checkpoint

type CheckpointInfo struct {
	// ID is the unique checkpoint identifier.
	ID string `json:"id"`

	// ThreadID is the thread/session identifier.
	ThreadID string `json:"thread_id"`

	// CreatedAt is when the checkpoint was created.
	CreatedAt time.Time `json:"created_at"`

	// UpdatedAt is when the checkpoint was last updated.
	UpdatedAt time.Time `json:"updated_at"`

	// Metadata holds additional checkpoint information.
	Metadata map[string]interface{} `json:"metadata,omitempty"`

	// Size is the approximate size in bytes of the checkpoint data.
	// Useful for storage management and cleanup decisions.
	Size int64 `json:"size"`
}

type Checkpointer interface {
	// Save persists the current state for a thread/session.
	Save(ctx context.Context, threadID string, state agentstate.State) error

	// Load retrieves the saved state for a thread/session.
	Load(ctx context.Context, threadID string) (agentstate.State, error)

	// List returns information about all saved checkpoints.
	List(ctx context.Context) ([]CheckpointInfo, error)

	// Delete removes the checkpoint for a thread/session.
	Delete(ctx context.Context, threadID string) error

	// Exists checks if a checkpoint exists for a thread/session.
	Exists(ctx context.Context, threadID string) (bool, error)
}

type CheckpointerConfig struct {
	// MaxHistorySize limits the number of historical states to keep
	MaxHistorySize int

	// MaxCheckpointAge is the maximum age before a checkpoint is considered stale
	MaxCheckpointAge time.Duration

	// EnableCompression enables state compression (for future implementation)
	EnableCompression bool

	// AutoCleanup enables automatic cleanup of old checkpoints
	AutoCleanup bool

	// CleanupInterval specifies how often to run cleanup
	CleanupInterval time.Duration
}

type CheckpointerWithAutoCleanup struct {
	// contains filtered or unexported fields
}

type DistributedCheckpointer struct {
	// contains filtered or unexported fields
}

type DistributedCheckpointerConfig struct {
	// PrimaryBackend is the primary checkpointer (e.g., Redis)
	PrimaryBackend Checkpointer

	// SecondaryBackend is the backup checkpointer (e.g., PostgreSQL, optional)
	SecondaryBackend Checkpointer

	// EnableReplication enables automatic replication to secondary backend
	EnableReplication bool

	// ReplicationMode determines how replication works
	// - "sync": Write to both backends synchronously
	// - "async": Write to primary, then replicate to secondary asynchronously
	ReplicationMode string

	// HealthCheckInterval is how often to check backend health
	HealthCheckInterval time.Duration

	// EnableAutoFailover enables automatic failover to secondary on primary failure
	EnableAutoFailover bool

	// MaxFailoverAttempts limits the number of failover attempts
	MaxFailoverAttempts int

	// FailbackDelay is the delay before attempting to fail back to primary
	FailbackDelay time.Duration
}

type InMemorySaver struct {
	// contains filtered or unexported fields
}

type RedisCheckpointer struct {
	// contains filtered or unexported fields
}

type RedisCheckpointerConfig struct {
	// Addr is the Redis server address (host:port)
	Addr string

	// Password for Redis authentication
	Password string

	// DB is the Redis database number
	DB int

	// Prefix is the key prefix for all checkpoint keys
	Prefix string

	// TTL is the default time-to-live for checkpoints (0 = no expiration)
	TTL time.Duration

	// PoolSize is the maximum number of connections
	PoolSize int

	// MinIdleConns is the minimum number of idle connections
	MinIdleConns int

	// MaxRetries is the maximum number of retry attempts
	MaxRetries int

	// DialTimeout is the timeout for establishing connections
	DialTimeout time.Duration

	// ReadTimeout is the timeout for read operations
	ReadTimeout time.Duration

	// WriteTimeout is the timeout for write operations
	WriteTimeout time.Duration

	// EnableLock enables distributed locking for concurrent access
	EnableLock bool

	// LockTimeout is the timeout for acquiring locks
	LockTimeout time.Duration

	// LockExpiry is the expiry time for locks
	LockExpiry time.Duration
}