feat: initial datastructure

types/money.go

@@ -0,0 +1,92 @@
+package types
+
+import (
+	"time"
+
+	"github.com/google/uuid"
+)
+
+// At the center of the application is the transaction.
+//
+// Every piece of data should be calculated based on transactions. This means potential calculation errors can be fixed later in time.
+//
+// If it becomes necessary to precalculate snapshots for performance reasons, this can be done in the future. But the transaction should always be the source of truth.
+type Transaction struct {
+	Id      uuid.UUID
+	GroupId uuid.UUID
+
+	AccountId uuid.UUID
+	// nil indicates that the transaction is not yet associated with a piggy bank
+	PiggyBankId *uuid.UUID
+
+	// The internal transaction is amove between e.g. an account and a piggy bank to execute a savings plan
+	Internal bool
+
+	// The value of the transacion. Negative for outgoing and positive for incoming
+	Value     int64
+	Timestamp time.Time
+
+	Note string
+
+	CreatedAt time.Time
+	// either "<username>" or "system-<subsystem>"
+	CreatedBy uuid.UUID
+	UpdatedAt time.Time
+	UpdatedBy uuid.UUID
+}
+
+// The Account holds money
+type Account struct {
+	Id      uuid.UUID
+	GroupId uuid.UUID
+
+	// "Bank-Name" or "Cash"
+	Type string
+	Name string
+
+	CurrentBalance  int64
+	LastTransaction time.Time
+	// The current precalculated value of:
+	// 	Account.Balance - [PiggyBank.Balance...]
+	OinkBalance int64
+
+	CreatedAt time.Time
+	CreatedBy uuid.UUID
+	UpdatedAt *time.Time
+	UpdatedBy *uuid.UUID
+}
+
+// The PiggyBank is a fictional account. The money it "holds" is actually in the Account
+type PiggyBank struct {
+	Id      uuid.UUID
+	GroupId uuid.UUID
+
+	AccountId uuid.UUID
+	Name      string
+
+	CurrentBalance int64
+
+	CreatedAt time.Time
+	CreatedBy uuid.UUID
+	UpdatedAt *time.Time
+	UpdatedBy *uuid.UUID
+}
+
+// The SavingsPlan is applied every interval to the PiggyBank/Account as a transaction
+type SavingsPlan struct {
+	Id      uuid.UUID
+	GroupId uuid.UUID
+
+	PiggyBankId uuid.UUID
+
+	MonthlySaving int64
+
+	ValidFrom time.Time
+	/// nil means it is valid indefinitely
+	ValidTo *time.Time
+
+	CreatedAt time.Time
+	CreatedBy uuid.UUID
+	UpdatedAt *time.Time
+	UpdatedBy *uuid.UUID
+}