feat(note): add bindings and api

lib/src/note.dart

@@ -0,0 +1,121 @@
+import 'dart:ffi';
+import 'bindings/libgit2_bindings.dart';
+import 'bindings/note.dart' as bindings;
+import 'oid.dart';
+import 'repository.dart';
+import 'signature.dart';
+
+class Notes {
+  /// Initializes a new instance of the [Notes] class from
+  /// provided [Repository] object.
+  Notes(Repository repo) {
+    _repoPointer = repo.pointer;
+  }
+
+  /// Pointer to memory address for allocated repository object.
+  late final Pointer<git_repository> _repoPointer;
+
+  /// Reads the note for an object.
+  ///
+  /// The note must be freed manually by the user.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  static Note lookup({
+    required Repository repo,
+    required Oid annotatedId,
+    String notesRef = 'refs/notes/commits',
+  }) {
+    final note = bindings.lookup(
+      repoPointer: repo.pointer,
+      oidPointer: annotatedId.pointer,
+      notesRef: notesRef,
+    );
+
+    return Note(note, annotatedId.pointer, repo.pointer);
+  }
+
+  /// Adds a note for an [object].
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  static Oid create({
+    required Repository repo,
+    required Signature author,
+    required Signature committer,
+    required Oid object,
+    required String note,
+    String notesRef = 'refs/notes/commits',
+    bool force = false,
+  }) {
+    return Oid(bindings.create(
+      repoPointer: repo.pointer,
+      authorPointer: author.pointer,
+      committerPointer: committer.pointer,
+      oidPointer: object.pointer,
+      note: note,
+      notesRef: notesRef,
+      force: force,
+    ));
+  }
+
+  /// Returns list of notes for repository.
+  ///
+  /// Notes must be freed manually by the user.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  List<Note> get list {
+    final notesPointers = bindings.list(_repoPointer);
+    var result = <Note>[];
+    for (var note in notesPointers) {
+      result.add(Note(
+        note['note'] as Pointer<git_note>,
+        note['annotatedId'] as Pointer<git_oid>,
+        _repoPointer,
+      ));
+    }
+
+    return result;
+  }
+}
+
+class Note {
+  /// Initializes a new instance of the [Note] class from provided
+  /// pointer to note object in memory.
+  Note(this._notePointer, this._annotatedIdPointer, this._repoPointer);
+
+  /// Pointer to memory address for allocated note object.
+  final Pointer<git_note> _notePointer;
+
+  /// Pointer to memory address for allocated annotetedId object.
+  final Pointer<git_oid> _annotatedIdPointer;
+
+  /// Pointer to memory address for allocated repository object.
+  final Pointer<git_repository> _repoPointer;
+
+  /// Removes the note for an [object].
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  void remove({
+    required Signature author,
+    required Signature committer,
+    String notesRef = 'refs/notes/commits',
+  }) {
+    bindings.remove(
+      repoPointer: _repoPointer,
+      authorPointer: author.pointer,
+      committerPointer: committer.pointer,
+      oidPointer: annotatedId.pointer,
+    );
+  }
+
+  /// Returns the note object's [Oid].
+  Oid get id => Oid(bindings.id(_notePointer));
+
+  /// Returns the note message.
+  String get message => bindings.message(_notePointer);
+
+  /// Returns the [Oid] of the git object being annotated.
+  Oid get annotatedId => Oid(_annotatedIdPointer);
+
+  /// Releases memory allocated for note object.
+  void free() => bindings.free(_notePointer);
+}