Merged PR 1945: fix(remission-list): auto-select single search result when remission started

fix(remission-list): auto-select single search result when remission started

Enhance search result handling to automatically select items when only
one result is found during an active remission. This improves user
workflow by eliminating the extra click required to select obvious
single results.

- Add preselectRemissionItem method to handle automatic selection
- Update emptySearchResultEffect to handle single hit scenario
- Clear selected items at start of effect to prevent stale selections
- Only auto-select if item has available stock and can be remitted
- Improve effect documentation with detailed behavior explanation

Ref: #5338

libs/remission/feature/remission-list/src/lib/remission-list.component.ts

@@ -396,27 +396,44 @@ export class RemissionListComponent {
   });
 
   /**
-   * Effect that handles the case when there are no items in the remission list after a search.
-   * If the search was triggered by the user, it opens a dialog to search for items to remit.
-   * If remission has already started, it adds the found items to the remission store and remits them.
-   * If not, it navigates to the default remission list.
+   * Effect that handles scenarios where a search yields no results.
+   * If the search was user-initiated and returned no hits, it opens a dialog
+   * to allow the user to add a new item to remit.
+   * If only one hit is found and a remission is started, it selects that item automatically.
+   * This effect runs whenever the remission or stock resource status changes,
+   * or when the search term changes.
+   * It ensures that the user is prompted appropriately based on their actions and the current state of the remission process.
+   * It also checks if the remission is started or if the list type is 'Abteilung' to determine navigation behavior.
+   * @see {@link
+   * https://angular.dev/guide/effects} for more information on Angular effects.
+   * @remarks This effect uses `untracked` to avoid unnecessary re-evaluations
+   * when accessing certain signals.
    */
   emptySearchResultEffect = effect(() => {
     const status = this.remissionResource.status();
+    const stockStatus = this.inStockResource.status();
     const searchTerm: string | undefined = this.searchTerm();
 
-    if (status !== 'resolved') {
+    if (status !== 'resolved' || stockStatus !== 'resolved') {
       return;
     }
 
-    const hasItems = !!this.remissionResource.value()?.result?.length;
-
-    if (hasItems || !searchTerm || !this.hasValidSearchTerm()) {
-      return;
-    }
+    this.#store.clearSelectedItems();
 
     untracked(() => {
-      if (!this.searchTriggeredByUser()) {
+      const hits = this.hits();
+
+      // #5338 - Select item automatically if only one hit after search
+      if (
+        !!hits ||
+        !searchTerm ||
+        !this.hasValidSearchTerm() ||
+        !this.searchTriggeredByUser()
+      ) {
+        if (hits === 1 && this.remissionStarted()) {
+          this.preselectRemissionItem(this.items()[0]);
+        }
+
         return;
       }
 
@@ -517,6 +534,27 @@ export class RemissionListComponent {
     this.#store.reloadReturn();
   }
 
+  /**
+   * Pre-Selects a remission item if it has available stock and can be remitted.
+   * Updates the remission store with the selected item.
+   * @param item - The ReturnItem or ReturnSuggestion to select.
+   * @returns void
+   */
+  preselectRemissionItem(item: RemissionItem) {
+    if (!!item && item.id) {
+      const inStock = this.getAvailableStockForItem(item);
+      const stockToRemit = getStockToRemit({
+        remissionItem: item,
+        remissionListType: this.selectedRemissionListType(),
+        availableStock: inStock,
+      });
+
+      if (inStock > 0 && stockToRemit > 0) {
+        this.#store.selectRemissionItem(item.id, item);
+      }
+    }
+  }
+
   /**
    * Handles errors that occur during the remission of items.
    * Logs the error, sets the error message signal, and displays an error dialog if applicable.