// Copyright 2020 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:async';
import 'dart:io';
import 'dart:isolate';

import 'package:path/path.dart' as path;
import 'package:pigeon/pigeon_lib.dart';

/// This creates a relative path from `from` to `input`, the output being a
/// posix path on all platforms.
String _posixRelative(String input, {required String from}) {
  final path.Context context = path.Context(style: path.Style.posix);
  final String rawInputPath = input;
  final String absInputPath = File(rawInputPath).absolute.path;
  // By going through URI's we can make sure paths can go between drives in
  // Windows.
  final Uri inputUri = path.toUri(absInputPath);
  final String posixAbsInputPath = context.fromUri(inputUri);
  final Uri tempUri = path.toUri(from);
  final String posixTempPath = context.fromUri(tempUri);
  return context.relative(posixAbsInputPath, from: posixTempPath);
}

/// This is the main entrypoint for the command-line tool.  [args] are the
/// commmand line arguments and there is an optional [packageConfig] to
/// accomodate users that want to integrate pigeon with other build systems.
Future<int> runCommandLine(List<String> args, {Uri? packageConfig}) async {
  final PigeonOptions opts = Pigeon.parseArgs(args);
  final Directory tempDir = Directory.systemTemp.createTempSync(
    'flutter_pigeon.',
  );

  String importLine = '';
  if (opts.input != null) {
    final String relInputPath = _posixRelative(opts.input!, from: tempDir.path);
    importLine = 'import \'$relInputPath\';\n';
  }
  final String code = """
// @dart = 2.12
$importLine
import 'dart:io';
import 'dart:isolate';
import 'package:pigeon/pigeon_lib.dart';
void main(List<String> args, SendPort sendPort) async {
  sendPort.send(await Pigeon.run(args));
}
""";
  final File tempFile = File(path.join(tempDir.path, '_pigeon_temp_.dart'));
  await tempFile.writeAsString(code);
  final ReceivePort receivePort = ReceivePort();
  Isolate.spawnUri(
    // Using Uri.file instead of Uri.parse in order to parse backslashes as
    // path segment separator with Windows semantics.
    Uri.file(tempFile.path),
    args,
    receivePort.sendPort,
    packageConfig: packageConfig,
  );

  final Completer<int> completer = Completer<int>();
  receivePort.listen((dynamic message) {
    try {
      // ignore: avoid_as
      completer.complete(message as int);
    } catch (exception) {
      completer.completeError(exception);
    }
  });
  final int exitCode = await completer.future;
  tempDir.deleteSync(recursive: true);
  return exitCode;
}