[TX] add utxo functions

trustwallet · Jul 2, 2021 · 09b9773 · 09b9773
1 parent 8a60c4c
commit 09b9773
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Showing 2 changed files with 116 additions and 0 deletions.
diff --git a/types/v1/tx.go b/types/v1/tx.go
@@ -276,6 +276,52 @@ func (t *Tx) determineTransactionDirection(address, from, to string) Direction {
 	return DirectionOutgoing
 }
 
+func (t *Tx) IsUTXO() bool {
+	return t.Type == TxTransfer && len(t.Outputs) > 0
+}
+
+func (t *Tx) GetUTXOValueFor(address string) (Amount, error) {
+	isTransferOut := false
+
+	var totalInputValue uint64
+	var addressInputValue uint64
+	for _, input := range t.Inputs {
+		value, err := strconv.ParseUint(string(input.Value), 10, 64)
+		if err != nil {
+			return "0", fmt.Errorf("input value for address %s: %v", input.Address, err)
+		}
+
+		totalInputValue += value
+
+		if input.Address == address {
+			addressInputValue = value
+			isTransferOut = true
+		}
+	}
+
+	var addressOutputValue uint64
+	var totalOutputValue uint64
+	for _, output := range t.Outputs {
+		value, err := strconv.ParseUint(string(output.Value), 10, 64)
+		if err != nil {
+			return "0", fmt.Errorf("output value for address %s: %v", output.Address, err)
+		}
+		totalOutputValue += value
+		if output.Address == address {
+			addressOutputValue = value
+		}
+	}
+
+	var result uint64
+	if isTransferOut {
+		result = addressInputValue - (totalInputValue-totalOutputValue)/uint64(len(t.Inputs)) - addressOutputValue
+	} else {
+		result = addressOutputValue
+	}
+
+	return Amount(fmt.Sprintf("%d", result)), nil
+}
+
 func InferDirection(tx *Tx, addressSet mapset.Set) Direction {
 	inputSet := mapset.NewSet()
 	for _, address := range tx.Inputs {

diff --git a/types/v1/tx_test.go b/types/v1/tx_test.go
@@ -368,3 +368,73 @@ func TestTx_GetDirection(t *testing.T) {
 	}
 
 }
+
+func TestUTXOValueByAddress(t *testing.T) {
+	tests := []struct {
+		name                 string
+		tx                   Tx
+		address              string
+		expected             Amount
+		expectedErrAssertion assert.ErrorAssertionFunc
+	}{
+		{
+			name: "transfer_self",
+			tx: Tx{
+				Inputs: []TxOutput{{
+					Address: "addr",
+					Value:   "1000",
+				}},
+				Outputs: []TxOutput{{
+					Address: "addr",
+					Value:   "1000",
+				}},
+			},
+			address:              "addr",
+			expected:             "0",
+			expectedErrAssertion: assert.NoError,
+		},
+		{
+			name: "transfer_in",
+			tx: Tx{
+				Outputs: []TxOutput{{
+					Address: "addr",
+					Value:   "1000",
+				}},
+			},
+			address:              "addr",
+			expected:             "1000",
+			expectedErrAssertion: assert.NoError,
+		},
+		{
+			name: "transfer_out_with_utxo",
+			tx: Tx{
+				Inputs: []TxOutput{{
+					Address: "addr",
+					Value:   "1000",
+				}},
+				Outputs: []TxOutput{
+					{
+						Address: "addr",
+						Value:   "100",
+					},
+					{
+						Address: "addr1",
+						Value:   "800",
+					},
+				},
+			},
+			address:              "addr",
+			expected:             "800",
+			expectedErrAssertion: assert.NoError,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			result, err := tc.tx.GetUTXOValueFor(tc.address)
+			tc.expectedErrAssertion(t, err)
+
+			assert.Equal(t, tc.expected, result)
+		})
+	}
+}