...

pkg/heroservices/billing/models/user.go

@@ -0,0 +1,78 @@
+package models
+
+import (
+	"encoding/binary"
+	"errors"
+)
+
+// User represents a user in the billing system
+type User struct {
+	ID       uint32   // Unique identifier, auto-incremented
+	Key      string   // Unique key for the user
+	Accounts []uint32 // Links to the accounts a user has
+}
+
+// Serialize converts a User to a binary representation
+func (u *User) Serialize() []byte {
+	// Calculate the size of the serialized data
+	// 4 bytes for ID + 2 bytes for key length + len(key) bytes + 2 bytes for accounts length + 4 bytes per account
+	size := 4 + 2 + len(u.Key) + 2 + (4 * len(u.Accounts))
+	data := make([]byte, size)
+
+	// Write ID (4 bytes)
+	binary.LittleEndian.PutUint32(data[0:4], u.ID)
+
+	// Write key length (2 bytes) and key
+	keyLen := uint16(len(u.Key))
+	binary.LittleEndian.PutUint16(data[4:6], keyLen)
+	copy(data[6:6+keyLen], u.Key)
+
+	// Write accounts length (2 bytes) and accounts
+	accountsOffset := 6 + keyLen
+	accountsLen := uint16(len(u.Accounts))
+	binary.LittleEndian.PutUint16(data[accountsOffset:accountsOffset+2], accountsLen)
+
+	for i, accountID := range u.Accounts {
+		offset := int(accountsOffset) + 2 + (4 * i)
+		binary.LittleEndian.PutUint32(data[offset:offset+4], accountID)
+	}
+
+	return data
+}
+
+// DeserializeUser converts a binary representation back to a User
+func DeserializeUser(data []byte) (*User, error) {
+	if len(data) < 8 { // Minimum size: 4 (ID) + 2 (key length) + 2 (accounts length)
+		return nil, errors.New("data too short to deserialize User")
+	}
+
+	user := &User{}
+
+	// Read ID
+	user.ID = binary.LittleEndian.Uint32(data[0:4])
+
+	// Read key length and key
+	keyLen := binary.LittleEndian.Uint16(data[4:6])
+	if 6+keyLen > uint16(len(data)) {
+		return nil, errors.New("data too short to read key")
+	}
+	user.Key = string(data[6 : 6+keyLen])
+
+	// Read accounts length and accounts
+	accountsOffset := 6 + keyLen
+	if accountsOffset+2 > uint16(len(data)) {
+		return nil, errors.New("data too short to read accounts length")
+	}
+	accountsLen := binary.LittleEndian.Uint16(data[accountsOffset : accountsOffset+2])
+
+	user.Accounts = make([]uint32, accountsLen)
+	for i := uint16(0); i < accountsLen; i++ {
+		offset := accountsOffset + 2 + (4 * i)
+		if offset+4 > uint16(len(data)) {
+			return nil, errors.New("data too short to read account ID")
+		}
+		user.Accounts[i] = binary.LittleEndian.Uint32(data[offset : offset+4])
+	}
+
+	return user, nil
+}