feat: prototype config api

example/config_example.dart

@@ -0,0 +1,17 @@
+import 'package:libgit2dart/libgit2dart.dart';
+
+void main() {
+  final repoConfig = Config(path: '.git/config');
+
+  final isBare = repoConfig.getBool('core.bare');
+  final isLoggingAllRefUpdates = repoConfig.getBool('core.logallrefupdates');
+  final repoFormatVersion = repoConfig.getInt('core.repositoryformatversion');
+  final remoteOriginUrl = repoConfig.getString('remote.origin.url');
+
+  print('Repository is bare = $isBare');
+  print('Logging all ref updates = $isLoggingAllRefUpdates');
+  print('Repository format version = $repoFormatVersion');
+  print('Remote origin url = $remoteOriginUrl');
+
+  repoConfig.close();
+}

example/repository_example.dart

@@ -4,5 +4,5 @@ import 'package:libgit2dart/libgit2dart.dart';
 
 void main() {
   final repo = Repository.open(Directory.current.path);
-  print(repo.path);
+  print('Path to git repository: ${repo.path}');
 }

lib/libgit2dart.dart

@@ -1,2 +1,3 @@
 export 'src/repository.dart';
+export 'src/config.dart';
 export 'src/error.dart';

lib/src/bindings/config.dart

@@ -0,0 +1,176 @@
+import 'dart:ffi';
+import 'package:ffi/ffi.dart';
+import '../error.dart';
+import 'libgit2_bindings.dart';
+import '../util.dart';
+
+/// Allocate a new configuration object
+///
+/// This object is empty, so you have to add a file to it before you can do
+/// anything with it.
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<Pointer<git_config>> newConfig() {
+  final out = calloc<Pointer<git_config>>();
+  final error = libgit2.git_config_new(out);
+
+  if (error < 0) {
+    throw LibGit2Error(error, libgit2.git_error_last());
+  }
+
+  return out;
+}
+
+/// Create a new config instance containing a single on-disk file
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<Pointer<git_config>> open(String path) {
+  final out = calloc<Pointer<git_config>>();
+  final pathC = path.toNativeUtf8().cast<Int8>();
+  final error = libgit2.git_config_open_ondisk(out, pathC);
+  calloc.free(pathC);
+
+  if (error < 0) {
+    throw LibGit2Error(error, libgit2.git_error_last());
+  }
+
+  return out;
+}
+
+/// Open the global, XDG and system configuration files
+///
+/// Utility wrapper that finds the global, XDG and system configuration
+/// files and opens them into a single prioritized config object that can
+/// be used when accessing default config data outside a repository.
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<Pointer<git_config>> openDefault() {
+  final out = calloc<Pointer<git_config>>();
+  final error = libgit2.git_config_open_default(out);
+
+  if (error < 0) {
+    throw LibGit2Error(error, libgit2.git_error_last());
+  }
+
+  return out;
+}
+
+/// Locate the path to the global configuration file
+///
+/// The user or global configuration file is usually located in
+/// `$HOME/.gitconfig`.
+///
+/// This method will try to guess the full path to that file, if the file
+/// exists. The returned path may be used on any method call to load
+/// the global configuration file.
+///
+/// This method will not guess the path to the xdg compatible config file
+/// (`.config/git/config`).
+///
+/// Throws a [LibGit2Error] if error occured.
+String findGlobal() {
+  final out = calloc<git_buf>();
+  final error = libgit2.git_config_find_global(out);
+  final path = out.ref.ptr.cast<Utf8>().toDartString();
+  calloc.free(out);
+
+  if (error < 0) {
+    throw LibGit2Error(error, libgit2.git_error_last());
+  }
+
+  return path;
+}
+
+/// Locate the path to the system configuration file
+///
+/// If /etc/gitconfig doesn't exist, it will look for %PROGRAMFILES%\Git\etc\gitconfig
+///
+/// Throws a [LibGit2Error] if error occured.
+String findSystem() {
+  final out = calloc<git_buf>();
+  final error = libgit2.git_config_find_system(out);
+  final path = out.ref.ptr.cast<Utf8>().toDartString();
+  calloc.free(out);
+
+  if (error < 0) {
+    throw LibGit2Error(error, libgit2.git_error_last());
+  }
+
+  return path;
+}
+
+/// Locate the path to the global xdg compatible configuration file
+///
+/// The xdg compatible configuration file is usually located in
+/// `$HOME/.config/git/config`.
+///
+/// Throws a [LibGit2Error] if error occured.
+String findXdg() {
+  final out = calloc<git_buf>();
+  final error = libgit2.git_config_find_xdg(out);
+  final path = out.ref.ptr.cast<Utf8>().toDartString();
+  calloc.free(out);
+
+  if (error < 0) {
+    throw LibGit2Error(error, libgit2.git_error_last());
+  }
+
+  return path;
+}
+
+/// Get the value of a config variable.
+///
+/// All config files will be looked into, in the order of their
+/// defined level. A higher level means a higher priority. The
+/// first occurrence of the variable will be returned here.
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<Int8> getConfigValue(Pointer<git_config> cfg, String variable) {
+  final out = calloc<git_buf>();
+  final name = variable.toNativeUtf8().cast<Int8>();
+  final error = libgit2.git_config_get_path(out, cfg, name);
+  final value = out.ref.ptr;
+  calloc.free(out);
+  calloc.free(name);
+
+  if (error < 0) {
+    throw LibGit2Error(error, libgit2.git_error_last());
+  }
+
+  return value;
+}
+
+/// Get the value of a config variable and parse it as a boolean according
+/// to git-config rules.
+///
+/// Interprets "true", "yes", "on", 1, or any non-zero number as true.
+/// Interprets "false", "no", "off", 0, or an empty string as false.
+bool getBool(Pointer<git_config> cfg, String variable) {
+  final value = getConfigValue(cfg, variable);
+  final out = calloc<Int32>();
+  libgit2.git_config_parse_bool(out, value);
+  final result = out.value;
+  calloc.free(out);
+
+  return (result == 0) ? false : true;
+}
+
+/// Get the value of a config variable and parse it as an integer according
+/// to git-config rules.
+///
+/// Handles suffixes like k, M, or G - kilo, mega, giga.
+int getInt(Pointer<git_config> cfg, String variable) {
+  final value = getConfigValue(cfg, variable);
+  final out = calloc<Int64>();
+  libgit2.git_config_parse_int64(out, value);
+  final result = out.value;
+  calloc.free(out);
+
+  return result;
+}
+
+/// Get the value of a config variable and parse it as a string.
+String getString(Pointer<git_config> cfg, String variable) {
+  final value = getConfigValue(cfg, variable);
+  return value.cast<Utf8>().toDartString();
+}

