// Copyright (c) 2017, 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.

/// @assertion
/// Future<RandomAccessFile> lock([
///     FileLock mode = FileLock.exclusive,
///     int start = 0,
///     int end = -1
/// ])
/// . . .
/// NOTE file locking does have slight differences in behavior across platforms:
///
/// On Linux and OS X this uses advisory locks, which have the surprising
/// semantics that all locks associated with a given file are removed when any
/// file descriptor for that file is closed by the process. Note that this does
/// not actually lock the file for access. Also note that advisory locks are on
/// a process level. This means that several isolates in the same process can
/// obtain an exclusive lock on the same file.
///
/// On Windows the regions used for lock and unlock needs to match. If that is
/// not the case unlocking will result in the OS error "The segment is already
/// unlocked".
///
/// @description Checks that on Windows the regions used for lock and unlock
/// needs to match.
/// @author ngl@unipro.ru

import "dart:io";
import "dart:async";
import "../../../Utils/expect.dart";
import "../file_utils.dart";
import "lock_check_1_lib.dart";

runMain() {
  int fLen = 10;
  File file = getTempFileSync();
  asyncStart();
  var rf1 = file.openSync(mode: FileMode.write);
  var rf2 = file.openSync(mode: FileMode.write);
  for (int i = 0; i < fLen; i++) {
    rf1.writeByteSync((i + 1) & 0xff);
  }
  var rfLock = rf1.lock(FileLock.exclusive, 4, 6);
  rf2.lock(FileLock.exclusive, 7, 8);
  String eScript = Platform.script.toString();
  rfLock.then((RandomAccessFile f) {
    var tests = [
      () => checkLocked(eScript, f.path, 4),
      () => checkUnlocked(eScript, f.path, 0, 4),
      () => checkUnlocked(eScript, f.path, 6, 7),
      () => checkUnlocked(eScript, f.path, 8),
      () => checkLocked(eScript, f.path, 7)
    ];
    if (Platform.isWindows) {
      tests.addAll([
            () => rf1.unlockSync(4, 6),
            () => rf2.unlockSync(7, 8),
            () => checkUnlocked(eScript, file.path)
      ]);
    } else {
      tests.addAll([
        () => rf1.unlockSync(4, 5),
        () => rf1.unlock(7, 8),
        () => checkUnlocked(eScript, file.path, 0, 5),
        () => checkLocked(eScript, file.path, 5),
        () => checkUnlocked(eScript, file.path, 6),
        () => rf2.unlockSync(5, 6),
        () => checkUnlocked(eScript, file.path)
      ]);
    }
    Future.forEach(tests, (Function f) => f()).whenComplete(() {
      asyncEnd();
      rf1.closeSync();
      rf2.closeSync();
      file.deleteSync();
    });
  });
}

main(List<String> args) {
  if(args.length > 0)
    runProcess(args);
  else {
    runMain();
  }
}