Initial BTC withdrawal fee test

2 files changed, 42 insertions, 4 deletions

diff --git a/routes/bitcoin/send.js b/routes/bitcoin/send.js
index 9d64bb59..526a89d0 100644
--- a/routes/bitcoin/send.js
+++ b/routes/bitcoin/send.js
@@ -1,4 +1,6 @@
 const btc = config.liquid.btcasset;
+const withdrawalFeeMultiplier = 0.01;  // 1% withdrawal fee
+const withdrawalFeeReceiver = "coinosfees";  // account that receives the fees
 
 module.exports = ah(async (req, res) => {
   let { user } = req;
@@ -17,20 +19,31 @@ module.exports = ah(async (req, res) => {
   let total = 0;
   let change = 0;
 
+  console.log("tx.vout is ");
+  console.log(tx.vout);
+
   for (let i = 0; i < tx.vout.length; i++) {
     let o = tx.vout[i];
     total += toSats(o.value);
 
-    if (await isChange(o.scriptPubKey)) {
-      change += toSats(o.value);
-    }
+    console.log(o.scriptPubKey.addresses[0]);
+
+    // if (await isChange("bcrt1q3y0af2vezj4w66zw397hmrglf4pk38pet3wr8g")) {
+    //   change += toSats(o.value);
+    // }
   }
 
   total = total - change + fee;
   let amount = total - fee;
 
+  // get withdrawal fee
+  // 'total' refers to the total before the withdrawal fee
+  // (i.e. the total bitcoin that leaves this server)
+  let withdrawalFee = amount * withdrawalFeeMultiplier;
+
   let account, params;
   try {
+    // withdraw bitcoin
     await db.transaction(async transaction => {
       account = await db.Account.findOne({
         where: {
@@ -52,15 +65,37 @@ module.exports = ah(async (req, res) => {
         });
       }
 
+      console.log("Account balance is " + account.balance);
+      console.log("Total is " + total);
+
       if (total > account.balance) {
         l.error("amount exceeds balance", amount, fee, account.balance);
         throw new Error("low balance");
+      } else if (total + withdrawalFee > account.balance) {
+        l.error("total (after withdrawal fee) exceeds balance", amount, fee, account.balance);
+        throw new Error("low balance (after withdrawal fee)");
       }
 
-      await account.decrement({ balance: total }, { transaction });
+      await account.decrement({ balance: (total + withdrawalFee) }, { transaction });
+      await account.reload({ transaction });
+    });
+
+    // pay withdrawal fee to receiver
+    await db.transaction(async transaction => {
+      let receiverAccount = await db.Account.findOne({
+        where: {
+          username: withdrawalFeeReceiver
+        },
+        lock: transaction.LOCK.UPDATE,
+        transaction
+      });
+
+      await account.increment({ balance: withdrawalFee }, { transaction });
       await account.reload({ transaction });
     });
 
+    // record the external bitcoin transaction
+    // no need to record the withdrawal fee - since that is internal only
     params = {
       amount: -amount,
       fee,
@@ -94,6 +129,7 @@ module.exports = ah(async (req, res) => {
   } catch (e) {
     if (e.message.includes("Insufficient")) e.message = "The coinos server hot wallet has insufficient funds to complete the payment, try again later";
     l.error("error sending bitcoin", e.message);
+    console.log(e);
     return res.status(500).send(e.message);
   }
 });
diff --git a/routes/liquid/send.js b/routes/liquid/send.js
index 59334103..6f3616e8 100644
--- a/routes/liquid/send.js
+++ b/routes/liquid/send.js
@@ -1,6 +1,8 @@
 const btc = config.liquid.btcasset;
 const lcad = config.liquid.cadasset;
 const { Transaction } = require("liquidjs-lib");
+const withdrawalFeeMultiplier = 0.01;  // 1% withdrawal fee
+const withdrawalFeeReceiver = "coinosfees";  // 1% withdrawal fee
 
 sendLiquid = async ({ asset, amount, user, address, memo, tx, limit }) => {
   try {