            takeUntil(this.destroy$),
+          )
+          .subscribe(send);
+      } else {
+        const sendView = new SendView();
+        sendView.type = this.type;
+        sendView.file = new SendFileView();
+        sendView.text = new SendTextView();
+        sendView.deletionDate = new Date();
+        sendView.deletionDate.setDate(sendView.deletionDate.getDate() + 7);
+        send.next(sendView);
+      }
+    }
   }
 
   async submit(): Promise<boolean> {
@@ -376,8 +394,8 @@ export class AddEditComponent implements OnInit, OnDestroy {
     this.showOptions = !this.showOptions;
   }
 
-  protected loadSend(): Send {
+  protected loadSend(): Promise<Send> {
-    return this.sendService.get(this.sendId);
+    return firstValueFrom(this.sendService.get$(this.sendId));
   }
 
   protected async encryptSend(file: File): Promise<[Send, EncArrayBuffer]> {