lib/src/config.dart

@@ -0,0 +1,58 @@
+import 'dart:ffi';
+import 'package:ffi/ffi.dart';
+import 'bindings/libgit2_bindings.dart';
+import 'bindings/config.dart' as config;
+import 'util.dart';
+
+/// [Config] provides management of global configuration options
+/// (system, global, XDG, excluding repository config)
+class Config {
+  /// Initializes a new instance of [Config] class.
+  ///
+  /// If [path] isn't provided, opens global, XDG and system config files.
+  ///
+  /// [path] should point to single on-disk file; it's expected to be a native
+  /// Git config file following the default Git config syntax (see man git-config).
+  ///
+  /// [Config] object should be closed with [close] function to release allocated memory.
+  Config({this.path}) {
+    libgit2.git_libgit2_init();
+
+    if (path == null) {
+      configPointer = config.openDefault();
+    } else {
+      configPointer = config.open(path!);
+    }
+
+    libgit2.git_libgit2_shutdown();
+  }
+
+  /// Path to on-disk config file provided by user.
+  String? path;
+
+  /// Pointer to memory address for allocated config object.
+  late Pointer<Pointer<git_config>> configPointer;
+
+  /// Get boolean value of `key` [variable]
+  bool getBool(String variable) {
+    return config.getBool(configPointer.value, variable);
+  }
+
+  ///Get integer value of `key` [variable]
+  int getInt(String variable) {
+    return config.getInt(configPointer.value, variable);
+  }
+
+  ///Get string value of `key` [variable]
+  String getString(String variable) {
+    return config.getString(configPointer.value, variable);
+  }
+
+  /// Set value of config key
+  // TODO
+
+  /// Releases memory allocated for config object.
+  void close() {
+    calloc.free(configPointer);
+  }
+}