add receipts support

src/lib/invoice-line-item.ts

@@ -0,0 +1,38 @@
+export type LineItemBillingType = "hourly" | "fixed";
+
+export function isFixedLineItem(hours: number): boolean {
+  return hours === 0;
+}
+
+export function getLineItemBillingType(hours: number): LineItemBillingType {
+  return isFixedLineItem(hours) ? "fixed" : "hourly";
+}
+
+export function calculateLineItemAmount(hours: number, rate: number): number {
+  return isFixedLineItem(hours) ? rate : hours * rate;
+}
+
+export function formatLineItemDetail(
+  hours: number,
+  rate: number,
+  formatCurrency: (amount: number) => string,
+): string {
+  if (isFixedLineItem(hours)) {
+    return "Fixed amount";
+  }
+  return `${hours}h @ ${formatCurrency(rate)}/hr`;
+}
+
+export function applyBillingTypeChange(
+  billingType: LineItemBillingType,
+  current: { hours: number; rate: number },
+): { hours: number; rate: number; amount: number } {
+  if (billingType === "fixed") {
+    const amount = calculateLineItemAmount(current.hours, current.rate);
+    return { hours: 0, rate: amount, amount };
+  }
+
+  const hours = current.hours > 0 ? current.hours : 1;
+  const amount = calculateLineItemAmount(hours, current.rate);
+  return { hours, rate: current.rate, amount };
+}