test start

src/ledger/file.go

@@ -26,7 +26,53 @@ func NewFiles(p string, q ...string) (Files, error) {
 }
 
 func (files Files) Amend(old, now Delta) error {
-	return io.EOF
+	xactions, err := files.transactions()
+	if err != nil {
+		return err
+	}
+	var transaction transaction
+	for _, xaction := range xactions {
+		if xaction.name != old.transaction {
+			continue
+		}
+		transaction = xaction
+		break
+	}
+
+	inverted := transaction.deltas()
+	for i := range inverted {
+		inverted[i].Value *= -1
+	}
+
+	if now.isSet {
+		return fmt.Errorf("cannot ammend: immutable isSet is set")
+	}
+	transaction.date = now.Date
+	transaction.description = now.Description
+	if transaction.payee == old.Name {
+		if len(transaction.recipients) != 1 {
+			return fmt.Errorf("cannot amend: modifying original payee, but many recipients cant share new value")
+		}
+		old.Value *= -1
+		old.Name = transaction.recipients[0].name
+	}
+	idx := -1
+	for i, recipient := range transaction.recipients {
+		if recipient.name == old.Name && recipient.value == old.Value {
+			idx = i
+		}
+	}
+	if idx == -1 {
+		return fmt.Errorf("cannot amend: no recipient with name %s found to set new value", old.Name)
+	}
+	transaction.recipients[idx].name = now.Name
+	transaction.recipients[idx].value = now.Value
+	transaction.recipients[idx].currency = string(now.Currency)
+	amendedDeltas := transaction.deltas().Like(func(d Delta) bool {
+		return d.Name != transaction.payee
+	})
+
+	return files.Add(transaction.payee, append(inverted, amendedDeltas...)...)
 }
 
 func (files Files) TempGetLastNLines(n int) ([]string, error) {
@@ -134,7 +180,16 @@ func (files Files) paths() []string {
 	return result
 }
 
-func (files Files) Add(payee string, delta Delta) error {
+func (files Files) Add(payee string, deltas ...Delta) error {
+	for _, delta := range deltas {
+		if err := files.add(payee, delta); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (files Files) add(payee string, delta Delta) error {
 	currencyValue := fmt.Sprintf("%s%.2f", delta.Currency, delta.Value)
 	if delta.Currency != USD {
 		currencyValue = fmt.Sprintf("%.2f %s", delta.Value, delta.Currency)
@@ -214,39 +269,7 @@ func (files Files) Deltas(like ...Like) (Deltas, error) {
 
 	result := make(Deltas, 0, len(transactions)*2)
 	for _, transaction := range transactions {
-		sums := map[string]float64{}
-		for _, recipient := range transaction.recipients {
-			sums[recipient.currency] += recipient.value
-			delta := newDelta(
-				transaction.name,
-				transaction.date,
-				transaction.description,
-				recipient.name,
-				recipient.value,
-				recipient.currency,
-				recipient.isSet,
-			)
-			result = append(result, delta)
-		}
-		for currency, value := range sums {
-			if value == 0 {
-				continue
-			}
-			if transaction.payee == "" {
-				//return nil, fmt.Errorf("didnt find net zero and no dumping ground payee set: %+v", transaction)
-			} else {
-				delta := newDelta(
-					transaction.name,
-					transaction.date,
-					transaction.description,
-					transaction.payee,
-					-1.0*value,
-					currency,
-					false,
-				)
-				result = append(result, delta)
-			}
-		}
+		result = append(result, transaction.deltas()...)
 	}
 
 	balances := make(Balances)