pkgs/jni/lib/src/errors.dart

// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'package:jni/src/third_party/generated_bindings.dart';

// TODO(#393): Add the fact that [JException] is now a [JObject] to the
// CHANGELOG.

final class UseAfterReleaseError extends Error {
  @override
  String toString() {
    return 'Use after release error';
  }
}

// TODO(#393): Use NullPointerError once it's available.
final class JNullError extends Error {
  @override
  String toString() => 'The reference was null';
}

final class DoubleReleaseError extends Error {
  @override
  String toString() {
    return 'Double release error';
  }
}

/// Represents JNI errors that might be returned by methods like
/// `JNI_CreateJavaVM`.
sealed class JniError extends Error {
  static const _errors = {
    JniErrorCode.JNI_ERR: JniGenericError.new,
    JniErrorCode.JNI_EDETACHED: JniThreadDetachedError.new,
    JniErrorCode.JNI_EVERSION: JniVersionError.new,
    JniErrorCode.JNI_ENOMEM: JniOutOfMemoryError.new,
    JniErrorCode.JNI_EEXIST: JniVmExistsError.new,
    JniErrorCode.JNI_EINVAL: JniArgumentError.new,
  };

  final String message;

  JniError(this.message);

  factory JniError.of(int status) {
    if (!_errors.containsKey(status)) {
      status = JniErrorCode.JNI_ERR;
    }
    return _errors[status]!();
  }

  @override
  String toString() {
    return 'JniError: $message';
  }
}

final class JniGenericError extends JniError {
  JniGenericError() : super('Generic JNI error');
}

final class JniThreadDetachedError extends JniError {
  JniThreadDetachedError() : super('Thread detached from VM');
}

final class JniVersionError extends JniError {
  JniVersionError() : super('JNI version error');
}

final class JniOutOfMemoryError extends JniError {
  JniOutOfMemoryError() : super('Out of memory');
}

final class JniVmExistsError extends JniError {
  JniVmExistsError() : super('VM Already created');
}

final class JniArgumentError extends JniError {
  JniArgumentError() : super('Invalid arguments');
}

final class NoJvmInstanceError extends Error {
  @override
  String toString() => 'No JNI instance is available';
}

// TODO(#395): Remove this when calltypes are removed.
extension on int {
  static const _names = {
    JniCallType.booleanType: 'bool',
    JniCallType.byteType: 'byte',
    JniCallType.shortType: 'short',
    JniCallType.charType: 'char',
    JniCallType.intType: 'int',
    JniCallType.longType: 'long',
    JniCallType.floatType: 'float',
    JniCallType.doubleType: 'double',
    JniCallType.objectType: 'object',
    JniCallType.voidType: 'void',
  };
  String str() => _names[this]!;
}

// TODO(#395): Remove this when `JniCallType`s are removed.
final class InvalidCallTypeError extends Error {
  final int type;
  final Set<int> allowed;

  InvalidCallTypeError(this.type, this.allowed);

  @override
  String toString() => 'Invalid type for call ${type.str()}. '
      'Allowed types are ${allowed.map((t) => t.str()).toSet()}';
}

// TODO(#393): Remove this class in favor of `JThrowable`.
class JniException implements Exception {
  /// Error message from Java exception.
  final String message;

  /// Stack trace from Java.
  final String stackTrace;

  JniException(this.message, this.stackTrace);

  @override
  String toString() => 'Exception in Java code called through JNI: '
      '$message\n\n$stackTrace\n';
}

final class HelperNotFoundError extends Error {
  final String path;

  HelperNotFoundError(this.path);

  @override
  String toString() => '''
Lookup for helper library $path failed.
Please ensure that `dartjni` shared library is built.
Provided jni:setup script can be used to build the shared library.
If the library is already built, ensure that the JVM libraries can be 
loaded from Dart.''';
}