Feature: Add Note to Budget Command

libs/models/budgetting/budget-notes/src/lib/domain/add-note.command.ts

@@ -0,0 +1,9 @@
+
+export class AddNoteToBudgetCommand {
+  constructor(
+    public readonly budgetId: string,
+    public readonly noteContent: string,
+    public readonly authorId: string,
+    public readonly timestamp: Date = new Date()
+  ) {}
+}

libs/models/budgetting/budget-notes/src/lib/domain/add-note.handler.ts

@@ -0,0 +1,72 @@
+import { AddNoteToBudgetCommand } from './add-note.command';
+import { FunctionHandler } from '@ngfi/functions';
+import { FunctionContext } from '@ngfi/functions';
+import { HandlerTools } from '@iote/cqrs';
+
+// Result type
+export interface AddNoteToBudgetResult {
+  success: boolean;
+  noteId?: string;
+  error?: string;
+}
+
+/**
+ * Handler for adding notes to budgets.
+ * Implements the Command pattern in CQRS architecture.
+ */
+export class AddNoteToBudgetHandler
+  extends FunctionHandler<AddNoteToBudgetCommand, AddNoteToBudgetResult>
+{
+  /**
+   * Executes the add note command with validation and error handling
+   *
+   * @param command - The command containing budget note data
+   * @param context - Function execution context with auth info
+   * @param tools - Handler tools providing repository access
+   * @returns Result indicating success or failure with noteId
+   */
+  public async execute(
+    command: AddNoteToBudgetCommand,
+    context: FunctionContext,
+    tools: HandlerTools
+  ): Promise<AddNoteToBudgetResult> {
+    try {
+      // Validation: Check note content
+      if (!command.noteContent || command.noteContent.trim() === '') {
+        return {
+          success: false,
+          error: 'Note content cannot be empty'
+        };
+      }
+
+      // Validation: Check budget ID
+      if (!command.budgetId) {
+        return {
+          success: false,
+          error: 'Budget ID is required'
+        };
+      }
+
+      // Get repository from tools (provided by the CQRS framework)
+      const repository = tools.getRepository();
+
+      // Add note to budget via repository
+      const noteId = await repository.addNote({
+        budgetId: command.budgetId,
+        content: command.noteContent,
+        authorId: command.authorId,
+        createdAt: command.timestamp
+      });
+
+      return {
+        success: true,
+        noteId
+      };
+    } catch (error) {
+      return {
+        success: false,
+        error: (error as Error).message || 'Failed to add note to budget'
+      };
+    }
+  }
+}