Make invoice due date optional with 14-day default

Datum vystaveni defaults to today and Datum splatnosti defaults to
14 days after the issue date. Both fields are now optional date
inputs and only override the default when a user enters a custom
value. Applies to the invoice editor and generated PDF.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

app/src/app.js

@@ -445,6 +445,20 @@ app.delete('/api/invoices', requireAuth, async (req, res, next) => {
 });
 
 const pdfText = (value) => String(value || 'Neuvedeno');
+const formatCzechDate = (value) => {
+    const date = new Date(`${value}T00:00:00`);
+    return Number.isNaN(date.getTime()) ? '' : date.toLocaleDateString('cs-CZ');
+};
+const toDateInputValue = (date) => date.toISOString().slice(0, 10);
+const resolveIssueDate = (issueDate) => issueDate || toDateInputValue(new Date());
+const resolveDueDate = (dueDate, issueDate) => {
+    if (dueDate) {
+        return dueDate;
+    }
+    const due = new Date(`${resolveIssueDate(issueDate)}T00:00:00`);
+    due.setDate(due.getDate() + 14);
+    return toDateInputValue(due);
+};
 const formatCzechNumber = (value) => Number(value || 0).toLocaleString('cs-CZ', {
     minimumFractionDigits: 2,
     maximumFractionDigits: 2
@@ -518,13 +532,25 @@ const renderInvoicePdf = async (document, invoice) => {
     const partyWidth = (pageWidth - 24) / 2;
     const customerX = document.page.margins.left + partyWidth + 24;
 
+    const issueDate = resolveIssueDate(data.issueDate);
+    const dueDate = resolveDueDate(data.dueDate, data.issueDate);
+
     const headerY = document.y;
     document.fillColor(navy).font(boldFont).fontSize(25).text('Faktura', document.page.margins.left, headerY);
     document.fillColor(navy).font(boldFont).fontSize(16).text(invoice.invoice_number, customerX, headerY, {
         width: partyWidth,
         align: 'right'
     });
-    document.y = headerY + 40;
+    document.fillColor(bodyText).font(regularFont).fontSize(9)
+        .text(`Datum vystavení: ${formatCzechDate(issueDate)}`, customerX, headerY + 22, {
+            width: partyWidth,
+            align: 'right'
+        })
+        .text(`Datum splatnosti: ${formatCzechDate(dueDate)}`, customerX, headerY + 35, {
+            width: partyWidth,
+            align: 'right'
+        });
+    document.y = headerY + 52;
 
     const partyTop = document.y;
     const drawParty = (x, title, profile, name) => {

app/src/static/index.html

@@ -308,13 +308,13 @@
 
                     <div class="due-date-group">
                         <div class="form-group">
-                            <label for="dueDateOption">Datum splatnosti</label>
-                            <select id="dueDateOption">
-                                <option value="14">14 dní</option>
-                                <option value="30">30 dní</option>
-                            </select>
+                            <label for="issueDate">Datum vystavení</label>
+                            <input type="date" id="issueDate" name="issueDate" placeholder="Dnešní datum" />
+                        </div>
+                        <div class="form-group">
+                            <label for="dueDate">Datum splatnosti</label>
+                            <input type="date" id="dueDate" name="dueDate" placeholder="14 dní od vystavení" />
                         </div>
-                        <output id="dueDateDisplay" class="due-date-display"></output>
                     </div>
                 </div>
 

app/src/static/script.js

@@ -40,8 +40,8 @@ const passwordForm = document.getElementById("passwordForm");
 const savePasswordButton = document.getElementById("savePasswordButton");
 const cancelPasswordButton = document.getElementById("cancelPasswordButton");
 const passwordStatus = document.getElementById("passwordStatus");
-const dueDateOption = document.getElementById("dueDateOption");
-const dueDateDisplay = document.getElementById("dueDateDisplay");
+const issueDateInput = document.getElementById("issueDate");
+const dueDateInput = document.getElementById("dueDate");
 const paymentPresetSelect = document.getElementById("paymentPresetSelect");
 const paymentPresetName = document.getElementById("paymentPresetName");
 const savePaymentPresetButton = document.getElementById("savePaymentPresetButton");
@@ -108,17 +108,17 @@ const getClientLabel = (client) => [
 
 const formatCzechDate = (dateValue) => new Date(`${dateValue}T00:00:00`).toLocaleDateString("cs-CZ");
 
-const getDueDays = () => Number.parseInt(dueDateOption.value, 10) || 14;
+const toDateInputValue = (date) => date.toISOString().slice(0, 10);
+
+const getIssueDate = () => issueDateInput.value || toDateInputValue(new Date());
 
 const getDueDate = () => {
-    const dueDate = new Date();
-    dueDate.setHours(0, 0, 0, 0);
-    dueDate.setDate(dueDate.getDate() + getDueDays());
-    return dueDate.toISOString().slice(0, 10);
-};
-
-const updateDueDate = () => {
-    dueDateDisplay.textContent = `Splatnost: ${formatCzechDate(getDueDate())}`;
+    if (dueDateInput.value) {
+        return dueDateInput.value;
+    }
+    const dueDate = new Date(`${getIssueDate()}T00:00:00`);
+    dueDate.setDate(dueDate.getDate() + 14);
+    return toDateInputValue(dueDate);
 };
 
 const updateClientTypeFields = () => {
@@ -234,6 +234,8 @@ deletePaymentPresetButton.addEventListener("click", async () => {
 });
 
 const readInvoiceData = () => ({
+    issueDate: getIssueDate(),
+    dueDate: getDueDate(),
     supplier: {
         ...readProfileFields("dodavatel"),
         typSubjektu: supplierTypeSelect.value
@@ -263,6 +265,8 @@ const clearInvoiceEditor = () => {
     currentInvoiceId = null;
     invoiceNumberDisplay.textContent = "Nová faktura";
     invoiceSaveStatus.textContent = "";
+    issueDateInput.value = "";
+    dueDateInput.value = "";
     writeProfileFields("odberatel", {});
     clientSelect.value = "";
     clientTypeSelect.value = "osoba";
@@ -282,6 +286,8 @@ const loadInvoiceIntoEditor = (invoice) => {
     currentInvoiceId = invoice.id;
     invoiceNumberDisplay.textContent = invoice.invoiceNumber;
     invoiceSaveStatus.textContent = "";
+    issueDateInput.value = invoice.data.issueDate || "";
+    dueDateInput.value = invoice.data.dueDate || "";
     writeProfileFields("dodavatel", invoice.data.supplier || {});
     supplierTypeSelect.value = invoice.data.supplier?.typSubjektu || "osoba";
     updateSupplierTypeFields();