feat: correct total tax on incoming invoices

frontend/pages/incomingInvoices/[mode]/[id].vue

@@ -103,6 +103,8 @@ watch(() => itemInfo.value.date, (value) => {
 
 // --- Berechnungslogik ---
 const useNetMode = ref(false)
+const editingTotalTax = ref(false)
+const totalTaxDraft = ref(null)
 
 const taxOptions = ref([
   { label: "19% USt", percentage: 19, key: "19" },
@@ -186,24 +188,17 @@ const totalCalculated = computed(() => {
     }
   })
 
-  totalGross = Number(totalNet + totalAmount19Tax + totalAmount7Tax)
+  const calculatedTax = Number(totalAmount19Tax + totalAmount7Tax)
+  const hasTaxOverride = itemInfo.value.taxAmountOverride !== null && itemInfo.value.taxAmountOverride !== undefined && itemInfo.value.taxAmountOverride !== ""
+  const totalTax = hasTaxOverride ? Number(itemInfo.value.taxAmountOverride) : calculatedTax
+  totalGross = Number(totalNet + totalTax)
 
-  return { totalNet, totalAmount19Tax, totalAmount7Tax, totalGross }
+  return { totalNet, totalAmount19Tax, totalAmount7Tax, calculatedTax, totalTax, totalGross, hasTaxOverride }
 })
 
 const hasAmount = (value) => value !== null && value !== undefined && value !== ""
 const hasValidNumber = (value) => hasAmount(value) && Number.isFinite(Number(value))
 const isDepreciationItem = (item) => isDepreciationBookingMode(item?.bookingMode)
-const getCalculatedTax = (item) => {
-  const taxRate = Number(taxOptions.value.find((tax) => tax.key === item.taxType)?.percentage || 0)
-
-  return Number((Number(item.amountNet || 0) * (taxRate / 100)).toFixed(2))
-}
-const hasManualTaxDifference = (item) => {
-  if (!hasValidNumber(item.amountTax) || !hasValidNumber(item.amountNet)) return false
-
-  return Math.abs(Number(item.amountTax) - getCalculatedTax(item)) >= 0.005
-}
 
 const updateBookingMode = (item) => {
   ensureDepreciationDefaults(item, itemInfo.value.date)
@@ -226,14 +221,6 @@ const recalculateItem = (item, source) => {
     calculateFromNet()
   } else if (source === 'gross') {
     calculateFromGross()
-  } else if (source === 'tax') {
-    if(!hasValidNumber(item.amountTax)) return
-
-    if((useNetMode.value || !hasAmount(item.amountGross)) && hasAmount(item.amountNet)) {
-      item.amountGross = Number((Number(item.amountNet) + Number(item.amountTax)).toFixed(2))
-    } else if(hasAmount(item.amountGross)) {
-      item.amountNet = Number((Number(item.amountGross) - Number(item.amountTax)).toFixed(2))
-    }
   } else if (source === 'taxType' || source === 'manual') {
     if(hasAmount(item.amountNet)) calculateFromNet()
     else if(hasAmount(item.amountGross)) calculateFromGross()
@@ -246,6 +233,19 @@ const moveGrossToNet = (item) => {
   recalculateItem(item, 'net')
 }
 
+const startEditingTotalTax = () => {
+  totalTaxDraft.value = totalCalculated.value.totalTax.toFixed(2)
+  editingTotalTax.value = true
+}
+
+const applyTotalTaxOverride = () => {
+  if (!hasValidNumber(totalTaxDraft.value)) return
+
+  const value = Number(Number(totalTaxDraft.value).toFixed(2))
+  itemInfo.value.taxAmountOverride = Math.abs(value - totalCalculated.value.calculatedTax) >= 0.005 ? value : null
+  editingTotalTax.value = false
+}
+
 // --- Saving ---
 const updateIncomingInvoice = async (setBooked = false) => {
   if (setBooked && hasBlockingIncomingInvoiceErrors.value) {
@@ -889,30 +889,13 @@ const hasBlockingIncomingInvoiceErrors = computed(() => blockingIncomingInvoiceE
                 </div>
 
