1 files changed, 42 insertions, 0 deletions
diff --git a/lib/ecash.js b/lib/ecash.js
new file mode 100644
index 00000000..d47513a4
--- /dev/null
+++ b/lib/ecash.js
@@ -0,0 +1,42 @@
+import config from "$config";
+import {
+  CashuMint,
+  CashuWallet,
+  getDecodedToken,
+  getEncodedToken,
+} from "@cashu/cashu-ts";
+import { g, s } from "$lib/db";
+
+let wallet = new CashuWallet(new CashuMint(config.mintUrl));
+
+let enc = (proofs) =>
+  getEncodedToken({
+    token: [{ mint: config.mintUrl, proofs }],
+  });
+
+let dec = (token) => getDecodedToken(token).token[0];
+
+export async function melt(user, amount) {
+  let { proofs } = dec(await g(`cash:${user.id}`));
+  let { proofs: current } = dec(await g(`cash`));
+
+  let { send, returnChange } = await wallet.send(amount, proofs);
+
+  await s(`cash`, enc([...current, ...send]));
+  await s(`cash:${user.id}`, enc(returnChange));
+}
+
+export async function mint(user, amount) {
+  let { proofs } = dec(await g(`cash`));
+  let { proofs: current } = dec(await g(`cash:${user.id}`));
+
+  let { send, returnChange } = await wallet.send(amount, proofs);
+
+  await s(`cash:${user.id}`, enc([...current, ...send]));
+  await s(`cash`, enc(returnChange));
+}
+
+export async function balance(user) {
+  let { proofs } = dec(await g(`cash:${user.id}`));
+  return proofs.reduce((a, b) => a + b.amount, 0);
+}