feat: invoice management

demo/Invoice.ts

@@ -0,0 +1,132 @@
+import { z } from "zod";
+import { getAddress } from "viem";
+import { encodeAbiParameters, toHex, keccak256, concat } from "viem";
+import fs from "fs/promises";
+import path from "path";
+
+const RepayTokenInfoSchema = z.object({
+  vault: z
+    .string()
+    .regex(/^0x[a-fA-F0-9]{40}$/)
+    .transform((val) => getAddress(val)),
+  amount: z.string().transform((val) => BigInt(val)),
+  chainId: z.string().transform((val) => BigInt(val)),
+});
+
+const InvoiceWithRepayTokensSchema = z.object({
+  account: z
+    .string()
+    .regex(/^0x[a-fA-F0-9]{40}$/)
+    .transform((val) => getAddress(val)),
+  paymaster: z
+    .string()
+    .regex(/^0x[a-fA-F0-9]{40}$/)
+    .transform((val) => getAddress(val)),
+  nonce: z.string().transform((val) => BigInt(val)),
+  sponsorChainId: z.string().transform((val) => BigInt(val)),
+  repayTokenInfos: z.array(RepayTokenInfoSchema),
+});
+
+const InvoiceIdSchema = z
+  .string()
+  .regex(/^0x[a-fA-F0-9]{64}$/, "Must be a 32-byte hex string");
+
+const InvoicesSchema = z.record(InvoiceIdSchema, InvoiceWithRepayTokensSchema);
+
+type InvoiceId = z.infer<typeof InvoiceIdSchema>;
+type InvoiceWithRepayTokens = z.infer<typeof InvoiceWithRepayTokensSchema>;
+type Invoices = z.infer<typeof InvoicesSchema>;
+
+interface InvoiceIO {
+  readInvoice(invoiceId: InvoiceId): Promise<InvoiceWithRepayTokens>;
+  writeInvoice(invoice: InvoiceWithRepayTokens): Promise<InvoiceId>;
+}
+
+/**
+ * InvoiceManager reads and writes invoices to a JSON file.
+ * FOR DEMO PURPOSES ONLY - implement InvoiceIO to use a real database in production.
+ */
+
+class InvoiceManager implements InvoiceIO {
+  private invoicesPath: string;
+
+  constructor(invoicesPath: string) {
+    this.invoicesPath = invoicesPath;
+  }
+
+  async readInvoice(invoiceId: InvoiceId): Promise<InvoiceWithRepayTokens> {
+    const invoicesJson = await JSON.parse(this.invoicesPath);
+    const invoices = InvoicesSchema.parse(invoicesJson);
+    const invoice = invoices[invoiceId];
+    if (!invoice) {
+      throw new Error(`Invoice ID ${invoiceId} not found`);
+    }
+    return invoice;
+  }
+
+  async writeInvoice(invoice: InvoiceWithRepayTokens): Promise<InvoiceId> {
+    try {
+      const invoices = await this.readInvoices();
+      const invoiceId = this.getInvoiceId(invoice);
+      invoices[invoiceId] = invoice;
+      const serializedInvoices = JSON.stringify(
+        invoices,
+        (key, value) => (typeof value === "bigint" ? value.toString() : value),
+        2,
+      );
+      await fs.writeFile(this.invoicesPath, serializedInvoices);
+      return invoiceId;
+    } catch (error: any) {
+      console.error("Error handling invoices:", error.message);
+      throw new Error("Failed to write the invoice.");
+    }
+  }
+
+  private getInvoiceId(invoice: InvoiceWithRepayTokens): InvoiceId {
+    const repayTokensEncoded = encodeAbiParameters(
+      [
+        {
+          type: "tuple[]",
+          components: [
+            { type: "address", name: "vault" },
+            { type: "uint256", name: "amount" },
+            { type: "uint256", name: "chainId" },
+          ],
+        },
+      ],
+      [invoice.repayTokenInfos],
+    );
+
+    const packed = concat([
+      invoice.account,
+      invoice.paymaster,
+      toHex(invoice.nonce),
+      toHex(invoice.sponsorChainId),
+      repayTokensEncoded,
+    ]);
+
+    return keccak256(packed) as InvoiceId;
+  }
+
+  private async readInvoices(): Promise<Invoices> {
+    try {
+      const fileContent = await fs.readFile(this.invoicesPath, "utf8");
+      const invoicesJson = fileContent ? JSON.parse(fileContent) : {};
+      return InvoicesSchema.parse(invoicesJson);
+    } catch (err: any) {
+      if (err.code === "ENOENT") {
+        throw new Error(`File not found at path: ${this.invoicesPath}`);
+      } else if (err.name === "SyntaxError") {
+        throw new Error(`Invalid JSON format in file: ${this.invoicesPath}`);
+      } else if (err instanceof z.ZodError) {
+        throw new Error(`Validation error: ${err.message}`);
+      } else {
+        throw new Error(`An unexpected error occurred: ${err.message}`);
+      }
+    }
+  }
+}
+
+export const invoiceManager = new InvoiceManager(
+  path.join(__dirname, "invoices.json"),
+);