// Package appbackup holds the self-contained app-data backup primitives:
// database dump and Docker-volume archive discovery/execution, plus the
// keep-side storage path helpers. It depends only on stable abstractions
// (the StackDataProvider interface) and has no dependency on the restic,
// cross-drive, or drive-mount code in the backup package.
package appbackup

import "path/filepath"

// FelhomDataDir is the namespace directory on storage drives for all felhom-managed data.
const FelhomDataDir = "felhom-data"

// NamespaceRoot resolves the felhom-data namespace ROOT for a drive path. All the path helpers
// below take this namespace root (the directory that directly contains backups/ and appdata/),
// NOT a bare drive path — they do not append felhom-data themselves.
//
// Model A (slice 10): the host agent binds <drive>/felhom-data onto the guest mountpoint, so an
// enrolled user-data drive's IN-GUEST mount already IS the namespace root (and its basename need
// NOT be "felhom-data" — e.g. /mnt/felhom-usb). For such mounts pass inGuestDrive=true → the path
// is returned as-is, so callers no longer double-nest into .../felhom-data/felhom-data/... .
//
// For a bare drive root that still holds a felhom-data SUBDIR — the SSD-only system-data fallback,
// or any legacy host-side layout — pass inGuestDrive=false → the felhom-data segment is appended.
func NamespaceRoot(drivePath string, inGuestDrive bool) string {
	if inGuestDrive {
		return filepath.Clean(drivePath)
	}
	return filepath.Join(drivePath, FelhomDataDir)
}

// PrimaryBackupPath returns the root primary backup directory under a felhom-data namespace root.
func PrimaryBackupPath(nsRoot string) string {
	return filepath.Join(nsRoot, "backups", "primary")
}

// AppDBDumpPath returns the DB dump directory for an app under a felhom-data namespace root.
func AppDBDumpPath(nsRoot, stackName string) string {
	return filepath.Join(nsRoot, "backups", "primary", stackName, "db-dumps")
}

// AppVolumeDumpPath returns the Docker-volume dump-tar directory for an app under a namespace root.
func AppVolumeDumpPath(nsRoot, stackName string) string {
	return filepath.Join(nsRoot, "backups", "primary", stackName, "volume-dumps")
}

// AppDataDir returns the app data directory under a felhom-data namespace root.
func AppDataDir(nsRoot, stackName string) string {
	return filepath.Join(nsRoot, "appdata", stackName)
}