fix: make payment event reduction monotonic

packages/payment/src/core.ts

@@ -39,7 +39,35 @@ const gatewayFault = <T>(reason: string): PaymentResult<T> => ({
   reason,
 });
 export function derivePaymentStatus(events: readonly PaymentEvent[]): PaymentStatus {
-  return events.at(-1)?.status ?? "created";
+  const ordered = [...events].sort((left, right) => {
+    if (left.sequence !== undefined && right.sequence !== undefined) {
+      const numeric = Number(left.sequence) - Number(right.sequence);
+      if (Number.isFinite(numeric) && numeric !== 0) return numeric;
+      const lexical = String(left.sequence).localeCompare(String(right.sequence));
+      if (lexical) return lexical;
+    }
+    return (
+      (left.occurredAt ?? left.at) - (right.occurredAt ?? right.at) ||
+      left.id.localeCompare(right.id)
+    );
+  });
+  let status: PaymentStatus = "created";
+  for (const event of ordered) {
+    if (status === "refunded") continue;
+    if (
+      status === "partially_refunded" &&
+      !["partially_refunded", "refunded"].includes(event.status)
+    )
+      continue;
+    if (
+      status === "captured" &&
+      ["created", "pending", "authorized", "failed", "cancelled"].includes(event.status)
+    )
+      continue;
+    if (status === "authorized" && ["created", "pending"].includes(event.status)) continue;
+    status = event.status;
+  }
+  return status;
 }
 export function defineGateway<T extends PaymentGateway>(gateway: T): T {
   if (!gateway.id.trim()) throw new Error("WRN-PAYMENT-GATEWAY: id is required");
@@ -269,6 +297,8 @@ export function definePayment(options: PaymentOptions) {
       type: event.type,
       status: event.status,
       at: Date.now(),
+      occurredAt: event.occurredAt,
+      sequence: event.sequence,
       payload: event.payload,
     });
   }