| 1 | package agent |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | "sort" |
| 6 | ) |
| 7 | |
| 8 | // SetRecoveryPreferred records exactly one explicit preferred lineage member. |
| 9 | // Clearing old choices first can only fall back to an unresolved group; an |
| 10 | // interrupted update can never leave two canonical choices. |
| 11 | func SetRecoveryPreferred(paths []string, chosenPath string) error { |
| 12 | chosenPath = canonicalSessionSavePath(chosenPath) |
| 13 | if chosenPath == "" { |
| 14 | return fmt.Errorf("empty preferred recovery path") |
| 15 | } |
| 16 | unique := map[string]struct{}{} |
| 17 | for _, path := range paths { |
| 18 | if path = canonicalSessionSavePath(path); path != "" { |
| 19 | unique[path] = struct{}{} |
| 20 | } |
| 21 | } |
| 22 | if _, ok := unique[chosenPath]; !ok { |
| 23 | return fmt.Errorf("preferred recovery path is outside the lineage") |
| 24 | } |
| 25 | ordered, err := validatedRecoveryPreferenceMembers(unique) |
| 26 | if err != nil { |
| 27 | return err |
| 28 | } |
| 29 | for _, path := range ordered { |
| 30 | if err := UpdateBranchMeta(path, false, clearRecoveryPreference); err != nil { |
| 31 | return err |
| 32 | } |
| 33 | } |
| 34 | chosen, err := LoadSession(chosenPath) |
| 35 | if err != nil || chosen == nil || chosen.normalizedDirty || chosen.eventLogDamaged { |
| 36 | return fmt.Errorf("could not fingerprint preferred recovery branch") |
| 37 | } |
| 38 | digest, err := digestSessionMessages(chosen.Snapshot()) |
| 39 | if err != nil { |
| 40 | return err |
| 41 | } |
| 42 | return UpdateBranchMeta(chosenPath, false, func(meta *BranchMeta) error { |
| 43 | meta.RecoveryPreferred = true |
| 44 | meta.RecoveryPreferredDigest = digestString(digest) |
| 45 | return nil |
| 46 | }) |
| 47 | } |
| 48 | |
| 49 | func validatedRecoveryPreferenceMembers(unique map[string]struct{}) ([]string, error) { |
| 50 | ordered := make([]string, 0, len(unique)) |
| 51 | recoveredMembers, normalMembers := 0, 0 |
| 52 | for path := range unique { |
| 53 | meta, ok, err := LoadBranchMeta(path) |
| 54 | if err != nil || !ok { |
| 55 | return nil, fmt.Errorf("invalid recovery lineage member") |
| 56 | } |
| 57 | if meta.Recovered { |
| 58 | recoveredMembers++ |
| 59 | } else { |
| 60 | normalMembers++ |
| 61 | } |
| 62 | ordered = append(ordered, path) |
| 63 | } |
| 64 | if recoveredMembers == 0 || normalMembers > 1 { |
| 65 | return nil, fmt.Errorf("invalid recovery lineage members") |
| 66 | } |
| 67 | sort.Strings(ordered) |
| 68 | return ordered, nil |
| 69 | } |
| 70 | |
| 71 | func clearRecoveryPreference(meta *BranchMeta) error { |
| 72 | meta.RecoveryPreferred = false |
| 73 | meta.RecoveryPreferredDigest = "" |
| 74 | return nil |
| 75 | } |
| 76 |