dirswap

type Input struct {
	OperationID     string
	ClientBindingID string
	Sequence        int
	OwnedBase       string
	ActivePath      string
	StagingPath     string
	Remove          bool
	// RequireAbsent rejects the whole operation, before any journal write or
	// filesystem mutation, if ActivePath already exists. It exists for a caller
	// reconstructing a target it has independently confirmed absent: an earlier
	// absence check can go stale before this call runs, and normal Apply
	// semantics would otherwise treat newly appeared content as an existing
	// directory to back up and later discard on Commit. Publication also uses
	// an exclusive rename so a newly appeared target is never overwritten.
	RequireAbsent bool
	// VerifyActive authorizes replacement/removal using the caller's ownership
	// or reviewed digest. It must verify the supplied physical path, including
	// after the directory has moved to backup. Logical locators stay unchanged.
	VerifyActive func(context.Context, string) error
}

type Manager struct {
	JournalDir string
	// Fault is a test seam around durable phases and otherwise unreachable
	// crash windows. Production callers leave it nil.
	Fault func(phase string) error
}

type Receipt struct {
	SchemaVersion         int    `json:"schema_version"`
	Operation             string `json:"operation"`
	OperationID           string `json:"operation_id"`
	ClientBindingID       string `json:"client_binding_id"`
	Sequence              int    `json:"sequence"`
	OwnedBaseIdentity     string `json:"owned_base_identity"`
	StagingParentIdentity string `json:"staging_parent_identity,omitempty"`
	OwnedBase             string `json:"owned_base"`
	ActivePath            string `json:"active_path"`
	StagingPath           string `json:"staging_path,omitempty"`
	BackupPath            string `json:"backup_path"`
	HadActive             bool   `json:"had_active"`
	Phase                 string `json:"phase"`
	BackupIdentity        string `json:"backup_identity,omitempty"`
	BackupDigest          string `json:"backup_digest,omitempty"`
	QuarantinePath        string `json:"quarantine_path"`
	PublishedIdentity     string `json:"published_identity,omitempty"`
	PublishedDigest       string `json:"published_digest,omitempty"`
}