feat: add payment module

modules/payment/schemas/transaction.ts

@@ -0,0 +1,40 @@
+import z from "zod";
+
+import { TransactionParticipantType } from "./transaction-participant.ts";
+
+/*
+ |--------------------------------------------------------------------------------
+ | Transaction
+ |--------------------------------------------------------------------------------
+ |
+ | A transaction is a description of value being moved from a source to a target.
+ | Transaction must have at least one "account" participant or it is considered
+ | invalid as our system does not support "external" -> "external" transactions.
+ |
+ | Which ledger the transaction resides in is determined by the participants
+ | account traced upwards tx -> account -> wallet -> ledger. A transaction is
+ | invalid if both source and target participant account leads to different
+ | ledgers.
+ |
+ */
+
+export const TransactionSchema = z.strictObject({
+  _id: z.uuid().describe("Primary identifier of the transaction"),
+
+  sourceType: TransactionParticipantType,
+  sourceId: z.string().describe("Identifier of the source sending value"),
+
+  targetType: TransactionParticipantType,
+  targetId: z.string().describe("Identifier of the target receiving value"),
+
+  amount: z.string().describe("Value amount being transferred"),
+  conversionRate: z
+    .number()
+    .optional()
+    .describe("Conversation rate from source to target if they operate in different currencies"),
+
+  occurredAt: z.coerce.date().describe("Timestamp of when the transaction occured"),
+  approvedBy: z.string().describe("Identifier of the individual who approved the transfer"),
+});
+
+export type Transaction = z.output<typeof TransactionSchema>;