feat: authsession service

authsession/internal/ports/config_provider.go

@@ -0,0 +1,42 @@
+package ports
+
+import (
+	"context"
+	"errors"
+	"fmt"
+)
+
+// ConfigProvider returns dynamic auth/session configuration required by later
+// service workflows.
+type ConfigProvider interface {
+	// LoadSessionLimit returns the current active-session-limit configuration.
+	// A nil ActiveSessionLimit means that the limit is disabled.
+	LoadSessionLimit(ctx context.Context) (SessionLimitConfig, error)
+}
+
+// SessionLimitConfig stores the active-session-limit configuration in a form
+// that preserves “limit absent” as a first-class state.
+type SessionLimitConfig struct {
+	// ActiveSessionLimit stores the configured limit when one is present. Nil
+	// means that no active-session limit is configured.
+	ActiveSessionLimit *int
+}
+
+// Validate reports whether SessionLimitConfig contains a valid limit value
+// when one is configured.
+func (c SessionLimitConfig) Validate() error {
+	if c.ActiveSessionLimit != nil && *c.ActiveSessionLimit <= 0 {
+		return errors.New("session limit config active session limit must be positive when configured")
+	}
+
+	return nil
+}
+
+// String returns a debug-friendly representation of SessionLimitConfig.
+func (c SessionLimitConfig) String() string {
+	if c.ActiveSessionLimit == nil {
+		return "session_limit=disabled"
+	}
+
+	return fmt.Sprintf("session_limit=%d", *c.ActiveSessionLimit)
+}