txdb: fee.

lib/wallet/txdb.js

@@ -2801,15 +2801,17 @@ function Details(txdb, tx) {
   this.network = this.db.network;
   this.wid = txdb.wallet.wid;
   this.id = txdb.wallet.id;
+
   this.hash = tx.hash('hex');
-  this.height = tx.height;
+  this.tx = tx;
+
   this.block = tx.block;
+  this.height = tx.height;
+  this.ts = tx.ts;
   this.index = tx.index;
   this.confirmations = tx.getConfirmations(this.db.height);
-  this.fee = tx.getFee();
-  this.ts = tx.ts;
+
   this.ps = tx.ps;
-  this.tx = tx;
 
   this.inputs = [];
   this.outputs = [];
@@ -2878,6 +2880,34 @@ Details.prototype.setOutput = function setOutput(i, path) {
   }
 };
 
+/**
+ * Calculate fee. Only works if wallet
+ * owns all inputs. Returns 0 otherwise.
+ * @returns {Amount}
+ */
+
+Details.prototype.getFee = function getFee() {
+  var inputValue = 0;
+  var outputValue = 0;
+  var i, input, output;
+
+  for (i = 0; i < this.inputs.length; i++) {
+    input = this.inputs[i];
+
+    if (!input.path)
+      return 0;
+
+    inputValue += input.value;
+  }
+
+  for (i = 0; i < this.outputs.length; i++) {
+    output = this.outputs[i];
+    outputValue += output.value;
+  }
+
+  return inputValue - outputValue;
+};
+
 /**
  * Convert details to a more json-friendly object.
  * @returns {Object}
@@ -2894,7 +2924,7 @@ Details.prototype.toJSON = function toJSON() {
     ts: this.ts,
     ps: this.ps,
     index: this.index,
-    fee: utils.btc(this.fee),
+    fee: utils.btc(this.getFee()),
     confirmations: this.confirmations,
     inputs: this.inputs.map(function(input) {
       return input.toJSON(self.network);