| 1 | package tinygit |
| 2 | |
| 3 | import ( |
| 4 | "errors" |
| 5 | "fmt" |
| 6 | "strings" |
| 7 | |
| 8 | "github.com/FelineStateMachine/tinyrelay/protocol/nostr" |
| 9 | ) |
| 10 | |
| 11 | // Metadata contains the claims parsed from a repository announcement (kind |
| 12 | // 30617) or state (kind 30618). Author is the event's claimed signer, not a |
| 13 | // resolved repository owner. Announcement fields are not inherited by states. |
| 14 | // A Metadata value conveys neither signature validity nor hosting authority. |
| 15 | type Metadata struct { |
| 16 | Kind int |
| 17 | Author string |
| 18 | Identifier string |
| 19 | EventID string |
| 20 | Private bool |
| 21 | Clone []string |
| 22 | Relays []string |
| 23 | Maintainers []string |
| 24 | Refs map[string]string |
| 25 | Head string |
| 26 | } |
| 27 | |
| 28 | // ParseMetadata checks and parses tinygit's supported repository metadata |
| 29 | // shape: identifier, state ref names and nonzero SHA-1 tips, and symbolic HEAD |
| 30 | // syntax. HEAD may name a branch or tag not present in Refs, including an unborn |
| 31 | // branch. Unknown tags and supported extension fields are ignored. |
| 32 | // |
| 33 | // This is a pure shape/semantic check, not full NIP or GRASP compliance. It does |
| 34 | // not validate the event ID or signature, consult announcements or maintainers, |
| 35 | // authorize hosting, check clone or relay endpoints, or inspect Git objects. |
| 36 | // Use nostr.Validate separately before trusting Author. GitRelay.Validate and |
| 37 | // ValidateImported combine signature validation, this parser and host admission; |
| 38 | // missing Git objects remain a separate pending-state concern. |
| 39 | func ParseMetadata(e nostr.Event) (Metadata, error) { |
| 40 | if e.Kind != 30617 && e.Kind != 30618 { |
| 41 | return Metadata{}, fmt.Errorf("unsupported: event kind %d is not GRASP repository metadata" , e.Kind) |
| 42 | } |
| 43 | id := nostr.Tag(e, "d" ) |
| 44 | if !validIdentifier(id) { |
| 45 | return Metadata{}, errors.New("invalid: repository identifier" ) |
| 46 | } |
| 47 | m := Metadata{Kind: e.Kind, Author: e.PubKey, Identifier: id, EventID: e.ID, Refs: map[string]string{}} |
| 48 | if e.Kind == 30617 { |
| 49 | for _, tag := range e.Tags { |
| 50 | if len(tag) < 2 { |
| 51 | continue |
| 52 | } |
| 53 | switch tag[0] { |
| 54 | case "private" : |
| 55 | m.Private = tag[1] == "true" |
| 56 | case "clone" : |
| 57 | m.Clone = append(m.Clone, tag[1:]...) |
| 58 | case "relays" : |
| 59 | m.Relays = append(m.Relays, tag[1:]...) |
| 60 | case "maintainers" : |
| 61 | m.Maintainers = append(m.Maintainers, tag[1:]...) |
| 62 | } |
| 63 | } |
| 64 | return m, nil |
| 65 | } |
| 66 | for _, tag := range e.Tags { |
| 67 | if len(tag) == 0 { |
| 68 | continue |
| 69 | } |
| 70 | if tag[0] == "HEAD" { |
| 71 | if len(tag) != 2 || m.Head != "" { |
| 72 | return Metadata{}, errors.New("invalid: repository state has multiple HEAD tags" ) |
| 73 | } |
| 74 | m.Head = tag[1] |
| 75 | continue |
| 76 | } |
| 77 | if len(tag) < 2 { |
| 78 | continue |
| 79 | } |
| 80 | if strings.HasPrefix(tag[0], "refs/" ) { |
| 81 | if _, duplicate := m.Refs[tag[0]]; duplicate || tag[1] == "" || !isObjectID(tag[1]) || strings.Trim(tag[1], "0" ) == "" { |
| 82 | return Metadata{}, fmt.Errorf("invalid: ref %s is not a SHA-1" , tag[0]) |
| 83 | } |
| 84 | m.Refs[tag[0]] = tag[1] |
| 85 | } |
| 86 | } |
| 87 | if err := validateRefs(m.Refs); err != nil { |
| 88 | return Metadata{}, err |
| 89 | } |
| 90 | if err := validateHead(m.Head, m.Refs); err != nil { |
| 91 | return Metadata{}, err |
| 92 | } |
| 93 | return m, nil |
| 94 | } |
| 95 | |
| 96 | func validateHead(head string, refs map[string]string) error { |
| 97 | if head == "" { |
| 98 | return nil |
| 99 | } |
| 100 | if !strings.HasPrefix(head, "ref: " ) { |
| 101 | return errors.New("invalid: HEAD must use ref: syntax" ) |
| 102 | } |
| 103 | ref := strings.TrimPrefix(head, "ref: " ) |
| 104 | if !strings.HasPrefix(ref, "refs/heads/" ) && !strings.HasPrefix(ref, "refs/tags/" ) { |
| 105 | return errors.New("invalid: HEAD must name a branch or tag" ) |
| 106 | } |
| 107 | if !validRef(ref) { |
| 108 | return errors.New("invalid: HEAD ref" ) |
| 109 | } |
| 110 | return nil |
| 111 | } |
| 112 | |
| 113 | func validateRefs(refs map[string]string) error { |
| 114 | for ref, oid := range refs { |
| 115 | if !validRef(ref) || oid != "" && !isObjectID(oid) { |
| 116 | return fmt.Errorf("invalid: ref %s" , ref) |
| 117 | } |
| 118 | } |
| 119 | return nil |
| 120 | } |