                 <div class="col-span-6 md:col-span-3">
-                  <UFormField label="Steuerbetrag" help="Kann bei Rundungsabweichungen angepasst werden">
-                    <UInput
-                        class="w-full"
-                        type="number"
-                        step="0.01"
-                        :model-value="item.amountTax"
-                        :disabled="mode === 'show'"
-                        @update:model-value="(val) => { item.amountTax = Number(val); recalculateItem(item, 'tax') }"
-                    >
+                  <UFormField label="Steuerbetrag" help="Automatisch berechnet">
+                    <UInput class="w-full" :model-value="item.amountTax" disabled color="gray">
                       <template #trailing>€</template>
                     </UInput>
                   </UFormField>
                 </div>
 
-                <div v-if="hasManualTaxDifference(item)" class="col-span-12">
-                  <UAlert
-                      color="warning"
-                      variant="soft"
-                      icon="i-heroicons-exclamation-triangle"
-                      title="Steuerbetrag manuell angepasst"
-                      description="FEDEO verwendet diesen Betrag für Auswertungen und Summen. Im DATEV-Export wird bei der Automatikbuchung nur der Bruttobetrag mit Steuerschlüssel übertragen; DATEV berechnet die Steuer dort erneut."
-                  />
-                </div>
-
                 <div class="col-span-12 flex justify-end gap-2">
                   <UButton
                       size="xs"
@@ -958,14 +941,34 @@ const hasBlockingIncomingInvoiceErrors = computed(() => blockingIncomingInvoiceE
                   <span>Netto Gesamt</span>
                   <span>{{ totalCalculated.totalNet.toFixed(2) }} €</span>
                 </div>
-                <div class="flex justify-between text-gray-500" v-if="totalCalculated.totalAmount7Tax > 0">
-                  <span>+ 7% USt</span>
-                  <span>{{ totalCalculated.totalAmount7Tax.toFixed(2) }} €</span>
-                </div>
-                <div class="flex justify-between text-gray-500" v-if="totalCalculated.totalAmount19Tax > 0">
-                  <span>+ 19% USt</span>
-                  <span>{{ totalCalculated.totalAmount19Tax.toFixed(2) }} €</span>
+                <div class="flex items-center justify-between gap-3 text-gray-500">
+                  <span class="flex items-center gap-2">
+                    USt gesamt
+                    <UBadge v-if="totalCalculated.hasTaxOverride" size="xs" color="warning" variant="soft">Manuell</UBadge>
+                  </span>
+                  <div v-if="editingTotalTax" class="flex items-center gap-1">
+                    <UInput v-model="totalTaxDraft" type="number" step="0.01" size="xs" class="w-28">
+                      <template #trailing>€</template>
+                    </UInput>
+                    <UButton icon="i-heroicons-check" size="xs" variant="ghost" @click="applyTotalTaxOverride" />
+                    <UButton icon="i-heroicons-x-mark" size="xs" color="neutral" variant="ghost" @click="editingTotalTax = false" />
+                  </div>
+                  <div v-else class="flex items-center gap-1">
+                    <span>{{ totalCalculated.totalTax.toFixed(2) }} €</span>
+                    <UButton
+                        v-if="mode !== 'show'"
+                        icon="i-heroicons-pencil"
+                        size="xs"
+                        color="neutral"
+                        variant="ghost"
+                        aria-label="Gesamten USt-Betrag bearbeiten"
+                        @click="startEditingTotalTax"
+                    />
+                  </div>
                 </div>
+                <p v-if="totalCalculated.hasTaxOverride" class="text-xs text-amber-600 dark:text-amber-400">
+                  DATEV berechnet die USt aus dem Bruttobetrag erneut. Der Export wird mit „USt prüfen“ markiert.
+                </p>
                 <div class="flex justify-between font-bold text-xl text-gray-900 dark:text-white pt-2 border-t dark:border-gray-700">
                   <span>Rechnungsbetrag</span>
                   <span>{{ totalCalculated.totalGross.toFixed(2) }} €</span>