supported attachment upload

app/lib/actions.ts

@@ -5,6 +5,7 @@ import { revalidatePath } from 'next/cache';
 import { redirect } from 'next/navigation';
 import clientPromise from './mongodb';
 import { ObjectId } from 'mongodb';
+import { BillAttachment } from './db-types';
 
 export type State = {
     errors?: {
@@ -18,17 +19,59 @@ export type State = {
 const FormSchema = z.object({
     _id: z.string(),
     billName: z.coerce.string().min(1, "Bill Name is required."),
-    billAttachment: z.object({ }),
     billNotes: z.string(),
   });
 
 const UpdateBill = FormSchema.omit({ _id: true });
 
+/**
+ * converts the file to a format stored in the database
+ * @param billAttachment 
+ * @returns 
+ */
+const serializeAttachment = async (billAttachment: File | null) => {
+
+    if (!billAttachment) {
+        return null;
+    }
+
+    const {
+        name: fileName,
+        size: fileSize,
+        type: fileType,
+        lastModified: fileLastModified,
+    } = billAttachment;
+
+    if(!fileName || fileName === 'undefined') {
+        return null;
+    }
+
+    // convert the file contents to a base64 string
+    const fileContents = await billAttachment.arrayBuffer();
+    const fileContentsBase64 = Buffer.from(fileContents).toString('base64');
+
+    // create an object to store the file in the database
+    return({
+        fileName: decodeURIComponent(fileName),
+        fileSize,
+        fileType,
+        fileLastModified,
+        fileContentsBase64,
+    } as BillAttachment);
+}
+
+/**
+ * Server-side action which creates a new bill
+ * @param locationId location of the bill
+ * @param billId ID of the bill
+ * @param prevState previous state of the form
+ * @param formData form data
+ * @returns 
+ */
 export async function updateBill(locationId: string, billId:string, prevState:State, formData: FormData) {
 
     const validatedFields = UpdateBill.safeParse({
         billName: formData.get('billName'),
-        billAttachment: formData.get('billAttachment'),
         billNotes: formData.get('billNotes'),
     });
 
@@ -43,7 +86,6 @@ export async function updateBill(locationId: string, billId:string, prevState:St
 
     const {
         billName,
-        billAttachment,
         billNotes,
     } = validatedFields.data;
 
@@ -52,6 +94,22 @@ export async function updateBill(locationId: string, billId:string, prevState:St
     // update the bill in the mongodb
     const client = await clientPromise;
     const db = client.db("rezije");
+    
+    const billAttachment = await serializeAttachment(formData.get('billAttachment') as File);
+
+    // if there is an attachment, update the attachment field
+    // otherwise, do not update the attachment field
+    const mongoDbSet = billAttachment ? {
+        "bills.$[elem].name": billName,
+        "bills.$[elem].paid": billPaid,
+        "bills.$[elem].attachment": billAttachment,
+        "bills.$[elem].notes": billNotes,
+    }: {
+        "bills.$[elem].name": billName,
+        "bills.$[elem].paid": billPaid,
+        "bills.$[elem].notes": billNotes,
+    };
+
 
     // find a location with the given locationID
     const post = await db.collection<Location>("lokacije").updateOne(
@@ -59,12 +117,7 @@ export async function updateBill(locationId: string, billId:string, prevState:St
             _id: locationId // find a location with the given locationID
         },
         {
-            $set: {
-                "bills.$[elem].name": billName,
-                "bills.$[elem].paid": billPaid,
-                "bills.$[elem].attachment": billAttachment,
-                "bills.$[elem].notes": billNotes,
-            }
+            $set: mongoDbSet
         }, {
             arrayFilters: [
                 { "elem._id": { $eq: new ObjectId(billId) } } // find a bill with the given billID
@@ -75,4 +128,8 @@ export async function updateBill(locationId: string, billId:string, prevState:St
     revalidatePath('/');
     // go to the bill list
     redirect('/');
+}
+
+export async function gotoHome() {
+    redirect('/');   
 }