package redisstate

import (
	"encoding/base64"
)

const defaultPrefix = "notification:"

// Keyspace builds the Notification Service Redis keys retained after the
// Stage 5 PostgreSQL migration: only the route lease, the persisted stream
// offset, and the inbound intent stream key are managed here. Durable
// notification state lives in the `notification` PostgreSQL schema.
//
// Dynamic key segments are encoded with base64url so raw key structure
// does not depend on caller-provided characters.
type Keyspace struct{}

// RouteLease returns the temporary Redis key used to coordinate exclusive
// publication of one notification_route across replicas.
func (Keyspace) RouteLease(notificationID string, routeID string) string {
	return defaultPrefix + "route_leases:" + encodeKeyComponent(notificationID) + ":" + encodeKeyComponent(routeID)
}

// StreamOffset returns the primary Redis key for one persisted intent-consumer
// offset.
func (Keyspace) StreamOffset(stream string) string {
	return defaultPrefix + "stream_offsets:" + encodeKeyComponent(stream)
}

// Intents returns the frozen ingress Redis Stream key.
func (Keyspace) Intents() string {
	return defaultPrefix + "intents"
}

func encodeKeyComponent(value string) string {
	return base64.RawURLEncoding.EncodeToString([]byte(value))
}