service backend

api/ledger/storage/model/account_balance.go

@@ -0,0 +1,27 @@
+package model
+
+import (
+	"time"
+
+	"github.com/tech/sendico/pkg/db/storable"
+	"github.com/tech/sendico/pkg/model"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+)
+
+// AccountBalance represents the current balance of a ledger account.
+// This is a materialized view updated atomically with journal entries.
+type AccountBalance struct {
+	storable.Base         `bson:",inline" json:",inline"`
+	model.PermissionBound `bson:",inline" json:",inline"`
+
+	AccountRef  primitive.ObjectID `bson:"accountRef" json:"accountRef"`   // unique per account+currency
+	Balance     string             `bson:"balance" json:"balance"`         // stored as string for exact decimal
+	Currency    string             `bson:"currency" json:"currency"`       // ISO 4217 currency code
+	Version     int64              `bson:"version" json:"version"`         // for optimistic locking
+	LastUpdated time.Time          `bson:"lastUpdated" json:"lastUpdated"` // timestamp of last balance update
+}
+
+// Collection implements storable.Storable.
+func (*AccountBalance) Collection() string {
+	return AccountBalancesCollection
+}