1 files changed, 85 insertions, 0 deletions
diff --git a/routes/liquid/taxi.js b/routes/liquid/taxi.js
new file mode 100644
index 00000000..14da9411
--- /dev/null
+++ b/routes/liquid/taxi.js
@@ -0,0 +1,85 @@
+const {
+  address: Address,
+  ECPair,
+  Psbt,
+  payments,
+  networks
+} = require("@asoltys/liquidjs-lib");
+const wretch = require("wretch");
+const fetch = require("node-fetch");
+wretch().polyfills({ fetch });
+const url = prod
+  ? "https://blockstream.info/liquid/api"
+  : "http://electrs-liquid:3002";
+const electrs = wretch().url(url);
+const network = networks.regtest;
+
+const key = ECPair.fromPrivateKey(Buffer.from(config.taxi, "hex"));
+
+module.exports = ah(async (req, res) => {
+  let { user } = req;
+  let { psbt } = req.body;
+
+  try {
+    if (user.username !== "silhouettes") {
+      throw new Error("taxi service only available to select customers");
+    }
+
+    let redeem = payments.p2wpkh({
+      pubkey: key.publicKey,
+      network
+    });
+
+    let out = payments.p2sh({
+      redeem,
+      network
+    });
+
+    let utxos = await electrs
+      .url(`/address/${out.address}/utxo`)
+      .get()
+      .json();
+
+    let tx = utxos.find(tx => tx.value >= 150);
+
+    let hex = await electrs
+      .url(`/tx/${tx.txid}/hex`)
+      .get()
+      .text();
+
+    let raw = Psbt.fromBase64(psbt)
+      .addInput({
+        hash: tx.txid,
+        index: tx.vout,
+        redeemScript: redeem.output,
+        nonWitnessUtxo: Buffer.from(hex, "hex")
+      })
+      .addOutput({
+        asset: network.assetHash,
+        nonce: Buffer.alloc(1, 0),
+        script: Buffer.alloc(0),
+        value: 150
+      })
+      .addOutput({
+        asset: network.assetHash,
+        nonce: Buffer.alloc(1),
+        script: out.output,
+        value: tx.value - 150
+      })
+      .signInput(1, key)
+      .finalizeInput(1)
+      .extractTransaction()
+      .toHex();
+
+    let txid = await electrs
+      .url("/tx")
+      .body(raw)
+      .post()
+      .text();
+
+    res.send({ txid });
+  } catch (e) {
+    console.log(e);
+    return res.status(500).send(e);
+  }
+});